When using the Wiseco 1200 upgrade kit, I see it is recommended to send the 883 heads out to be ported, even when using the domed pistons supplied in the kit. Can used factory 1200 heads be used "as is" with the domed pistons and still achieve reasonable results as far as gains in horsepower?

 

"domed" or "dished" pistons?

 

Dished, my bad.

 

The 1250cc kits come with around 10.1:1 CR pistons, so if yours are similar you should be fine. In all cases improved results can be had by porting, but from what I see a lot of owners are happy with the results they get, with unmodified heads!

 

If you have 1200 heads, just get the pistons to go with them. It only takes a phone call. but you can run stock 883 heads. Thats why the kit comes with the dished pistons. I'm going to have my head worked on.

 

No. The dished conversion pistons are designed for the small 49.5cc chambers of a stock 883 head. 1200 heads have either 62cc or 67cc chambers depending on what year and version you're talking about. If you put 1200 heads over dished conversion pistons, your compression ratio falls through the basement. Your power follows. Bottom line, the pistons have to be matched to the heads.

 

I’ve been looking around at this too. A local shop asking for 1500$ for stage one cam, gkt kit, dyno tune & programmer, and lifters.
they say rejetting or upsizing injectors in useless because they remap the bikes computer.
I don’t think Harley even has a dyno? Not a lot of people around me do.
northern wi
they Said they would install the 883-1200cc conversion for 3000$ parts labor everything. But I like the sound of 1500 better and I’ll have about 3 months to pay plus my bike will be out of the winter. Lol.
I honestly feel the bikes should be remapped from factory lol.
installed a new k&n factory air filter in and it took some of that throttle lag out.
I use to have a quad with a cam build. It was fun. Granted this engine is double the size haha. Should be better!

 

What are you trying to achieve?

From what to what?

 

Do nothing. Ride the 883 as is. When you decide to "move up" sell/trade the 883 for what you want. You will save money.

 

Get the heads ported and polished or you will not get the full benifit of the upgrade i will also recommend having a 5 angle valve cut done to max out the head work upgrade