Cranking pressure ?

[Gearhead88]

I'd like to get an idea on what some of these engines we've built make for cranking pressure , measured with a compression guage.

Mines a short rod , twelve counterweight 4.7 with + .060" unmolested Sealed Power #677CP pistons. Piston dish volume on these is 15.1 cc

Cranking pressure is 185 psi





What's yours ?

[gremlinsteve]

sounds good to me. whats the quench? which cam is this?

steve

[dwg86]

185 cranking pressure? what gas do you run?

[gremlinsteve]

true but what can and at what quench. ive run stuff over 250 cranking on 93 pump with no issues.

a/f and a good tuner would help also.

steve

[Gearhead88]

I only run premium , there's no way I'll run with mid or reg.

Cam is Comp # 68-232-4 , installed straight up.

Quench is not where I could / should have set it , I'll have to look at my build notes to get a number , I remember not being happy with it and went ahead any way due to a very long backlog of work at the machine shop I used and could not stomache yet a further delay to the completion of the engine. I was thinking about freshening the engine in the future and dealing with it then . I am building a second engine that will not be under such tight time constaints so I could take care of the quench on that one . The next one will probably be a long rod / four counterweight version , I'm still gathering parts and have a nice cylinder head prepared to use on it.

No tuner used on this one either , , I did use Accel 24 lb/hr injectors , Rubicon express 62mm throttle body , ported head w/ stock sized valves , Bank's full exhaust system.

I'm planning on adding an air /fuel ratio guage in the near future.

Other than busting a few rocker arms , it's been a great engine.