Hot Rod HEMI Interviews
Posted: Mon Apr 06, 2009 10:35 pm
Hot Rod Hemi Interviews
http://www.hotrod.com/web/113_0508_hemi/
You read the story in the August 2005 issue of HOT ROD. Now read the full length, unedited interviews with some of the men who helped shape the Hemi into the cultural icon it is today. -Steve Magnante
--------------------------------------------------
JAY LENO
JAY LENO: Tonight Show host and car collector
HRM: When did you see your first Hemi and what effect did it have on you?
I grew up in Andover Massachusetts and in 1966 there was a kid in our high school who got a green Belvedere with a 426 Hemi. To me, this might as well as have been the space shot. When you grow up in a small town, you don't really see that many exotic cars. I grew up in the kind of place where you'd hang out at the McDonalds parking lot until about 11:00 o'clock then you'd go home and get a call that a Corvette went through at 11:15 and you'd scream because you missed it. To me, the biggest anybody got in my town was a 318, or maybe somebody had a 383 or a Hemi from the Fifties. So when that Belvedere came out, I mean, 0-to-60 in under seven seconds and a top speed of 140 mph, that was considered just unbelievable. We'd always hear stories about how the kid with the Hemi out ran the police, or how he'd come off the highway exit and the cops would overshoot it and go onto the grass, just all that silly teenage stuff.
HRM: Did this guy have a name, you know, like Ace or something cool like that?
I don't remember his name but another Hemi thing that really hit me was a magazine ad that showed the Hemi and it said stuff like "volumetric efficiency". None of us had any idea what it meant at the time but we went around repeating it because we knew it had something to do with the Hemi. And there was another ad with a kind of Peter Max illustration of a Hemi engine and I remember it said something like "You can't make an engine like this with facts and figures alone. It's gotta be voodoo baby". It was one of those mythical urban legend type vehicles.
HRM: We all know that you got into comedy and came to Los Angeles. When did you start buying Hemi cars?
It was the early nineties, about 1992. I got a '66 426 Street Hemi Coronet. I paid $28,000 for it and people said "Are you crazy?" And I said, "Yeah, but I want it". And I like it, its a dog dish hub cap car with not a lot of scoops and whistles on it. I know everybody likes GTX's and all that kind of beep-beep stuff, but to me I just like the plain Jane looking car. It's a sleeper. It is the one car in my collection that my wife has no idea why I find it attractive. She can look at other cars in my collection and understand why I have them but when she looks at the Coronet she says; "That looks like a taxi cab, its got black wall tires, what's the appeal?" It's one of those things that you either get it or you don't. It's really, at least in those days, a guy thing. My wife says "Oh I've gotta' get a Prada purse", I have no idea what that is. The guy equivalent of the Prada purse is a Street Hemi. Then I got a Challenger R/T with the Street Hemi. You don't see many of those, the Challengers. I really wasn't looking for it, it just kind of fell into my lap and became available. It's a four-speed car, my '66 is an automatic. I always kind of liked that brutal Chrysler four speed transmission. It couldn't be more agricultural. It's got the big machete handle Pistol Grip shift lever. Also the Hemi was the first car, I can remember being in high school and talking cars like we did and someone said they had a Hemi automatic, it was understood that it was probably faster than a Hemi four speed. That was just unbelievable. Kids almost got into fisticuffs yelling; "There's no way an automatic is faster than a four speed. Is too, is not, is too, is not" and so on. That kind of ninth grade stuff was rampant. But back in those days when you thought of an automatic transmission, you thought of a two speed Powerglide, and yet here was this Torqueflite transmission that could take this tremendous abuse. In fact when I first got the '66, I remember driving it down the street and thinking; "It's not shifting". I'd put it in Drive and it'd go waaaaah and just stay there. So I contacted a Hemi buddy of mine and told him it doesn't seem to be shifting right. He says; "Are you just keeping your foot in it?" and I said; "Well I am but I'm backing off because I don't want to blow it up", he goes; "no, no, just keep your foot in it and it'll upshift". I said; "Well OK" and I did it and at about 7200 rpm it went waaaah, screech and finally hit Drive. For an American V8 I had never seen a big motor rev that high before. I've also got a '56 Chrysler Imperial with a 354 early Hemi engine.
HRM: We all know that the Hemi is back and making waves in the new Dodge Ram trucks, Chrysler 300 and Dodge Magnum, how do you feel about the continuation of the legacy?
It's OK. It's Frank Sinatra Junior. First of all, as big as the name Hemi is, the numbers 4-2-6 played a big parting that. The new motor isn't quite the same as saying "426 Hemi". Back then a Hemi engine was a Hemi engine. Now it's a brand. I'm not even sure it's a Hemi, isn't a pent-roof design? Anyway, now it is a brand, like when you go into Costco and you get the men's black "turbo" hair dryer? You say; "Is this really a turbo?" Well not really, it's a hair dryer. You know the new Hemi is good but not quite the same.
DAN KNOTT
DAN KNOTT: Director of Street and Racing Technology (SRT) at DaimlerChrysler
HRM: Tell us about the importance of the word Hemi to your work at SRT.
Well, it really started about two years ago when we started building SRT as a cross brand. We already had the Viper and the Neon SRT4. We sat down and we said; "We need a foundational V8 engine that is a foundation for SRT in the V8 engine market arena. Of course we knew we had the Chrysler 300C coming along and we knew the 300 series had a well established performance heritage throughout the years.
So the first thing we did is we looked at the 5.7 Hemi and thought; "Well OK, if you're going to do a performance V8 engine, you'd better start with the Hemi". Then we did what I like to call inject SRT steroids into the 5.7 and created a 6.1 liter Hemi. We gathered all of the racers together in the SRT group, by the way, it's great that we have a bunch of enthusiasts in SRT who race on the weekend and bring their experiences to work on Monday. We sat them down and we said; "We're going to do this engine and what do you think it should have?" So we talked about things like the forged crankshaft, piston oil squirters, floating piston pins, hollow intake and exhaust valves to get the weight down and get the rpm up, and we raised the compression ratio from 9.6 to 10.3.
When we set the objective for the horsepower and torque initially, at 425 the engineers came back and said; "Well, we think we can get about 400". I said; "No that isn't good enough". I wanted as much as possible because there is never enough, and I knew there were competing engine designs that were going to sneak over the 400 horsepower mark shortly. The end result is we took it from 340 horsepower in the 5.7, to 425 in the 6.1. We also took the torque up to 420 lb/ft. We were extremely pleased and I am really proud of the team, they did an outstanding job.
HRM: We see that the SRT 6.1 Hemi has beautiful streamlined double wall exhaust manifolds and a different intake manifold than the 5.7 Hemi Magnum. Are those items what put you over the 400 horsepower mark?
Absolutely. The dual wall exhaust manifolds are just good old fashioned headers. Normally, fabricated exhaust headers need heat shields. You usually design the header and then you attach the heat shield and the heat shield is not part of the structural member. What we did is design them both together so that they're both part of the structure and you get a lot more efficiency and cost effectiveness as well. We were able to get about 15 horsepower just with the headers. Another thing we did to appeal to the HOT ROD readership and guys who are serious about cars, is we painted the block Hemi Orange and put a black wrinkle finish on the rocker arm covers to define a link with the 426 Hemi. We wanted buyers to look at the engine and say; "Those guys at Chrysler get it and understand what is important".
HRM: We all know that the 426 Hemi made 425 horsepower using the old gross rating system. In 1971, when the industry adopted the more realistic net rating system, the 426 Hemi's output was re-listed at 350 horsepower. Is it possible the new SRT 6.1 Hemi makes more SAE net horsepower than the legendary Street Hemi?
Yes it is. There is an SAE standard for rating engines so comparisons can be made with accuracy. And yes, under this system an SRT 6.1 Hemi will make more real horsepower than a 426 Street Hemi. Torque output is not as high as the Street Hemi due to the significant 54 cubic inch difference in displacement, but horsepower is superior. One thing about SRT products is that we tend to be conservative in our advertised horsepower ratings.
We want the customer, and the media, to get better numbers. For example we advertise that the 300C SRT-8, which this engine is in, does 0-to-60 in around 5-seconds. Well Motor Trend got 4.9 and we know of another magazine that is getting ready to publish, that got better than that. It is the same with our horsepower ratings, they're a bit conservative.
HRM: How does the SRT 6.1 Hemi intake manifold differ from the standard 5.7 piece?
It is a tapered runner manifold and there is also more volume. The tapered runners increase the airflow. It gets to the intake port of the cylinder heads at a higher rate of speed for a slight ram tuning effect, just like the old days of cross rams. The increased intake plenum volume gives the engine greater access to fuel with greater power output as the natural result.
HRM: What does the future hold for the new Hemi engine? Is it at its maximum displacement at 6.1 liters (372 cubic inches)? We've heard talk of an upcoming 6.3 liter version.
I can't talk about future product, but I will tell you this. In the performance industry, there's been a renaissance on for some time now. We know from our customers that there is never such thing as too much performance. While we have to balance that with resources, building viable business cases and making sure these things make money, and also that they are very acceptable and safe for every day use. They also must have high levels of quality and reliability. I'll just say that SRT doesn't rest on its laurels.
We always look for ways to raise the bar. The improvements may be in an engine or in the suspension. Like the SRT4. Six months after we launched it we brought out a limited slip differential to take it to the next level. So we're always looking for ways to improve already excellent products. That's what we want people to expect and demand from SRT.
