when some one is cc'ing a head do you put the spark plugs into the holes before cc'ing them? most places i read says you are suspost too. but my problem is when i cc my Y8 head with the spark plugs in the holes. i get 32.1 cc's and thats with having probably 1 extra cc removed to deshorud where the valves opens into the combustion chamber( just guessing on the 1 cc more, thats why im trying to messaure it) and every where i read says that a stock y8 has 32.8cc combustion chambers

so my problem is when i cc, my bigger combustion chambered y8 head, i get 32.1 cc's but a stock head is suposted to be 32.8.

im guessing when honda told us the specs they didnt have the spark plug in the hole. and if that is the case every one using 32.8cc's would be wrong when figuring out there comp ratios

does any one know about this??
thanks

 

too much material taken off the surface can decrease the chambers volume too.

 

There is a variance with cylinder heads. If your cylinder head has ever been resurfaced, you'll see a variance across the cylinders of that head.

You want to CC your head WITH the plug you're going to use in the head. That's going to give you the most precise number.

You've got to take into account that different valves have different displacements, too. Take away from this: trust your measurement if it's one that you've repeated. Or, you can see if someone else gets a similar measurement.

 

ok, thank you for the replys. i have gotten the same numbers over and over again so ill just trust them.