Originally Posted by Hillsidecycleco
Not to contradict, but we normally see the 103"s at 9.6 cr.
The .570 will also dump heat much better than the "school bus" cam, and set up correctly will have more "under the curve".
I'm not really disagreeing with you at all. I put a similar cam to the S&S.570 (Andrews 54H) in my 103, replacing the SE255 for the sake of reducing temps (and it did!). That danged SE255 is very hot.
I was just making a general statement that he could not just change cams and be at 10:1 compression and therefore what to expect in how the bike would feel. That SE255 cam hits like a hammer in the low RPMs.That's its strength. But I've found that my 54H hits hard enough down low (though not as hard as the 255) but at about 2500 it comes alive and then keeps its pull much longer than the 255. One thing I like about the 570EZ cam is its built in compression release. That's an excellent idea...especially if one were to bump up the compression. If I bump up the compression while running my 54H (and I probably will very soon), I'll have to have my heads drilled for compression releases. With his 11SG he's already got ACRs so he wouldn't need the EZ version. Since he's already got the CNC ported heads, Harley does CC those heads and I believe they are set to 85CC. He's very possibly already at 9.7:1 static compression(depending on his deck) or better, and with just the .30" headgaskets might very well get real close to 10:1, which as you suggested would make the S&S570 cam come alive. That would definitely firm up the bottom...you are right...he'd love it.