Engine compression

[sean clark]

Does anybody know what the compression should be for a "45" flathead.I have 70# and 75#,this seems low to me.I always thought 100# was the minimum.Any answers would be appreciated,Thanks

[Rubone]

Depending on which heads are on it, the altitude where you took it, and the method you used the numbers can vary greatly. 75 on a 45 isn't bad, and 100 is very hard to find on one...

[duffeycycles]

Normally you turn a motor about 8-9 revs at canking speed to check compression--good luck doing that with a kicker

[sean clark]

thank you for your help.This will help me alot.