Is there a way to determine if a head has been milled/shaved? My head is a D8 and would like to know how to determine the current cc volume. It was cleaned up at the machine shop of about .005 for a slight warp issue. I had read somewhere that the D8 head was able to be milled about .09. I may have a missing 0 in both the numbers, not sure, and I am not sure if its been worked before. Is this something the machine shop would be able to determine or is there a way to measure? I will be having some machine work done soon to the head, valve guides,and valve stems for seals. Thanks
How to measure head cc size?
- Thread starter Idastang
- Start date
kukm66
Famous Member
Have them CC the head.
The process involves filling a 100 cc syringe with liquid(water), then filling the chamber. The difference between the new reading and the original 100 cc yields the amount in the chamber. Spark plugs must be installed and a substance like vaseline placed around the valves and plugs to stop leakgage. You can do this yourself but since you are going to take it to the shop, just have them check a few chambers to get a reasonable reading.
The process involves filling a 100 cc syringe with liquid(water), then filling the chamber. The difference between the new reading and the original 100 cc yields the amount in the chamber. Spark plugs must be installed and a substance like vaseline placed around the valves and plugs to stop leakgage. You can do this yourself but since you are going to take it to the shop, just have them check a few chambers to get a reasonable reading.
You can do it yourself.
You need a syringe probably between 30cc to 75cc. I bought mine at Tractor Fleet (or is it farm?) supply.
You need a clear sheet of Plexiglas with a small hole cut in middle
You need some axle grease to smear on head surface to form A liquid tight seal.
1) Make sure valves and spark plug are in head
2) smear grease around combustion chamber.
3) Place Plexiglas over combustion chamber so that hole is in center. Try to make sure deck surface of head is level.
4) Fill syringe with water, make note of how much is in syringe. Inject water through hole until combusion chamber is full. Try not to have any air bubbles. I have also seen people use rubbing alcohol since alcohol has less surface tension than water.
5) Make a note of how much water is left. Subtract from how much you started with.
That should be your combustion chamber size.
You need a syringe probably between 30cc to 75cc. I bought mine at Tractor Fleet (or is it farm?) supply.
You need a clear sheet of Plexiglas with a small hole cut in middle
You need some axle grease to smear on head surface to form A liquid tight seal.
1) Make sure valves and spark plug are in head
2) smear grease around combustion chamber.
3) Place Plexiglas over combustion chamber so that hole is in center. Try to make sure deck surface of head is level.
4) Fill syringe with water, make note of how much is in syringe. Inject water through hole until combusion chamber is full. Try not to have any air bubbles. I have also seen people use rubbing alcohol since alcohol has less surface tension than water.
5) Make a note of how much water is left. Subtract from how much you started with.
That should be your combustion chamber size.
DupleDreux
Active member
one additional hint, if you drill a second small hole in the plexi, it will allow air to escape as you fill and the air pressure from the syringe won't try to break the axle grease seal. 
Mark
Mark
The shop should easily be able to do it. To know for sure what your CR is going to be you also need to do the block with the pistons installed. Don't forget to figure in the head gasket thickness. My head is tiny but I have some strange 60 over piston setup that still did not get me much over 8 to 1.
If I recall correctly it is common for replacement pistons to reduce the compression height to account for the deck being milled to true it.
Stock 200 pistons compression height is 1.511", my pistons build sheet says the compression height is 1.500"
Stock 200 pistons compression height is 1.511", my pistons build sheet says the compression height is 1.500"
