Measuring CCs

53003jason

New member
When measuring CCs where do measure the top of the fill line on the head or the top of the fill bolt? How close should you get the min tolerance?
 

Kart43

Member
I am assuming you are using an approved cc tool(Ladd) I am not aware of them having fill lines. The chamber is filled with 26.5cc of MM oil and rolled over TDC no fluid is allowed to overflow tool.
 

Familyman

New member
I am assuming you are using an approved cc tool(Ladd) I am not aware of them having fill lines. The chamber is filled with 26.5cc of MM oil and rolled over TDC no fluid is allowed to overflow tool.
If you are teching an engine this is the procedure. If you are building an engine keep the engine at TDC and see how many CC's it holds.
 

cking

Member
The cc tool seems like a waste of money. If an engine holds 27cc to the top of the spark plug threads, what will it hold with the cc tool?? Thanks for any help
 

Kart43

Member
The cc tool seems like a waste of money. If an engine holds 27cc to the top of the spark plug threads, what will it hold with the cc tool?? Thanks for any help
There is very little difference between the tool and the plug hole, I never gave up a .5cc I always made certain the engine would pass using the prescribed inspection method. That way if there is a question of legality, it would have to be shown to me or explained what part of the rules I or they did not comprehend. The cc tool prevents a lot of ingenious engineering to skirt the rules.
 

Familyman

New member
If the plug hole is in good shape and has not been tampered with it holds the same as with the cc plug. I hear people in the past would somehow enlarge the plug hole so it would tech higher cc's
 
I tried to cc a engine that has been ran with MM, and it leaked past the rings fast enough I couldn't get a good reading??? And, it makes great power still.
 

backyardhack

New member
How many people out there are building motors using the .290" total depth method including low side of piston in hole + head gasket thickness + depth to top of combustion chamber? What is the accuracy of this? What is the normal range of piston in hole measurement before the accuracy gets skewed by too much of the total being full bore diameter (for example a piston .040" in the hole would have to affect total cc volume).
 

Kart43

Member
Not sure what the question is, but the difference between an engine at .010" in the hole and one at .040 is 2.8cc that is substantial

Let's say your buddy cc his engine right on he is at 8.39:1 compression ratio
You have the same head and gasket but are .040 in the hole you are 7.69:1 compression ratio

You will measure that on a dyno you will see it on the track all other things equal.
 

Kart43

Member
I tried to cc a engine that has been ran with MM, and it leaked past the rings fast enough I couldn't get a good reading??? And, it makes great power still.
Never had one leak down like that, what would it show on a leak down test? I know the air pressure will seal the rings up some but the oil does also.
 
Never had one leak down like that, what would it show on a leak down test? I know the air pressure will seal the rings up some but the oil does also.
I don't know on a leak down, but I know the numbers are great. And I loaned it out a few weeks ago and it performed very well. No blow bye, or smoke. Im not doing anything to it,,LOL. Its going to Dawgwood in a few weeks..:)
 

C&L_MOTORSPORTS

New member
How many people out there are building motors using the .290" total depth method including low side of piston in hole + head gasket thickness + depth to top of combustion chamber? What is the accuracy of this? What is the normal range of piston in hole measurement before the accuracy gets skewed by too much of the total being full bore diameter (for example a piston .040" in the hole would have to affect total cc volume).
I shoot for .300 just to be on the safe side then assemble and CC. normally we remove .025 off head after we CC. never know what the head will CC so I sneak up on it.
 

Krakkergreg

New member
With it leaking that much by the rings there is a very good possibility that it wont pass tech on the rings having to support the piston and rod in the cylinder a with the oil ring and the otjers having to support themselves in the cylinder JUST A THOUGHT hope this helps
I tried to cc a engine that has been ran with MM, and it leaked past the rings fast enough I couldn't get a good reading??? And, it makes great power still.
 

backyardhack

New member
To clarify my earlier question: say you have 2 engines, both are .290" total but one is .040" in the hole and one is .010" in the hole. The engine that is lower in the hole has a greater percentage of the .290" at full bore diameter as opposed to the combustion chamber depth that is not full bore diameter. The low in the hole engine has a greater cc with the same total depth. That said, what is the typical "in the hole" depth that works with this method?
 

Racer14sl

New member
The cc tool seems like a waste of money. If an engine holds 27cc to the top of the spark plug threads, what will it hold with the cc tool?? Thanks for any help
Has anyone checked this method against the approved AKRA cc tech procedure? Also, rougly how many cc's does the stock dished piston add? I'm sure there is some variation, but should be within a CC...
 
Has anyone checked this method against the approved AKRA cc tech procedure? Also, rougly how many cc's does the stock dished piston add? I'm sure there is some variation, but should be within a CC...
I will have to check, but I am pretty sure the cc's of the block, with the piston .010 in the hole has been coming up to 5cc in my builds. I don't know about the piston itself though, I just check it in the cylinder, and then the head, add in gasket and adjust from there.
 
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