Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[chicoman]

Cant find my old paperwork on these and cant find anyone local that knows. I think the dome is .125 but not sure. Need to know for upcoming project. Thanks in advance

[clubbie]

11cc from memory. Don't use that as gospel but it does work out to 10.5 on the boyz calculator with a stock .045 gasket.

clubbie

[chicoman]

They are in the bike now, and i machined .045 off the dome because of a ping i could not get rid of. That solved that problem.  Got enough miles on lifters and tensioners now, so Im going to change them out along with a new set of cams. Want to go with the tc 24d or the genesis 577, but doing the math looks like my compression should be at @ 10.1 if the dome is .125. Dont want to tear down any farther then needed so if anyone has a piston they could actually measure for me that would help in my cam decision. The cams i thinking of sounds like 10.0 is what is best

[HILLSIDECYCLE.COM]

At a 10.0 ratio, it is MIGHTY tough to beat, an S&S .570.
Scott

[clubbie]

Chico did you install the 10.5 with the stock 255 cams? Those stock cams build some pretty serious cylinder pressures with the stock comp ratio, the motor will ping incessantly with 10.5 pistons.

That setup would have 220+ccp.

[chicoman]

No not a 255, this is 2007 se ultra classic that had the early problems and I did these changes before there was much info as to the problems. There was not much info on these early on
Cam I put in is a se 253, it runs pretty good, at 60,000 miles just changing out the possible wear parts and going to get a cam that is actually designed for this motor. The last dyno was at 109 hp and 109 tq, took apart darkhorse bottom end, good rods, stock heads, machined .045 off piston dome, but i dont remember how high the dome was in inches. Dont want to pull all apart was hoping somebody had a piston they could measure for me. I think doing math if stock was 9.3 and se piston stock is 10.5 and if the dome was .125, .045 off should put me around 10.0 or 10.1. Want to run the genesis 577 and it seems that 10.0 is what it likes. Anyone have one to measure for me?, thanks.

[Fattbaggernknox]

At a 10.0 ratio, it is MIGHTY tough to beat, an S&S .570.
Scott

I agree 110% on that statement!