Tech Tip - Dry Sumping 308s/328s

By: Bill Pound

Before I embark upon describing the dry sump system I developed for the 308/328, it?s important to recognize that there is nothing wrong with the stock system if the car is driven in the manner Ferrari designed it for. Ferrari never intended the 308 to be a competition car and, frankly, would probably prefer we did not monkey around with them.

But since we are all Ferrari nuts, the 308/328 is the most logical and inexpensive model to play with, so we do.

In the last issue we talked at length about the limited options available to remedy the oil pressure fluctuations in the 308/328-type motors on right-hand corners. Some owners say they do not have the problem but believe me, all these cars share this problem but the combination of not looking at the gauge constantly and the slow reaction time of the electric gauge may lead one to believe that everything is fine.

During a 308 2V IMSA engine development program I undertook back in 1990, we built a Fuel Injected shortened 308 2V motor in North/South arrangement driving through a Hewland DGB transaxle. These motors were all converted to dry sump systems using a Weaver 3 stage pump for both pressure and scavenge.

We later tried to adapt a lot of these high performance parts from this program to club racing cars, all using the standard Ferrari 308 ZF transaxle with the stock wet sump. We immediately ran into the oil surge problem. With power in the 325 bhp range and the subsequent increased bearing loads, the oil pressure took on a whole new meaning.

The cost of dry sumping was at that time prohibitive and most of the early Ferrari dry sump stuff had been used up by all the guys running the Marenello Challenge series in the UK. Therefore, we decided to start with a clean sheet of paper and come up with something both inexpensive and effective to cure this oil problem.

The result was a relatively simple solution. We simply used the standard Ferrari internal pump just to scavenge oil and fitted an external pump mounted to a special bracket mounted where the A/C compress normally goes to supply pressure. This extra pump is driven by a .750" toothed Gates Powergrip belt similar to the ones driving the camshafts. The belt is driven off a special drive mounted to the stock crankshaft damper. It leaves the original alternator/water pump belt in place.

The system requires installation of a 9" dia oil tank in the trunk compartment. You will need to bore a hole in the rear fender well to the trunk large enough to pass two oil lines and a breather hose through.

How it works:

Oil in the tank is gravity fed to the external pump, which then supplies pressure to the engine through the oil filter housing as the standard pump does. Once about 3 quarts of oil are in the engine oil pan, the internal pump picks it up and pumps it back to the tank via the oil coolers. The Ferrari pump turning at 90% engine speed will scavenge all but 3 quarts of oil from the motor and will maintain a constant level in the tank. The external pump turning at just over 50% of engine speed has an extenal presure relief valve and will maintain up to 100 psi of oil pressure.

Cost for complete kit is $2995, which includes everything needed (tank, pump, brackets, drive, lines, and instructions). It is available through Bill Pound at (909) 245-6017.

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