HRM: To you personally, Dan, what does the word Hemi mean?
My dad and grandfather watched NASCAR racing and you'd see Richard Petty running wild out there with his Hemi cars before they phased out in the early seventies. Even before I knew what makes a Hemi a Hemi, I was aware that the basic word meant power, and performance and an image of supremacy in the automotive marketplace.
When we brought the 5.7 Hemi back, I thought: "Man, this is really going to do well". But I had no idea how well it has done. To be honest with you, it stunned us all. It reinforces the fact that consumers have always been about product and performance. If you've got a name like Hemi, which has walked the walk, you can always revive it if you put credibility behind it. And that's exactly what our SRT team strives to do.
TOM HOOVER
TOM HOOVER: Former Chrysler employee and "God father" of the 426 Hemi
HRM: What was your first introduction to Hemi engines?
I was off driving trucks in the Korean war when the first Chrysler Hemi entered production in 1951. Before my arrival at Chrysler in 1955, I was fully aware that they were something special what with stock rated power that was consistently 25 to 30 horsepower higher than competing wedge head V8 designs of similar displacement.
The thing that was the most significant to me was the A311 program that explored the potential of the Chrysler 331 Hemi as a potential Indianapolis 500 racing engine. The A311 report became the most desirable reading material among those of us enrolled in the Chrysler Institute. I graduated from the Chrysler Institute in 1957 and at about the same time a group of Chrysler employees formed the Ram Chargers group, a loose knit bunch of engineers who drag raced their cars on weekends. Even though the A311 program didn't produce an Indy victory due to USAC rule changes, the technical report it generated was a guiding light for me.
HRM: How did you become involved in the 426 Hemi development program?
Luckily I was standing there with some applicable experience when the 426 Hemi program got under way. It started when Lynn Townsend became chief executive officer of the company with a desire to establish a performance image. Lore has it he had a couple of teenage sons who enjoyed street racing on Woodward Avenue. At the time I had a '59 Plymouth with a 392 Chrysler Hemi transplant.
The long and short of it is that Townsend listened to his sons' talk about the hot Pontiacs on Woodward and issued an edict that he wanted us to come up with a combination that could beat them in sanctioned and not-so-sanctioned competition. So I was made race program coordinator for the engineering division and that was October of 1961. The first result was the 413 and 426 Max Wedge. These were very successful at the drags, but less so on NASCAR tracks where Pontiac reigned supreme.
After the 1963 Daytona 500, won by Pontiacs, Mr. Townsend passed down the word; "What would it take to beat them and win the 1964 Daytona 500?" In response, the engineering vice president, a man named Bob Roger, called a group of four or five of us together and we told him the best thing would be to go with the design we had experienced the greatest power with, and that was the Hemi. The outcome of all that was that in April of 1963 we were given the green light to fit Hemi heads onto the wedge block. And we did, very successfully.
HRM: The 426 Hemi was an evolution of the RB wedge engine family. Before the decision was made to adapt Hemi heads to the RB, was there any consideration given to simply reviving the earlier Chrysler 392 Hemi, which was discontinued after the 1958 model year?
Not really. The tooling had very likely been disposed of in the 5 years between the 392 termination and the 1963 decision to prepare for a Daytona victory. Besides, it was a shorter path, really, to develop the Hemi head for the wedge block than it would have been to revive the older Hemi. The early Hemi also had less structure to support the crankshaft at high output levels and high speed. By contrast, the deep skirt RB block was a natural for the job. We could put unbelievable cylinder pressure on it and the crankshaft stays where it is supposed to be. It doesn't get pushed out onto the street where you have to drive over it. The guy that drew the 426 Hemi was Frank Bialk. Certain people are put on this planet with three dimensional insight that many of the rest of us don't have and Frank, now deceased, was one of those people. Before our group got the actual green light to proceed with the 426 Hemi project, in anticipation we got Frank started laying out the design a few weeks in advance. The big thing was that we didn't want to make the exhaust rocker arm any larger, that is to say, with any more rotational inertia, than the one used on the 392. We knew that Garlits, Keith Black and company were capable of running their 392's at 7000 to 7500 rpm so and we didn't want to compromise the new engine's valve gear speed capability through getting the rocker gear too cumbersome. That made a real challenge to get the exhaust pushrod by the edge of the bore at the cylinder head gasket face.
My input to all that was to tilt the cylinder head inboard. This had two effects really. We could limit the length of the exhaust rocker and still have space for a good gasket bead arrangement to seal the engine and it also made more favorable the frontal view of the inlet port. What I'm trying to say is it tilted the whole inlet port and inlet valve arrangement inboard on the vee, which for any naturally aspirated, carbureted scenario, turned out to be a flow advantage. The only real penalty to tilting the heads inboard was that the surface to volume ratio increased a little bit. This means you lose a little bit more heat to the water.
HRM: As the Sixties unfolded, racers like Ronnie Sox, Richard Petty, Don Garlits and countless others were winning with your team's engine design. On a day to day basis, you weren't in the lime light. How did this make you feel?
We were very proud of them. A few people singled me out from time to time but we actually got plenty of exposure doing regional seminars every spring throughout the country. Between 10 and 16 per year. We'd do a Friday in Seattle then a Monday in the San Francisco bay area. Our mission was to make what we had to offer available to as many people as possible on a face-to-face basis. I'd say that was our main mechanism for spreading what we believed t be the best approach for utilizing the engine in racing. I did the first one in 1964 in Centerline, Michigan. Then we went on the road with it and the last ones that I remember were in 1979. So we did it for 15 years. I got as much exposure as I wanted.
HRM: To an observer of the sixties musclecar offerings, the Street Hemi stands out as a particularly good engineering and performance value when compared to the likes of a Pontiac 400 GTO engine or even a Chevy 427. Did you feel that the competition was taking the easy way out by not offering a comparably exotic engine option?
Not necessarily, I've always had a lot of respect for Chevrolet. I think they've done a very good job over a long period of time. I have less respect for Ford. They took more of a knee-jerk reaction approach where they'd realize they had a problem with their street image and they'd pour obscene money all over it for a while, then they'd disappear again and fall behind They were not consistent. We tried to be consistent and in my opinion, Chevrolet was also very accomplished at being consistent.
HRM: The amazing thing about Chevrolet's success is that after March of 1963, GM was officially out of racing by edict of it's own upper management. How did you feel about this?
We knew Chevrolet was still providing plenty of back door engineering support. We knew their pull-out was all a farce for media consumption.
HRM: Coming up to the present time, what is your take on the DaimlerChrysler Hemi revival?
It has really been neat. Pat Behr, the head of NASCAR performance engine development, visited me at home in Pennsylvania in 1997. We went to Ray Barton's, also in Pennsylvania, we all spent the day looking over the cylinder head flow models for the 5.7 liter Hemi that was still in its infancy of development at the time.
The discussion turned to the question of what I thought I'd learned during all of the Hemi years of racing in the Sixties and I said to them; "Well, had it been possible at the time, one of the first things I would like to have done is to move the camshaft up in the block. Chrysler always made a great effort to make the distance from the crankshaft to the camshaft the same on as many engine families as possible to ensure interchangeability of timing sets and communize certain machining lines. But if we could have raised the camshaft in the 426 back in 1963, it would have alleviated the urgency of tilting the heads inboard and simplified the challenge of getting the exhaust pushrods where we needed to have them.
So guess what, on the new engine, one of the first things they did was to move the cam up in the block. This allows for short, stiff pushrods that reduce valve train inertia and make it so the exhaust rocker arms don't have to resemble pump handles any more. That's the first thing they did. I also recalled for those guys that one of the last engines in production on the world scene that didn't require catalytic converters to meet emission standards, was the Nissan NAPS-Z hemispherical chamber inline four. Guess what, it had twin spark plugs that helped it run so clean.
I also urged the guys to add some squish area for improved light load and low speed combustion efficiency for reduced emissions. Again, the new engine has more squish than the 426 Hemi. Without question, what we learned from the 426, particularly the gasoline activity, paid off in terms of making contributions to the new Hemi.
HRM: Do you have any ongoing involvement with 5.7 or 6.1 Hemi development?
Well Pat Behr and I talk every now and then. In fact I'm headed to Martinsville, Virginia tomorrow. We're going to go to the race and the NASCAR engine development shop happens to be there. We'll probably stop by and say hello.
HRM: The sanctioning bodies are known to have taken a "If you can't beat them, outlaw them" policy toward the 426 Hemi. Any thoughts on this?
There was always an internal struggle. Bob Cahill and the late Dick Maxwell did most of the negotiations with the drag people. When we developed something that made more power, their inclination would be to hold it in reserve for a while so we wouldn't get factored yet again. It finally got to the point where we just couldn't handle it anymore so we pulled the plug. I remember that vividly. I just knew when I was walking out of Indianapolis on Labor Day of 1974, that it just wasn't worth doing it anymore. So we didn't.
One of the interesting things that happened in hindsight took place at the Hemi exhibit preview at the Walter P. Chrysler museum in Auburn Hills, Michigan a few years back. Wally Parks was there and he came up to me offered some thoughts that made me feel better about the whole thing. He said he felt over the intervening years that the NHRA should have been less harsh on Chrysler. You know, in the late Sixties and early Seventies, we supported drag racing full bore. We spent a lot of the company's money. I've got to say Ronnie Sox didn't help the situation by winning all the Super Stock eliminators for a number of years. And of course when Pro Stock got rolling, for the first couple years of that we really did well.
