Ok, here's the deal. I like my 224/230, but I'm already wanting something bigger. I know my heads will easily support 400 RWHP, so I'm looking at a cam that will do it. 230/230 is up there, but I'm really considering the GM847 grind. Now here's the question:

I had the heads milled .005 for a slight increase in the compression ratio. Am I going to have to undercut the valves due to the almost .600 lift on the 847 cam?? Or will I be all right??

 

.005 is nothing, you will be fine AT less then .600. If it is at or .590 you will have to check piston to valve clearance.

 

Ummmm so which is it that I'll be chancing it?? .600 or .590??? I believe the lift on the exhaust with a 1.6 for the 847 is .595??

 

Are the heads stock aluminum shaved? Or the cast iron?

 

Stock aluminum milled.

 

Just do not use 1.6 rockers and you will be fine. also you will need new springs.

 

Well, I'm using 1.6 rockers. That .595 was with 1.6 rockers. And I already have brand new springs good to .600 lift on the heads. The whole setup doesn't even have 1000 miles on it yet.

 

Springs that are good to .600 and you are going with .595 lift, those springs will not last very long, now you will need springs good to .610 or .640 so the valve(s) will not "bounce", If you choose not to go with higher lift springs pay in mind you are just pushing your luck

 

You already want something bigger huh? Anything with over .550 lift is going to be pretty hard on springs...get good ones!

 

I realize that I'm going to need better springs. That goes without saying. It's like using hotcam kit springs with a CC305. You could, but would you want to??

Back to the original question, I really need to know if I'm going to need to undercut the valves or not.

I'm actually quite happy with my setup as it is right now, but I'm very strongly considering the bigger setup because A: I want to go over 400 at the wheels, and the heads will easily do it, and B: Emissions are now a non-factor for me.

 

If you had someone do your heads they would most likely know...

 

Fear not Fastbird93. my heads have been milled over .030, I run thinner headgaskets and the GM847 cam with larger valves. My piston to valve clearance was .085" Typically you want atleast .100 exh and .080 int for valve clearance. You should be fine.

 

That's what I wanted to hear!!!! Thanks for the info!!