Donovan Aluminum heads in a streetable car

Discussion of the 331-354-392 HEMIs.

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Paul
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Donovan Aluminum heads in a streetable car

Postby Paul » Tue Sep 01, 2009 11:52 pm

I'm considering running a pr of aluminum Donovan (water) heads on a semi-"streetable" car (392 w/large cubes). Hasn't anybody tried this? I was told the earlier aluminum isn't as high of a grade (& subjected to some long term water leaks) I'd like to avoid forced induction, if possible. I will also build my own headers. Might have to build a intake :lol: :evil: :lol:
Last edited by Paul on Mon Oct 05, 2009 9:45 am, edited 1 time in total.

dan miller
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Re: Donovan Aluminum heads in a streetable car

Postby dan miller » Wed Sep 02, 2009 6:41 am

Hello Paul

A couple things come to mind. The Donovan heads might have ports that are a little large for the street. If they're a really nice set, they have good value, and could probably be sold for enough loot to purchase a set of new Hot Heads, which are absolutely perfect for the street. If they're not a really nice set, then I suspect that you might have trouble with them.

What are you planning for induction? The Hot Heads dual plane is a nice single 4 bbl manifold, able to support well over 500 hp on a 354. Other than that, there are not many options.

We're using 48IDA Webers on our Engine Masters Challenge engine (Chinese/EMPI 51.5 carburetors, Hot Heads Weber Manifolds, and 1" thick delrin spacers above and below the manifolds). They're showing good promise (600+ hp thus far), but it's an expensive and time consuming deal. I believe that we're getting close, and when the smoke clears, I'll share the end result. I had Scott Parks (Neil and Parks Race Cars) water jet cut the delrin, so he has the pattern in the computer and could duplicate the parts. The difficulty is that it takes a lot of filling (Splash Zone) and porting.

Danny

Paul
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Location: Tulsa Oklahoma

Re: Donovan Aluminum heads in a streetable car

Postby Paul » Thu Sep 17, 2009 11:20 am

I'm still waiting on them. The guy didn't take pay pal, so I had mail out a check. Yep, I know they are flow monsters & lack that low end "streetable" response....all out high rpm's . I just want to drive to the track "streetable". There's a few egomaniacs around here that need to be put in their place. I've been building mild 115 lb spring pressure hydralic cam hotrods. They are extremely fast , since they don't weigh very much however, theres a couple of braggers around here running full bodied cars (transporting them on fancy trailers) running high 10's. (one high 9) I want to take one of these lightweight (homebuilt) hotrods (27-2800lbs)drive to the track , blow them away & drive home. I was thinking 354 however, will opt for a stroked 392 for cubes. Dan Davorak can weld me up a crank 5/8" stroked 462 cubes. Use 7.100 chevy rods. I think the stroke works out to 4.250 or so!
re:
((We're using 48IDA Webers on our Engine Masters Challenge engine (Chinese/EMPI 51.5 carburetors, Hot Heads Weber Manifolds, and 1" thick delrin spacers above and below the manifolds). They're showing good promise (600+ hp thus far), but it's an expensive and time consuming deal. I believe that we're getting close, and when the smoke clears, I'll share the end result. I had Scott Parks (Neil and Parks Race Cars) water jet cut the delrin, so he has the pattern in the computer and could duplicate the parts. The difficulty is that it takes a lot of filling (Splash Zone) and porting.))
Yes, I love the 481 Weber idea. They are supposed to be smooth. They also look cool ( 4 look like 8 ) There's got to be a reason the extremely hp VW & Cobra guys use them for performance applications.

DblAdigger
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Re: Donovan Aluminum heads in a streetable car

Postby DblAdigger » Thu Sep 17, 2009 9:47 pm

FYI, a 5/8 arm on a '92 crank is 4.525 stroke.
Chuck Stevens
Some people can break a cannon ball, in a sand box, with their bare hands.

