Posted by George on Sunday, September 29, 2002 at 7:45AM :
referring back to the McNabb thread started on the 27th...
Check the site http://www.bgsoflex.com/autoleft.html
where there are calculators for lots of automotive applications.
for example, if you estimate horsepower for a 230 engine at 3600 rpm with CR at 7, you get 105 HP. If you change to 8.5 CR, you get 128 HP. That is a huge difference based only on CR.
You have to be careful not to over interpret such formulas, they are estimates and not based on this particular engine. But what it suggests is that increasing CR is pretty effective in raising HP.
Years ago, when I drag raced a 1950 Plymouth, I milled the head 60 thou and got better times. When I calculated the increase in HP based on the higher terminal velocity at the end of the quarter, it amounted to about a 5% gain.
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