I have a set of Andrews 57h cams that are going to go into my 2014 103 FXDF in the near future, but while I am doing that I may as well have the heads ported and set the optimum compression ratio.

So - my question is, is there an optimum compression ratio that suits these cams best?

I am shooting for a good all around bike with strong bottom and mid range.

Thanks in advance!

 

Gary Wallace with Andrews will tell you that the 57 cam was designed to install in a 103" motor with stock heads/chamber volume. Port the heads, keep chambers at 85cc, use a .030" Cometic MLS head gasket and static CR will be about 10.15, corrected CR about 9.4 and CCP about 196psi. Personally I would not set static above 10.2 on a street or touring motor but that's just me.

EDIT: I need to clarify that the comment regarding "10.2 static in a street or touring motor" was within the context of the OP's question WRT to compression and the 57 cams.

 

Excellent - many thanks for that. Gasket ordered!

 

If you are planning headwork and compression bump, ya ought to be looking at a different cam. 57 is a great bolt-in but there are better choices for headwork and compression. Talk to who ever is doing the headwork.

 

Well....I'm not planning a horsepower monster or anything like that - just a good well fettled daily driver which is why I went for the 57h cams. I don't want a big compression bump - was just trying to find out what the best compression was for these cams. If it's just to use a 0.030" gasket, then so be it, that's what I will do.

As for headwork, I'll not be going crazy on that either. Again, just mild to mid porting and polishing. No bigger throttle body or anything like that either.