Wally related that perhaps the association over reacted to this success. He indirectly put a lot of us out of the high performance business. I went off to work on diesel locomotives in 1979. I took over the General Electric locomotive diesel engine laboratory. The great locomotive fuel conservation race of the nineteen eighties was on and we won that one too, by the way.
GEORGE WALLACE
GEORGE WALLACE: Former Chrysler Engineer in charge of 426 Hemi development.
HRM: Describe your title at Chrysler and how it pertained to the Hemi.
At the time the Hemi came out, which was '64, I was working in what we called the performance lab. We did what would be called today "vehicle simulation", using a computer to calculate acceleration, fuel economy, gradability and other performance parameters for all sorts of cars and combinations of engines and transmissions and all that. There wasn't enough race stuff at that time to warrant a full time person for racing so I worked mostly on stock production vehicles.
Later, starting in 1968 I worked in the race group, full time, but at the time the 426 Hemi came out in 1964 I was working mostly on production stuff. One of my race related jobs when the Hemi first came out was to calculate its performance at Daytona. The Hemi was introduced at the 1964 Daytona 500 and obviously the Daytona race, then like now, is THE important stock car race. Win that and it's a successful season. Lose that but win everything else and it is still not successful.
When I first got seriously involved was with the task of calculating the lap speed at Daytona. I had never seen Daytona live, I didn't have any clear idea of the exact dimensions, the banking and all that. Ronnie Householder, who was in charge of the Chrysler racers, dug up some information on the banking angles, the corner radiuses and such. I started out initially with the 426 wedge engine (hood call outs read 385 horsepower in NASCAR race trim), trying to calculate the lap speed that we'd observed the previous year.
In about December of '63 or January of '64 the Hemi was actually running on the dyno to the point where we had real data. In early January of '64 I was given real, genuine Hemi power curve numbers, I was told I was one of about 12 or 13 people in the company who actually had the numbers, because Ford obviously knew we were reviving the Hemi, with all the outside supplied tooling required for the project, we couldn't keep it a secret, but the actual power output was only made available to a very few people on a need-to-know basis. We had the actual numbers, but a lot of numbers were floating around as rumors, some were way too high, some were way too low, a few of them were right, but most of them weren't.
Based on the observed dyno output, I did some calculations and finally came up with a predictive lap speed number. I was remarkably lucky, and found out a few years later when the race teams had more data to do this correctly, that my errors happened to cancel out and I came up with a lap speed prediction that was within 1/2 of a mph of the fastest speed that anybody ran during the practice sessions conducted before the race. My calculations predicted a lap speed of 174.2 mph, and the pole speed was 174.92 mph, notched by Paul Goldsmith's Plymouth.
It particularly impressed Richard Petty that some engineer up in Detroit can figure out "how fast I'd go in a car I hadn't even run yet". I had met Richard before and knew him a little bit, but this has put me in good standing with him ever since. When I saw him at Talladega this year, he commented that he still needs somebody to figure out what all the date he is collecting means, even today. But that was my introduction to the Hemi.
The other racing related project that I was involved in at about the same time was working with the transmission people on getting the then-new Chrysler A833 four-speed transmission to be reliable in a road racing situation, particularly at Riverside.
HRM: Part of the Hemi lore is the driveline that was installed behind it. Tell me about your involvement in the driveline components like the A833 and Dana 60 rear axle.
During the initial design phase of the A833 four-speed transmission, two levels of strength were anticipated and developed. The input shaft and the gear tooth combination were the focal point. The standard version of the A833 was used in everything from the Slant Six to the 383. It had a 23 tooth input shaft. For the Hemi and the RB wedge engines, more input torque was available so fewer, coarser teeth, which are stronger, but noisier, were used. The regular V8 A833 used finer pitched gears and was designed to be perfectly adequate for use with a 383 but wouldn't live with the Hemis. The input shaft for the Hemi and RB transmission also got an 18-tooth input shaft with a greater root diameter for added resistance to failure under the higher loads generated.
HRM: How did you evaluate the strength and durability requirements of the transmission?
Initially it was just done by theoretical calculation. Calculating gear strength is a very well established procedure. In those days there were very few computers and it was a very long procedure. But it was something that had been done in Detroit for years. In racing, there were two different applications to worry about for the Hemi, drag racing and road racing. Initially they both started with the same design but quickly went their own separate paths. I wasn't particularly involved in the drag racing part of it, but quite a lot of work was done there to strengthen the case, to make some minor changes internally, and by the end of '64 the drag race four-speed was quite satisfactory.
In road racing, the most important race was the Motor Trend 500 at the much lamented Riverside Raceway. This was probably only second in importance to the Daytona 500 because it was the first race of the year, it was held in Southern California, which was the biggest market, and you people at Petersen Publishing did a very good job of promoting the race and making everybody think it was really important. And it really was.
Our major problem at the Riverside race was a fellow named Dan Gurney. Who until 1970 was driving Fords. He was at the time head and shoulders above anybody else running stock cars on a road race circuit in driving ability. Later, the Southerners caught up, but initially Gurney was worth about 3 seconds a lap. Parnelli Jones was pretty good, A.J. Foyt was pretty good, but Gurney was particularly good. In fact in 1970, he did come and drive for Chrysler. Plymouth had struck a deal for him to run Barracudas in Trans Am that year and as an add-on, Dan drove a Petty Plymouth in the Motor Trend race.
We did test with him on one occasion and it was quite amazing looking at all the on-board instrumentation at how different Gurney's methods of driving the car were than the Southerners. Even though we had very good road racers by NASCAR standards, Dan was just so much smoother and so much faster through the twisty parts. As far as the transmission goes, leaving the driver out, the two critical factors at Riverside, were brakes and transmissions.
In those days we were still using drum brakes. It wasn't until about '73 or '74 that Frank Airheart developed a disc brake that would live at Riverside or Martinsville, that was all after I had gotten out of it. Before that, we used 11x31/2 drum brakes and making a drum brake live at Riverside was quite a task. And because the transmission was shifted about six times a lap, transmission durability was a big factor. The first race we had the A833 in was a fall race in 1963 when we were still using the wedge. There were six or seven Mopars running in the race and none of them finished. As I recall, it was about half and half that retired with brake failure and half that retired with transmission failure. These early failures were from over heating, bearing failures, synchronizer ring breakage and cracking of the experimental aluminum case.
Through the whole 1964 season we worked on transmission development and improving bearings, lubrication, the case itself, which was rendered in cast iron to address the strength issue. It was a whole variety of things. In addition to the one NASCAR race at Riverside, the USAC series had about five stock car races so we were working mostly with the USAC people in developing the transmission. By the start of the 1965 season, we had almost eliminated transmission problems as a factor by careful inspection and measurement of all the parts during assembly and polishing the bearing surfaces.
Brakes took another year or so to develop, but starting in 1966 we had the mechanical durability of the cars living up to the performance of the Hemi engine. We still didn't have the drivers to compete with Dan Gurney, but at least we had cars that would finish the race and we'd have a good chance at seconds and thirds so we could build up points toward the NASCAR points system.
HRM: When did the name Hemi come to represent the 426?
That's an interesting point. Internally at Chrysler the engine wasn't referred to as the Hemi until 1965 or 1966. The reason for this is traceable back into the Fifties when we used the terms single rocker shaft and double rocker shaft to designate the V8's. The double rocker shaft name referenced the Chrysler Fire Power, Desoto FireDome and Dodge Red Ram, all of them with hemispherical heads, but not called Hemis internally at the time. The single rocker shaft designation applied to the family of polyspherical head engines. So the momentum was in place to set the stage for the 426 hemispherical head engine to initially be referred to as the double rocker shaft engine during its design and initial test and production phase.
The other name we used was the A864, the engineering designation for the program. Oh sure we had rocker cover stickers that read Ramcharger for Dodge and Super Stock 426 for Plymouth but it wasn't until late 1965 that Chrysler began to capitalize on the Hemi name and began using it in magazine print ads. By the advent of the Street Hemi package in 1966, the Hemi moniker was fully embraced as a marketing tool and is evidenced by the numerous die cast metal badges and vinyl stickers used over the years to identify and help sell Hemi powered vehicles. The 1965 Race Hemi was the first engine to actually bear the word Hemi. It's valve cover stickers read "Hemicharger", in one word.
HRM: When the Street Hemi arrived in 1966, there were numerous body shell reinforcements made to the cars (torque boxes, gusset plates, etc.). Were you involved in designing them?
No, not at all.
HRM: How about the Dana 60 rear axle, were you involved in its inclusion in the Street Hemi package on manual transmission models?
Only in gear ratio development. The Dana was a good but very expensive axle. Obviously we didn't want to put extra money into the car if it didn't need it. When it came to durability testing that might have revealed the need for the Dana or added body structure bracing, there was an awful lot of stuff going on. If it isn't in you area, you may not know about it. It is not necessarily secret, you just never think to ask.
HRM: During the Sixties, did Chrysler give you a Hemi powered company car?
No, I'm one of those guys that likes little cars. I was driving four cylinder stuff in the Fifties and Sixties. I drove Fiats. Later when it was pointed out to me that driving Fiats was not helping me at Chrysler, I got a Sunbeam Imp. That was a rear engine, four cylinder 850-cc car with a die cast aluminum engine. Then as now, I like little cars, even when gas was 20-cents a gallon.