Bored&Stroked
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Re: Donovan Aluminum heads in a streetable car

Postby Bored&Stroked » Sat Sep 19, 2009 8:18 pm

Are you talking about the 417 Donovan heads? If so, then hopefully you know all the things that are different between those heads and regular 392's. Donovan made quite a few different versions - mainly because they were primarily top-fuel heads and people wanted to try all sorts of different port sizes, port shapes, etc.. If you have the early ones where the combustion chamber was not quite round - had a funny O-Ring groove, then they'll be more work than the later ones. You need to know the details of all the nuances - before you attempt to run these heads, or you'll spend a lot of money and you may not like the results. Unless you're really building a high-end blown motor -- I don't see a whole lot of reason to run them. You'd spend less money on the HotHeads setup and find it a whole lot easier to setup and run . . . and you'd still have the light-weight setup.

Things you need to think about include:

a) The valves are longer and the pushrod spacing is a bit different than a 92. Due to this, you'll need special rockers for the 417 heads. I had Gary at Rocker Arm Specialists make mine - and we had to prototype, fit and work them to get them right. The rockers were about $2000 by themselves -- took almost 2 years to get them.

b) Every 417 head I've seen only has water on the exhaust side - with dry decks. This means there is no water moving from the block through the heads. You can drill holes through the head to pickup some lower water ports (toward bottom of the deck), but it still will probably not be enough. I tapped a 5/8 NPT fitting on the back of the block deck to bring the water back into the head. Hopefully it will flow enough to keep things cool.

c) There is no place to pickup oil and get it to the rockers. We notched the head to bring the oil over to the head stud - so the oil will move up the stud and into the rocker base.

d) The combustion chambers are bigger than a 392 - as the 417 typically had 4.125 of larger bores. Due to this, your CR will be low if you're running regular 92 pistons. With a blown motor, it should be okay.

e) The ports are typically huge - both intake and exhaust. Due to this, I think a naturally aspirated motor will have a hard time getting out of the hole -- these things beg for a blower.

f) If the heads you're buying came off a blown fuel car, you better be prepared for some work. I'd definitely pressure test them before I put any money in them. I spent $1400 on just welding on my first set -- had about $4000 in them before I was done (including the purchase price and NOT the rockers).

g) Due to the longer valves and the larger valve springs, many valve covers will not fit. You'll find it impossible to locate a set of original 417 covers. M/T ones usually won't fit. The regular 392 Donovan ones will usually not fit. The ones from Junior Thompson will probably fit and clear the springs. Just something to think about before you buy some cool M/Ts and find out the bad news.

I have not fired my motor as of yet - am working through the chassis (34 coupe). It has been a long 4 year process to say the least. Hopefully this combination will work on the street -- I'm not aware of anybody else actually doing this. I've seen Ceridono's book mention that Junior Thompson was building a 417 headed 92 for the street -- but when I actually prompted him for the details, he admitted that he never completed the project. So - it may be just you and I my friend!

PS: If you end up running them and need header flanges - I designed mine in CAD and can have a set laser cut out of mild steel or stainless - I'll post a picture down below.

Here are a couple pictures of the motor - mocked up on the stand:

Rockers-IntakePorts copy.jpg


BlockAndHeads copy.jpg


RightFront4 copy.jpg
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Last edited by Bored&Stroked on Sat Sep 19, 2009 8:27 pm, edited 1 time in total.
57' 392 Hemi -- much to learn!

Bored&Stroked
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Re: Donovan Aluminum heads in a streetable car

Postby Bored&Stroked » Sat Sep 19, 2009 8:23 pm

Here are a couple more pictures:

IntakePorts copy.jpg


ExhaustPorts copy.jpg


FrontView copy.jpg
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57' 392 Hemi -- much to learn!

Bored&Stroked
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Re: Donovan Aluminum heads in a streetable car

Postby Bored&Stroked » Sat Sep 19, 2009 8:29 pm

Here are the header flanges - these are stainless:

Stainless_Flange copy.jpg


On my spare set of heads:

Stainless_OnHead copy.jpg


Best of luck!

