Different Types Of Oil Filter Systems

[mattimuss]

Hey All,

 

I was at my local mom & pop parts store today and the topic of installing a spin-on oil filter adapter was brought up.  The guy behind the counter is an older gentleman with lots of experience with pre WWII cars, so I often ask him a lot of questions.

 

He informed me that putting one of these adapters on my '41 would be a waste as only a portion of the oil in the old flat head engines is filtered.  That not all of the oil is pumped through the filters.  That the oil filtration system is not a fully enclosed system.

 

Is this true?

[Doug&Deb]

As I understand it it’s a bypass filtration system so not all of the oil is filtered. I’m not sure about that so hopefully others will chime in.

[desoto1939]

The gentleman is correct and he is very knowledgeable. Take his information and get to know this salesperson.  The system was a By-Pass system and only portions of the oil is filtered.  They made an oil canister throwawy metal filter call by Fram PB1/2.  These are no longer made and if found cost around $70 and are good for 8000 miles.  Get the newer style that has a drop in filter that goes into a metal housing. The filter element cost around $15. and is easier to chnage and less costly.

 

If have the drop in style on my 39 desoto and it works just fine keeps the oil clean. I use 10W40 oil for the past 35 years that I have owned the car.  The next question that you will have what oil should i use.  The oils of today are much better than th eoils from the 30-40-50's.  Even the cheap oil sold at Walmart is far better than the oil that was oringally used.

 

So if you car does not have a current filter then do no and again DO Not use a multi viscocity weitgh detergent oil. It will loosen up the sludge in the oil pan. Stay with a conventional oil straight weight 30 weight oil.

 

Rich Hartung

Desoto1939@aol.com

 

Rich Hartung

desoto1939@aol.com

Edited June 24, 2021 by desoto1939

[Sniper]

I don't know that it would be a waste so much as it is overkill.

 

When you have the optional bypass filter it operates like this, when the oil pressure gets high enough the bypass allows the excess oil to go to the filter.  It gets filtered then dumped back into the pan, the filtered oil does not directly feed the engine. 

 

On modern oiling systems all the oil goes thru the filter before it goes thru the engine.  The bypass is before the full flow filter and usually either built into the oil pump housing or right at it's output and it simply controls the maximum oil pressure.  In this syste the engine gets fully filtered oil, unless the filter plugs up and hte filter bypass opens allowing oil to the engine unfiltered. 

 

By running a modern spin on filter, assuming you plumb it like the original bypass setup, it will still function like a bypass filter, but it's like buying a 1 ton diesel to pick up a loaf of bread from the grocery store.  It'll do it fine but it's overkill for the job.

 

Now if you wanted to mod the oiling system for full flow filtering, you could do that.  But it's more than just a spin on adapter.

[Loren]

The by pass oil filter was an original Chrysler idea, nobody had one before.

The bypass oil filter cleans a small portion of what the pump puts out as many here have said, BUT it cleans the oil to a greater degree than a full flow filter can.

Full flow filters have to pass the oil in a volume that doesn't restrict the oil pressure the engine needs so it can't filter out the finer particles that the slower bypass filter can.

There are spin on by pass oil filters available from WIX (NAPA sells their own using 4 digits of the WIX 6 digit p/n). They use a thread size smaller than the typical FL1A which is good because even in by pass duty an FL1A won't filter as fine as a proper by pass cartridge. There has been a write up on the installation on this web site. Then there is always the Frantz By Pass Filter. Frantz has ready made filter media now which I am sure works even better than the old toilet paper.

For the Hot Rod Cool Factor you can even get a reproduction "Bee Hive" by pass filter off eBay.

 

For my money the drop in cartridge by pass filter is worth having and maintaining.

 

If you really want to keep your oil free of sludge, then install a PCV system such as the one Vintage Power Wagons sells.

By putting a small vacuum on the crankcase you eliminate the moisture from combustion blow by that combines with acid which forms the sludge. (all my engines had PCV systems, even the race cars)

Detergent oil will take care of the acid and the by pass filter will take care of the rest.

