Reply to "Joules5: non bypassing oil filter"

Joules,

As a filter gets dirty, the differential pressure across the filter becomes greater. The engineers who designed your motor believed it is better to supply your motor with dirty oil rather than having a clogged filter restricting oil to the motor. In other words, dirty oil is better than no oil. So they designed the filter with a spring loaded bypass valve that bypasses the filter element when the differential pressure reaches 8 to 10 psi.

The non-bypassing filter for a 351C is a Purolator L30119.

However, MSD specifying a non-bypassing filter doesn't sit right with me. The only reason for MSD to specify a non-bypassing filter is because MSD expects the distributor they have sold you to be putting something abrasive, like metal shavings, into your oil. If the filter "bypasses" oil the abrasive material would not be filtered out and would ruin your bearings & crank journals, at a minimum.

So why is MSD specifying a non-bypassing filter? what is their distributor doing that would make them print that requirement? Do you want to install a part the manufacturer believes may pollute or ruin your motor?

I know the issue is the distributor gear. There are currently 4 materials distributor gears are made from: iron, steel, brass or a non-metallic composite. There have been issues in the recent past with distributor gears wearing very quickly & polluting (and ruining) engines. This has been either a function of the wrong gear material for a given camshaft, or improperly cut gears, or both. Others claimed the rapid gear wear was due to increased loading of the gears from running high volume oil pumps. I have been under the impression that these issues have been resolved. Perhaps not?

The distributor gears mesh with gears ground into the camshafts. Camshafts are either made of cast iron or billet steel. You use iron gears with iron cams & steel gears with steel cams. The brass gears are supposed to be good with either type of cam, but they have a reputation for wearing fast & polluting your oil & motor with fine brass shavings. In my opinion, the brass gears were a bad idea. The composite gears are relatively new on the market and I haven't heard of anybody using one yet.

If you are running the appropriate gear for your cam (steel or iron), there should be no need for a non-bypassing filter.

Your friend on the DTBB, George