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Anatomy Of A Frantz Oil Bypass Filter

Old 11-02-2007, 11:58 AM
gary - k7gld's Avatar
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Originally Posted by wrglrroper View Post
If I get one of these where is the best place to tap into?
Here's the tap point most use - the plugged port on top of the OEM filter housing:

THEN, for a return point, many use a neat swivel fitting that is attached to the oil fill cap - these are available thru Amsoil dealers for about $10:


Bypass filters probably are best suited for guys like me, who plan to keep their truck for a LONG time, and MANY miles, or guys who simply want the BEST they can install on their trucks as enthusiasts - after all, their greatest advantage is to extend the lifespan of the engine! And what's the point of installing one if you only keep a truck for several years and perhaps 100K miles before trading for something else? The only one to benefit in that case, will be the NEXT owner(s)!

Guys using their trucks commercially for their living - and who will KEEP their trucks for as long as it will run and operate economically will benefit from a good bypass filter, but if they are hot-shot, long distance haulers, they will probably be better off with one of the longer usage spin-on type filters such as the Amsoil - they won't filter quite as efficiently as the TP type, bur are lots more convenient to use - and FAR better than just the OEM full-flow!

Yes, the TP type bypass filters work just as efficiently and beneficially on gas engines as on diesel - and all the above comments apply there as well. My first use of this filter was on a gasser - and then on several others as I myself changed vehicles - the one pictured above is about 40 years old!
Old 11-02-2007, 12:19 PM
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Is charmon ok?
Old 11-02-2007, 02:36 PM
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Thanks for the in depth look. Answers a few lingering questions I've had.
Old 01-19-2008, 03:26 PM
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I was exchanging email with Deb at, and she mentioned a special she has going on now for the Frantz setups - just in case anyone is interested. Along with a lower price, she is including the swivel fitting for the oil return line setup that many of us prefer.
Old 01-19-2008, 04:01 PM
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Heck of a deal and thanks for the write-up Gary!!!
Old 01-20-2008, 03:30 PM
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Looks good, I wish I would of looked more into Frantz before I got my FS2500.
Old 07-24-2009, 05:56 PM
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Gud article Gary but I don't understand the Particle Count? >= 2 Microns 176. Is that 176 parts per million (PPM)? Some says the Frantz could filter down to 0.1 micron. Was the oil smple taken from the filter output or from the oil pan???

Old 07-24-2009, 06:17 PM
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So now somebody her needs to oganize a group buy with these fine folks that deal the bypass filters.
Old 01-18-2011, 12:30 PM
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Wonderful write up Gary, my question is this. What is the working pressure for this filter set up? Thanks, Rich.
Old 01-22-2011, 12:57 PM
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This question is very easy to answer since the bypass filter is directly connected to the engine oil circuit.
The bypass pressure is the same as the engine oil circuit. The restriction only decreases the amount of oil in this parallel circuit. Usually its a 1/10 of the overall flow.

Every oil pump is designed to pump more oil than needed. Even aging (wear) is already taken into consideration. So a bypass really doesn't matter as long as you have the restriction inserted into the bypass line.

Last edited by Deezel Stink3r; 01-22-2011 at 12:59 PM.
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