Oil Pumps & too much pressure

[jkarlsso@metabolex.com (Jonas K.)]

On 6/8/02 3:35 PM, "T Berk" <tberk@mindspring.com> wrote:

> - What happens if you have too much oil pressure?

You can blow out the headgasket. Also it takes power to generate that oil
pressure, power from the crank. Meaning that you'll have un-necessary drag
from the pump. 
 
> - What is the benefit of upgrading an oil pump, what sizes are
> applicable?

IIRC, there are about 3 standard pump versions, and one aftermarket. The
early solid liftered cars had the lowest output pump, followed by the pump
in the 1.8 hydro cars (although my 85 JH had this kind also), both of these
had 30mm gears. The "heavy duty" pump from Autotech is also 30mm, dunno what
makes it "heavy duty". The 2.0l motors had pumps with 36mm gears. They all
bolt up to the blocks just fine, the ones for 2.0l motors were clearanced
for the crank. Of course the new 2.0l's (99-up) have a totally different oil
pump setup. Driven directly off crank, no intermediate shaft.

I used a non-clearanced oil pump in my ABA swap, and it worked fine.

> - How are these effects different if you have a solid lifter head vs
> Hydro?

All I've heard is that the 36mm geared pump should not be used in cars with
solid liftered heads. Not enough passages in the head to make use of all
that flow. 
 
> - What are the differences if we are talking 1.6, 1.8, 2.0 liter blocks?

See above. 

> - What should be augmented if you have an external oil cooler?

The oil cooler will generate some pressure loss, but not much, and only when
the thermostat is open. If you pick a pump that will maintain pressure when
it is hot and flow is through the cooler, then cold pressure will be way
high, since flow is not through the cooler.

The difference in pressure is small enough that you shouldn't need to
upgrade your pump. If yours is tired, replace with new of same kind.

> - And then there are cam covers, crank shields, baffled pans, pickup
> tubes, screens, recirculating blow by gasses, etc., etc.

Pickup tube on 3a oil pump is wrong for transverse motor. Swap in the old
one, after a good cleaning.

HTH, 
Jonas