How to CC a Combustion Chamber

[BogusSVO]

How to CC a Combustion Chamber

The subject head is a Chevy LT1 Head


Original Poster: BogusSVO

Difficulty: 3 out of 10

Time to install: appox 5 Mins




Brief Explanation: used to find out true CC of a combustion chamber or runner



Tools Needed:
- CC'ing kit
-Head stands
_water/alcohol


Parts Needed:
-the head to be measured
-Spark plug

The first set up is used when the valves do not protrude above the gasket surface.
This is simple in procedure. Fill the CC burette with a fluid, I use water, some use a color alcohol, cover with the sealing plate, then flow the fluid through the hole in the seal plate till all air bubbles are out of the combustion chamber. Then read how much fluid has flowed from the burette.
This stock head measured 54cc

The second set up is used when the valves do protrude above the gasket surface.
This is a little more difficult in its set up.
Since the valve heads protrude above the gasket surface, the seal plate can not be used, I use my dial indicator with a point, The indicator must be zeroed, with no pre load to the deck surface. Once that is done it is a matter of leveling the head and filling the combustion chamber just till the fluid touches the indicator point. Then read the burette.
This LT1 head measures 49cc

Alcohol would have given a more accurate reading with this method, since alcohol does not “dome” like water.

 

[gw33gp]

It is a good idea to add a little alcohol to the water to help it wet out and not trap air bubbles.

 

[Mac]

A lot of people don't have access to a burette. What I used was a large siringe marked in cc's found at a farm store. Not so accurate when comparing one chamber to the next but sure help in identifing one head from another.
Dave