964 Oil Pump in early engines
05-12-2003, 01:12 PM
#1
Rennlist Member
Thread Starter
964 Oil Pump in early engines
Any power advantages to the late 964/3,3 Turbo oil pump?
I'm re-building a 911 engine for a vintage racing car under 2.5 liters. The engine has all the late engine oil mods i.e. pressure bypass re-drilled and plugged, late bypass pistons and springs, small cam oiling fittings, venturi pick up etc. I use the early 901 oil pump with the large scavenge pump, oil pressure is perfect with this and bearing wear is very accepable, so I don't need more pressure/flow in the bearing oiling circuit.
It seems to me though that the large scavenge pump of the 964/3.3 Turbo may help clear oil from engine and help the engine make more power by decreasing the windage fog inside the case, however the larger pressure side pump of the 964/3.3 Turbo pump may just waste power recircing oil in the bypass circuit.
Curious what others think or what experience others may have... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />
I'm re-building a 911 engine for a vintage racing car under 2.5 liters. The engine has all the late engine oil mods i.e. pressure bypass re-drilled and plugged, late bypass pistons and springs, small cam oiling fittings, venturi pick up etc. I use the early 901 oil pump with the large scavenge pump, oil pressure is perfect with this and bearing wear is very accepable, so I don't need more pressure/flow in the bearing oiling circuit.
It seems to me though that the large scavenge pump of the 964/3.3 Turbo may help clear oil from engine and help the engine make more power by decreasing the windage fog inside the case, however the larger pressure side pump of the 964/3.3 Turbo pump may just waste power recircing oil in the bypass circuit.
Curious what others think or what experience others may have... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />
05-12-2003, 08:58 PM
#2
Those are 2 different pumps
the 964 is mg,pressure side = 65g/min, scavange side = 1.84 x pressure side
the 930 3.3 is al/cast iron,pressure side = 100 g/min(best I remember) and is 8mm longer than the 964 pump ie needs a different shaft
There is another even larger pump available but the above 2 are sufficient for most of us mortals.
the 964 is mg,pressure side = 65g/min, scavange side = 1.84 x pressure side
the 930 3.3 is al/cast iron,pressure side = 100 g/min(best I remember) and is 8mm longer than the 964 pump ie needs a different shaft
There is another even larger pump available but the above 2 are sufficient for most of us mortals.
05-12-2003, 10:17 PM
#3
Rennlist Member
Thread Starter
I talked on the phone with a prominent engine builder today. His favorite stock pump (i.e. other than a real racing pump like a 935 or GT1 pump) is the 964 pump because of its bearing design. He thought that any power increase would be marginal or non-existent with a bigger scavenge pump. He said if he were to replace a worn small pump it would be with a 964 pump though. <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />
