given the current technology, what do you think the max redline would be for a small block, push rod, chevy? someone's been telling me that back in the late 60's-early 70's he's had a .060 over 327 that would spin to 8200+ rpm, and cruise easily at 7500 rpm. that high revving small block was in a 57 4-door, capable of 156 mph (on the street). all this on drum brakes and bias ply tires. personally, I think it's a major, major, major load of BS.

 

Metric instruments possible in 57?

 

Given the correct valve train setup I wouldnt see an issue with a SBC going to 8k. Just need to make sure the valve springs are strong enough to close the valve springs fast enough for 8k rpm and remove as much friction from the valve train as possible, roller cam, double roller rockers, etc. Double roller timing chain to be safe and hardened chromemoly pushrods would be a must. The only real issues with an SBC revving that high is if it would be worth it, given the great majority of SBC setups reaching peak power and falling off well before even 6500rpm. To make it reliable de-stroking the engine would also be advised and to make power that high in the RPM range a turbo or two would be a good idea.

TLDR version: Some can rev that high without major modifications, but would soon have catastrophic engine failure and if they didn't blow up, wouldn't make any power up that high in the rpm range.

 

This is quite believable really. When you consider a stock 64 327 with the Duntov 30 30 cam would spin easily to 7000 rpm why is race engine to 8200 hard to understand?
The real difference between then and now is being able to build the same hp at 1000 rpm less. I had a factory 69 302 Camaro that was capable of 7500 rpm, and ran a destroked 400 in 1980 that would run to 7500 also.

 

I am not sure what you are looking for like street car or race car but in all out drag race trim a SBC can run 10,500 RPM approximately. Some of the class racers who run 283's leave the line at 10,500 and shift at 10,100. The Nascar 358's (when they used to be based on a production engine) would run 9000 RPM for 500 miles!

 

OK, so it sounds like 8200+ is quite possible. I guess its the rest of the story that has me throwing out the BS flag...

 

Buzzing one to 7K in neutral is one thing.

Sustained and crusing at 7,500 RPM is quite another.

NASCAR engines were turing under 8,000 RPM until the late 1990's then in the early 2000's made the leap to about 8,200 RPM and stayed in that range for another couple of yrs.

Today in NASCAR the unrestricted engines turn 9,800 RPM at the end of the straight at a mile and half track.

Pushrod motors can turn plently of RPM... we have a 297 inch Dart Buick headed Comp Eliminator Drag engine that turns a tick over 10,000 RPM thru the traps... 9,600 RPM shift points and it's about 12-13yr old engine. Valve springs last half a season... We have flat tappet limited late model dirt track engines that turn 8,200 RPM for 40 laps a night and the valve springs last all season. It can be done- Just don't think you can build that kind of engine with parts out of Summit and Jegs.

Just FYI - A Duntov 30 30 makes peak power about 6300 RPM in a 327... while it's very large seat timing and lazy ramp speeds will allow it to turn 7000 RRPM - it quite making power a long time ago. Plenty of unknowing people turned them that hard thou.

Anyways the smart folks running GM stuff back then always had the Z28 "off road" cam....

Your friends exaggerating a weee bit about his tri-five.
Will

 

The Duntov 30 30 produced peak hp at 6700 in the 302, and assuming gear changes are 500 over it really sang for a production car.

http://www.hotrod.com/techarticles/e...vy_dz_302.html

 

At least read the thread content before quototing my post and linking an article that doesn't have the correct info....

A 327 (which is what the OP stated and I gave info on) has a 1/4" more stroke which will reduce the peak power a few hundred rpm compared to a 3" stroke 302.

Not that it would matter as 63-6700 is light years from 8200... unless his tach was set to 6cyls.
Will

 

Will,
I just thought it was interesting the difference stroke made. Here's a 8200 rpm cam for a sbc.

http://www.crower.com/camshafts/chev...core-6315.html

They've been turned that high for years. If the factory sold cars that would go to 7k then 8k is simple with a little more work.

 

Nascar motors arent built with production tolerances
Driven on the street they wouldnt last too long and vice versa

The older some get the faster they were.

 

I'm surprised that no one has mentioned rods and bolts. I thought that was the "weak" link on some of the stock sbc stuff.

I have some "old school" friends that ask me if I shift at like 7800 and I say no, more like 6800. They then tell me about their 327's that spun 8k all day long. I think they remember those cars being a bit faster than they were. LOL

 

Rich Guasco campaigned this car with a 327 in the early 60's from my hometown.

http://www.aa-fuelaltered.com/purehell.shtml

8000 rpm is probably stretching the truth? You people forget that the 60's was about big nasty cams and power.

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