Recommended Max RPM Modified Rebuilt Engine
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Joined: Sep 2006
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Recommended Max RPM Modified Rebuilt Engine
I have recently rebuilt my engine on Darth Vader my black 1980. It's a 1984 L-83 block with Iron Eagle 165 72cc heads with 110# springs, 9.4 compression, 204/214 Melling MTC-1 and Roller tipped Comp Cams Magnum 1.52 Rocker arms which gives me .428/.450 I/E lift. 1980 intake manifold and quadrajet with original 2" rams horns feeding 2.5" dual exhaust. I have a stock TH350. I'm in Alabama and have lost the cats and EGR system. It really revs freely now and I'm concerned about the redline. Without paying attention after break in, as I was playing around, it pulled north of 6000 rpm as I was accelerating with out any valve float and, as far as I can discern, no damage. Nevertheless, I am installing an MSD HEAT HEI rev limiter #83647 on the engine. I am seeing redline recommendations ranging from 5200 to 6500 as I google and read the forums. Can someone provide me with a good max rpm to program in? My math on the engine seems to indicate I really don't benefit past 5500 rpm.
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
as mentioned, we're all guessing, but with 2" rams you might be way over your power peak at 6000 even if it wants to rev. my engine builder(a professional racer) told me that after he builds a sb, he never sees it again. that should indicate these engines durability.
get it dynoed to find your best shift points.
get it dynoed to find your best shift points.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
First, congrats on the rebuild and having fun with a warmed over SBC 
It's a good call to install a rev limiter - but keep in mind that you really don't want be bouncing off of it all the time.
There's kinda two aspects to this - how high CAN you go, and how high SHOULD you go. A GEN I SBC with a cast crank that hasn't been balanced should stay south of 5500 RPM IMHO...but as noted with that cam and exhaust manifolds, I'd be surprised if you're making power past about 5K...so no reason to wind it tighter than that.
Generally these types of questions have no definitive answer without more detail
It's a good call to install a rev limiter - but keep in mind that you really don't want be bouncing off of it all the time.
There's kinda two aspects to this - how high CAN you go, and how high SHOULD you go. A GEN I SBC with a cast crank that hasn't been balanced should stay south of 5500 RPM IMHO...but as noted with that cam and exhaust manifolds, I'd be surprised if you're making power past about 5K...so no reason to wind it tighter than that.
Generally these types of questions have no definitive answer without more detail