Dale
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57' 392 Hemi -- much to learn!

Paul
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Re: Donovan Aluminum heads in a streetable car

Postby Paul » Sun Sep 20, 2009 10:41 am

Thanks Dale, you were very informative. Please keep us posted on your progress.........now that's a bad @ss Hemi!
Ye, I've never had a pair of Donovan 417 heads in my grasps till now. I just got them & they flow even more than I imagined. The "earlier"combustion chambers are also huge (as mentioned ) These probably wouldn't work on even a large cube normally aspirated 392. (even if I built it to race & ran a dominator) I picked them up for 800 (with hope of selling them for a profit, if they were too much of a project) I've seen the rockers on rare occasions. I do have access to a "custom work" machinist.
I have a ? These appeared to be in reasonable condition with the exception of what looks like a "hack job" repair.
Somebody drilled out the pushrod holes & inserted aluminum sleeves & held them in w/set screws. When I looked into the intake ports, I could see part of those sleeves exposed in the intake port. They tried to grind them flush. I think they even added epoxy to some of them to avoid leaks. Has anybody ever seen repairs like that on these. The repairs look to be in poor taste. (I doubt pushrod problems would do much damage in that area) It looks as if they opted to drill out the pushod holes roughly 5/8" & inserted aluminum sleeves to repair them. The craftsmanship on the repairs are a joke, these guys were hacks. I have also accumulated all the parts to build a Max Wedge 426 for my streetable race project. I'd be using a 71 industrial wedge block, so it wouldn't be like racing a original #s block anyway. later paul.
Last edited by Paul on Mon Oct 05, 2009 9:38 am, edited 2 times in total.

Bored&Stroked
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Re: Donovan Aluminum heads in a streetable car

Postby Bored&Stroked » Sun Sep 20, 2009 10:46 am

Paul wrote:Thanks Dale, you were very informative.
Ye, I've never had a pair of Donovan 417 heads in my grasps till now. I just got them & they flow even more than I imagined. The "earlier"combustion chambers are also huge (as mentioned ) These probably wouldn't work on even a large cube normally aspirated 392. (even if I built it to race & ran a dominator) I picked them up for 800 (with hope of selling them for a profit, if they were too much of a project) The rockers are too pricey alone. I do have access to a "custom work" machinist.
I have a ? These appeared to be in reasonable condition with the exception of what looks like a "hack job" repair.
Somebody drilled out the pushrod holes & inserted aluminum sleeves & held them in w/set screws. When I looked into the intake ports, I could see part of those sleeves exposed in the intake port. They tried to grind them flush. I think they even added epoxy to some of them to avoid leaks. Has anybody ever seen repairs like that on these. In my opinion they hacked them to get few more passes & had problems with them leaking n disgarded them. The repairs look to be in poor taste. I'm contacting the guy who sold them to to get out of this purchase. I don't think they are worth 1/2 that price. They must have had some cracks in the intake ports (I doubt pushrod problems would do that much) & opted to drill out the pushod holes roughly 5/8" & inserted aluminum sleeves to repair them. I'd have welded them & ground it flush. The craftsmanship on the repairs are a joke, these guys were hacks.


In top fuel heads like this, they normally came with thin steel pushrod tubes. I had all the tubes replaced with mine - as part of making sure the geometry worked (pushrod angles, etc). At you noted, these are not the heads you'll want to run on a NA motor. Heck, I may even be better off with ported 392's or the ones from HotHeads. I wanted to have 417 heads and the 417 valve covers - hopefully they'll run with a blower (believe they will). Best of luck - let me know if you need anything else.
57' 392 Hemi -- much to learn!

Paul
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Re: Donovan Aluminum heads in a streetable car

Postby Paul » Sun Sep 20, 2009 10:57 am

Were those tubes meant to protrude into the intake ports? in otherwords when you pull them out will there be elongated holes roughly 2"X9/16" in the intake ports?

