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Old 11-14-2012, 02:32 PM
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Originally Posted by allansmith859 View Post
(3) What is effective dome volume, and how would I figure that out
The dome or dish volume might be expressed as a positive OR a negative number, depending on the calculator you are using. Also catalog descriptions can vary the same way.

All this means is you need to pay attention to what the calculators or specs are calling for. Best to use one calculator and stick w/it. The one I use is here. There are others, obviously.

Below are two dynamic compression ratio (DCR) calculators. To use them you need the intake valve closing point from the cam card and the length of the connecting rod (stock SBC is 5.7 except for the 400 which is 5.565"):

Dynamic CR

United Engine & Machine Co. Incorporated

When you go to calculate the "quench" distance, be aware there are pistons for the SBC 350 that have a compression height (or CH, the distance from the wrist pin c/l to the top of the piston) of 1.56" (stock) or 1.54" (known a "rebuilder" pistons). Because of the difference in CH, these two types of pistons will have different quench figures, all else being equal.
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