PerformanceTrucks.net Forums

PerformanceTrucks.net Forums (https://www.performancetrucks.net/forums/)
-   INTERNAL ENGINE MODIFICATIONS (https://www.performancetrucks.net/forums/internal-engine-modifications-158/)
-   -   9,000rpm oem rotating assembly, how would you do it? (https://www.performancetrucks.net/forums/internal-engine-modifications-158/9-000rpm-oem-rotating-assembly-how-would-you-do-499102/)

CAGRacing Mar 21, 2012 03:32 PM

9,000rpm oem rotating assembly, how would you do it?
 
I've been kicking around the idea of building a high revving budget build. Oxymoron I know

Here's my idea
6.0 block
4.8 crank
Arp bolts
Regular gasket set
Cam
Valve springs
Intake

Is a longer rod like the 4.8 necessarily better than the 6.0 rod?

Are shaft mount rockers necessary?

I'm expecting 15,000-25,000 miles out of this motor. I'd like to see it with a turbo.

What're your guys opinions and ideas?

TXSZ66AVLANCHE Mar 21, 2012 03:34 PM

I can't offer any advice, but would like to see a video of a 9K rpm LS series...

BlackGMC Mar 21, 2012 03:34 PM

You will need to upgrade to Big Stuff 3 or mega squirt, the stock PCM for the Gen III motors can only goto 8k, bad stuff happens above that.

smokeshow Mar 21, 2012 03:39 PM

What's the application?

CAGRacing Mar 21, 2012 03:41 PM

3000 lb highway monster/Texas mile competitor

What's the ECM do above 8,000?
Are the injectors going to flip at that speed?

nonnieselman Mar 21, 2012 03:46 PM

The PCM only reads to 8000.. anything above that and i dont wanna know :D
Have you talked to any engine builders? Maybe they have tried it and it didnt work so great.. might be a good starting point to save yourself a headache and money.

Good luck!!

CAGRacing Mar 21, 2012 03:50 PM

I have
They suggested 305 or 283 crank with oversized bearings in a bored 400 block. They've clocked 10-11,000 rpm. I'm relatively tame compared to that.

So carb and msd.
Anything else you guys can think of right off the bat?

Shaft mount rocker arms necessary?
Longer rods better?

nonnieselman Mar 21, 2012 03:53 PM

305 283 crank?
Did you tell them your working with a LS engine?

chevybowtie Mar 21, 2012 04:00 PM

"oem rotating assembly" That is like coming swinging out of the gates. I feel sorry for the stock rods going in that motor. This should be interesting....

CAGRacing Mar 21, 2012 04:01 PM

I asked around and haven't encountered anyone destroking the gen III yet.

I did find guys up by the iowa border running bored 454 blocks with custom cranks around 400 ci in their mud racers. I bought tires off a guy that showed me first hand what 11,000 rpm sounds like from a 397? Or so ci big block he had built. If I wasn't an idiot and it wasn't snowing at night I would have one bad ass video.

That guy is who convinced me to sell my 426 small block chevy and consider a destroked motor.


All times are GMT -5. The time now is 03:27 AM.


© 2026 MH Sub I, LLC dba Internet Brands