Paul
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Re: Donovan Aluminum heads in a streetable car

Postby Paul » Sun Sep 20, 2009 11:52 am

I posted this at the same time you did. So you may not have got the message.

Were those tubes meant to protrude into the intake ports? in otherwords when you pull them out will there be large elongated holes roughly 2"X9/16" in the intake ports? Do the sleeves normally seal off big holes in the intake ports?

These are all homemade sleeves in all different thicknesses, not ground flush or even close in inner diameters (that's why I say they did a hack job) I'm more concerned about whether this is normal / or whether these are drilled out into the intake ports. I buy this stuff for value. If this is normal, I can just replace them & these heads still have value. If they cut into the intake ports & that's not normal , then I may have purchased some old race junk. I appreciate your replys.

Bored&Stroked
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Re: Donovan Aluminum heads in a streetable car

Postby Bored&Stroked » Sun Sep 20, 2009 5:05 pm

Yes - you'll see tubes like this in many heads - especially ones like this where they had such huge damn intake ports and there was no easy way to get the pushrods to the rockers without this technique. Both sets of my 417 heads have steel tubes - they pretty much go from the bottom to top of the port sides - the amount they stick out depends on how big your ports are. The ones that I included pictures of have the largest ports of my two sets of heads (on the intakes). On my other set, the intakes are smaller, but the exhausts are bigger - go figure! Like I said earlier, this was a period in racing where they were trying all sorts of stuff . . . too bad that Donovan didn't get this motor out before the 426 boys really figured out how to run. He was really the first purpose built aftermarket top-fuel engine - at that time, everybody was still running 92's. Keith Black was also building an aluminum TF motor - but he decided to use the later 426 style (which was a smart move). It wasn't long before everybody in TF (well almost everybody!) was running some derivative of the 426.

Best of luck.

Dale
57' 392 Hemi -- much to learn!

oldngood
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Re: Donovan Aluminum heads in a streetable car

Postby oldngood » Fri Oct 02, 2009 6:39 pm

Paul wrote:I'm considering running a pr of aluminum Donovan (water) heads on a street car. Hasn't anybody tried this? I was told the earlier aluminum isn't as high of a grade (& subjected to some long term water leaks) I plan on resurfacing them & they won't be forced induction. I will also build my own headers. Might have to build a intake :lol: :evil: :lol:


what is the intake port cc's of the Donovan heads ? You can make big ports work on the street, by putting a lot of cubic inches under them, i.e. 450-470 CID, and use a loose converter or stick shift.

big ports on a street car with pump gas, yes- it can be done naturally aspirated but with careful parts selection- my experience, not a hemi, but on a wedge- it took me a couple tries but eventually I got tunnel port heads to run on 470 CID with a tunnel ram and 9:1 on 93 octane pump gas, in a 3600 lb. car. What made it all work was dishing the pistons 30 cc's to 9:1 CR, zero deck, and a custom 9" converter that cost $650 shipped price. The converter cruises at 2200 rpm part throttle lockup, but flashes to 4000 rpm at WOT. The intake ports are 290 cc's and flow 317 cfm, the exhausts flow 202 cfm- at 28" on a bench. Cam is 250 @ .050" solid flat tappet.

those big Donovans would need a stroked 392 with around 470 CID and one 750 cfm carb. Big ports can be tuned with a normal sized carb- what happens is the carb acts like a choke and the ports seem "smaller" to the engine, the carb limits the big ports. Ford did the same thing to the Boss 429 to make it streetable in the Mustangs 1969-70. If you try big ports-big carb it will just bog below 5000 rpm, I tried an 1150 cfm Dominator, it would need an even looser converter. The 750 runs much better on the street, but perhaps the 1150 would e.t. quicker at the track on the top end.

HemiHatchard
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Re: Donovan Aluminum heads in a streetable car

Postby HemiHatchard » Tue Jan 12, 2016 6:56 am

Wonderful subject and superb info!
Did you have any joy with fitting the Donovans Paul?
Thanx from hemiHatchard


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