SE 103+ Piston Compression Ratio

[JaviAir]

Building a 113". What kind of compression ratio can I expect with these pistons in conjunction with an 85cc head? My engine builder took a look at the pistons and figures he might have to machine them flat otherwise the compression would be to high. Any thoughts?

[Mike]

What piston part number are you looking at? H-D has three to choose from. In any case, none are flat tops and will be 11:1 (with the 85cc chamber, assuming stock heads) or more. Axtell may offer flat top pistons for the 4.060 bore and you may wish to give them a call.