Good morning all,

I have a question about CNC'ing a stock set of LS6 heads...

1) How much does this cost - and who is the best place to do this?

2) Will the valves need to be replaced? will this widen the valve holes

3) Is there a certain level one asks for when getting this done or is it a standard process? meaning how much material to be removed for compression ratio's etc...

4) Is this a waste of $$ compared to buying a set of 205's already to go?

Thanks for the assistance!

 

Texas Speed, a site sponsor quoted me a very resonable price for CNC porting.

Their flow number and HP#s look pretty good.

 

Hello, 243/Z06 heads are a great starting point for a modified head. It is probably your best value vs an after-market set of heads (such as '205' '215's, etc.). You can expect to pay $400-700 over the cost of the heads alone to get what you want. It all depends on how much work done and what upgraded hardware you need (valves, springs, seals, retainers, etc). The modified heads are usually sold as level 1,2 or 3 depending upon how much work and upgrades are put into them.

There are several suppliers that provide these modified heads off the shelf, such as, Texas Speed and Patriot.

You don't have to 'widen the valve holes' to get have them CNC ported. They can be run with stock valves. The CNC porting usually is only done in the runners and chamber area. You will likely want to get an upgrade to the valve job though, such as a multi-angle valve job that will smooth the flow transition when the valve is off the seat. It will help promote flow and power potential.

If you are running stock pistons most shops can calculate how much to mill from the head to reduce the chamber volume and raise compression ratio if needed. Although, all you probably need is .005-.010 taken off to clean them up (if that).

It is not waste of money. After-market 205cc heads will run you from $1800-$2200. Worked 243s should come in between $1000-$1400.
Get educated, decide what is best for you and put your money down. TP