Was reading about the Puradyne bypass style multi stage filtration system http://www.puradyn.com/products/overview.html (http://www.puradyn.com/products/overview.html)
It seems to be commonly used on a lot of commercial equipment. What appears to be unique about this unit is that they claim that their filtration element releases additives into the oil to replace those depleted in service, besides filtering out particulates down to 1um as well as water and fuel condensates (which are evaporated after separation by a 150w heater).
The smallest unit is designed for 12 quart sumps and is less than $400. Oil life can be extended 2-9x with the exact change interval being determined initially through oil analysis with periodic checking as the engine accumulates hours.
Here is a picture from the website: (http://www.puradyn.com/images/PFT_Filterprocesswithtext.jpg)
Westcliffe01,
I got mine for $99.00 on Ebay. It is the PFT 60 model which can handle 80 quart oil capacity.
PURADYN PFT60 Bypass Oil Filtration Component: eBay Motors (item 230395753921 end time Jun-07-10 17:46:20 PDT)
I'm going to install it on my rebuild Witte which has a 3 gallon oil capacity and I have two massive Caterpillar oil filters (also just bought) for my full flow needs. I put an Amsoil bypass system on all my HD engines and this is my first Puradyn system. They make different filters as well, I purchased the extended life filters for it and I'm planning to go 3 months 24/7 without an oil change or shutdown. I have other safety systems for engine security as well. Start it and forget it, is my mindset.
Diesel guy
I use a Motorguard bypass filter, like the old days. It has an element that looks like, but is not toilet paper. However, many people convert them to use Scott TP.
My oil remains black, but visually clean.