| Author | Message | ||
     Outdoors |
I have a set of XB heads that I want to send to Cycle Rama for some work, new valve gear, etc and I have been wondering if it is best to have the chambers modified for thunderstorm style pistons or switch to flat tops, etc? They are to go on my '00 M2. I was going to stick with the factory thunderstorms as the bike has really low miles but since it will be apart anyway... I thought that I might upgrade to better forged pistons so could go to which ever shape and combustion chamber that is preferred. This is a road bike and I will be keeping the CR pretty mild @10.5-1 with a set of SE .575 cams or similar,race exhaust and intake. Thoughts with an explanation welcomed. In the end I will likely seek and follow Wes Brown's advise but just doing some research at this point. | ||
| Buelliedan |
XB heads with flat top pistons would yield 10:1 with a 1250cc bore. To get 10.5 will require domed pistons of some sort. You can either get pisons with just the dome in the midle to match the XB bathtub shaped chamber or you can do an angled squish band to get the desired cr. Both work well but there is a little extra power to be had with the angled squish vs. the standard dome if you take the time to set them up properly with a tight squish band. |
