The Stovebolt Site Forums The Shop Area Engine Shop By pass oil filter question

On here they say oil by pass filters only filter 10% of the oil. So would it be safe to say that you wouldn't need to change the filter every oil change, since they don't filter 100% of the oil like a full flow filter does? Probably a dumb question, but if you don't ask, you will never know.

Thanks.

They only filter a percentage of the total amount re-circulated by the pump, so it all gets filtered - eventually. Change this filter less often.

A bypass filters BETTER than any full flow can- - - -the mesh is much tighter so smaller particles are trapped. Full flow filters are for rocks, marbles, and medium-sized boulders- - - -stuff big enough to score the bearings if they got past the filter. Change the bypass filter every oil change- - - -it's a lot less expensive than engine parts.
Jerry

Jerry is likely right but I go by the less often plan. I change it every other year with the annual oil change. I put about 1500 miles a year on the coupe.

No. I just put up some numbers in another thread but I'll put them here also.

A C4 bypass filter (or P115) cross references to a WIX 51006 HERE ARE THE SPECS is a 32 micron filter. THOSE ARE BOULDERS.

A PH8A filter is WIX 51515 HERE ARE THE SPECS and is a 21 micron filter.

Bypass filter a not necessarily BETTER, its just that they are not designed to take the FULL PUMP OUTPUT for whatever reason. Since most engines didn't have the internal plumbing to handle a full flow filter they bypass type was popular and easy to add/alter the block to accommodate.

So bypass filters are not better by design... they can be, but are really more of an afterthought.

I always change the filter when I change the oil in any of my cars and trucks. I just had this dumb thought, and thought I would ask.

Bypass filters are not merely an afterthought nor are they obsolete. In the over 45 years I have owned Cummins Engines, they have had both full flow and bypass filters. In 1986 Cummins combined a full flow and a bypass into one can.


http://www.cumminsfiltration.com/pdfs/product_lit/americas_brochures/LT15034.pdf

I have been using the LF3000 Since its inception in 1986. My smaller 10.8 Liter engines also use a combination full flow , bypass filter.

http://www.cumminsfiltration.com/pdfs/product_lit/americas_brochures/PD10010.pdf

It is still OEM on current production engines.

Way back when they were... you can't take today's methodology and apply it to 50+ years ago.

At the time... you didn't filter oil, you threw it out. Saying bypass filters on a Cumming diesel have anything to do with a car motor in the 40's 50's is comparing apples to watermelons.

I posted the specs.... the bypass filters of the time (Fram C4s) offered LESS filtration as a PH8A full flow filter today. Media technology of the time was nowhere near what we have today. Although the 50's DID invent the Frantz toilet paper filter that is like today with AMSOIL filters... sure they are available, but not production standard because you threw out the oil.. you didn't try and filter it.

As for OPs question typically you would change NOT change the filter ever oil change, from my specific manual:

OIL FILTER. Every 1,000 miles, when engine is drained remove
drain plug from oil filter to drain oil and sediment in filter.
Every 6,000 miles, remove filter element (par. 81). Clean inside of
shell with clean rag and install new element (par. 81). Run engine
a few minutes and check oil level. Add oil to bring crankcase oil
level up to "FULL" mark on gage. [sic]

The Chevvy S-6 filter decals state:

Change the filter when the oil on the dipstick appears dark.

I would let it go at least till every other oil change. The size of the element can hold a LOT of debris. But you WILL want to drain and clean the filter body every oil change to remove debris that would have settles out to the bottom of the filter.

An oil filter is an oil filter and has one purpose....to help remove particles from the oil.
I am a bit more inclined to listen to Kenneth's opinion rather than a bunch of mumble jumble. I'm sure he and his operation have logged more miles on the roads than some of the people who continue to jump on a soap box.

What soap box? What have I stated that is 1. incorrect or 2. 'soap boxy'? This is all in the CHEVVY MANUALS. I guess CHEVVY is all full of themselves to??

The 235s of the 40's 50's were never set up for full oil filtration. Why? Because as Chevvy said it it's manuals you were to throw the oil away at 2000-3000 miles and THAT was how the oil was kept clean. The 235 and early 261s never had the internal passages cast into them to accept a full flow oil filter.

The bypass filters of the time are not 'good' or 'bad' but are, by design, not able to handle the full flow of oil at operating RPM. The reason is that there is no place on the motor to take the oil FROM to filter it BEFORE the bearings without negatively affecting oil pressure to the bearings. Most people equate bypass filters with higher levels of filtration. In the 50's that was not true... The oil filters of the days were 20-30 micron filters. The only bypass filter that I know of that was in the sub 5 micron range was the Frantz type filters.... and they used toilet paper as elements.

In the late 50's and 60's Chevvy made revolutionary changes to the motors... the first one being full flow oil filters and *finally* getting rid of cast babbit bearings. The switch to precision insert bearings, closer engine tolerances and wide availability of detergent oil meant that Chevvy finally had to make changes to the otherwise very successful motor lineup.

I eagerly await any corrections you can make so that I can better understand what I was wrong about.

I'm going to print this thread out and put it under the hood of my car- - - - -all the hot air will save me a bunch of gasoline for warmup purposes!
Jerry

I think that I'll also print it out and take it to the reading room and use it.......

Must be nice to think you are so smart yet you can't explain anything to anyone.

Remember post count <> knowledge

I eagerly await any and all corrections to what I have posted.

Boy at the cost of this p!ssing match, I did learn something. A micron is pretty darn small. It puts it in perspective, a picture is a thousand words.
People may not always agree, but may we always take something positive from the debate.

