Trojan Boat Forum

For years I've been using Moroso racing oil filters (with bypass) on my 350. The engine has a Moroso filter relocating kit which makes it essential to use a filter with a bypass. I'm now looking at using a Mercury Racing filter 35-881126K01 which looks like it has a bypass however it doesn't state it anywhere.

Can any one tell me anything about these filters?

Could always get one and cut it open to find out. Seems a good Merc tech would know too.

I have remote routed filters as well. I am confused as to why use a bypass filter. Searching the net indicates the bypass is a separate filtration system that filters a small portion of the oil sump contents and is not in the lubrication loop. Mostly used in large engines that hold 20 qts or more. It seems the main reason the second system is used it to extend the life of the oil for economics. Why would one need the bypass just because the filter is remote?

Hi Larry,

On small block GM based engines, the oil filter spins onto the bypass valve located in a pocket at the bottom rear of the block. In order to install the Moroso filter re-location kit, the factory bypass must be removed and a bypass filter must be used.

The whole idea behind a bypass, weather factory or aftermarket in filter, is to get oil to the engine without being restricted at the filter. At an idle, the filter may be able to handle the full volume of oil pumped from the pan and required by the engine. However at higher engine RPMs, the filter cannot keep up to the oil volume required by the engine so the bypass opens up to make up the difference. If this bypass didn't occur, the bearings would probably go away pretty fast.

Hope this clears things up.

well sort of my remote just comes from the old filter mount to a duplicate mount, this is in a 318, seems to work fine in it. I had previously assumed most filter had a bypass valve in them to keep from blowing the can off at rpm.

does this work like the pressure relief valve in 318s oil pump?