3.2 oil pump; pressure vs scavenge ratio

[Tea Tray]

I am wondering if anyone has measured the lengths of the pressure and scavenge gears inside a 3.2 oil pump to calculate the scavenge / pressure ratio. For example the two sections of a Norton Commando oil pump produces a 162% scavenge ratio (pump returns 62% more volume to the tank than it draws from the tank).
Thanks!

[Tea Tray]

El Bumpo

[cmonref]

Can't answer your question directly -- no knowledge of lengths of segments of oil pump -- but I do know that the scavenge side draws on foamy oil of an indefinite depth whereas the pressure side draws from several inches of head of oil. Even if you knew the relative lengths of the two segments, you would not be able to calculate the ratio of scavenge vs pressure pumping. Good luck tho'.

[tharbert]

Bill Verburg posted these numbers a while back:

GT3 RS pump (83 liters per minute, scavenge side 135 liters per minute).

GT1 pump, also used on the Turbo LeMans GT and certain other race cars (83 liters per minute, scavenge side 160 liters per minute)

the 964 is mg,pressure side = 65l/min, scavange side = 1.84 x pressure side
the 930 3.3 is al/cast iron,pressure side = 100 l/min(best I remember) and is 8mm longer than the 964 pump ie needs a different shaft

The 964 pump is mg. w/ separate bearings for durabiliy. It is a quality piece as is the 930.

The 964/50 3.6t uses the same oil pump as the other '93 on 964s

[KTL]

Originally Posted by tharbert

and is 8mm longer than the 964 pump ie needs a different shaft

Actually the 964/993 pumps use generally the same short driveshaft tube as the 930 and GT3 pumps. Part number for the 930 shaft (930.107.143.00) is different than the later pumps (930.107.143.03) but the later .03 shaft for the 964, 993 (and both 964T and 993TT), 996TT and GT3 is called out as superseding the .00 shaft

Apparently the extra 8mm doesn't matter because they either shortened the shaft coming out of the pump a little bit, or the driveshaft has enough "float" between the retaining rings where the extra 8mm is not an issue.?

The smaller pumps like Carrera 3.2 and older all use the longer driveshaft tube