I am doing a 1200 conversion and trying to figure out what compression to go with.

I was going to do a 10.1 however I was told that it would ping and possibly blow up the tops.

Any input would be accepted,,,, has anyone done the 10.1?

Modee

 

A stock 04up 1200 is 9.7:1. Are you using the stock 883 heads? Doing headwork and cams? Flat top pistons? going to 10.1 is quite easy if your using the right parts.

 

I am going to purchase the 1200 kit with the cylinders, piston etc.

I just need to know if I should go with the 10.1 or 9.5 compression kit.

I have a 2004 883c, not boring out the jugs or anything just replacing...

 

The 10.1 should be no problem. The only consideration might be the octane of premium fuel where you live. At over 10:1, 93 octane would likely work best but some in areas of the country 91 is the highest you can get.

 

Blowing the top at 10:1? No way. The buell's come stock with 10:1. As for 9.5:1 vs. 10.0:1. The difference between them will be very little. 10:1 in theory should provide slightly better performance, but with half a point in compression difference it's not really a concern. On the other hand 9.5:1 should run cooler head tempertures: again with such a slight difference it's not really a concern. I am going to assume this is a street bike and not a high performance machine and you don't plan to do any furthur mods. If that is the case, then go with 9.5:1 if you live in a hotter climate and 10:1 if you live in a cooler climate.

My advice to you differs if you ever plan to go with high performance cams. Those usually have a long duration and you will need more static compression to get good cranking compression.

 

Thanks, yes its a street bike, I guess I should go with the 9.5