Chris,
Use a your chemistry glassware to determine actual cc's of the head; don't
forget the head gasket.
As for valve clearance, modeling clay works well. You can take the piston
to deck to 0 using the low compression pistons in a all probability.
Frankly, were I you, I would spring for piston instead of carving up the
head. Then I would do a little port reshaping and -poof- instant power.
Ray
At 02:09 PM 12/4/97 -0500, Chris Delling wrote:
>I am looking for some advice on potential head modifications. In Peter
>Burgess's book, "How to Powertune the MGB" he gives a formula for
>calculating engine compression ratio, and the effects of shaving the head
>on compression ratio. You must know the displacement of the cylinder at
>TDC, and BDC, as well as the displacement of the combustion chamber.
>
>I have an old style head - pre-smog. Does anyone know the displacement of
>the combustion chamber, or do I need to use a burette to measure it? For
>the cylinder, is it safe to assume that 1798 CC's (engine displacement)/4
>is accurate, or do I need to be more precise? How does on account for the
>area above the top cylinder ring when the piston is at TDC?
>
>Also, when modifying the head, how can one know how much can be safely
>removed from the head without causing potential valve-to-piston contact?
>Trying to determine how much CR increase I can obtain w/o changing pistons.
> This is an 18V engine with low compression pistons.
>
>Thanks in advance for the help.
>
>Regards,
>
>Chris Delling
>
>
>
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