[fox440]

i just rebuilt the motor on an indy 400 i got from a buddy, and i honed it out and put new cranck case seals, rings and all around gaskets, i ran a compresion test and it has 120 pounds in each cylinder. i know that thats pretty good compresion but on a rebuild shouldnt it be around 135? i was thinking and with these pistons it only takes one ring which is probably why it dosnt have more compresion than that, right?

 

[Dragon700]

that sounds alright. with 1 ring it will be a little lower, plus once rings seat compression will go up.

 

[fox440]

okay thanks, i just wanted to make sure that 120 was right with one ring. i mabey have 5 miles on it from just foolin around, and it seems like the copresion rose a little it about 122 right now.