1955 Chrysler 300B 1/4 e.t./mph from 1955 Hot Rod Magazine

[oldngood]

a few years ago I obtained a vintage old 1955 Hot Rod magazine that has an original 1955 Chrysler 300B road test in it. I had forgotten that I had it, but recently going through some stuff found it again.

here's the 1/4 mile times:

17.0 flat e.t. at 84 mph- that was 331 hemi , exhaust manifolds, solid cam, 2-4 bbl carbs, and Powerflite 2-speed auto trans, with 3.54 axle gear ratio

the first thing that came to mind was, how heavy was the car, so I looked it up:

4020 lbs. shipping weight- that is with all fluids, but no fuel or driver- so figure around 4250-4300 lbs. w/driver and a tankful of gasoline

[johnny5]

That was pretty fast back then considering dragsters were only running in the 10's. The auto industry sure has come a long way.

[polyspheric]

Yes, a big paid ad, a few dollars (or just lunch) to the columnist, a few hours porting the heads and manifolds, quick cam swap, rejetting and a few mothballs do wonders for the "stock road test". The actual cars were always slower.
This was almost universal back in the day - well into the 1960s.

[George]

Yes, a big paid ad, a few dollars (or just lunch) to the columnist, a few hours porting the heads and manifolds, quick cam swap, rejetting and a few mothballs do wonders for the "stock road test". The actual cars were always slower.
This was almost universal back in the day - well into the 1960s.

One of the car mags was talking about how a machine was delivered to them that tested the cylendar to tell what the CID of the engine was by screwing it into a spark plug hole. They had 3 cars setting on the lot, delivered for testing. 2 tested right on, but a 389 GTO measured as 450 CID!

[oldngood]

That was pretty fast back then considering dragsters were only running in the 10's. The auto industry sure has come a long way.

you hit the nail there, the early 1950's Ford flathead powered rails were only running 12's

[oldngood]

Yes, a big paid ad, a few dollars (or just lunch) to the columnist, a few hours porting the heads and manifolds, quick cam swap, rejetting and a few mothballs do wonders for the "stock road test". The actual cars were always slower.
This was almost universal back in the day - well into the 1960s.

One of the car mags was talking about how a machine was delivered to them that tested the cylendar to tell what the CID of the engine was by screwing it into a spark plug hole. They had 3 cars setting on the lot, delivered for testing. 2 tested right on, but a 389 GTO measured as 450 CID!

a CID bubble machine can be tricked quite easily- putting a high overlap cam in the engine with hang the valves open while cranking it, and pump some of the cylinder volume back out the intake, and show a smaller CID size- the only way to check CID accurately is measure bore/stroke

[polyspheric]

I've never heard of using a pump displacement tester on an assembled engine.
Every engine built in the last 90 years will test far below it's actual size.

IMO the tool he's referring to is the threaded extension and probe, which expands to span the bore, and picks up the piston height at TDC/BDC.
SCTA not only recommends it (i.e., "this is the tool we use, and if it says the engine is legal that's the end of the conversation"), they encourage you to buy them at $325.00.

I explained, quite patiently to the "officials":
1. how many other variables affect the stroke reading, rendering the tool's output a bad guess
2. how much of the engine parameters must be taken on faith (i.e., either what the owner tells you it is, or what your book says the engine should be), because the only way to be sure is the strip-down that you're trying to avoid
3. how easy it is to either cheat (illegal for class but test OK) or be cheated (DQ with a legal engine)
4. how large the consequences of error

...

They weren't interested.

[oldngood]

the compression pump tool I"m referring to, is used by the small local dirt and paved circle tracks, perhaps not part of any sanctioning organization like NASCAR or SCTA or NHRA, etc. Often these tools are home-made or custom made by the track owner or tech man, but there are a few available commercially, they aren't cheap- here's one made by Mr. Gasket- to use it all the plugs are removed from the engine, the tool attached, then the engine cranked over with the starter

http://performanceparts.com/part.php?partID=184652

this tool screws into the spark plug hole like a compression tester, and is calibrated to measure the cubic inch displacement while cranking the engine, very similar to a compression tester- most of the tracks have a 358 CID rule, based on using the traditional small block Chevy V8 that runs in 95% of these cars (very few Fords or Mopars)- so the tester is calibrated and marked using a known 358 CID engine of legal compression and legal bore/stroke/CID, with a common size camshaft used at the track- now, anything one does to run a lot more CR or CID will cause the meter to read higher, and raise the tech man's curiousity- leading to a teardown

yes, it can be tricked and cheated to some extent, but a 383 or 400 CID with same compression and cam will get caught, because it will bubble somewhat higher. One could add more CID and drop compression and cheat it, but then the added CID is offset by the lower CR. Another approach would be add CID and a HUGE cam and bleed off a ton of cranking compression, but in that case the car would be a soggy dog off the corners anyway, and actually may be slower than a legal car. You may be able to sneak by a 360 CID or 366 CID with a slightly larger cam, but those few cubic inches won't mean much against other legal 358's that are handling well with experienced drivers.

it may be a moot point, because any racer can simply pay a nominal fee to have any other racer's engine torn down and checked for cam-compression-CID; refusing a teardown means you're DQ'd and they take the win away- but flunking the bubble test is the litmus, that leads to being torn down and eventually being caught cheating- the bubble test will definitely catch someone trying to pass a 406 small block in the 358 CID class, or someone with 13:1 CR on the 9:1 rule

below is picture of a Mr. Gasket CID tester, with instructions link.

http://www.sportcompactonly.com/manuals ... t/3200.pdf