Hello all. I am a lurker and not much of a poster. I am about to start building up my 454 and was wondering how much HP and TQ the stock cast crank will hold. I am planning a street/strip build up.


Thanks
Ben

 

The GM 454 cast crank is fine to way over 550hp.
What you do need to get your head around, is RPM.
Keep the rpm under 6600 and your BBC will have a long happy life.
That leaves you a lot of room to play.
Build your cast crank/stock oiling system 454 for power in the 3000-6000rpm range. It will make all the power you'll need and outlive ya.

 

So you think it will hold a healthy 700hp and 750ftlbs?

 

The crank itself is not going to be a problem. Wether the motor will withstand 700hp depends on how much you abuse it. (detonation, excessive rpm, spark scatter, improper fuel octane lean AFR etc etc)

Many NHRA superstock oval port cast crank 454 have been built and run sucessfully at over 700hp. (oiling system mods for high rpm)

Many low compression (7.5:1) 8-71 superchargered 454's have been run on the street and raced on pump gas with the cast crank making well in excess of 700hp.

It takes a lot lot lot of power to break a BBC cast crankshaft.
It does not take a lot to break a crank or something else when the tune is not right.

 

Same thing for the stock connecting rods. Will they hold up to the same force?

thanks
again

 

The BBC rotating assembly is quite strong. Have the rods rebuilt with top notch rod bolts and you should have no problems.

 

For 700hp I would burp the wallet for some better rods.

 

I haven't used a stock crank in a few years now. The only thing stock about my current engine is the alternator. Everything is aftermarket.

 

Thanks all for your responses.

 

I have been looking a engine combos and have a question. Is it even possible to reach 700HP and 700+TQ with a .030 over standard stroke on pump gas?

 

Yes, the easy way to 700+hp with a 454 on pump gas is with a supercharger. requires intercooling, water injection or a low compression ratio (7.5:1)

 

.....or nitrous. I'm ready to drop in the mildy warmed over 454 I built months ago. With AFR heads and a slightly lumpy solid lifter cam it should make a legit 550HP on the motor and around 700HP with a plate shot. Plenty of power to kill myself with.

And it's got a cast crank in it (properly machined and assembled with care in a clean environment). My motor is a weekend toy and won't see high RPMs for any extended period of time (hopefully less than 11 seconds at a time).

The faster you spin it or the harder you lean on it the shorter it's life will be. If it spends most of it's time putzing around town at light throttle it'll last a long long time. But if it's going in a road racer or some other application where it's going to get beat on and revved to the moon for extended periods of time you'll want to be looking at a better crank.

 

wow! the .060 over 454 in my pickup scares the heck outa me and it only produces 385 HP and 525lb/ft of torque turning thru a th350, 3.42 gears, and 32x11.5's pushing a 6200 lb truck. I'd love to put that into my camaro with the 3.73's but would be leary of opening the secondaries.

 

I am now stuck between going stock stroke and rod or stroking it. I will most likely be getting some H beam rods. This big block stuff is way more complicated than the small blocks.