I'm trying to decide what to build.
Do you know of anyone who has broken a stock crank or even a scat 9000 crank and what rwhp were they at.
I don't think I have ever heard of one break

 

They break, very rarely though (of course top fuel cars are a different story), but usually the rods go first. Usually with a nitrous or blower application. NA? Stock or Scat 9000's should be just fine up to 600hp give or take. YMMV depending on rpm and such.

 

rpms are death on cranks-
much more than hp is anyway

 

I'm running the times in sig with a completely stock shortblock. This guy is running 9.50's @ 140+ in the 1/4 with a stock crank. So I'd say with a proper tune and setup they are pretty durable.

 

he doesn't count, hes Jesus

 

It's just a matter of time and contrary to what the Jagger said, it aint on your side. Not in racing.

So Jesus or not, it'll let go eventually running the nitrous to get those times. I wish him luck though.

Like I said before Trey, rpm aint the only factor. If the piston, pin and rod are lightweight pieces then the engine will live alot longer under extreme n/a rpm. I used to turn a stock nodular gm crank to 7500 rpm all the time.... I was running lightweight venolias, howe wristpins and lightweight crower i-beams though. Your mileage will vary.

-Mindgame

 

Well most LT1's had the same pistons and rods

I should have said "all things being equal, rpm is a killer"

 

Like 'Game.. I know drag guys (stockers) who wind their poor stock stuff up well over 7000rpm with heavy cast pistons...

That sure as hell doesn't mean I don't cringe & start mentally calculating a debris radius to stay out of .

You didn't really tell anyone what you're trying to build anyway, or what your goals are... so who knows. FWIW, cast stuff is "enough" for most people's needs IMO. You want up to 500ish hp in a street car that won't see peak rpm all the time? I'd probably just stud the 2bolt mains and run a stock crank... maybe nitride it, but probably not.

 

Irelevent.

The one in question.... Mr Jesus' car, does not have stock rods and pistons. Hence my point young one.

And Phil, I think the nitriding is a good thing to do in that case.
The studding should be a no brainer.

-Mindgame

 

Definitely a good thing, but people who don't want to spend the $ to do things right probably wouldn't want to put $ in a stock crank .. by the time you ship the heavy bastard back & forth, pay for treating it. Dunno, I wouldn't if I were just throwing something cheap together. Of course if I were building any performance engine, it'd be done "right," lest I have to spend the $ again.

Maybe that's why my projects tend to get a little more expensive than I'd planned.. I'm paranoid

 

The reason I didn't post what my goals are is because I just wanted to see who has broken a stock crank?

I want 400+rwhp NA and the ability to spray up to a 200 shot
somewhere down the road. Probably only 100 initially.
I have a A4 and I would like closer to 450rwhp if I do a stroker but I don't know if that is possible.

It's guys like "Jesus" and Skarodom,Dr Mudge who make me wonder about just building a strong 355. If guys are doing it with a stock bottom end, good rods and pistons are the weak link right?
I figure I have two options go all out on a stroker and make maybe 30 more hp or build a 355 with a say maybe a scat 9000 crank, Eagle H beams and SRP pistons.
I have a new 4 bolt block that will be studed and I have some lingenfelter ported LT4's

Thanks
Tom

 

Maybe so, but don't forget the boost to your torque curve.

 

anyone else?

How durable would this be for a 355

4 bolt block with studs
scat forged 4130 crank
scat 4340 billet I beam rods
SRP or Ross pistons.

I would be using Ported LT4's, big cam no more than 7k rpm

I want atleast 400rwhp na and the ability to spray up to a 200 shot in the future

 

wow!
Had you raced your car much?