Howdy,

I have a stock 99 1200C sportster that is under the knife, and currently operating on the motor. I already have a set of Andrews N4 cams and dynatek 2000i ignition that will be running. I am currently in the process of replacing all gaskets, including the base gaskets. Whilst having it apart, I am considering upgrading the pistons to a higher compression piston. Wiseco has a domed piston upgrade, that would increase the compression ration to either 11.4-1 (per J&P Cycles) or 10.5-1 (per Wiseco). The item in question is Wiseco part# K1685. I am wondering if anyone has run a similar combo, and if it is advantageous to upgrade. Any feedback would be tremendously appreciated.

 

Sounds like a cool project. I’d think hard about skipping the 11:4 pistons with the AZ heat and mid-grade octane, the N4 should work well with 10:5.

I’m new to the HD & evo world with only one build (not completed) under my belt, so hopefully more experience will chime in.

Hammer performance has a nice tech library on their site, helped me out big time, love the Dan.

Double check the base & head gasket selections, there’s a bunch of options to get the correct squish.

 

Fantastic feedback! I totally forgot about the tech section @ Hammer, I have his 1250 in my other sportster and love it! Definitely a good call on considering the heat, the good news is, this is a chopper build and won’t be the primary ride, so won’t see a lot of summer riding. Thanks a bunch for the feedback.

 

I don't think I'd go too crazy unless you want to run race fuel but a cam change will effect compression anyway, with the right cam it can be a wash.

 

I am planning on going 93 octane, but definitely wanting to avoid race fuel. The 10.5-1 is ideally what I am after. With the cylinders already pulled off, it seems like a fairly easy upgrade, since the ignition timing will already be adjustable, just trying to decide if the juice is worth the squeeze with a $400 set of pistons.

 

I'd do the 10.5's, it isn't that big of a compression change and this is where you're going to build power.

 

Have you considered a stroker kit?

 

Agreed, I like your style.

 

I didn’t even know those were available. It’s probably not in the budget for this build, but I do need to rebuild the bottom end on my other 99 w/ the 1250 hammer kit. Is there one you recommend?

 

Are you going to have the pistons fitted or are you just tossing them in? What’s the cost of boring/honing. Another 1250/1275 kit might be there better option imho