A question for you "master engine builders" out there.
I am in the process of modding my '03 Raptor with the following:
HMF full system, SixSixt intake, Carb tuning, Hotcams stage 2, upgraded valve springs, 12:1 JE 102mm piston, ported cylinder head.

My question is this - Has anyone out there gone larger on the intake valves? I recently bent the center intake valve and am playing with the idea of installing a 1mm oversized center valve. I don't think I will need to oversize all 3 due to the fact that I plan on staying with the stock carbs and it's only a 686.

Has anyone done just the center valve? if so, what was the outcome?
If you don't want the rest of the world to see your response PM me and it will not go any farther than there. I realize most of you guys are on the West coast so you don't have to worry about spilling your secrets to the competition because I don't plan on leaving the Northeast.

Come on guys, help out a fellow Raptor enthusiast.

 

I can't believe no one replied!

 

to be honest it wouldnt be worth it. if you ar goin to go over size do all 3, even like that there wont be much more gain. and i dont think the atomization would be correct with one bigger valve. just my own opinion though

 

Talk to Trinity. I believe part of their head mods are a 1mm larger center intake valve. I went with 1mm larger valves on all 5 of mine.

 

yammyyfz- trinity does the 1 mm larger center intake valve. I had one of there 686 kits with the larger intake valve. Save the 100 bucks. All it did was lighten my wallet by another 100bucks. Most 686's can get by with the stock size valves. Get stainless steel for long life. I can port as good as trinity with a hatchet, screwdriver, chisel and my wifes emory file.

 

This is good theropy 14, let it out, let it all out............


OK, group hug!!

 

Get It !!!!!!!!!!!!!!!!![img]i/expressions/face-icon-small-happy.gif[/img]

 

RaptorAz,
Was there a noticeable difference by going oversize on all the valves?
Was the port work done by you or a machine shop?

 

Are you telling me to do the oversized center valve?

 

I had the engine built by KENZ CYCLE TECH here in Arizona. He did the 727, porting, and big valves all at once. So I can't tell you if the bigger valves made much difference by themselves.