He did, but since both cylinders share the intake port the test didn't really show the true gains. He had to weld up a little divider in the middle to actually be able to test it. I know that this caused a lot of excess turbulence and didn't account for the true flow of the head. Even with the divider I remember that the head picked a surprising amount of cfm!Did the flow test the head before and after?
The stage 3 head with 1mm over sized valves and full port work flows nearly 40% more then it does stock.This is the most that I have ever seen a head opened up. On most, I can still see some of the casting marks, and none never come so close, much less remove material around the valve guides. Although I can't see much from the photo, I have not seen any others clean up the exhaust side, because it is so tight. Obviously opening the head up, no matter how much, it will move more CFMs. I understand that it is hard to get a true number on the flow bench, but my concern would be the turbulence. How can you tell that both sides flow the same? I went to the web site, and signed up, but I could find nothing about porting the RZR.
That's a great price considering the gains and that the seals alone are $42!For a heads with Stock valves and stock springs but with full port work would be $699 that's with new seals ect.Matt, did you ever figure out what it would cost for the port work... and do you just open the intake or do you also polish the exhaust side?