Bypass Oil Filtration - Any Hard Data Available?

[BillL]

what drives the frequent oil drain cycle in our engines is the fact that the lead blow-by particles load the oil to the level that it cannot hold any more in suspension and therefore we must refresh it or accept sludge build up. So, the question is, how large is a lead particle nad can one of these things filter them out. If not, we cannot extend our drain interval, at least not with 100LL. It was my understanding that soot and other carbon debris is the issue on diesels and believe that stuff is much larger particle size than the almost aerosolized lead we use in our fuel.

Larry

This was my thought as well. I drained some oil at 30 hrs and put some samples in clear glass jars for a humidity testing. Left them for a couple of months and there was a sludge layer (lead?) in the bottom of the jar. Diesels use bypass filtration for long(er) life and TBN (total base number) monitoring of lubricants for drastically long oil changes. Also they have very large sumps compared to aviation engines. None of this field data (of which I am aware) would support benefits for our Lycs.

Further, the over the road diesel engines are not" large clearance" in any sense. Europeans use centrifugal filters in bypass but have not gathered large following in the US. They do the best job of getting small stuff out of oil and would be perfect for our engine, except for the G thing. Kidney loop shop based systems are very practical and cost effective for off highway to extend life of the products. Not so much for engines.

It "might" be functional for a Lyc, to hook up every time it is parked (at home), but again it just becomes and external sump and perfect oil only leaves the engine at risk to the next thing down the list. I sketched up a kidney loop with centrifugal filter for my -7, priced it and then abandoned as more overhead with a decade return if any.

There is proven data that circulated soot from diesels effect wear in micron clearances of fuel systems, but not sure it is applicable to lead suspension.

 

[Toobuilder]

Just got back from a 0.6 test flight and saw no change in operating characteristics. And contrary to the concerns of some posters in this thread, the oil pressure remained unchanged despite the addition of the bleed through the filter. Visual inspection of the new equipment shows no leaks or other distress. Will continue to monitor the installation at frequent intervals but I’m cautiously claiming success and now just looking for enough hours to pull a sample. I’m thinking 10, 25 and 50 for this load of oil.