Tim,
After you guys taught me the proper way to do a compression test (plugs
pulled, WOT) I get 195-205 psig depending on which cylinder and which day.
I'm at sea level here, but of course that doesn't affect psig, just psia.
Bob
At 07:57 AM 1/21/00 -0600, Ronak, TP (Timothy) wrote:
>Bob,
>I have to agree with you about the effect removing and sharp spots from the
>combustion area will have on detonation. The key to avoiding the excessive
>pressures is by changing where the Intake valve closes in relation to the
>piston traveling up on the compression stroke. What is your cylinder
>pressure warm with all of the plugs out ... or have you tested it? The
>method I will use on y 302 will be to chose the desired cam profile and then
>increase compression (or advance the cam) until I obtain about 195 lbs
>cylinder pressure cranking. My experience is similar to yours in that
>compression is fine provided that the combination once assembled gives you a
>usable cylinder pressure. It may be that the guy who has to run race gas
>needs to install a cam with a little more overlap or one that closes the
>intake valve a little later reducing the amount of cylinder pressure the
>piston can build. I do know that back in the race car days we had an engine
>that was 14:1 (remember that car Theo .. it was blue and yellow) it made
>over 220 cranking cylinder pressure and we had to run C-14 and methanol in a
>15% and 85% ratio respectively or it detonated like crazy.
>My 2 cents too,
>Tim Ronak
>B382000680
>PS: It is amazing how a well placed email gets us back on the performance
>topic....YEEHaaaww!
Robert L. Palmer
UCSD, Dept. of AMES
619-822-1037 (o)
760-599-9927 (h)
rpalmer@ucsd.edu
rpalmer@cts.com
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