DeTomaso Mailing List: August 2000, Message #59

Paul & Dave,

With a 10 quart pan and a high volume pump, running out of oil due to too
much oil remaining in the valve cover area should not be a problem,
especially if the 10 quart pan is properly baffled to keep the oil near the
pickup.  In my experience, the standard volume/pressure pump works fine as
long as your bearing clearances haven't opened up to the point to need the
extra volume so I tend to use a high volume pump only on a worn motor that
is exhibiting low oil pressure.  Three disadvantages to a high pump volume
are:
1) It takes more horsepower to turn it for a given oil pressure since it has
less mechanical advantage to pump the oil.
2) Your risk of the dreaded Cleveland "shearin-Pin-Itis" is increased due to
the greater amount of torque needed to turn the distributor gear.
3)   Greater distributor drive gear wear (especially a problem if you're
using a bronze gear with a steel cam!)

Doug Braun
# 5505 Blue 73L for autocross and a yellow '70 MACH1 351C-4V in restoration
(sounds a little like Asa Jay's combo doesn't it?)

 -----Original Message-----
From: 	detomaso@realbig.com [mailto:detomaso@realbig.com]  On Behalf Of
David Doddek
Sent:	Tuesday, August 01, 2000 7:31 PM
To:	Multiple recipients of list
Subject:	Re: Oil Pumps

Myself, I prefer Standard pressure High volume.  High pressure is not good
for engines.  All you need is enough volume so that you keep pressure on
the bearings.

Dave "my turbos make my oil pressure low " D

09:45 PM 8/1/00 -0400, you wrote:
>Any opinions on oil pumps?  Standard, Hi-Volume, Hi-Pressure, both?  To run
>in an engine with a solid lifter cam, oil restrictors, roller rockers and
10
>quart pan installed?
>
>I'm leaning toward standard.  I had good oil pressure with a hi-volume pump
>and hydraulic lifters, but I always felt that I had too much oil up in the
>heads.  If I rev'ed the engine with the valve covers off, it would threaten
>to spill over.  Now I expect that you can't run the engine without valve
>covers at any speed much over idle.  So the combination of making it more
>difficult for oil to reach the heads, should keep more oil in the pan for
>the bottom end.  If I keep the hi volume pump then that means less oil in
>the heads and more for the crank, but is the hi volume pump even necessary
>then?
>
>Either way...
>
>Paul
>#9270
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