Thanks All.
I don't think I'm being nit-picky on the compression issue,
just cautious.
Here's a lttle more info. I don't want to take the motor
over about 6000. This should assure some good low RPM street
manners. In view of this, I won't need huge intake ports,
manifold, or carb. So all that limits cam duration to something
maybe around 250 degrees ? Less ?
That is not a big cam, so what can I get away with for
compression with aluminum heads, polished chambers and
piston tops, and zero quench ?
I am not an expert on Hemi's but do street drive a warm wedge with manual transmission. Compression that is OK for a short blast on the strip may not work for extended street driving. Heat builds up cruising and a manual transmission can let the engine lug under load. I was conservative by standards of the board with 10.2 CR and tight quench on 496 wedge. 243 @.050 fast mechanical cam. The car also has a stout cooling system that keeps temps right on the 180 stat when rolling... even driven hard. With the conservative CR I still have to watch timing. Transition from light cruise (50 deg) to WOT (34 deg) needed some care to prevent rattle. I have gradual timing curve vs RPM at WOT to prevent rattle coming out of the corners when hot lapping the road course.
First time I noticed the cruise rattle was on I8 along the Mexican border. Cruising at sea level in OD, about 95 degrees F and just starting to climb the coastal mountains. I pressed the pedal a little more and that cleared it up... I also enjoyed a fast trip to ~4,000'. When I got home I took 2 degrees timing out in that transition area.
Point is, cruising (and road racing) needs a little bit conservative CR and tune.