HRM: How did you feel about the not-always kind treatment of the Hemi by the various sanctioning bodies at the time?
We viewed it as an engineering challenge to see if we could still win with the restrictions they put on us. In 1965 NASCAR outlawed us, period. Then for about three quarters of the year we concentrated on USAC stock cars and a variety of other things. That's when Petty went off drag racing. We were going to put Richard Petty and David Pearson in the Mobil Economy Run that year, but USAC, who sanctions the Mobil Economy Run, didn't want to get involved in the battle with NASCAR so they were not eligible drivers. Instead they went match racing on the drag strip until the Street Hemi made the Hemi eligible once again for the 1966 NASCAR race season.
ERIC HANSEN
ERIC HANSEN: Proprietor of Stage V Engineering, manufacturer of aftermarket aluminum Hemi heads, intake manifolds, valve covers and rocker arms since 1985.
HRM: What has caused you to focus your life on designing and manufacturing parts for this particular type of engine?
I've always been attracted to the motor. My aspiration from early on was to run a Top Fuel dragster. I watched Don Prudhomme as a kid and was a big fan. He was a local name, a frequent winner and a really big name in the sport. We used to see him test at Orange County (OCIR) and it was always impressive. Sure there were some Fords and Chevys I watched, but the Hemi stuff pretty much dominated. When I was in high school, driving a 271-horsepower four-speed Mustang, the display cases in the hall ways were frequently filled with student photos and drawings of funny cars and dragsters and what was the focal point of them? The 426 Hemi. Kids all knew what it was and even the Chevy and Ford guys knew enough to respect it. I can't imagine anything like that today.
But that generation of kids is now the adults who are taking so well to the new Hemi advertising campaign. I never actually got to run a Top Fuel car, but a stepping stone was my Top Alcohol dragster. The obvious choice at the time was the Hemi. At the time (about 1978) the alcohol racers were mostly running the aluminum Donovan, which is based on the early 392-style Hemi, not the later 426 type. I started buying pieces to put together a Donovan but the more I looked at it, I realized my ultimate goal was to run Top Fuel, where the late Hemi seemed to have the clear advantage. So I abandoned the idea of building the Donovan and decided to go with the late Hemi even though everybody told me that it wouldn't work. Of course, time has proven that the late Hemi does work quite well in alcohol racing.
The thing that really impressed me about the 426 Hemi versus the earlier Hemi was that you could make lots of tuning mistakes and you still had a motor at the end of the day. They were so strong compared to the 392. The ironic thing is that at the time, you could build two 426 alcohol Hemis for the cost of one Donovan. Alcohol racers like Billy Williams did well with the Donovan but there were others like Darryl Gwynn who did just about as well with 426 Hemis. It was kind of a follow the leader situation. My Top Alcohol racing efforts ended with an iron block 392 and a few 426's before I turned my attention to making Hemi parts for other racers in 1984.
Our Stage V cast aluminum water heads were record holders with drivers like Frank Bradley, Raymond Beadle, Tom McEwen, Larry Minor, Ed McCulloch, Gary Beck and others before the advent of solid billet heads sidelined them in the late Eighties. Since then I've concentrated my cylinder head manufacturing on making cast aluminum heads for drag racers, tractor pullers, boat racers and the high performance street market.
Another aspect of Stage V is our line of cast aluminum Hemi intake manifolds and cast aluminum and cast magnesium valve covers. But the biggest effort is our line of roller rocker intake and exhaust rocker arms. Nearly 100 percent of Top Fuel and Top Alcohol racers use our intake rockers and more than half run our exhaust rockers.
Another thing that impressed me about the Hemi early on was the amount of penalties placed against it by sanctioning bodies. Be it NASCAR or the NHRA or whatever, if you run a small block Chevrolet or a wedge type motor, you get what amount to subsidies to even the score. I'd never heard of a Hemi race car having a weight advantage. It's a big, fairly heavy motor yet it is handicapped by rule makers whenever it starts to win too much. There is something appealing about this, I guess its an under dog thing.
HRM: What's the big difference that makes the 426 a better choice than a 392 for Top Fuel racing?
While the aluminum Donovan was a head and shoulders improvement over the iron 392 used by fuel racers all through the Fifties and Sixties, it was limited by its bore spacing which restricted the amount of cubic inches you could build into it. Though racers like Don Garlits did well in Top Fuel with the early style Donovan, you have to really like that engine family to stick with it. By contrast, the 426 has a greater distance between bore centerlines for bigger piston diameters and massive cubes if your rule book allows them. Plus there's a lot more head bolts keeping the heads on. The early Hemi only has 10 head bolts, the 426 has nearly twice as many at 17, and it makes a big difference in containing supercharged cylinder pressure.
Other hemispherical Chrysler advantages that are shared by both engine families are the short flame travel afforded by the centrally located spark plugs. This design feature is ideal for igniting slow burning fuels like nitromethane. This issue of short flame travel is probably the leading reason why the Hemi is the best suited engine type for Top Fuel racing versus all the others that have been tried over the years. It is also an extremely durable cylinder head in that the intake valve and the exhaust valve are not right next to each other. Instead, there is a wide space between them. Wedge heads have proven very unreliable in Fuel racing because the close proximity of the valves creates a localized region between them that has to cope with very hot exhaust and very cold intake temperatures. To try to get that area to last has been a very difficult hurdle for people that have tried to run big block Chevys in fuel cars over the years.
A popular misconception about the Hemi is that the valve train is trouble. I know that Pro Stock racer Warren Johnson has been a vocal critic of the Hemi and comments that with pushrods going this way and rocker arms going that way, it's not his idea of a promising configuration. Actually it is an extremely durable valvetrain. You've got alcohol dragsters running 10,500 rpm routinely and the parts last for years and years and years. I've got Stage V Engineering rocker arms on several competitive alcohol cars that are ten years old. I can't think of a better testament to the durability of the double rocker shaft design layout and validity Chrysler's execution.
Another thing is that Hemis are easy to work on and, what I would call, fairly non-critical. By this I mean they are forgiving. For example on an overhead cam design, if the head warps, the cam won't spin. On the Hemi, the rocker shafts and stands can be bolted to a warped head and still function very well. Of course, you wouldn't do this on purpose, but in the world of fuel racing, I've seen many between rounds thrash repairs work just fine that would prove fatal on other engine types. Parts can be physically compromised but still function in the heat of battle. The Hemi has a well deserved reputation for this.
HRM: Is the recent wave of rekindled Hemi awareness making a difference in your business at Stage V Engineering?
Yes definitely, there is a lot more interest and a lot more people building Hemis now than ever before. I think there are also a lot more people who always wanted a Hemi who are finally stepping up and buying or building one. They always dreamed of having a Hemi and now they have one. Dick Landy once told me that you can pull into any gas station and open the hood and if its got a Hemi in it, it's always impressive. You might have a wedge that goes just as fast, but the sight of a Hemi just draws crowds, it is timeless.
COTTON OWENS
COTTON OWENS: Nascar Race Hemi pioneer
HRM: What was your opinion of the new 426 Hemi when it arrived on the scene at the 1964 Daytona 500?
In 1963 we were running a Dodge with a 426 wedge engine. It did not have enough stuff to outrun the Pontiac engine at that time. But then they came out with the Hemi which changed everything. I had been urging Chrysler to return to the Hemi design based on my success racing one in the Fifties. It was a Chrysler 354 in a modified Plymouth that I won Daytona Beach with in '53 and '54. In 1962 when Dodge wanted me to go racing with them I said; "Why don't you go back and pick up with the Hemi engine because you don't have anything to compete with the Pontiac engine right now". Back then we had to go by AMA (Automobile Manufacturers Association) specifications. You couldn't modify the engines like you can now. They had to be strictly stock with factory part numbers on them. The head had to hold so many cc's, you could only bore the block so much, the deck clearance had to be the same as what the manufacturers supplied to the AMA. I pointed at the 1955 Chrysler Firepower Hemi engine I had sitting on my shop floor from my Modified car and said; "That's what you need to go back to to take on the Pontiacs". Gale Porter, my contact from Chrysler, promised me a Hemi engine in 1964.
HRM: What did you think when you uncrated your first 426 Hemi?
Oh, I knew it would run.
HRM: It's no secret that an iron headed Hemi is quite a bit heavier than a wedge headed 426. Was this a problem on the racetrack?
There certainly was a weight difference, but it was outweighed by the power increase. We had to weigh so much anyway, I think it was close to 4000 pounds, so the extra engine weight wasn't a factor. Tire wear wasn't affected much either.
HRM: What was your daily driver?
I had a 1964 Hemi Dodge that my son drove back and forth to college.
HRM: When NASCAR put a temporary ban on the 426 Hemi in 1965, you went drag racing. Was that fun?
It was a great experience. We put a Hemi in the back of a 1965 Dodge Dart station wagon, painted it yellow and called it The Cotton Picker. You could adjust the car to transfer so much weight to the rear wheels it would do wheelies. But when NASCAR accepted the Street Hemi as a regular production powerplant, we went right back. I was always a roundy round racer at heart anyway.
HRM: How does the recent revival of the Hemi engine design at DaimlerChrysler make you feel today?
