I picked up an '08 Street Bob for a good price yesterday, and have a S.E. stage II 103'' bb kit just collecting dust. Also picked up a set of Woods TW555 cams from a forum member that I'm thinking of putting in with this setup. It has 211's in it now and as you can imagine, it is flat from 2000 to around 2600.
My question is: will these cams work well with the 10:1 pistons that come in the 103" kit and larger displacement, or should I just leave the 211's? Not a big fan of the 255's that come with the kit.
Thanks

 

there are a lot of part numbers out there. the stock 103 stage II kit has a compression ratio of about 9.5:1, these are the flat top pistons. If you use the forged SE HC pistons...you would get 10.5:1.

 

Yea, that's the problem. The SE catalog says the flat tops are p/n 21966-07 and with stock heads 10:1 compression. But I agree, I don't think so either. I bought 22144-08b's, which they claim are 10.5:1 with stock heads, so how accurate is that information?

 

You need to use s/w like the bigboyz calculator to figure out what the static compression is really doing. Stock heads figure on about 86 cc chamber volume. Plan on installing .030" Cometic head gasket. Flat tops come in around 10.0:1. I believe stock HG is .045", so that's how they get 10.5:1 with a domed piston. Throw in the 555 intake valve closing into the calculator and shoot for around 9.2 corrected compression for that cam to do its thing.