why are hydraulic 8v oil pumps different?

[tberk@mindspring.com (T Berk)]

Robbie Cotner wrote:
> 
> I need a new oil pump and am about to order one from potterman, but
> I would like to upgrade to the 36mm oil pump, however the
> description on www.parts4vws.com states: "OE VW Pump. Fits All 2.0
> 8v Hydraulic Motors. Also an Upgrade for 1.8 8v Hydraulic motors"
> What?  Why do hydraulic motors have different oil pumps?  Could I
> still use this pump, would it be good/bad?  Thanks-
> 
> Rob
> 
> --------


I'm going to take a leap at this one:


Hydro valves need more oil flow available than mech valvers- that's
pretty evident. Don't the two liters (at least some) also have oil
squirtters on the bottom end?

There is some concern in going two sizes too big on the pump size
because you can get too much pressure on seals and such. (Any other
problems folks?)

One size over stock sounds great, unless you have some other reason
contributing to a bigger pump.

TBerk