1QWIKZ

How many thousands of an inch equals 1 cc?

This relates to milling heads just in case you were wondering lol..

Thanks

F-BIRD'88

.....

Head Milling vs. Compression


Ever wonder how much you need to mill off your head to make a cc difference in the combustion chamber size. What about the difference that makes in where you need to machine the port side of the intake as well as the front and rear so you get proper sealing. Now you will know.


Engine/Head Type
Amount to mill to reduce chamber volume by 1cc
Proper amount to mill port sides of intake for correct alignment and sealing for each .010 removed the on heads or block
Proper amount needed to mill intake ends for correct alignment and sealing for each .010 removed on the heads or block

Cylinder head Mill head | intake face | manifold bottom
to reduce 1cc

SBC 64cc chamber .0055 .0123 .0173
SBC 76cc chamber .0059 .0123 not required
BBC 109cc closed chamber .0065 .0070 .0193
BBC 118cc open chamber .0050 .0070 .0193
Ford 65-77 289-302 engine .0060 .0100 .0143
Ford 69-77 351W engine .0055 .0100 .0143
Ford 78-up 302/5.0L/351W engines except 86 5.0 HO .0045 .0100 .0143
Ford 351C engine .0050 .0100 .0143
Ford 69-71 429-460 engine, quench head .0050
.0100 .0143
Ford 429-460 engine, open chamber head .0030
.0100 .0143
Chrysler 273-318ci engine, 57-61cc chamber .0053 .0095 .0144
Chrysler 340-360ci engine, 63-71cc chamber .0048 .0095 .0144
Chrysler B/RB engine, 66.5cc or 73.5cc chamber .0062 .0123 not required
Chrysler B/RB engine, 79/81/83cc chamber .0042 .0123 not required
Chrysler B/RB Max Wedge Engine, 81 or 86cc chamber .0050 .0120 .0170
Olds 403-455 Big Block engines .0050 .0130 .0169
Olds 350 Small Block engine .0060 .0130 .0169
Pontiac 65-67 .0061 .0061 not required
Pontiac 68-70 .0052 .0052 not required
Pontiac 71-79 .0047 .0047 not required

92 zzz28

That is an extremely difficult question to answer.

To start with, a THOUSANDTH of an inch (.001) is a unit of length.
A CC, is a unit of volume. And the units are in a different system so a conversion is required.

I assume the purpose of this exercise is to gain some CR. Your best bet would be to mill the heads and then measure the cylinder volume and the chamber volume and then you can get your exact CR. Just my 2 cts

1QWIKZ

Thanks for replying 88, and 92..............This was a question posed at work and I never heard or saw a conversion between the 2 so I figured that somebody on the board could help me out and 88 just ripped some figures out with the quickness lol....Thanks again 88 I'll so the guys this post tomorrow...

Apeiron

It depends on the shape and size of the chamber.

1QWIKZ

I knew there would be alot of variables, so really it would come down to what 92 said about checking it after so much is milled..

RacerM

Ok, I am a machinist, and what I do at the machine shop is, I build cylinder heads. For every one CC, you take off roughly .006, that's six thousandts. That goes for any shape size head you can think of. It dosent matter if it is a FORD or Chevrolet or Chrysler, Honda... whatever

tom3

Always heard, for one CC of volume, .008 for flat milling and .006 for angle milling.

RacerM

I have alway's herd that it is .006, but I could be wrong, I asked my boss and he said that some heads are different, so my mistake. Small blocks are around .006-.007 a CC. If you know what CC you want you can fill the chamber up with varisol to the correct CC, and then measure so see how much you need to cut off.