Chevrolet Big Block Trivia or : Where were they hiding them Horses!?

[DriveHard]

Agreed, but would have breathed better, and so perhaps avoided the scorn poured on the 305. It's a trade-off for sure.

In general, for engines of the same displacement, oversquare (i.e. bore > stroke) results in slower piston speed, and thus greater ability to rev higher. The undersquare engine would have more low-end torque, but be limited in the upper RPM range, and generally turn in better (lower) fuel consumption.

It's hard to find real-life examples, as there are so many confounding variables - camshaft, compression ratio, carburetion, etc.

However, I would have loved to see the 305 tested vs. the 307 with all the variables controlled.

Mean Piston Speed (MPS)...I think that is what you are looking for. Long stroke engines have a faster MPS for a given RPM than a shorter stroke engine. MPS is limited to about 25-27 m/s (motorcycles and F1).

VERY generalized statement that would be fun to explore (all else being equal)
short stroke engines seem to be able to run higher compression ratio...would that increase CR offset a lower efficiency due to the shorter stroke?

I realize due to the MANY variables that dictate an engine performance it is hard to make blanket statements like "pushrod engines produce more torque" or "DOHC engines produce more HP and rev higher", but it seems short stroke engines tend to rev higher and be more HP focused, and long stroke engines do produce more torque and can be more efficient.

I know this is a big block thread, but I used to have a boat with a 5.0L small block (~200hp) with Vortec heads. Well...I was young, dumb, and well...yeah...dumb and failed to winterize it one year. Well the next summer I got a 4 bolt main 350, had it bored to 355 and prepped for marine use. Used the same heads and cam that were in the 5.0L...I did a ton of research and I want to say it was generally agreed if I stayed below 5000 rpm I would be good to go. That boat went from topping out at 51-53 to breaking 60 (all done with GPS). That had to put me in the neighborhood of low 300's hp, as I was running with similar sized bowriders with 350 mags (350 hp)

 

[userfriendly]

Mean Piston Speed (MPS)...I think that is what you are looking for. Long stroke engines have a faster MPS for a given RPM than a shorter stroke engine. MPS is limited to about 25-27 m/s (motorcycles and F1).

VERY generalized statement that would be fun to explore (all else being equal)
short stroke engines seem to be able to run higher compression ratio...would that increase CR offset a lower efficiency due to the shorter stroke?

I realize due to the MANY variables that dictate an engine performance it is hard to make blanket statements like "pushrod engines produce more torque" or "DOHC engines produce more HP and rev higher", but it seems short stroke engines tend to rev higher and be more HP focused, and long stroke engines do produce more torque and can be more efficient.

I know this is a big block thread, but I used to have a boat with a 5.0L small block (~230hp) with Vortec heads. Well...I was young, dumb, and well...yeah...dumb and failed to winterize it one year. Well the next summer I got a 4 bolt main 350, had it bored to 355 and prepped for marine use. Used the same heads and cam that were in the 5.0L...I did a ton of research and I want to say it was generally agreed if I stayed below 5000-5500 rpm I would be good to go. That boat went from topping out at 51-53 to breaking 60 (all done with GPS). That had to put me in the neighborhood of low 300's hp, as I was running with similar sized bowriders with 350 mags (350 hp)

Good post. Engine geometry geeks will argue that short connecting rods increase the effective intake stroke by moving the piston away from TDC sooner and dwelling the piston longer near BDC. The higher piston speed generated from a shorter connecting rod increases intake port speed and/or allows for a larger intake port.
Where does it end for the big block Chev excluding the mountain motors? 500 cid NHRA pro-stock 10,000 rpm rule limit.

 

[wtd]

Yes, and so was the 69 265 hp 9:1 compression 396.
I still have the 2V intake manifold from the 69 Canadian built Pontiac station wagon my parents bought. VIN 7563691138291
The other BBC option for full size Canadian built 1969 Pontiacs and Chevs was the 10.25:1 390 hp 427.

I'd like to see the 6.6L L8T engine offered in the Camaro, 1500s, Tahoe, Suburban & Yukons as is, marketed as a 396, without ruining it with start-stop, AFM or phony engine noises generated and broadcast through the stereo system.

The 396 that is in my 1970 Monte Carlo is the 265 hp version that came out of a 1969 Caprice. I also still have the 2V intake with the 2 barrel carb sitting in my shed. My engine is bored .60 over and has an Edelbrock performer intake and Edelbrock Q-jet on it now.

 

[wtd]

1969 only year you could get a low compression 396 with a 2 bbl carb. 265 hp and only available in full size cars. I have seen 2 in my life and both were in a station wagon .

I have this engine in my 1970 Monte Carlo. It came out of a 1969 Caprice four door.

 

[SammyChevelleTypeS3]

Mean Piston Speed (MPS)...I think that is what you are looking for. Long stroke engines have a faster MPS for a given RPM than a shorter stroke engine. MPS is limited to about 25-27 m/s (motorcycles and F1).

VERY generalized statement that would be fun to explore (all else being equal)
short stroke engines seem to be able to run higher compression ratio...would that increase CR offset a lower efficiency due to the shorter stroke?

I realize due to the MANY variables that dictate an engine performance it is hard to make blanket statements like "pushrod engines produce more torque" or "DOHC engines produce more HP and rev higher", but it seems short stroke engines tend to rev higher and be more HP focused, and long stroke engines do produce more torque and can be more efficient.

