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  #1  
Old 11-02-2001, 10:03 AM
RDF73Charger RDF73Charger is offline
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Question Compression for the street.

I am building a 440 up using Federal-Mogul L2355F .030
pistons and 906 casting heads. This is a street car that sees some time at the track. I am worried that the ten to one compession ratio may be to high for pump 93-94 octane gas.
The cam is the comp cams 21-305-4 muscle car cam .464 lift 222 duration at .050, 110 degree lobe separation. Does anybody run this combo? If so does it work well?
The 906 heads cc at 78.
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Old 11-02-2001, 02:19 PM
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rumblefish360 rumblefish360 is offline
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That combo should be OK. You may not be able to run the advance you want though. That ratio will realy like 100 octane.
For the street, a little race gas would be good.
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Old 11-02-2001, 08:39 PM
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Glen440 Glen440 is offline
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Well I have those pistons in my 440 and with open chamber heads it specs out to 9.5 comp. I had 160 psi cylinder pressure with the .509 cam. Ok your heads are milled quite a bit so you have over 10-1. With that small cam it will be too much.
We need to switch places cause I need more comp to run the big duration cam I want and you need less for that short duration cam you have. Usually 9.5 is max for pump gas unless you have a long duration cam to kill cylinder pressure.
The car will be a little sluggish and may foul plugs if you have to run around with the timing retarded.
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Old 11-02-2001, 08:48 PM
ohioDemon ohioDemon is offline
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hello. you shouldn't have any gas problems. i have a 10.2 cr 360 engine with a comp cams xtreme 284/296 (240/246@.050)hyd cam . just try to run the best grade of fuel you can find . i like sunoco ultra 94 octane.
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Old 11-03-2001, 02:46 AM
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rumblefish360 rumblefish360 is offline
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ohioDemon;

The reason you can run the pump gas is because your cam is bleeding of compression. RDF73chargers cam is smaller, keeping the pressure in the cylinders higher.
My 360 has 10.5-1 comp. and a purple 292/.509 cam. It will run on 93 though 94 or should I say 94+ is prefered. The old purple cams rate of lift isn't a radical as yours. It will experance run on when 93 is used. To rid myself of it, I retarded distributor timing a bit. This engine could use more cam. (Next spring)
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Old 11-03-2001, 01:05 PM
RDF73Charger RDF73Charger is offline
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Biggrin

Thanks for the feedback. I have a MP .484 lift cam and may use that instead of the Comp Cam.
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