This for conversation, just something to toss around...
For years we have read and heard many proffesional engine builders state to keep the compression at about max 9.5 to 1 on iron heads for pump gas. And yet we often hear about the hero super tuners out there touting they run 10 and even 10.5 with IRON heads and no apparant issues. Similar situation with aluminum heads, many proffessionals suggest no more than about 10.5 for pump gas, sometimes less. One such example, Dave Bisschop recommends a max of 10.25 with the 87cc Edelbrock chamber design. And for the 72cc chamber design about 10.5 max.
Now assuming for this conversation we did limit the compression ratio to no more than the often recommended 10.5 with the Edelbrock heads chamber design. And presumbing the heads are not ported, just out of the box. Now which would be the easiest and possibly better deal ... use the 72 cc chamber and presumably custom dished pistons, with the presumed extra piston cost, to bring down the compression ? Or just use regular flat top pistons with the 87cc chambers for the lower compression ? And bringing into the discussion, is it worth using the smaller 72cc chamber for ONLY 10 cfm extra flow at peak lift (and about 4 more cfm area under the curve) ?
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