IMO the best way to exploit the bypass system is by using an Amsoil filter and head. The head has a restrictor built in with a 1/16" metering hole and the filter has an effiency rating of 98% absolute at 2 microns. Oil this clean remains translucent as combustion carbon is continually removed.

The Frantz-style bypass filter element I sold for the LuberFiner 750 big rig filter canisters had a 1 micron filtering capability back in the late 1970's. We changed the filter every 10,000 miles, topped off the crankcase with 1 gallon of fresh oil, and never changed the oil in the sump. With oil capacities of 10-12 gallons that was a huge saving in preventive maintenance cost for the rigs I serviced. Some of those rigs had 100,000+ miles on the oil with no loss of efficiency, confirmed by the spectrometric analysis we did at every filter change. Oil doesn't wear out- - - -it just gets dirty.
Jerry

I'll throw my hot air in the mix, perhaps the reason the bypass filters work better is because the oil flows much slower through them. The heavier stuff could settle to the bottom (as I've seen when changing them). (No scientific facts to back this statement up) It just seems to me that if the oil is flowing slower, then the filter can do it's job better even if the micron rating is larger than other filters. Keep in mind too that as these filters do catch trash, the area for other trash to get through will get smaller.

That's my rant good or bad.

No matter how good the filtration is, I would still change the oil fairly often on these old beasts with their carbureted systems. Unless they are running very well tuned, and probably even then, there is fuel dilution/contamination. Not so much with newer computer controlled, injected systems. I say this, yet I didn't get around to hooking up my bypass filter for a year after doing some maintenance.

Dennis

OK I put my feelers in the tool box. They can't be hurt. A filter is better than no filter. Can we agree on that? Full flow filters have a bypass valve. Can we agree on that? Why? So the filter is not damaged and rendered useless by over-pressure. When the bypass valve is open..there is no filter in the system. In a perfect engine, there still will be stuff that breaks down the oil. Water, acids, and other chemical processes. Oil wears out. Can we agree on that? I have never seen a perfect engine...never. We have old engines, but access to modern filters. Yay! We have access to modern oils..Yay! I like the bypass filter system. It works. I like the full flow system. It works. My engine won't see a machine shop just to put a full flow filter on it. My choice. I won't take out the full flow filter on the wife's' much more modern car, why?, cause it was designed to have one. Running both a full flow filter and a bypass filter? Makes sense for some operations more than others. Some engines are very efficient and produce less chemical reactions. Some fuels are less likely to make those chemical reactions. Some engines are operated in an environment that bears very little resemblance to my truck. I start when cold, Take short trips, I start when damp, and might not get to operating temp before the trip is over. I some times do this many times a day. And my truck is ..old. I change the oil and the filter...maybe I could get away with keeping the filter..but it is 10 bucks. Less than 1/2 the cost of the oil...I am OK with that.

The main stated error is that Mr. Lincoln stated:

"A bypass filters BETTER than any full flow can"

WRONG. A bypass filter is simply a system that bypasses a significant portion of the oil around the filter. A full flow filter can take the entire pump output under normal operation.

The C3 and C4 filter (or even the Modern WIX equivalents) are not filtering anywhere near what a modern screw on, full flow filter does. The C3-C4 are 30+ micron filter.. screw on filters are in the low 20's.

I guess Mr. Lincoln doesn't know that 30u (micron) converts to 0.0011811023622047244 of an inch lets just round that to .001in

Well, if your main bearing clearance is .001 (or .0005 per side.. remember where talking diameter here) is a .001 particle going to fit through a .0005 space??? Or is it going to touch something? With any luck it will embed harmlessly into the babit and not touch the polished crank journal.

So now, Mr. Lincoln... tell me how many 30u particles would you like in your oil????

Don't feed the troll!
Jerry

pfarber, have you ever heard the term "Making a mountain out of a mole hill"?

I know I really have to stop discussing things on a discussion board. What am I thinking... talking shop and learning stuff.

I guess all my fancy facts and figures and maths really have to no place once one of 'the chosen' have spoken.

I like how most didn't know that while 1micron is small... 20-30 micron is a very real problem.

Admit it..... you learned something today.

Not really... I sold filters for thirteen years. For just about anything with a combustion engine or hydraulic system.

Discussions are good, till a person gets to a point that they HAVE to be right about everything and they do all they can to try and prove how right they are. I'm afraid this thread has deteriorated to the point it's no longer a teaching thread, but one upmanship at best.

Sometimes I walk away from a subject because there's not any use in trying to make someone else feel inferior. In the case of this thread, with a moderate amount of care (regular oil changes among other things) these old stovebolt engines should run many years with no oiling problems with the newer / improved oils we have now over what was available when these rigs were built.

As far as I'm concerned, if a person isn't taking proper care of the engine, it won't matter what the micron rating of the filter is. Nor if it's a full flow filter or bypass filter or a combination of the two.

I also think that if a person is taking proper care of the engine with regular oil changes, it really won't matter what the micron rating of the filter is either.

After all, if the engine is clean, the filter won't have a lot of work to do. If the engine is very dirty, the filter may not can do its job before stopping up any way.

So it all boils down to whether or not the owner of the vehicle takes care of the engine properly or not.

We can get so caught up with the small details that we lose sight of the bigger picture.

If you want to open another can of worms, start comparing one brand filter to another. Some will swear by Baldwin, some by Wix, others by Fram. But none will be any better than the other if proper maintenance isn't followed.

The purpose of this forum is to help each other, not prove someone right or wrong. This thread is locked.