heinrich

Does someone understand accusump really well? Would you please explain the differences between it and a dru sump?

Jim bailey - 928 International

A dry sump engine simply means no oil is held in the oil pan it is scavenged by a pump and deposited in a separate reservoir . Oil from the reservoir then feeds back by gravity to the pressure oil pump . This allows you to carry more oil in the system and assures a constant supply of oil to the pressure pump . The other advantage is getting the oil away from the spinning crankshaft which saves horsepower and helps reduce oil foaming and mist being lifted by the crankcase vents into the intake . The ACCUSUMP is an oil pressure accumulator / reservoir . When properly plumbed into the standard oiling system ( with a check valve to direct oil to the bearings) the accusump holds 2-3 quarts of pressurized oil which IF the oil pump sucks air and the oil pressure drops it adds oil . The stock 928 oil pump can move about 50 liters per minute as I recall so 2-3 quarts is not much HOWEVER the accusump when installed correctly and " turned on " has helped prevent the 2-6 rod bearing failure for several racers . Part of the reason the accusump "helps" I believe is simply that you tend to keep the oil level high and as you run the engine and the oil gets hot the lower pressure lets some of the "reserve" oil back into the oil pan .

heinrich

Thanks Jim. So, I understand the dry sump very well since I've spent a lot of time considering it. I was wondering about the Accusump, which from your explanation to me looks like a (good) workaround. To me, why not plumb a nice line from the pickup, and another from the existing oil pan lowest point, and slap a pump inbetween, having the Porsche pump draw from a nice tall dry sump with a large content of oil. This sounds very simple to me, and guaranteed effective.

SHRKBIT

Nice explanation, Jim.

There is also more info under the "tech menu" at http://www.accusump.com/ -- even a couple diagrams.

John Veninger

That is sort of what is done to dry sump a 928. Use a dry sump pump as a suction only device w/ the stock 928 oil pump supplying pressure.

A few problems doing this on a stock street 928.

Need a custom pan so you can get all the oil out and into the dry sump tank. Mounting a dry sump tank in a street 928 can be a real challenge. You will need to custom mount and drive assembly for the dry sump pump to be turned by the crank.

It's challenging enough to find a place for the accusump!

heinrich

http://www.emp-corp.com/html/product...c_oil_pump.htm

John Veninger

Looks neat, but they don't show specifications or cost.

Jim bailey - 928 International

the reservoir for the washer system holds 7.5 to 9 liters of fluid it is a bit too small and wrong material but there is some space in the fender plus the charcoal canister space !! the 911s usually carried their tanks in the right rear , rear fender or in front of the right rear wheel .

heinrich

Exactly!!! So where's the rocket science? :-)