Bypass filtration of automotive lubricants

Those of you who know me, know that every now and again something shiny catches my attention, I target-fixate, become an expert on the subject, and then move to something else.

A couple years ago I targeted on lube filtration with an eye toward extended drain intervals- we're talking 30,000 miles or more without draining the oil...

Yes, I know- "everyone knows that you have to change the oil when it wears out every 3000 miles"...

.. uh, no.

Oil does not wear out. It gets full of trash and the additive package wears out/gets consumed. This is why we drain the oil- to remove the trash and replenish the additives....

What if we had a way to get almost every bit of trash out of the oil, could increase crankcase capacity and thus the amount of additives, and could remove just enough oil when we removed the trash from the system to allow us to add about a quart, replenishing the additive package?

Well- The Military, heavy industry, and savy motorists have been doing precisely this for years. There are different mechanisms- everything from using rolls of toilet paper in a canister (NOT kidding!) to using very large canisters using 3 rolls of paper towels, to very expensive "boutique" systems that resemble the normal (aka "full flow") filter already on your car.

I wanted something inexpensive to try out, both in the sense of the initial outlay and the price of filters. Amsoil has a system- but it's $270 or so, plus $40 for the filter. Uh, no...

I ended up using a couple pieces from my local Grainger industrial supply house. Cost me about $70, all up- $15 of that was for shipping. You need a Baldwin B50 filter and the matching mount- it's referenced in the catalog, think it's OB1305 (edit: yes, it is). Combine this with properly-rated hose (I used 3/8" ID transmission hose because I had it, but 1/4" will be fine- this isn't a high volume affair- in fact it's more like a drip coffeemaker). Fittings on the mount are 1/8MNPT, and I elected to use 3/8" right-angle hosebarb to attach everything because once this is assembled there shouldn't be cause for disassembly.

I used a 1/8NPT Street-tee to attach the pressure side to the oil pressure sender on my 1994 Jeep Grand Cherokee 4.0 motor. This moved the pressure sender about 2" from the block- this is fine- and I used another 1/8MNPT to 3/8 hosebarb 90 to lay in the pressure side to the filter block. The block was mounted under the vehicle as the vehicle is rarely offroaded, is lifted, and there is a dearth of underhood space. I plan on putting a Clayton longarm kit under the Jeep in the next year or so, and that comes with a hefty skidplate, so I'm not going to concern myself with the location too much.

Running back from the discharge side of the filter (you MUST pay attention when plumbing this- filters are designed to flow one way and only one way!) I used another 90-degree 1/8MNPT to 3/8 barb fitting into more 3/8" hose. To get the discharge of the bypass filter back into the engine, I purchased a swivel return fitting from Amsoil ($10, PN forthcoming), and drilled the rivet out of the stock oil filler cap. Note that this destroys the cap... but yet it doesn't. The cap will fall into three pieces and if you're doing this at 2100 on a school night you immediately start calculating which auto parts store has the part and will be open at 0630. Stop. Think. The return fitting passes through the hole you drilled and will take the place of the rivet, holding things together. No wuckin' furries, mate!

You DID make sure there wouldn't be any interference with the valvetrain or breather chennels in the valce cover, right?

I had to chet to attach the hose to the swivel fitting- I needed another 90 degree 1/8MNPT to 3/8 hosebarb but apparently there wasn't another one in town till next week. I found one similar, but with a 5/16" barb- bought it, I'll just clamp down a bit. I want to use a JIC fitting at the top of the engine anyway as it's the one piece that MAY need disassembly at some point, will fix that later.

This system goes in parallel with your fullflow filter- and doesn't flow much pressure or volume at all- about 5psi and less than a quart a minute- so it won't rob your engine oil pressure. What it will do is scrub your oil of 98% of the crap that's floating about in it. My install added nearly 3 quarts of oil to the sump capacity- that only started as 6.1 quarts. I have added 50% capacity to my engine, without risking pressure effects from the level being too high. This increases oil thermal stability, cleaning effect, cooling, you name it.

My oil started out black- I'm going to keep an eye on it as things go by nd if I can find sample jars, I'll pull samples at 500 miles, 1000, 2000, and 3000- normal duration for an oil change- and I'll be sending off a used oil analysis kit to Blackstone labs as well- if you're going to extend drain intevals you must know what is going inside the engine- this is where analysis comes into play.

Another trick I did is to put small 8mmX1mm neodymium magnets I bought off ebay ($15 shipped for 100 of them) on the feed side of the filter so that anything magnetic that passes through my engine will be right there looking at me when I change the filter so I'll know something not cool is up. Sounds strange? You mechanical sorts that have been inside a transmission, transfer case, or oil pan know that this is a VERY common thing to do- in fact my NP231C and 700R4 transfer case and transmission both had them from the factory!

Next trick will be to add a fullflow spin-on filter to the transmission cooling circuit return line, along with a bypass filter there.... and a fullflow filter to my power steering system (which is now doing duty as my power steering and power braking system as I've retrofitted hydroboost from an Astro)- and a bypass filter to my coolant system... All for less than the price of one bypass filter from the "Big A"...

On that subject, I should note that I am using Amsoil XL series 15W30. It's full synth and actually CHEAPER than Mobil1. I was going to use Mobil1 but at $9/qt versus the $6.60/qt I paid for the Amsoil product- think I'm good to go...