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Author Topic:   stock oil pump or high volume
posted March 09, 2004 09:40 PM
bilding a street stock motor. wondering
if I should use a high volume pump. In
my pure stock I used a stock pump with
a heavy spring. I have a 6qt. pan. If
I use the high volume pump,do I use
th heavier spring?

posted March 10, 2004 08:18 AM
A high volume pump will raise the pressure 5-7 psi on it's own. Don't really need the high pressure spring.

Do you know what the bearing clearances are? If it's more on the tight side, run the stock volume pump. A litte on the loose side, run the high volume.

I just put my new motor together with .0025-.0027 main clearance, .0018-.0024 rod clearance and a stock volume high pressure pump (M55a). With 10w40 it idle with about 35psi and about 60-65 psi @ 2500rpm. It's more of you want enough flow & pressure at operating speeds with the oil you use. Last year year I had .003" main clearance and .0025-.003" rod clearance. Used a high volume pump with the spring that came in it (stock pressure I believe) and 20w50. Idled at 40psi and ran at 65-70 psi.

Hope that helps some.

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