Are full flow oil filters really necessary?

[Mystic]

I remember my Dad's old 1948 Chevy pick-up truck and his 1952 Ford car. Both had bypass oil filters and no full flow oil filter. Both ran great for a long, long time. Some people at this web site have talked about how with some full flow oil filters they had valve train noise and low oil pressure at start -up. Well, my Dad's old truck and old car ran just fine at start-up.

And it was easy as can be to change out the bypass oil filter element located near the top of the engines. A little messy, but super easy. You could even add oil when you put the new element in so that there would not be a shortage of oil at start-up.

Is it really necessary to have a full flow oil filter? Is a bypass oil filter good enough? All of the oil gets filtered eventually anyway by a bypass oil filter, and furthermore gets filtered better, with no oil pressure problems.

 

[TC]

Am I correct in thinking that heavy diesel trucks often have ONLY bypass filtration..? Never worked on one, so I can't say. But IF so, this should prove that they're perfectly fine working solo, with no full-flow "bro" workin' down the oil line.

 

[Mystic]

I think you are correct that at least some big trucks have a bypass but not full flow oil filters. I don't know for sure since I don't have experience working on big trucks. My Dad was a mechanic at one time for a trucking company but I was only a young boy and I can't remember a great deal about the trucks. But I do seem to remember that they had some sort of bypass oil filter system.

A bypass oil filter actually does a better job of filtering over time and a properly designed bypass oil filter system does not reduce oil flow and oil pressure. All of the oil gets filtered very well over time.

 

[slalom44]

I think that at minimum you need a mesh screen (like the old VW Beetle engines)so that you don't get large particles doing some major wear or plugging up some of the oil ports. The rest can be gotten with a bypass filter. That's the concept behind the Trasko filter, and UOAs posted so far with the Trasko have been pretty good.

 

[Mystic]

I remember a post by Bob who was able to get very low wear using Schaeffer's conventional motor oil and a FRAM oil filter! Maybe with a bypass oil filter the quality of the full flow oil filter would not be very important. A full flow oil filter with very good flow characteristics would be best. The bypass oil filter would do most of the filtering.

 

[jthorner]

I seem to recall reading somewhere that some of the modern Japanese engine designs feed one half of the "V" in the V-6 with filtered oil and the other half with unfiltered oil, effectively making the engine design a partial flow oil filtration design.

Now I can't find the reference.

Does this ring a bell with anyone?

John

 

[Bill Kapaun]

quote:

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Originally posted by Mystic:
I remember my Dad's old 1948 Chevy pick-up truck and his 1952 Ford car. Both had bypass oil filters and no full flow oil filter. Both ran great for a long, long time.

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Back then, a "long time" was 50k miles, at which time the engine needed rings, bearings and a valve job. Another 20-30k miles and it was rebuild time.
People only drove 5-6k miles/yr.

Of course oil technology has drastically improved, along with engine build quality.
We don't have road draft tubes pulling air through the mesh screen oil filler cap anymore to vent the crankcase either.

It would be interesting to see how many miles an engine from that era would go using todays oils, a PCV valve and unleaded gas (barring the problems unleaded has with OLD valves).

 

[Neil Womack]

If memory serve both of owners of bitog use this system. And a search should gather you some UOA results.

How about it Bob and Vetteman!

I'd like to figure out how to do this with my TDI but the integral canister filter and oil cooler complicate the situation. For anyone with a spin on filter adapters are available.

 

[Gary Allan]

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but the integral canister filter and oil cooler complicate the situation

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Why? You've got it easy. Just pull out the cartridge filter and forget it. Plumb the bypass to the sending tap and have a happy life! What more could you ask for?

....or am I missing something??

 

[TC]

I suspect that bypass filtration is now only done IN CONJUNCTION WITH full flow filtration. From the website below:

"Early diesel engines used bypass filters exclusively, according to the Cummins Engine Co. A bypass filter has a relatively high pressure differential and usually flows only about 10 percent of the total pump output. It is called a bypass because the oil it filters flows back to the sump, bypassing the engine itself...In the early 1960s, a move away from the use of bypass filters was made by some engine manufacturers. Full-flow filtering systems grew in popularity."
http://bestsyntheticoil.com/dealers/amsoil/cummins-bypass-article.shtml

 

[Mystic]

I can not remember my Dad having to ever rebuild the engines in the 1948 Chevy pickup truck or the 1952 Ford car. With my Dad maintaining them (he could keep any car or truck running) they just keep going and going. My Dad kind of liked Chevy pickup trucks and Ford cars, although he had a little 1962 Rambler American car that ran like a top. The idle was so smooth at a stop light you would think the engine had stopped running.

The 1948 Chevy pickup truck was my Dad's work vehicle. He finally replaced it with a used 1963 Chevy pickup truck. I do remember that we had to pull that engine out and rebuild it. We used a makeshift hoist. At times my Dad even used the 1952 Ford car as his work vehicle. After he worked for the trucking company he worked for (and retired from) a construction company. He would put a lot of miles on going to and from work. They did maintenance themselves on their own heavy equipment. Some of the roads in the Raton Pass area were built by my Dad and his company, just to give one example.

I think bypass oil filter systems should be an option that people could get, at least for pickup trucks and SUVs that are going to be somebody's work vehicle.

 

[Dropout]

Has anyone ever cut apart a ff filter that was used in conjunction with a bypass system?

If the ff has little or no contamination, then conventional wisdom is wrong and the ff could be replaced less than the bypass or even never.

 

[Gary Allan]

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Has anyone ever cut apart a ff filter that was used in conjunction with a bypass system?

If the ff has little or no contamination, then conventional wisdom is wrong and the ff could be replaced less than the bypass or even never.

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Most who use the Amsoil spin ons use the ff change to replenish the additives. I believe that Bob Woods says that he doesn't change his ff.

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I suspect that bypass filtration is now only done IN CONJUNCTION WITH full flow filtration.

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Only because ff filtration is standard on virtually every engine. It's not convenient to get rid of your full flow filtration (unless you have a canister filter). Typically bypasses are plumbed to the sending unit. The only other installations USE the full flow via adapters.

If I had the inclination to do TP changes as often as required AND had a canister filter, I would probably try it without it ...do the UOA like we're all doing ..and make an intelligent decsion on whether it pays to have it in place or not. I think that you would find it redundant.