WAAAAaayyyy back when I first became aware of diesel engines, I started asking questions from those experienced in diesel operation and maintenance. The earliest tidbit of info I received was, that for maximum life and freedom from failures, the absolutely BEST thing you can do for a diesel engine, is KEEP THE FILTERS CLEAN!

And of course, use GOOD quality filters as part of that treatment.

One such approach to better filtering, as related to engine oil, is use of an efficient high quality bypass oil filter. There are many good brand choices out there, and bypass oil filtration is pretty common on many diesel engine types, including commercial 18-wheel trucks.

Here's what I use:



That filter does NOT replace the existing stock fuel filter, it simply provides a separate additional filter down at lower particle sizes that the stock full-flow filter misses.

I first started using the Frantz brand of bypass filters back in the late 50's , on the Chevy small block engine in the truck I had at that time - in fact, that's my ORIGINAL Frantz base and clamp from that first filter from the 50's seen in the above picture - I still use the original outer canister as well, and rotate it in use with the one seen here. I'm no stranger to bypass oil filtering, so figure I'm as qualified as any to give a rundown on what they are, and what they can do. And yeah, especially in those earlier years, I heard all the usual misinformed comments from critical guys related to use of TP or paper towels as a filtering material - "Toilet paper belongs in the bathroom, not an engine!" and "Hell, that TP will just all fall apart when the oil hits it, and end up down in the pan, or WORSE!"

WRONG!

Bypass oil filtration involves diverting a very small percentage of the engine's oil flow from the lube system, and running it thru a high-density filter cartridge at a low flow rate to provide filtration of impurities and contamination down at particle sizes FAR smaller than a stock full-flow filter is capable of.

Here's a pic of the flow restriction in one of my Frantz filters:



YUP - that little 1/8 diameter hole is where all the oil flows thru on the way to the filter cartridge.

The diverted flow is quite small, and poses no risk to overall lube flow and pressure. A stock oil filter is typically adequate in filtering down in the 10-20 micron range - but a bypass filter like the Frantz pictured above will take out stuff down in the SUB-micron range!

Why is that significant? Because wear particles larger than 2-3 microns are capable of bridging the usual layer thickness of oil film in rings and bearings, and causing accellerated engine wear - and obviously, the stock filters are pretty useless down at those particle sizes.

A filter like the Frantz uses a toilet paper cartridge as the filter material, and a new TP cartridge loaded in the filter canister ready to install, looks like THIS:



The bypass oil flow must pass LENGTHWISE thru that entire compressed roll of TP before being returned to the engine - believe me, it gets VERY well filtered by the time it comes out the other end!

Frantz website:

www.wefilterit.com

Frantz sells their own brand of excellent specially produced TP replacement cartridges - but I've always used a good off-the-shelf brand selected for it's quality and tightly wound characteristics that guarantee best filtering qualities:



These Scott rolls cost about 80 cents a roll - not too hard on the wallet!

I usually swap in a new TP cartridge replacement every 3000 miles or so - or typically 1-2 changes for every oil change - and that also requires adding a quart of new oil to make up for what's absorbed by the old/new TP cartridge.

Here's a shot of the newly removed old TP cartridge showing separate components, and how little oil loss and mess are commonly experienced:



There are a few mods seen to my filter - I'll explain them later if desired - meanwhile, here's a pic of the old TP cartridge removed from the canister:



And NO, no "TP falling apart into the pan and engine"!

One nice feature of this setup, is the ability to actually SEE any of the larger captured particles on the top surface of the cartridge - there SHOULD be VERY few evident on a NEW, unseated engine, declining over 20,000 miles or so, until NONE are visible once the engine is fully broken in.

SO, how's the Frantz bypass installed? The lead pic showed mine attached with it's bracket to the battery hold-down bolt on the passenger side of the engine bay - the high pressure supply hose to the Frantz picks off from the normally plugged port on top of the stock oil filter housing - do ya suppose Cummins had a bypass filter in mind when they thoughtfully provided that port?



The oil return FROM the Frantz on my engine goes to a neat Amsoil supplied swivel fitting installed on the oil fill cap on the valve cover - this allows easy normal use of that cap, and also provides a convenient point to capture sample oil for oil analysis if desired:



So how is a new TP cartridge installed? On a Frantz provided roll, it's simply inserted into the canister - it's all ready to go as supplied. On the Scotts TP I use, the outer layers of the roll must be peeled off to get the roll down to a size that provides a tight fit into the canister:



THEN, with application of a little force and a twisting motion, the new cartridge is seated into the housing:



All done, and the new cartridge is ready for installation on the base section - the whole operation from removal of the old cartridge to reinstallation typically takes less than 15 minutes and RARELY is there even a DROP of waste oil to be cleaned up outside the filter itself!

SO - how effectively does the Frantz clean the oil? Here's a pic of my dipstick at about 5000 miles on the Delo 400 I use:



And here's an oil analysis on that same oil:



That was on my '91 truck at over 113,000 miles on the engine, and here's an analysis on the '02 at 42,000 miles, on oil with *20,000* miles on it:



NOW, let's address the concerns and old wives tales about use of TP as a filtering agent:

1. NO, the TP does NOT "fall apart" and all end up down in the oil pan and plugging oil galleries - paper normally is QUITE stable when exposed to oil - sometimes is even STRONGER oiled than it is dry! Ever notice what the stock filters are made of in our trucks? P-A-P-E-R!

Different structure, but PAPER just the same! AND , did you notice in the oil analysis posted earlier, the extremely LOW Insoluables numbers? That refers to stuff like soot and any OTHER contaminent - INCLUDING paper fibers!

2. "Toilet paper belongs in the outhouse!". OK, if you believe that, one of these TP and paper towel bypass filters is NOT for you - no problem, I don't sell them, and haven't the least to gain as to whether you use one or not - this thread is PURELY for information - not a sales pitch!

3. "Use of a bypass fIlter will void your warranty!" *I* haven't had the SLIGHTEST issue with my local dealerships with mine on about 6 different vehicles, including the last 2 Dodges - in fact, I usually get a big from the service guys when they see that filter - BUT all dealerships are NOT the same, if you have concerns, ask your dealer, or DON'T USE one of these filters!

4. "Too much trouble and expense to change out the TP cartridge!" Well, if a 80 cent filter, and a $1.75 quart of oil and 15 minutes is too much, you probably won't like this filter - but for me and other users, the VASTLY cleaner oil is well worth the small extra effort and expense - YMMV!

For extra, independent reading on use of bypass filtering, try this:

http://p2library.nfesc.navy.mil/P2_O...ok/6_II_1.html

In a thread over on TDR similar to this, enough interest was generated that a group buy ended up with nearly 100 units bought immediately and in later followups - as I said, *I* have no financial interest in who does or does NOT want what a bypass filter provides - but if you ARE interested, contact www.wefilterit.com and ask for Deborah Harley - if you mention you were sent by Gary Davidson in Canyon City Oregon in regards to a group price for a filter, I'm pretty sure she will still honor the earlier special pricing, but I can't speak for her or guarantee a thing!

SO, have I taken earlier advice as to using good filtering on my engine to extend it's lifespan? Judge for yourself:



Some might laugh at that BHAF, the Frantz oil bypass and the Frantz fuel filter over on the right side as "overkill" - but it seems to me that after spending the $$$ we do to increase performance and add potential wear to the increasingly stressed engine the FEW extra dollars seen in mine to RESTORE some of that lifespan is hardly money wasted! Barring something well out of the ordinary, I feel this engine will still be going strong long after *I* am no longer around to use it - and THAT'S OK too!