Looking for some insight from some of the experienced head guru's and engine builders. I'm currently having a gsr head worked and was wondering if there would be any benefit to adding a 30* degree back cut behind the already 45* angle on the valve. I know in most domestic heads this tends to increase low lift flow in some cases as much as 15 cfm have been found around to .400 area. Just wondering if it was worth the time and effort to do this while it already apart.

 

yeah its worth it. we do it all the time and you can get creative with the cut as well and not just do a 30 degree

 

What kind of "creative things" are you all doing to make it more efficient?

 

That is a cash money question.

 

Yea I figured that would be the answer that I got.

 

My machinist also does a backcut on my valve jobs, for only $20 bucks more why not.

 

we have a couple angles but like stated we have done r-n-d to find out what works and what doesnt would be to easy to just give the angles away. gonna have to see what the person doing the valve cutting recommends