Folks
I just CC-ed my head, 3698447, and it's right at 59/60 CC's. This is a 75-77 BL Style Sparkplug head. My old engine manual says cut .0063 to reduce 1 CC.
My questions are, has anyone else CC-ed this head, and what numbers did you get?
Is the .0063 for 1 CC correct for this chamber shape?
And why are the numbers in the engine book so small? (they list 54, 52.5 and 51 cc's)

Thanks!

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Hyper_pak

Has your head ever had a valve job before, or two or three.

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There's no such thing as too much cam....only not enough engine!

I have 4 or 5 of those in my shop off stock engines and have had 2-447's built up for OS vavle heads...they typically range at 52-54cc stock with no previous work done to them. Be careful if taking a big cut out of it...I did one and got too greedy when checking the .0066=1cc once the cut started into the 'shelf' section of the chamber...needless to say a 38.5cc head is kind of limited once you've decked the crap out of the block...

-D.Idiot

I am not sure, I have had it for years, been in the shop. The valves don't look sunk, but I don't have another to compare.

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Hyper_pak

I don't need mine that small. I am thinking .060 will get me right at 10 to 1 on the zero deck 170 I am building.

So from your message are you saying .0066=1, instead of .0063=1?

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Hyper_pak

Doc's article on stroking the slant lists the cut as that conversion, so far it works as long as the cut is in the round part of the chamber before it hits the chamber shelf.

-D.Idiot