I had my plug holes relocated and went to the smaller plugs.

Question is- do I really need to re-cc the head? I wouldn't think that the volume would not change any more than a half "cc" at the most.

I guess that small amount could make a sizeable difference in the CR calulations.

Probley only take me about 15 minutes to set up and do the measuring again.

Thoughts anyone....

TIA

KP

How close are your CR tolerances? If a slight increase of decrease wont mess up your power or ability to use the fuel you wish then I wouldnt bother.

What makes you think your cylinder heads were exactly the same before.

Sometimes they pair can be significantly different.

Do it again. A cc or two is enough to make a difference... Make sure they're still the same volume.

--DD

What if the heads had a volume differential before??
Never assume anything. Check everything, every time.

The heads were the same before I had the the plug holes relocated. ( Len Hoffman did the work for me). I had cc'd them before the work. Now that I have gone to the smaller plugs of course the over all volume is going to change some. I am going to remeasure again but I was wondering how much of a real difference I should expect to be seeing in The CR ratio due to this small change in volume.

Thanks for everyones thoughts on this matter. I didn't know what to expect to see when I remeasure.

KP

If Len did the work I am sure he measured chamber volumes after the work was done and balanced them if need be. Len covers all the bases.

Yup, from what I have seen he writes the CC volume right in the chamber.

Rich