Whats a good C.R.?

Reply Subscribe

Thread Tools

Search this Thread

Nov 12, 2006 | 08:05 PM

THE LAST Z

Thread Starter

TECH Enthusiast

iTrader: (5)

Joined: Jul 2005

Posts: 626

Likes: 0

From: Rain Island, NY

Whats a good C.R.?

Whats a good compression ratio for an all motor car with 93 octane? How much is too much & how does it affect HP?

Nov 12, 2006 | 08:28 PM

mullenh

TECH Enthusiast

iTrader: (1)

Joined: Oct 2006

Posts: 506

Likes: 0

From: pensacola, florida

67 tempest

Quote:

Originally Posted by THE LAST Z

Whats a good compression ratio for an all motor car with 93 octane? How much is too much & how does it affect HP?

That has many variables. First lets assume you are talking about an ls1. Next if you are talking about changing compression ratios I would guess you are thinking about milling the heads or the equivalent. Then we still have to decide on a cam (very important). Many cams like compression and are designed for it with pump gas in mind while other may requre race gas. i have heard of ls6 heads being milled 30 thous. and i think you can find a thread on it. I do not recall the compression that was achieved or if timing had to be retarded + (cam position). Check a vendor that sells aftermarket heads and cam combo for best results.

Nov 12, 2006 | 08:33 PM

THE LAST Z

Thread Starter

TECH Enthusiast

iTrader: (5)

Joined: Jul 2005

Posts: 626

Likes: 0

From: Rain Island, NY

It would be a 408 with a street cam...

Nov 12, 2006 | 08:34 PM

yak

TECH Fanatic

iTrader: (15)

Joined: May 2004

Posts: 1,393

Likes: 3

From: SE Wisco

well quech is the most important thing. so before you run off and mill the **** out of your heads consider swapping to a thinner gasket so you have a tight quench. What size cam are you running? a 224/224 and a t rex will be very differnt with the same compression.