It makes me feel great because I feel that I was one of the instigators who helped establish the Hemi's legend in the first place. Today I'm not involved with the Dodge NASCAR program. I run a Chrysler salvage yard. But I just got done building a '64 Dodge like we raced in '64 with a Hemi engine. In fact it has the second Hemi engine I ever got from Chrysler in 1964. I've got several of them left to this day.
http://www.hotrod.com/web/113_0508_hemi/
You read the story in the August 2005 issue of HOT ROD. Now read the full length, unedited interviews with some of the men who helped shape the Hemi into the cultural icon it is today. -Steve Magnante
--------------------------------------------------
JAY LENO
JAY LENO: Tonight Show host and car collector
HRM: When did you see your first Hemi and what effect did it have on you?
I grew up in Andover Massachusetts and in 1966 there was a kid in our high school who got a green Belvedere with a 426 Hemi. To me, this might as well as have been the space shot. When you grow up in a small town, you don't really see that many exotic cars. I grew up in the kind of place where you'd hang out at the McDonalds parking lot until about 11:00 o'clock then you'd go home and get a call that a Corvette went through at 11:15 and you'd scream because you missed it. To me, the biggest anybody got in my town was a 318, or maybe somebody had a 383 or a Hemi from the Fifties. So when that Belvedere came out, I mean, 0-to-60 in under seven seconds and a top speed of 140 mph, that was considered just unbelievable. We'd always hear stories about how the kid with the Hemi out ran the police, or how he'd come off the highway exit and the cops would overshoot it and go onto the grass, just all that silly teenage stuff.
HRM: Did this guy have a name, you know, like Ace or something cool like that?
I don't remember his name but another Hemi thing that really hit me was a magazine ad that showed the Hemi and it said stuff like "volumetric efficiency". None of us had any idea what it meant at the time but we went around repeating it because we knew it had something to do with the Hemi. And there was another ad with a kind of Peter Max illustration of a Hemi engine and I remember it said something like "You can't make an engine like this with facts and figures alone. It's gotta be voodoo baby". It was one of those mythical urban legend type vehicles.
HRM: We all know that you got into comedy and came to Los Angeles. When did you start buying Hemi cars?
It was the early nineties, about 1992. I got a '66 426 Street Hemi Coronet. I paid $28,000 for it and people said "Are you crazy?" And I said, "Yeah, but I want it". And I like it, its a dog dish hub cap car with not a lot of scoops and whistles on it. I know everybody likes GTX's and all that kind of beep-beep stuff, but to me I just like the plain Jane looking car. It's a sleeper. It is the one car in my collection that my wife has no idea why I find it attractive. She can look at other cars in my collection and understand why I have them but when she looks at the Coronet she says; "That looks like a taxi cab, its got black wall tires, what's the appeal?" It's one of those things that you either get it or you don't. It's really, at least in those days, a guy thing. My wife says "Oh I've gotta' get a Prada purse", I have no idea what that is. The guy equivalent of the Prada purse is a Street Hemi. Then I got a Challenger R/T with the Street Hemi. You don't see many of those, the Challengers. I really wasn't looking for it, it just kind of fell into my lap and became available. It's a four-speed car, my '66 is an automatic. I always kind of liked that brutal Chrysler four speed transmission. It couldn't be more agricultural. It's got the big machete handle Pistol Grip shift lever. Also the Hemi was the first car, I can remember being in high school and talking cars like we did and someone said they had a Hemi automatic, it was understood that it was probably faster than a Hemi four speed. That was just unbelievable. Kids almost got into fisticuffs yelling; "There's no way an automatic is faster than a four speed. Is too, is not, is too, is not" and so on. That kind of ninth grade stuff was rampant. But back in those days when you thought of an automatic transmission, you thought of a two speed Powerglide, and yet here was this Torqueflite transmission that could take this tremendous abuse. In fact when I first got the '66, I remember driving it down the street and thinking; "It's not shifting". I'd put it in Drive and it'd go waaaaah and just stay there. So I contacted a Hemi buddy of mine and told him it doesn't seem to be shifting right. He says; "Are you just keeping your foot in it?" and I said; "Well I am but I'm backing off because I don't want to blow it up", he goes; "no, no, just keep your foot in it and it'll upshift". I said; "Well OK" and I did it and at about 7200 rpm it went waaaah, screech and finally hit Drive. For an American V8 I had never seen a big motor rev that high before. I've also got a '56 Chrysler Imperial with a 354 early Hemi engine.
HRM: We all know that the Hemi is back and making waves in the new Dodge Ram trucks, Chrysler 300 and Dodge Magnum, how do you feel about the continuation of the legacy?
It's OK. It's Frank Sinatra Junior. First of all, as big as the name Hemi is, the numbers 4-2-6 played a big parting that. The new motor isn't quite the same as saying "426 Hemi". Back then a Hemi engine was a Hemi engine. Now it's a brand. I'm not even sure it's a Hemi, isn't a pent-roof design? Anyway, now it is a brand, like when you go into Costco and you get the men's black "turbo" hair dryer? You say; "Is this really a turbo?" Well not really, it's a hair dryer. You know the new Hemi is good but not quite the same.
DAN KNOTT
DAN KNOTT: Director of Street and Racing Technology (SRT) at DaimlerChrysler
HRM: Tell us about the importance of the word Hemi to your work at SRT.
Well, it really started about two years ago when we started building SRT as a cross brand. We already had the Viper and the Neon SRT4. We sat down and we said; "We need a foundational V8 engine that is a foundation for SRT in the V8 engine market arena. Of course we knew we had the Chrysler 300C coming along and we knew the 300 series had a well established performance heritage throughout the years.
So the first thing we did is we looked at the 5.7 Hemi and thought; "Well OK, if you're going to do a performance V8 engine, you'd better start with the Hemi". Then we did what I like to call inject SRT steroids into the 5.7 and created a 6.1 liter Hemi. We gathered all of the racers together in the SRT group, by the way, it's great that we have a bunch of enthusiasts in SRT who race on the weekend and bring their experiences to work on Monday. We sat them down and we said; "We're going to do this engine and what do you think it should have?" So we talked about things like the forged crankshaft, piston oil squirters, floating piston pins, hollow intake and exhaust valves to get the weight down and get the rpm up, and we raised the compression ratio from 9.6 to 10.3.
When we set the objective for the horsepower and torque initially, at 425 the engineers came back and said; "Well, we think we can get about 400". I said; "No that isn't good enough". I wanted as much as possible because there is never enough, and I knew there were competing engine designs that were going to sneak over the 400 horsepower mark shortly. The end result is we took it from 340 horsepower in the 5.7, to 425 in the 6.1. We also took the torque up to 420 lb/ft. We were extremely pleased and I am really proud of the team, they did an outstanding job.
HRM: We see that the SRT 6.1 Hemi has beautiful streamlined double wall exhaust manifolds and a different intake manifold than the 5.7 Hemi Magnum. Are those items what put you over the 400 horsepower mark?
Absolutely. The dual wall exhaust manifolds are just good old fashioned headers. Normally, fabricated exhaust headers need heat shields. You usually design the header and then you attach the heat shield and the heat shield is not part of the structural member. What we did is design them both together so that they're both part of the structure and you get a lot more efficiency and cost effectiveness as well. We were able to get about 15 horsepower just with the headers. Another thing we did to appeal to the HOT ROD readership and guys who are serious about cars, is we painted the block Hemi Orange and put a black wrinkle finish on the rocker arm covers to define a link with the 426 Hemi. We wanted buyers to look at the engine and say; "Those guys at Chrysler get it and understand what is important".
HRM: We all know that the 426 Hemi made 425 horsepower using the old gross rating system. In 1971, when the industry adopted the more realistic net rating system, the 426 Hemi's output was re-listed at 350 horsepower. Is it possible the new SRT 6.1 Hemi makes more SAE net horsepower than the legendary Street Hemi?
Yes it is. There is an SAE standard for rating engines so comparisons can be made with accuracy. And yes, under this system an SRT 6.1 Hemi will make more real horsepower than a 426 Street Hemi. Torque output is not as high as the Street Hemi due to the significant 54 cubic inch difference in displacement, but horsepower is superior. One thing about SRT products is that we tend to be conservative in our advertised horsepower ratings.
We want the customer, and the media, to get better numbers. For example we advertise that the 300C SRT-8, which this engine is in, does 0-to-60 in around 5-seconds. Well Motor Trend got 4.9 and we know of another magazine that is getting ready to publish, that got better than that. It is the same with our horsepower ratings, they're a bit conservative.
HRM: How does the SRT 6.1 Hemi intake manifold differ from the standard 5.7 piece?
It is a tapered runner manifold and there is also more volume. The tapered runners increase the airflow. It gets to the intake port of the cylinder heads at a higher rate of speed for a slight ram tuning effect, just like the old days of cross rams. The increased intake plenum volume gives the engine greater access to fuel with greater power output as the natural result.
HRM: What does the future hold for the new Hemi engine? Is it at its maximum displacement at 6.1 liters (372 cubic inches)? We've heard talk of an upcoming 6.3 liter version.
I can't talk about future product, but I will tell you this. In the performance industry, there's been a renaissance on for some time now. We know from our customers that there is never such thing as too much performance. While we have to balance that with resources, building viable business cases and making sure these things make money, and also that they are very acceptable and safe for every day use. They also must have high levels of quality and reliability. I'll just say that SRT doesn't rest on its laurels.
We always look for ways to raise the bar. The improvements may be in an engine or in the suspension. Like the SRT4. Six months after we launched it we brought out a limited slip differential to take it to the next level. So we're always looking for ways to improve already excellent products. That's what we want people to expect and demand from SRT.
HRM: To you personally, Dan, what does the word Hemi mean?
