What's my Power / Redline?
 

Hello LS1 Tech,

I have a 2006 LQ4 6.0 with:

L92 Heads
Lunati valve springs
LSx 454 Cam; Intake: 236 / Exhaust: 246 / LSA: 110
Edlebrock 4-Barrel Carburetor Single Plane Intake
Holley Sniper EFI (800 cfm Throttle Body)
MSD Ignition controller
14" Air Cleaner
1 3/4" Long Tube Headers

I was wondering if anyone could help me figure out what the redline of my motor should be, and how much HP/TQ it makes. I know there's not a accurate way to figure it out without a dyno, but this is a pretty common build, so I'm sure we can get pretty close. The motor just got machined and rebuilt. Let me know if I'm missing any information, thank you guys!!

Here is a link to an article by HotRod where they took a very similar engine with a carb instead of the EFI I have:

http://www.hotrod.com/articles/ccrp-...ylinder-heads/

They made 551hp and 464 tq, so I'd like to think I'm in the neighborhood of this, but I could be wrong.

I think you will be down a good bit on power, certainly at the low end, and possibly into the mid-range due to the cam compared to the article you linked. L92-style heads flow like crazy and to generate a nice, broad torque curve, it has been my experience that the successful cam gurus are recommending much more mild cams compared to what you indicated here. Totally different mentality compared to the cathedral-port set where big/max effort power seems to start in the 240s.

Case in point: in that article, they opted for a 228/230 piece. Now I am usually of the opinion that the magazine guys could go further with a lot of their builds, but I think this is one case where that likely isn't the case. Don't think I didn't notice they stacked the deck against the cathedral heads a bit comparing a Hot Cam to an aftermarket grind--sometimes the magazine guys do things that are hard to explain. :)

Combined I/E, you are looking at an additional 24 degrees of duration. I think you should consider a different cam.

I don't know what you plan on doing with this engine, so perhaps you are going to spin it to the moon and never see below 4K RPM. If that is so, you might not notice the difference much.

I recognize that I didn't directly answer your question about predicted power output. I don't know because I wouldn't normally run that much duration on 6 liters with L92 heads unless I were running an ITB intake to make up for it.

**I also haven't run a carb intake on the same setup and this may be where my logic breaks down; hopefully some of the carb guys can give more specific input.