Bottom end limits?

GO 4LO

Member
Joined
Nov 28, 2001
I recently purchased a Stage 2 car, and I'm trying to put together a build plan to put me at least deep into the 8's next year. The engine was assembled ten years ago but only has a little break-in time on it. I'll probably at a minimum tear it down for inspection and reassembly, but I am evaluating my options. I am looking for some input on what you think a bottom end with these components will handle:

LA billet crank
Carillo forged rods
JE 9:1 pistons

How much power/tq should it handle? Searching through old posts here leads me to believe that the Carrillos will be my weak link, so my second question is how much more power could I expect it handle with billet rods? Thanks.

Chris
 
I don't think they are Nascar rods. The prior owner didn't have a receipt for them, but he did tell me they're forged Carrillos - I assumed they were purchased new. I'll need to verify it during disassembly, I guess. Are the Nascar rods H-beams like the aftermarket Carrillos?

And just to clarify, the parts list in the first post is what I believe is currently installed in the engine.

Chris
 
There were many of the S2 Nascar engines floating around, some yrs ago. {I had 3}. All were used, all had those rods in them. Those engines were set up to run in the 500HP range, not at 1200.
W/o knowing where they came from, your guess is as good as anyone's.
 
I don't think they are Nascar rods. The prior owner didn't have a receipt for them, but he did tell me they're forged Carrillos - I assumed they were purchased new. I'll need to verify it during disassembly, I guess. Are the Nascar rods H-beams like the aftermarket Carrillos?

And just to clarify, the parts list in the first post is what I believe is currently installed in the engine.

Chris

Even the upgraded Carrillos I wouldn't take much past 750 ... @ 900 you will get pretzels
 
Thanks, guys - appreciate the feedback. Any recommendations for better rods? Most folks seem to point to Crower or Oliver, with very mixed opinions as to whose are stronger...

Chris
 
I'd personally order a new set of rods and pistons so I could nail down my exact needs for compression ratio, rod strength and piston design. Depending on what block it is you won't hit an hp limit in a mid 8 sec or slower build.


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Cunningham also makes a custom billet rod. Strangely enough my two motors with LA Billet cranks have Kryptonite rods with them, those setups are well over 20 years old. My new motor to be assembled has Crower 6.300 rods and a Crower billet crank, undecided on piston brand at the moment. New rods will be in the 1300 - 1450 range and count on a rotating assembly balance session. With those solid components you will "most likely" never ever see the limit of your bottom end. If you dont mind, what heads are you running?
 
More than likely if they are Carrillo rods they will be 6.500" long. Based on the length you can be sure they came from a road racing application. There are 2 distinct versions of the Carrillo rod neither is really up to the H.P. level you're shooting for. A 6.300" I beam rod like one of those mentioned above is what you need. The crank and block should be fine for whatever you want to shoot for H.P. wise.

Neal
 
I've got S2 heads ported by Chapman (no flow numbers), a cam in the 230 to 236 range, and valvetrain to support 8k redline, according to the previous owner.

I've not heard of kryptonite rods before - are they any good?

Thanks for the tip on the rod length. Are all the billet rod options I-beams, out curiosity?

One last question - does anyone have experience with the Crower Ti rods?

Thanks again.

Chris
 
Kryptonite rods are great but old and no longer produced. LA Billet/Kryptonite was bought out by Pankl Racing Systems and from the last time I emailed them, there was no immediate interest in making Buick parts anymore. Which means never. I think all high powered rods are I beam, Oliver, Cunninghan, Crower. The Crower Ti's are very expensive. There was someone selling a set on the board a few years ago, maybe if I was running an exotic 218 cu in. motor for Indy. I don't know how they would work in our motors on the strip, maybe a little too "brittle". Chapman heads are great and should flow near 340.
 
Allan G (AKA: Turbobitt) has titanium Crower rods in his motor. I have a set for my spare engine which has yet to be assembled. I wouldn't drop the money for a new set but if you came across a good used set for a reasonable price I'd say buy them.

Neal
 
Allan G (AKA: Turbobitt) has titanium Crower rods in his motor. I have a set for my spare engine which has yet to be assembled. I wouldn't drop the money for a new set but if you came across a good used set for a reasonable price I'd say buy them.

Neal

Yes I do have a set in my engine and bought them used with no knowledge of the previous usage. I sent them back to Crower to refurbish them and been running them ever since. So that's about 17 years ago.
AG


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Thanks for the estimate on the Chapman head flow and for the Ti rod info, guys. I'll keep my eyes open for used Ti rods; if I can't find anything by winter, I'll stick with the billet 4340. Thanks again.

Chris
 
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