Compression Ratio
Elder User
Joined: Sep 2000
Posts: 936
Likes: 0
From: Bay area
Compression Ratio
I am researching on rebuilding a 400ci with the 9:1 CR pistons. People are telling me I am not going to be able to run these with out pinging on 91 octane gas.
Some one said if I polish the insides of the heads where the combustion chamber is I will be not pinging at all.
Please advise me :-)
Some one said if I polish the insides of the heads where the combustion chamber is I will be not pinging at all.
Please advise me :-)
Posting Guru
Joined: Jun 2002
Posts: 1,099
Likes: 0
Compression Ratio
9:1 should not be a problem with 91 octane. If you polish the chamber, it may help. Do it before a valve job and put a couple junk valves in to protect the seats. Don't get carried away trying to make them perfect.
