[DeTomaso] Oil Pump Pressure

michael@michaelshortt.com michaelsavga at gmail.com
Wed Jan 30 23:07:46 EST 2013


Worth sharing I thought.

Michael Shortt
---------- Forwarded message ----------
From: "Ronak, T.P. (Timothy)

> Karl,
> The term Hi-Output pump is not descriptive enough ... it is either
Hi-Volume
> standard pressure or Hi-Volume High Pressure. All you need for a stock
engine
> is 10 Pounds of pressure for each 1000 RPM of engine speed. Any pressure
> beyond that and you are introducing parasitic HP losses by forcing the
engine
> to work harder to spin the pump. The max pressure you need in a stock
6000 RPM
> engine is 60 pounds when revving at 6000. I personally feel best with a
> minimum pressure at idle of 25-28 lbs. Unless you are starting the car at
-40
> or you have a mechanical interference inside the pump it is not likely you
> will twist off the oil pump drive or excessively wear the Cam distributer
> drive due to the additional loads generated by the High VOLUME pump.
>
> I am assuming you were sold a Hi-Volume standard pressure pump and the
> pressure bypass spring in the pump itself will ensure you do not create an
> excessive oil pressure in the system. I would leave the pump alone and
simply
> observe the oil pressure at startup. Ideally you want to run 10/30 or
> equivalent synthetic oil and after breakin simply note the oil pressure
once
> warm and know that you may be able to mitigate some of the pressure by
running
> a thinner or lower viscosity oil like 10/20. I would not advocate a '0'
weight
> oil as the tolerances we run on the older V8 engines are too large and
require
> some oil wedge to develop to prevent bearing contact. It does depend on
the
> climate you intend to operate the car and weather there will be lots of
COLD
> sub zero starts.
>
> Sounded like you were looking for a recommendation ... so here it is ...
If
> you are running a Hi-Volume pump leave it in and you will be fine just
look to
> observe that Oil pressure does not exceed 60 PSI when revving above 4500
RPM
> and that you have at least 25 pounds at idle ... If you KNOW for a fact
you
> are running a HI-PRESSURE pump (Not a HIGH VOLUME pump) you might want to
> reconsider your choice. I can not imagine that you used a hi-pressure
pump as
> they are very difficult to obtain and are not easily purchasable from a
NON
> performance company as they are rarely stocked or sold so most likely the
term
> hi-output refers to Volume and NOT pressure. If you have your receipt for
the
> pump we could look up the part number and stop speculating and determine
which
> pump you have.
>
> Lunati actually recommended that I NOT EXCEED 60 PSI on my stroker motor
as
> they said it would create too much windage at RPM inside the crankcase
and it
> would make the oil rings work too hard to prevent oil in the combustion
> chamber and felt that the 58psi regulated Hi-Volume pump they sold me was
the
> best alternative next to a dry sump.
>
> If you have any questions feel free to call me.
> Best Regards,
> Tim Ronak
> Senior Services Consultant
> AkzoNobel Automotive and Aerospace Coatings NA



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