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WERK I WERK I is offline
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Join Date: Jan 2003
Location: Wisconsin
Posts: 3,291
Originally Posted by Rob 930 View Post

Andy is right, but in reading the quote from WERK-1, I think he meant the same thing: on a 911 or 930, the oil is filtered only as it enters the tank. This occurs when oil flows back into the tank from the engine -- either directly or from the front-mounted oil cooler (if the thermostat sent it there first). Oil from the turbo scavenge pump goes right into the tank unfiltered. Any oil (or dirt) flowing from the tank to the engine goes first to the pressure side of the oil pump, then upward to the thermostat housing for the engine-mounted oil cooler (and perhaps through the cooler), then into the main oil gallery and right into the crankshaft bearings.

Actually, what I was trying to say was the oil scavenged from the engine sump goes back to the oil tank unfiltered. The oil is filtered only when the oil returns back to the engine.
Thought I read this either in Bruce Anderson's 911 Performance book or Paul Friere's excellent book; Porsche 911 Story. My understanding was Porsche was concerned about oil volume through the engine if a filter was added on the sump-to-tank side of the dry sump system. I guess some more research is in order tonight.
'85 930 Factory Special Wishes Flachbau
Werk I Zuffenhausen 3.3l/330BHP Engine with Sonderwunsch Cams, FabSpeed Headers, Kokeln IC, Twin Plugged Electromotive Crankfire, Tial Wastegate(0.8 Bar), K27 Hybrid Turbo, Ruf Twin-tip Muffler, Fikse FM-5's 8&10x17, 8:41 R&P

Last edited by WERK I; 10-07-2007 at 05:58 AM..
Old 10-07-2007, 05:54 AM
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