My dad and grandfather watched NASCAR racing and you'd see Richard Petty running wild out there with his Hemi cars before they phased out in the early seventies. Even before I knew what makes a Hemi a Hemi, I was aware that the basic word meant power, and performance and an image of supremacy in the automotive marketplace.
When we brought the 5.7 Hemi back, I thought: "Man, this is really going to do well". But I had no idea how well it has done. To be honest with you, it stunned us all. It reinforces the fact that consumers have always been about product and performance. If you've got a name like Hemi, which has walked the walk, you can always revive it if you put credibility behind it. And that's exactly what our SRT team strives to do.
TOM HOOVER
TOM HOOVER: Former Chrysler employee and "God father" of the 426 Hemi
HRM: What was your first introduction to Hemi engines?
I was off driving trucks in the Korean war when the first Chrysler Hemi entered production in 1951. Before my arrival at Chrysler in 1955, I was fully aware that they were something special what with stock rated power that was consistently 25 to 30 horsepower higher than competing wedge head V8 designs of similar displacement.
The thing that was the most significant to me was the A311 program that explored the potential of the Chrysler 331 Hemi as a potential Indianapolis 500 racing engine. The A311 report became the most desirable reading material among those of us enrolled in the Chrysler Institute. I graduated from the Chrysler Institute in 1957 and at about the same time a group of Chrysler employees formed the Ram Chargers group, a loose knit bunch of engineers who drag raced their cars on weekends. Even though the A311 program didn't produce an Indy victory due to USAC rule changes, the technical report it generated was a guiding light for me.
HRM: How did you become involved in the 426 Hemi development program?
Luckily I was standing there with some applicable experience when the 426 Hemi program got under way. It started when Lynn Townsend became chief executive officer of the company with a desire to establish a performance image. Lore has it he had a couple of teenage sons who enjoyed street racing on Woodward Avenue. At the time I had a '59 Plymouth with a 392 Chrysler Hemi transplant.
The long and short of it is that Townsend listened to his sons' talk about the hot Pontiacs on Woodward and issued an edict that he wanted us to come up with a combination that could beat them in sanctioned and not-so-sanctioned competition. So I was made race program coordinator for the engineering division and that was October of 1961. The first result was the 413 and 426 Max Wedge. These were very successful at the drags, but less so on NASCAR tracks where Pontiac reigned supreme.
After the 1963 Daytona 500, won by Pontiacs, Mr. Townsend passed down the word; "What would it take to beat them and win the 1964 Daytona 500?" In response, the engineering vice president, a man named Bob Roger, called a group of four or five of us together and we told him the best thing would be to go with the design we had experienced the greatest power with, and that was the Hemi. The outcome of all that was that in April of 1963 we were given the green light to fit Hemi heads onto the wedge block. And we did, very successfully.
HRM: The 426 Hemi was an evolution of the RB wedge engine family. Before the decision was made to adapt Hemi heads to the RB, was there any consideration given to simply reviving the earlier Chrysler 392 Hemi, which was discontinued after the 1958 model year?
Not really. The tooling had very likely been disposed of in the 5 years between the 392 termination and the 1963 decision to prepare for a Daytona victory. Besides, it was a shorter path, really, to develop the Hemi head for the wedge block than it would have been to revive the older Hemi. The early Hemi also had less structure to support the crankshaft at high output levels and high speed. By contrast, the deep skirt RB block was a natural for the job. We could put unbelievable cylinder pressure on it and the crankshaft stays where it is supposed to be. It doesn't get pushed out onto the street where you have to drive over it. The guy that drew the 426 Hemi was Frank Bialk. Certain people are put on this planet with three dimensional insight that many of the rest of us don't have and Frank, now deceased, was one of those people. Before our group got the actual green light to proceed with the 426 Hemi project, in anticipation we got Frank started laying out the design a few weeks in advance. The big thing was that we didn't want to make the exhaust rocker arm any larger, that is to say, with any more rotational inertia, than the one used on the 392. We knew that Garlits, Keith Black and company were capable of running their 392's at 7000 to 7500 rpm so and we didn't want to compromise the new engine's valve gear speed capability through getting the rocker gear too cumbersome. That made a real challenge to get the exhaust pushrod by the edge of the bore at the cylinder head gasket face.
My input to all that was to tilt the cylinder head inboard. This had two effects really. We could limit the length of the exhaust rocker and still have space for a good gasket bead arrangement to seal the engine and it also made more favorable the frontal view of the inlet port. What I'm trying to say is it tilted the whole inlet port and inlet valve arrangement inboard on the vee, which for any naturally aspirated, carbureted scenario, turned out to be a flow advantage. The only real penalty to tilting the heads inboard was that the surface to volume ratio increased a little bit. This means you lose a little bit more heat to the water.
HRM: As the Sixties unfolded, racers like Ronnie Sox, Richard Petty, Don Garlits and countless others were winning with your team's engine design. On a day to day basis, you weren't in the lime light. How did this make you feel?
We were very proud of them. A few people singled me out from time to time but we actually got plenty of exposure doing regional seminars every spring throughout the country. Between 10 and 16 per year. We'd do a Friday in Seattle then a Monday in the San Francisco bay area. Our mission was to make what we had to offer available to as many people as possible on a face-to-face basis. I'd say that was our main mechanism for spreading what we believed t be the best approach for utilizing the engine in racing. I did the first one in 1964 in Centerline, Michigan. Then we went on the road with it and the last ones that I remember were in 1979. So we did it for 15 years. I got as much exposure as I wanted.
HRM: To an observer of the sixties musclecar offerings, the Street Hemi stands out as a particularly good engineering and performance value when compared to the likes of a Pontiac 400 GTO engine or even a Chevy 427. Did you feel that the competition was taking the easy way out by not offering a comparably exotic engine option?
Not necessarily, I've always had a lot of respect for Chevrolet. I think they've done a very good job over a long period of time. I have less respect for Ford. They took more of a knee-jerk reaction approach where they'd realize they had a problem with their street image and they'd pour obscene money all over it for a while, then they'd disappear again and fall behind They were not consistent. We tried to be consistent and in my opinion, Chevrolet was also very accomplished at being consistent.
HRM: The amazing thing about Chevrolet's success is that after March of 1963, GM was officially out of racing by edict of it's own upper management. How did you feel about this?
We knew Chevrolet was still providing plenty of back door engineering support. We knew their pull-out was all a farce for media consumption.
HRM: Coming up to the present time, what is your take on the DaimlerChrysler Hemi revival?
It has really been neat. Pat Behr, the head of NASCAR performance engine development, visited me at home in Pennsylvania in 1997. We went to Ray Barton's, also in Pennsylvania, we all spent the day looking over the cylinder head flow models for the 5.7 liter Hemi that was still in its infancy of development at the time.
The discussion turned to the question of what I thought I'd learned during all of the Hemi years of racing in the Sixties and I said to them; "Well, had it been possible at the time, one of the first things I would like to have done is to move the camshaft up in the block. Chrysler always made a great effort to make the distance from the crankshaft to the camshaft the same on as many engine families as possible to ensure interchangeability of timing sets and communize certain machining lines. But if we could have raised the camshaft in the 426 back in 1963, it would have alleviated the urgency of tilting the heads inboard and simplified the challenge of getting the exhaust pushrods where we needed to have them.
So guess what, on the new engine, one of the first things they did was to move the cam up in the block. This allows for short, stiff pushrods that reduce valve train inertia and make it so the exhaust rocker arms don't have to resemble pump handles any more. That's the first thing they did. I also recalled for those guys that one of the last engines in production on the world scene that didn't require catalytic converters to meet emission standards, was the Nissan NAPS-Z hemispherical chamber inline four. Guess what, it had twin spark plugs that helped it run so clean.
I also urged the guys to add some squish area for improved light load and low speed combustion efficiency for reduced emissions. Again, the new engine has more squish than the 426 Hemi. Without question, what we learned from the 426, particularly the gasoline activity, paid off in terms of making contributions to the new Hemi.
HRM: Do you have any ongoing involvement with 5.7 or 6.1 Hemi development?
Well Pat Behr and I talk every now and then. In fact I'm headed to Martinsville, Virginia tomorrow. We're going to go to the race and the NASCAR engine development shop happens to be there. We'll probably stop by and say hello.
HRM: The sanctioning bodies are known to have taken a "If you can't beat them, outlaw them" policy toward the 426 Hemi. Any thoughts on this?
There was always an internal struggle. Bob Cahill and the late Dick Maxwell did most of the negotiations with the drag people. When we developed something that made more power, their inclination would be to hold it in reserve for a while so we wouldn't get factored yet again. It finally got to the point where we just couldn't handle it anymore so we pulled the plug. I remember that vividly. I just knew when I was walking out of Indianapolis on Labor Day of 1974, that it just wasn't worth doing it anymore. So we didn't.
One of the interesting things that happened in hindsight took place at the Hemi exhibit preview at the Walter P. Chrysler museum in Auburn Hills, Michigan a few years back. Wally Parks was there and he came up to me offered some thoughts that made me feel better about the whole thing. He said he felt over the intervening years that the NHRA should have been less harsh on Chrysler. You know, in the late Sixties and early Seventies, we supported drag racing full bore. We spent a lot of the company's money. I've got to say Ronnie Sox didn't help the situation by winning all the Super Stock eliminators for a number of years. And of course when Pro Stock got rolling, for the first couple years of that we really did well.
Wally related that perhaps the association over reacted to this success. He indirectly put a lot of us out of the high performance business. I went off to work on diesel locomotives in 1979. I took over the General Electric locomotive diesel engine laboratory. The great locomotive fuel conservation race of the nineteen eighties was on and we won that one too, by the way.
GEORGE WALLACE
GEORGE WALLACE: Former Chrysler Engineer in charge of 426 Hemi development.
HRM: Describe your title at Chrysler and how it pertained to the Hemi.
At the time the Hemi came out, which was '64, I was working in what we called the performance lab. We did what would be called today "vehicle simulation", using a computer to calculate acceleration, fuel economy, gradability and other performance parameters for all sorts of cars and combinations of engines and transmissions and all that. There wasn't enough race stuff at that time to warrant a full time person for racing so I worked mostly on stock production vehicles.
Later, starting in 1968 I worked in the race group, full time, but at the time the 426 Hemi came out in 1964 I was working mostly on production stuff. One of my race related jobs when the Hemi first came out was to calculate its performance at Daytona. The Hemi was introduced at the 1964 Daytona 500 and obviously the Daytona race, then like now, is THE important stock car race. Win that and it's a successful season. Lose that but win everything else and it is still not successful.
When I first got seriously involved was with the task of calculating the lap speed at Daytona. I had never seen Daytona live, I didn't have any clear idea of the exact dimensions, the banking and all that. Ronnie Householder, who was in charge of the Chrysler racers, dug up some information on the banking angles, the corner radiuses and such. I started out initially with the 426 wedge engine (hood call outs read 385 horsepower in NASCAR race trim), trying to calculate the lap speed that we'd observed the previous year.
In about December of '63 or January of '64 the Hemi was actually running on the dyno to the point where we had real data. In early January of '64 I was given real, genuine Hemi power curve numbers, I was told I was one of about 12 or 13 people in the company who actually had the numbers, because Ford obviously knew we were reviving the Hemi, with all the outside supplied tooling required for the project, we couldn't keep it a secret, but the actual power output was only made available to a very few people on a need-to-know basis. We had the actual numbers, but a lot of numbers were floating around as rumors, some were way too high, some were way too low, a few of them were right, but most of them weren't.
Based on the observed dyno output, I did some calculations and finally came up with a predictive lap speed number. I was remarkably lucky, and found out a few years later when the race teams had more data to do this correctly, that my errors happened to cancel out and I came up with a lap speed prediction that was within 1/2 of a mph of the fastest speed that anybody ran during the practice sessions conducted before the race. My calculations predicted a lap speed of 174.2 mph, and the pole speed was 174.92 mph, notched by Paul Goldsmith's Plymouth.
It particularly impressed Richard Petty that some engineer up in Detroit can figure out "how fast I'd go in a car I hadn't even run yet". I had met Richard before and knew him a little bit, but this has put me in good standing with him ever since. When I saw him at Talladega this year, he commented that he still needs somebody to figure out what all the date he is collecting means, even today. But that was my introduction to the Hemi.
The other racing related project that I was involved in at about the same time was working with the transmission people on getting the then-new Chrysler A833 four-speed transmission to be reliable in a road racing situation, particularly at Riverside.
HRM: Part of the Hemi lore is the driveline that was installed behind it. Tell me about your involvement in the driveline components like the A833 and Dana 60 rear axle.
During the initial design phase of the A833 four-speed transmission, two levels of strength were anticipated and developed. The input shaft and the gear tooth combination were the focal point. The standard version of the A833 was used in everything from the Slant Six to the 383. It had a 23 tooth input shaft. For the Hemi and the RB wedge engines, more input torque was available so fewer, coarser teeth, which are stronger, but noisier, were used. The regular V8 A833 used finer pitched gears and was designed to be perfectly adequate for use with a 383 but wouldn't live with the Hemis. The input shaft for the Hemi and RB transmission also got an 18-tooth input shaft with a greater root diameter for added resistance to failure under the higher loads generated.
HRM: How did you evaluate the strength and durability requirements of the transmission?
Initially it was just done by theoretical calculation. Calculating gear strength is a very well established procedure. In those days there were very few computers and it was a very long procedure. But it was something that had been done in Detroit for years. In racing, there were two different applications to worry about for the Hemi, drag racing and road racing. Initially they both started with the same design but quickly went their own separate paths. I wasn't particularly involved in the drag racing part of it, but quite a lot of work was done there to strengthen the case, to make some minor changes internally, and by the end of '64 the drag race four-speed was quite satisfactory.
In road racing, the most important race was the Motor Trend 500 at the much lamented Riverside Raceway. This was probably only second in importance to the Daytona 500 because it was the first race of the year, it was held in Southern California, which was the biggest market, and you people at Petersen Publishing did a very good job of promoting the race and making everybody think it was really important. And it really was.
Our major problem at the Riverside race was a fellow named Dan Gurney. Who until 1970 was driving Fords. He was at the time head and shoulders above anybody else running stock cars on a road race circuit in driving ability. Later, the Southerners caught up, but initially Gurney was worth about 3 seconds a lap. Parnelli Jones was pretty good, A.J. Foyt was pretty good, but Gurney was particularly good. In fact in 1970, he did come and drive for Chrysler. Plymouth had struck a deal for him to run Barracudas in Trans Am that year and as an add-on, Dan drove a Petty Plymouth in the Motor Trend race.
We did test with him on one occasion and it was quite amazing looking at all the on-board instrumentation at how different Gurney's methods of driving the car were than the Southerners. Even though we had very good road racers by NASCAR standards, Dan was just so much smoother and so much faster through the twisty parts. As far as the transmission goes, leaving the driver out, the two critical factors at Riverside, were brakes and transmissions.
In those days we were still using drum brakes. It wasn't until about '73 or '74 that Frank Airheart developed a disc brake that would live at Riverside or Martinsville, that was all after I had gotten out of it. Before that, we used 11x31/2 drum brakes and making a drum brake live at Riverside was quite a task. And because the transmission was shifted about six times a lap, transmission durability was a big factor. The first race we had the A833 in was a fall race in 1963 when we were still using the wedge. There were six or seven Mopars running in the race and none of them finished. As I recall, it was about half and half that retired with brake failure and half that retired with transmission failure. These early failures were from over heating, bearing failures, synchronizer ring breakage and cracking of the experimental aluminum case.
Through the whole 1964 season we worked on transmission development and improving bearings, lubrication, the case itself, which was rendered in cast iron to address the strength issue. It was a whole variety of things. In addition to the one NASCAR race at Riverside, the USAC series had about five stock car races so we were working mostly with the USAC people in developing the transmission. By the start of the 1965 season, we had almost eliminated transmission problems as a factor by careful inspection and measurement of all the parts during assembly and polishing the bearing surfaces.
Brakes took another year or so to develop, but starting in 1966 we had the mechanical durability of the cars living up to the performance of the Hemi engine. We still didn't have the drivers to compete with Dan Gurney, but at least we had cars that would finish the race and we'd have a good chance at seconds and thirds so we could build up points toward the NASCAR points system.
HRM: When did the name Hemi come to represent the 426?
That's an interesting point. Internally at Chrysler the engine wasn't referred to as the Hemi until 1965 or 1966. The reason for this is traceable back into the Fifties when we used the terms single rocker shaft and double rocker shaft to designate the V8's. The double rocker shaft name referenced the Chrysler Fire Power, Desoto FireDome and Dodge Red Ram, all of them with hemispherical heads, but not called Hemis internally at the time. The single rocker shaft designation applied to the family of polyspherical head engines. So the momentum was in place to set the stage for the 426 hemispherical head engine to initially be referred to as the double rocker shaft engine during its design and initial test and production phase.
The other name we used was the A864, the engineering designation for the program. Oh sure we had rocker cover stickers that read Ramcharger for Dodge and Super Stock 426 for Plymouth but it wasn't until late 1965 that Chrysler began to capitalize on the Hemi name and began using it in magazine print ads. By the advent of the Street Hemi package in 1966, the Hemi moniker was fully embraced as a marketing tool and is evidenced by the numerous die cast metal badges and vinyl stickers used over the years to identify and help sell Hemi powered vehicles. The 1965 Race Hemi was the first engine to actually bear the word Hemi. It's valve cover stickers read "Hemicharger", in one word.
HRM: When the Street Hemi arrived in 1966, there were numerous body shell reinforcements made to the cars (torque boxes, gusset plates, etc.). Were you involved in designing them?
No, not at all.
HRM: How about the Dana 60 rear axle, were you involved in its inclusion in the Street Hemi package on manual transmission models?
Only in gear ratio development. The Dana was a good but very expensive axle. Obviously we didn't want to put extra money into the car if it didn't need it. When it came to durability testing that might have revealed the need for the Dana or added body structure bracing, there was an awful lot of stuff going on. If it isn't in you area, you may not know about it. It is not necessarily secret, you just never think to ask.
HRM: During the Sixties, did Chrysler give you a Hemi powered company car?
No, I'm one of those guys that likes little cars. I was driving four cylinder stuff in the Fifties and Sixties. I drove Fiats. Later when it was pointed out to me that driving Fiats was not helping me at Chrysler, I got a Sunbeam Imp. That was a rear engine, four cylinder 850-cc car with a die cast aluminum engine. Then as now, I like little cars, even when gas was 20-cents a gallon.
HRM: How did you feel about the not-always kind treatment of the Hemi by the various sanctioning bodies at the time?
