bypass filter interval change question.

[cryptokid]

ok, some bypass filters are supposed to be changed every 5K miles, some are supposed to be changed every 10K miles, but wouldnt it make more sence to only change it when it is dirty? lets say your filter is capable of going 20K before it gets clogged and reduces flow. but you change it anyways at every 5K because thats the suggested interval. well i was thinking about this and if i used a length of clear high pressure plastic tubing (similar to the tubing for remote oil pressure guages) so that i could see the flow of oil, and only change the bypass filter when i see the oil flow slowing down.

how would i test it?
every morning before i start the engine the bypass filter clear plastic inlet tube has drained dry from gravity. so as i start the engine i would watch the tube fill up with oil, and when it gets enough mileage that it slows the flow i would see each morning on inital startup, then i would know its time to change the filter.

what do you guys think of my idea? im espically curious about ralph woods comments. i think this could go a long way to offsetting the price of a bypass setup. if i could get by changing the filter only when its clogged.

 

[Bill Plock]

Crytpto,

Your idea sounds interesting... Another way to determine when to change the filter would be to monitor pressure drop across your bypass. As the filter plugs, the pressure drop will increase. A while back when I was researching various bypass filter options, I stumbled onto the Donaldson website. They make some real nice hydraulic filters and heads that would work well as a bypass (little expensive but nice). The heads have an option for a built in differential pressure monitor - either visual or electrical. The following link is one example.

http://www.donaldson.com/en/ih/support/datalibrary/000644.pdf

I've also though about adding an oil pressure gauge to the output of my (OilGuard) bypass so I could monitor pressure relative to the (input) pressure I see on the OEM gauge in my truck. I guess if your using the Gulfcoast type filter it's a moot point since the filter elements are very inexpensive.

 

[Dick in Falls Church]

Only ones I've used/sold are AMSOIL, so comments may not apply to all.

Best way to tell when to change is by use of oil analysis. When soot starts building up to about 3%, generally means that the filter is getting filled. Rough and quick way is to (carefully) feel the bypass element. If it is hot it is working. If it is cold, it is filled--there is no internal bypass valve.

 

[RalphPWood]

I brought back the Motor Guard M-30 because it is the easiest to service of any of the bypass filters. The free oil is under the element instead of on top. They filter from the bottom up. Actually the Motor Guard will filter either direction.I've been selling M-30's to boat engine owners that love them because they are known to not spill oil or leak. My point is for what it cost to have the oil analyzed I can change the filter every 4,000 miles and add a qt of oil on my Camry four cylinder. I did fine changing a Frantz every 12,000 miles on my 84 Subaru.
You are doing OK if the oil looks and feels like new. The filter element still looks good and the engine is immaculate inside. The Frantz, Motor Guard and Gulf Coast filters don't clog. They absorb contaminants like a sponge until they can't hold anymore then the small stuff starts going on thru. It is hard to clog a filter these days with modern engines and modern oils. I've seen them clog in 50 miles back in the 60's. You don't see sludge up engines as much these days.
I have a problem with people that claim their filter will go farther between changes than others. What determines how often a filter needs to be changed is the load it has on it and size. The better the filter is at cleaning oil and the smaller it is the more often it needs to be changed. Synthetic oil doesn't change anything. I saw a dual remote filtration system down at a Napa store. It had a smaller element than a Motor Guard M-30 but it was a "magic" filter that could go farther than others. They should add that you will also get a higher wear rate. I hear talk about normal oil analysis reports. I don't want normal wear.
I am getting ready to manifold 2 or 3 M-30's together for larger engines. Motor Guard does it for industrial use with synthetic oil using their special elements. They have managed to make them work only with their elements. I set them up to use good old high quality toilet paper. That's how they started. The name Motor Guard didn't come from filtering compressed air or vacuum pump oil.
I found a guy in Minnesota with some M-100's still in the box left over from a VW repair business he sold in the seventies. Actually he found me. He needed to drill out a motor Guard to filter bio diesel. I needed Motor Guard lube installation instructions. We worked out a deal.
Remove the orifice on a M-30 and you have a fuel filter. If anyone needs any 30 year old literature on the Motor Guard I have it.

Ralph

 

[cryptokid]

interesting, i have been contemplating making my own bio-diesel as well, and had not thought of using a motorguard to filter the fluid.

i also see your point about bypass filter not clogging.

 

[Ken2]

Crypto---
I wouldn't use clear plastic tubing on an oil filter. I want high pressure, high temperature hydraulic hose. If the hose leaks, you'll lose all the oil and destroy the engine.

With the exception of the toilet paper/paper towel filters, I'd just feel the temperature of the bypass filter housing. If the engine is warm and the filter isn't, it's clogged and overdue for changing.

Pressure gauges on the inlet and outlet would be useful, but you'd have to be sure that you're comparing at identical oil temperature from the clean filter differential pressure.


Ken

 

[RalphPWood]

If you run a filter until it plugs up or is restricted you are screwing up big time. The ideal would be to change the filter just before it reaches it's capacity. Since it is impossible to know just when that happens I just change the filter a little more often than I need to.
When a filter maker makes change recommendations they are just guessing. The engine owner knows more about his engine than the filter salesman. It's just a matter of getting a feel for it.
I just sent a M-30 to a guy with a Mercedes engine in a Chevy pickup. He will figure out his own change intervals. I have run clear plastic lines between the filter and sump for demonstration purposes. Probably not a good idea.

Ralph

 

[Jeffrey Behr]

quote:

---

Originally posted by Bill Plock:
Crytpto,

Your idea sounds interesting... Another way to determine when to change the filter would be to monitor pressure drop across your bypass. As the filter plugs, the pressure drop will increase.

I've also though about adding an oil pressure gauge to the output of my (OilGuard) bypass so I could monitor pressure relative to the (input) pressure I see on the OEM gauge in my truck.

---

If one has plumbed a bypass filter (BPF) the most-common way, with the outlet dumping into the pan or valve/cam cover or oil-drain plug, there is NO pressure at the outlet port of the filter. If the BPFs' outlet were feeding a pressurized point, you could get away with never changing the filter element because it would be filtering virtually nothing, not the goal of using one, obviously.

 

[deepsquat]

I just sent a M-30 to a guy with a Mercedes engine in a Chevy pickup. He will figure out his own change intervals. I have run clear plastic lines between the filter and sump for demonstration purposes. Probably not a good idea.

WOW, that sounds like a hell of a retro-fit....some people apparantly just like to tinker!