I know this is a big block thread, but I used to have a boat with a 5.0L small block (~200hp) with Vortec heads. Well...I was young, dumb, and well...yeah...dumb and failed to winterize it one year. Well the next summer I got a 4 bolt main 350, had it bored to 355 and prepped for marine use. Used the same heads and cam that were in the 5.0L...I did a ton of research and I want to say it was generally agreed if I stayed below 5000 rpm I would be good to go. That boat went from topping out at 51-53 to breaking 60 (all done with GPS). That had to put me in the neighborhood of low 300's hp, as I was running with similar sized bowriders with 350 mags (350 hp)

Big block / short block.... they all were good to me. I actually always loved the short blocks too. A little more room to work around, but a heck of a lot less heat thrown off and certainly less stops at those gas pumps. I have had several SB Chevy and a couple Ford SB that were just flat out great running engines. Actually had a Chevy or two end up outlasting the US steel they were born into. For the Fords that was no probem. Better body and paint from the factories. We used to joke and say the best truck would be a Ford body running any Chevy engine under the hood.

 

[Snagglefoot]

In 1971, Chevy published both the gross and net HP ratings, so you don't have to guess how much of a hit the numbers took. Here is what was available in the Monte Carlo.

The 402 is in this chart. It’s the “ Turbo-Jet “ 400.

 

[Snagglefoot]

In 1974 the 400 in the Monte Carlo was a small block, called the Turbo-Fire, much like what was available in the Chevelle that year.

 

[Snagglefoot]

In 1974, NASCAR went to the 358 ci limit for engines. So what did Chevrolet run in 1973 ? Here is part of an article on Benny Parson’s restored 1973 NASCAR Chevelle. It was a 427.

 

[Snagglefoot]

The late model Chevelles were eventually banned from NASCAR for being too aerodynamic.

 

[Snagglefoot]

The 396 that is in my 1970 Monte Carlo is the 265 hp version that came out of a 1969 Caprice. I also still have the 2V intake with the 2 barrel carb sitting in my shed. My engine is bored .60 over and has an Edelbrock performer intake and Edelbrock Q-jet on it now.

That 2V manifold and carb would make a good boat anchor.

 

[SammyChevelleTypeS3]

In 1971, Chevy published both the gross and net HP ratings, so you don't have to guess how much of a hit the numbers took. Here is what was available in the Monte Carlo.

The 402 is in this chart. It’s the “ Turbo-Jet “ 400.

View attachment 221097

For many years now even with a fair amount of the very first generation Montes available to collectors and Chevy fans of which many just want one to serve as a neat daily driver antique car, the SS454 Monte Carlo's prices just keep marching on and up due to its rarity.

The late model Chevelles were eventually banned from NASCAR for being too aerodynamic.

View attachment 221124View attachment 221125

Right. There is an article by a NASCAR / Automtive writer called The 5-10 Most High Impact Cars of the NASCAR Daytona Speedway and the 1975/1976 Chevy Chevelle Laguna Type S3s won more races and Championships in the short lived (2) year period than even the wild Plymouth SuperByrds or Dodge Daytonas. Lagunas could only be purchased from GM for the streets with chocked down low outout engines but they were actually designed to fly on the superspeedway when Chevy designed those Camaro like aero front end clips. Fuuny thing was after NASCAR banned the TypeS3 from the tracks , Oldsmobile simply designed a similar front clip for the Olds 442s and even the King Richard Petty jumped into an Olds 442 they had such a similar aero desing like the last Chevelles , the TypeS3s that I have owned several of. My last one became a show car until my health issues forced me to let it go so I sold it and said goodbye to my last "toy" in 2019.

 

[jkasch]

Lets pick a vehicle weight. I got into trouble about running 10's in old Camaros with another poster. Pick a weight and we can calculate how much HP is required for 9.9. I would guess you can strip down a 3500 lb car to 3200 lbs. A 9.9 would required about 650 dyno horsepower according to some of the ET calculators.

Here is a normally aspirated 441 ci LS engine that can do that, revving to 6500 rpm.

MEDIA=youtube]UM3H-HPAKIA[/MEDIA]

Sounds about right. A friend had stripped down ‘68 L88 Vette that was balanced and blue printed at the GM Tech Center and said to dyno at 640hp. Although I never witnessed it, I was told it could run 9’s with slicks. IIRC, a 4.56 rear end, too.

 

[Chris142]

That olds motor was a dog from what I remember.

Yep. combined with a 2.56 axle ratio and you timed aceleration with an hourglass. The 403 was not a bad engine. It belonged in a station wagon and not what was considered a hot rod for its time. A Datsun B210 would scare one off.

 

[CharBaby]

For many years now even with a fair amount of the very first generation Montes available to collectors and Chevy fans of which many just want one to serve as a neat daily driver antique car, the SS454 Monte Carlo's prices just keep marching on and up due to its rarity.

Right. There is an article by a NASCAR / Automtive writer called The 5-10 Most High Impact Cars of the NASCAR Daytona Speedway and the 1975/1976 Chevy Chevelle Laguna Type S3s won more races and Championships in the short lived (2) year period than even the wild Plymouth SuperByrds or Dodge Daytonas. Lagunas could only be purchased from GM for the streets with chocked down low outout engines but they were actually designed to fly on the superspeedway when Chevy designed those Camaro like aero front end clips. Fuuny thing was after NASCAR banned the TypeS3 from the tracks , Oldsmobile simply designed a similar front clip for the Olds 442s and even the King Richard Petty jumped into an Olds 442 they had such a similar aero desing like the last Chevelles , the TypeS3s that I have owned several of. My last one became a show car until my health issues forced me to let it go so I sold it and said goodbye to my last "toy" in 2019.

View attachment 221144

Letting go of a car this beautiful must have been a sad day for sure.