We viewed it as an engineering challenge to see if we could still win with the restrictions they put on us. In 1965 NASCAR outlawed us, period. Then for about three quarters of the year we concentrated on USAC stock cars and a variety of other things. That's when Petty went off drag racing. We were going to put Richard Petty and David Pearson in the Mobil Economy Run that year, but USAC, who sanctions the Mobil Economy Run, didn't want to get involved in the battle with NASCAR so they were not eligible drivers. Instead they went match racing on the drag strip until the Street Hemi made the Hemi eligible once again for the 1966 NASCAR race season.
ERIC HANSEN
ERIC HANSEN: Proprietor of Stage V Engineering, manufacturer of aftermarket aluminum Hemi heads, intake manifolds, valve covers and rocker arms since 1985.
HRM: What has caused you to focus your life on designing and manufacturing parts for this particular type of engine?
I've always been attracted to the motor. My aspiration from early on was to run a Top Fuel dragster. I watched Don Prudhomme as a kid and was a big fan. He was a local name, a frequent winner and a really big name in the sport. We used to see him test at Orange County (OCIR) and it was always impressive. Sure there were some Fords and Chevys I watched, but the Hemi stuff pretty much dominated. When I was in high school, driving a 271-horsepower four-speed Mustang, the display cases in the hall ways were frequently filled with student photos and drawings of funny cars and dragsters and what was the focal point of them? The 426 Hemi. Kids all knew what it was and even the Chevy and Ford guys knew enough to respect it. I can't imagine anything like that today.
But that generation of kids is now the adults who are taking so well to the new Hemi advertising campaign. I never actually got to run a Top Fuel car, but a stepping stone was my Top Alcohol dragster. The obvious choice at the time was the Hemi. At the time (about 1978) the alcohol racers were mostly running the aluminum Donovan, which is based on the early 392-style Hemi, not the later 426 type. I started buying pieces to put together a Donovan but the more I looked at it, I realized my ultimate goal was to run Top Fuel, where the late Hemi seemed to have the clear advantage. So I abandoned the idea of building the Donovan and decided to go with the late Hemi even though everybody told me that it wouldn't work. Of course, time has proven that the late Hemi does work quite well in alcohol racing.
The thing that really impressed me about the 426 Hemi versus the earlier Hemi was that you could make lots of tuning mistakes and you still had a motor at the end of the day. They were so strong compared to the 392. The ironic thing is that at the time, you could build two 426 alcohol Hemis for the cost of one Donovan. Alcohol racers like Billy Williams did well with the Donovan but there were others like Darryl Gwynn who did just about as well with 426 Hemis. It was kind of a follow the leader situation. My Top Alcohol racing efforts ended with an iron block 392 and a few 426's before I turned my attention to making Hemi parts for other racers in 1984.
Our Stage V cast aluminum water heads were record holders with drivers like Frank Bradley, Raymond Beadle, Tom McEwen, Larry Minor, Ed McCulloch, Gary Beck and others before the advent of solid billet heads sidelined them in the late Eighties. Since then I've concentrated my cylinder head manufacturing on making cast aluminum heads for drag racers, tractor pullers, boat racers and the high performance street market.
Another aspect of Stage V is our line of cast aluminum Hemi intake manifolds and cast aluminum and cast magnesium valve covers. But the biggest effort is our line of roller rocker intake and exhaust rocker arms. Nearly 100 percent of Top Fuel and Top Alcohol racers use our intake rockers and more than half run our exhaust rockers.
Another thing that impressed me about the Hemi early on was the amount of penalties placed against it by sanctioning bodies. Be it NASCAR or the NHRA or whatever, if you run a small block Chevrolet or a wedge type motor, you get what amount to subsidies to even the score. I'd never heard of a Hemi race car having a weight advantage. It's a big, fairly heavy motor yet it is handicapped by rule makers whenever it starts to win too much. There is something appealing about this, I guess its an under dog thing.
HRM: What's the big difference that makes the 426 a better choice than a 392 for Top Fuel racing?
While the aluminum Donovan was a head and shoulders improvement over the iron 392 used by fuel racers all through the Fifties and Sixties, it was limited by its bore spacing which restricted the amount of cubic inches you could build into it. Though racers like Don Garlits did well in Top Fuel with the early style Donovan, you have to really like that engine family to stick with it. By contrast, the 426 has a greater distance between bore centerlines for bigger piston diameters and massive cubes if your rule book allows them. Plus there's a lot more head bolts keeping the heads on. The early Hemi only has 10 head bolts, the 426 has nearly twice as many at 17, and it makes a big difference in containing supercharged cylinder pressure.
Other hemispherical Chrysler advantages that are shared by both engine families are the short flame travel afforded by the centrally located spark plugs. This design feature is ideal for igniting slow burning fuels like nitromethane. This issue of short flame travel is probably the leading reason why the Hemi is the best suited engine type for Top Fuel racing versus all the others that have been tried over the years. It is also an extremely durable cylinder head in that the intake valve and the exhaust valve are not right next to each other. Instead, there is a wide space between them. Wedge heads have proven very unreliable in Fuel racing because the close proximity of the valves creates a localized region between them that has to cope with very hot exhaust and very cold intake temperatures. To try to get that area to last has been a very difficult hurdle for people that have tried to run big block Chevys in fuel cars over the years.
A popular misconception about the Hemi is that the valve train is trouble. I know that Pro Stock racer Warren Johnson has been a vocal critic of the Hemi and comments that with pushrods going this way and rocker arms going that way, it's not his idea of a promising configuration. Actually it is an extremely durable valvetrain. You've got alcohol dragsters running 10,500 rpm routinely and the parts last for years and years and years. I've got Stage V Engineering rocker arms on several competitive alcohol cars that are ten years old. I can't think of a better testament to the durability of the double rocker shaft design layout and validity Chrysler's execution.
Another thing is that Hemis are easy to work on and, what I would call, fairly non-critical. By this I mean they are forgiving. For example on an overhead cam design, if the head warps, the cam won't spin. On the Hemi, the rocker shafts and stands can be bolted to a warped head and still function very well. Of course, you wouldn't do this on purpose, but in the world of fuel racing, I've seen many between rounds thrash repairs work just fine that would prove fatal on other engine types. Parts can be physically compromised but still function in the heat of battle. The Hemi has a well deserved reputation for this.
HRM: Is the recent wave of rekindled Hemi awareness making a difference in your business at Stage V Engineering?
Yes definitely, there is a lot more interest and a lot more people building Hemis now than ever before. I think there are also a lot more people who always wanted a Hemi who are finally stepping up and buying or building one. They always dreamed of having a Hemi and now they have one. Dick Landy once told me that you can pull into any gas station and open the hood and if its got a Hemi in it, it's always impressive. You might have a wedge that goes just as fast, but the sight of a Hemi just draws crowds, it is timeless.
COTTON OWENS
COTTON OWENS: Nascar Race Hemi pioneer
HRM: What was your opinion of the new 426 Hemi when it arrived on the scene at the 1964 Daytona 500?
In 1963 we were running a Dodge with a 426 wedge engine. It did not have enough stuff to outrun the Pontiac engine at that time. But then they came out with the Hemi which changed everything. I had been urging Chrysler to return to the Hemi design based on my success racing one in the Fifties. It was a Chrysler 354 in a modified Plymouth that I won Daytona Beach with in '53 and '54. In 1962 when Dodge wanted me to go racing with them I said; "Why don't you go back and pick up with the Hemi engine because you don't have anything to compete with the Pontiac engine right now". Back then we had to go by AMA (Automobile Manufacturers Association) specifications. You couldn't modify the engines like you can now. They had to be strictly stock with factory part numbers on them. The head had to hold so many cc's, you could only bore the block so much, the deck clearance had to be the same as what the manufacturers supplied to the AMA. I pointed at the 1955 Chrysler Firepower Hemi engine I had sitting on my shop floor from my Modified car and said; "That's what you need to go back to to take on the Pontiacs". Gale Porter, my contact from Chrysler, promised me a Hemi engine in 1964.
HRM: What did you think when you uncrated your first 426 Hemi?
Oh, I knew it would run.
HRM: It's no secret that an iron headed Hemi is quite a bit heavier than a wedge headed 426. Was this a problem on the racetrack?
There certainly was a weight difference, but it was outweighed by the power increase. We had to weigh so much anyway, I think it was close to 4000 pounds, so the extra engine weight wasn't a factor. Tire wear wasn't affected much either.
HRM: What was your daily driver?
I had a 1964 Hemi Dodge that my son drove back and forth to college.
HRM: When NASCAR put a temporary ban on the 426 Hemi in 1965, you went drag racing. Was that fun?
It was a great experience. We put a Hemi in the back of a 1965 Dodge Dart station wagon, painted it yellow and called it The Cotton Picker. You could adjust the car to transfer so much weight to the rear wheels it would do wheelies. But when NASCAR accepted the Street Hemi as a regular production powerplant, we went right back. I was always a roundy round racer at heart anyway.
HRM: How does the recent revival of the Hemi engine design at DaimlerChrysler make you feel today?
It makes me feel great because I feel that I was one of the instigators who helped establish the Hemi's legend in the first place. Today I'm not involved with the Dodge NASCAR program. I run a Chrysler salvage yard. But I just got done building a '64 Dodge like we raced in '64 with a Hemi engine. In fact it has the second Hemi engine I ever got from Chrysler in 1964. I've got several of them left to this day.