Compression ratio and cams
Thread Starter
TECH Veteran
iTrader: (53)
Joined: Feb 2004
Posts: 4,433
Likes: 0
From: Monticello, Kentucky
Compression ratio and cams I got to reading in the internal engine section and some guy had a thing going about compression and cam size. It was mentioned a healthy cam in an LS1 (like Trex stature) could support 12.0:1 on pump gas! Anybody know what an LT1 can do as far as CR goes with bigger cams? Just out of curiousity............ Oh btw, what's the stock combustion chamber size on the LT1? I don't even know.
Thread Starter
TECH Veteran
iTrader: (53)
Joined: Feb 2004
Posts: 4,433
Likes: 0
From: Monticello, Kentucky
Well I never thought about it much but he was making sense. The bigger the cam, the higher the compression you can run due to the overlap reducing the dynamic CR. I was wondering how much CR an LT1 could support on pump gas.
I have a 355 with a CC306 cam, 51cc heads, 0 deck block, -5cc pistons and .039 head gaskets. Which brings my compression to 12.335:1. I run that setup on 93 octane every day. No problems at all.
Last edited by solid95z; May 6, 2004 at 10:30 AM.
Thread Starter
TECH Veteran
iTrader: (53)
Joined: Feb 2004
Posts: 4,433
Likes: 0
From: Monticello, Kentucky
Wow! That's up there. Reverse coolant flow must help with that. I should've hit higher on mine as well. I'm going with a bigger cam but my CR will still be low. What kinda power does that sucker make? Better yet, what are your times? I'm curious as to how much power lies within a couple points of compression.
I'm not sure how much power it's making as of yet. I have not had the chance to finish tuning it and get it to a dyno. I will say that even with the bas tune, this thing PULLLLLS above 3000 rpm. Once I finish tuning it and get a 12 bolt, it'll be track time 
Scott
Scott
Trending Topics
i'm close to 13 to 1 on pump gas. this is pushing the limits even with my cam
264/270 @ .050" .680" . the motor only sees race fuel at the track but it does run ok on pump gas in street trim.
264/270 @ .050" .680" . the motor only sees race fuel at the track but it does run ok on pump gas in street trim.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Senior Member
Joined: Jun 2003
Posts: 9,339
Likes: 3
From: NYC metro area
Originally Posted by lafnlt1
i'm close to 13 to 1 on pump gas. this is pushing the limits even with my cam
264/270 @ .050" .680" . the motor only sees race fuel at the track but it does run ok on pump gas in street trim.
264/270 @ .050" .680" . the motor only sees race fuel at the track but it does run ok on pump gas in street trim.
