Wednesday, June 30, 2010

HP is in the HEADS

I built the engine on my 09 883 sportster this winter, increasing the displacement to 1200cc's.
I wanted to do something different to the cylinder heads so I bought a set of bare 883 castings because they have such a small chamber and ports leaving me with material to work with.
Then I proceeded to weld up the chambers and exhaust port floors. I started to rough out the
chamber shape and machine out the original seats to install larger ones. The valvejob came from a hours of development on the flowbench and dyno. I used a set of shelf wiseco pistons with skirt coatings but I could only get them with the dome or a dish, needing a flattop forged piston I machined the domes off. So what did all this fucking around accomplish?

A 11.5:1 engine with small chambers, flat pistons, and tons of squish. Combined with Woods .630" lift camshafts with an intake closing event of 50 degrees ABDC and I've got one bad machine that runs on pump gas. It goes by big-inch Twin Cams like they are in reverse and boy is it FUN!

1 comment:

BonerDonor said...

i don't know what a twin cam is... but I DO KNOW it is fucking FUNN!