This morning I was thinking about V8 engines, and....
- Thread starter Kern Dog
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Single four barrel 315 inch D500 Hemi.
In the early fifties, Chrysler Corp decided to emulate GM and let each brand develop its own motor. So we had a Chrysler Hemi beginning in 1951, a DeSoto Hemi beginning in 52, and a Dodge Hemi beginning in 53, with less-expensive-to-produce poly versions of the Chrysler and Dodge coming 3-4 years later, followed by an all new Plymouth poly in 56. Completely different engine lines, with almost no interchangeable parts, but (as they grew) overlapping cubic inches - i.e., 331 Chrysler, 330 DeSoto and 325 Dodge, or 301 Chrysler and 301 Plymouth.
Chrysler realized having so many different engine lines was a dumb idea, and by the late fifties had consolidated into a corporate big block in low and raised deck versions, and a corporate small block - basically the Plymouth A and later LA. Different cubic inch versions of each, but basically only two V8 engine lines. (Plus sixes, of course.)
The 313 was a Canadian version of the Plymouth poly, the 315 was a Dodge motor.
Why Canadians got a 313 A motor while Americans got a 318 (and in 1956 Canadians got a 303 A motor, while Americans got a 277) - who knows? And why Canadian Plymouths (and 56 Fury) got a 303, while American Plymouths got a 301 (in 57) - who knows?
The above skips over the fact that for 2-3 years some Plymouths and DeSotos got Dodge poly motors, and some Canadian Dodges got Plymouth motors.
Simple, no?
A few years later, Plymouth had to fight like hell just to get a different cam for the Road Runner than the cam in the standard 383. It complicated production.
I never could figure out why all of that happened. Like the 241 Dodge Red Ram Hemi. Why waste all the time and money developing such a small V8? Got to start somewhere I guess.
Well, in fairness, that was slightly bigger than Studebaker's first V8 in 51 (232) and also bigger than Ford's first OHV V8 in 54 (239). But Chrysler and Ford and Studebaker all underestimated how large engines would become in the fifties, so none of their early V8s could be enlarged enough to be really competitive. Even the Chrysler Hemi was maxed out at 392 cubes, while the Dodge and DeSoto were undersquare motors by the end (the 325 Dodge had a small bore but a longer stroke than a 440). In 1958, Ford introduced its FE big block for performance work, Chevy got a 348 big block, and Chrysler Corp got its first wedge big block. Studebaker's V8 never got larger than a 289 (and they didn't have the money to develop a new motor). There was no performance development of the Ford Y block or Plymouth poly after 1957, and (I think) the only reason performance development continued with the small block Chevy after 1957 was the Corvette. Then, as we all know, there was a resurgence of small block performance in the sixties, by all of the big three (and arguably even Studebaker with its R1, R2 and R3 motors).
jos51700
Green Bearing thread connoisseur
The engineers would've said, "It isn't broke, don't fix it".
You need to talk to sales, the accounting people, and possibly the customers and competitors about such decisions.
dano
Evil Handy Man
They like to swap and stroke the 400, so they scour for the 400's that used the FMX. Seen a few builds with Aussie heads.
A friend had a Pantera. I got to take it for a short drive one night. Took off from a stop light heading out of town. 135 in third and I still had 4th and 5th! Fun car.
33IMP
Well-Known Member
Rootes group developed the tiger (based on the alpine, obviously) and used Ford engines.
Then Chrysler bought Rootes group....... and since a 273 wouldn't fit, that was the end of Tigers. They did sell more mundane Sunbeams. (Alpines?)
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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I think it had more to do with what Chrysler's philosophy was in those days. As much as we like 8or9 pounds of car per cubic inch, for our Hotrods, the Bulk of new car sales were for basic transportation, and so 12 pounds is just fine. for a bit more pep, 11 was nice. and 10 was better.
So then a 3200 pound car can do fairly well with 273 cubes. a 318 makes it 10 pounds per cube, and a 340 gets to 9.4
As cars got heavier after 1967, by 3600 pounds, eventually we needed that 360, for 10 pounds per cube again.
The engines could be tuned in those weight breaks to anywhere from .65 to say .90 hp per cube, and the torque moved around accordingly, so Mopar didn't need a whole lotta engines to pick from.
One of the reasons that the Early 318 was so well liked is that it made a really good amount of torque, at a pretty low rpm. As I recall, they were rated 340 ftlbs@2400 rpm/230hp @4400. That's a pretty good balance between power and torque, considering it was factory stock.
Obviously IDK the exact thinking, but this is how I see it.
So then a 3200 pound car can do fairly well with 273 cubes. a 318 makes it 10 pounds per cube, and a 340 gets to 9.4
As cars got heavier after 1967, by 3600 pounds, eventually we needed that 360, for 10 pounds per cube again.
The engines could be tuned in those weight breaks to anywhere from .65 to say .90 hp per cube, and the torque moved around accordingly, so Mopar didn't need a whole lotta engines to pick from.
One of the reasons that the Early 318 was so well liked is that it made a really good amount of torque, at a pretty low rpm. As I recall, they were rated 340 ftlbs@2400 rpm/230hp @4400. That's a pretty good balance between power and torque, considering it was factory stock.
Obviously IDK the exact thinking, but this is how I see it.
Don't forget AMC's 390! They also didn't have a small and big block series, just wanted to mention it. A friend had a 68 AMX with a 390 and a 4 Spd. It ran well.
i have a worked 69 390 was one of the faster car in town when i bought it
have no idea what to do with it ...have a 69 crusty amx but looking for a rambler.....
funny when you look at euro v8s some were 2.0 liter
have no idea what to do with it ...have a 69 crusty amx but looking for a rambler.....
funny when you look at euro v8s some were 2.0 liter
RustyRatRod
Caput villa stultus
slantsixdan
=..=
Exact displacement wasn't dictated. Performance characteristics and approximate displacement range were; the harder points of the design brief were manufacturability, cost-effective manufacturability, packaging constraints (must fit XYZ vehicles), compatibility constraints (must work with XYZ transmissions), competitivity benchmarks (must equal or exceed the various characteristics of engines in comparable applications from other companies – sometimes with the marketing department and others putting extra weight on certain characteristics), and otherwise like that.
Exact displacement wound up as a byproduct of optimizing for the hard points in the specs.
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