Valves

Reply Subscribe

Thread Tools

Search this Thread

09-05-2004 | 09:06 PM

#31

02Reaper

TECH Resident

iTrader: (2)

Joined: Jul 2003

Posts: 780

Likes: 1

From: Swainsboro GA

Quote:

Originally Posted by SportSide 5.3

What is it, a 75% exhaust to intake ratio that seems to make the best results? How do you come up with this ratio? Can you just compare valve sizes to find this ratio?

Any guidance would be appreciated

edited: exhaust to intake , not intake to exhaust.

Well, I really dont know how they figure that. I am just not in it that deep, but to answer your question a 75% exhaust to intake ratio on our heads would be a 1.89 intake and 1.42 exhaust valve. On the other ls1 heads, it would be 2.00" intake and 1.50" exhaust. Right now we have 82% intake to exhaust ratio and the other ls1 heads have 77 1/2% intake to exhaust ratio.

Reply Like

09-06-2004 | 12:19 PM

#32

Sport Side

Thread Starter

TECH Veteran

iTrader: (6)

Joined: Nov 2003

Posts: 4,397

Likes: 0

From: Tallahassee, FL

If the ex-in. ratio is found by comparing valves then your correct. But,

I'm thinking it may be found by the flow numbers. If it is by valve diameter, then it would make since why 2.02in,1.57ex, is popular amung the 346 crowd, where there keeping the stock 77.5% ratio by upping diameter by .02 on in., and ex.