Max Rpm
 

What Is The Max Rpm For A 91 454? No Lonhger Stock

Here Is What I Have
Srp L2399f Pistons 10:1
Arp Rod Bolts
Crank Is Original And Has Been Fluxed And Polished
Aluminum Heads
Retro Fit Lifters
Crane Roller Rockers 1.8
750 Holley
502 Intake
Gm High Perf Ignition

The Only Parts That Are Original Are The Block And Crank. Everything Else Has Zero Hours.

I Have Been Told Every Thing From 5000 To 5500
What Is Safe?
Thanks

Re: Max Rpm
 

ARP rods??? I assume you mean ARP rod BOLTS.

Was this a Magnum engine?

If it was a Magnum, you can turn 5500 with no issues.

Re: Max Rpm
 

YES ARP ROD BOLTS AND NO IT WAS A 7.4L 330.

Re: Max Rpm
 

The cast crank of the 7.4 limits you, but as you have replaced the rods/pistons, (7/16" rod bolts?, forged pistons?), you are in pretty good shape. My only change would be that your max RPM would still be 5500, but I'd not run it for long periods of time up there. 5000 for long runs should be no problem.

Re: Max Rpm
 

I'd have no problem with rotating assembly if machined / installed / balanced correctly.

Valvetrain is the # limiter with RPM - especially with hyd roller pieces.

We'd have to know what your are running for valves, retainers, springs, rocker arms, etc, etc especially what the installed (on your motor) spring closed and open psi's are.

Re: Max Rpm
 

Thanks Thats What I Needed. Now I Just Need To Stop Looking At It And Put It Back Together.

Re: Max Rpm
 

MY HEADS ARE GM PERFORMANCE ALUMINUM OVAL PORT
I AM NOT SUR OF THE SPEC BUT THE CASTING NUMBER IS 12363391 THEY CAME FULLY ASS. AS FOR PSI I DON'T KNOW

Re: Max Rpm
 

I would not run that engine over 4600 with a Cast crank. I had a modified engine with a cast crank and I broke it in 2 pieces. Forged crank is the only way to go. Just my 2 cents.

Re: Max Rpm
 

Even if they came with a spec, you need to find out. This goes with any cyl head from any manufacturer.

Without knowing this means you do not have any idea where the valvetrain will bounce and bust you up.

Therefore, no one can answer your 'where's my rpm limit' question. Not being a dick, but we just can't.

Re: Max Rpm
 

I RAN THE STOCK ENGINE AT 5000RPM ALL THE TIME BEFORE I DECIDED TO RIP IT APART FOR THE MODS.