Oil filters were optional for years on a lot of cars after WWll. My first car a 1959 Hillman didn't come standard with an oil filter.

[mattimuss]

Hello All,

 

Thanks for the info and replies!

 

Attached is a picture of the oil canister type I have.  I have been using a WIX 51080 filter and straight 30w oil when I do oil changes.  I have been doing changes once a year since the car seldom sees over 1K miles a year.

 

The car does not smoke and probably leaks more oil that anything else!

 

After reading your replies I think I am going to stick with what I have been doing.  I might increase the oil/filter change frequency if the yearly miles increase.

 

Any additional thoughts/advise?

[kencombs]

A spin on adapter is fine, if and only if , the spin on cartridge is one designed for bypass usage.  Also if you plan the location well.  The original is sure to cause spills. 
As others stated they filter smaller particles.  Much more convenient than the originals.  A lot of diesels use both.  One filters the oil that goes into the oil gallery’s while the other filters the oil excess to what is needed to maintain pressure.   
 

 

mine is in work to do a full flow conversion. Holes drilled, tapped and the separating plug installed.  Started on the lines and got sidetracked. 

[JBNeal]

  On 6/25/2021 at 1:21 AM, mattimuss said:

...

Any additional thoughts/advise?

Expand  

there are several varieties of drop-in filter housings, so you'll need to choose the filter that fits not only inside the housing but works in that housing.  The 51080 would need to seal onto the center tube for oil flow to pass through the filter media from the inside outwards.

 

additional information - flathead bypass oil filter function

additional information - oil filters

[Sam Buchanan]

Here is the spin-on bypass system I installed on my P15:

 

https://p15-d24.com/topic/50622-installing-a-spin-on-bypass-oil-filter-photos/?tab=comments#comment-537063

 

[greg g]

30% is the typical flow rate of a bypass filter system.  So at typical operation 1/3 of the oil flow of the engine is being directed through the filter at any given time.  So the pump needs to push three times around to get all the oil through the system.

 

Sort of like a modern fuel system where the pump runs all the time but what isn't needed is returned to the tank.

[mattimuss]

Good Morning All!

 

Thanks for the replies and info.

 

After reading Sam's post, and instructional topic, I think I am going to go this route.  I like the clean look of the setup, the availability of filters, and the ease of a spin off filter.

 

Thanks again!

[Sniper]

Before anyone assumes a bypass filter is more effective you need data.

 

Two types of bypass filters have been shown in this thread

 

Wix 51080, nominal micron rating of 21, no flow rating given https://www.wixfilters.com/Lookup/PartDetails.aspx?Part=159970

Wix 51051 nominal micron rating of 10, max flow rate of 1 gpm https://www.wixfilters.com/Lookup/PartDetails.aspx?Part=155265

 

Compare it to the Wix 51515 full flow later mopars use, nominal micron rating of 21, flow rate of 7-9 gpm.  https://www.wixfilters.com/Lookup/PartDetails.aspx?Part=193964

 

Then consider this, full flow filter systems filter all the oil going to the engine all of the time.  Bypass filter systems only filter some of the oil, some of the time and none of it goes directly to the engine.

 

So on a micro scale a bypass filter may appear to be more effective, Wix 51051 only in this example, but when you consider on a macro scale that the oil is only partially filtered and then is dumped back into the sump rather than fed to the engine the bypass filter is a sorry setup. That is probably the is a reason no one uses it any more as the only filter setup.  I have seen bypass filters used to filter the oil in wind turbines when the main pump and filter are off and only as a way to really clean up the oil.  Oil changes there are every 5 years with this setup with filter changes every year.

 

My personal opinion is that a bypass setup, regardless of what filter you use, is better than no filter but not much better.  I plan to convert to full flow filtering on the 230 I am building.

 

[kencombs]

Agree with Sniper's opinion and conclusion.  The low micron rate of the bypass is why diesels often used both.  I may do both also.  Cost very little and adds a layer of protection.  Full flow for sure, bypass also, maybe. I'm making up hard lines for my full flow setup using the oil line adapter fittings originally used inside the engine.  The use a larger line than normal for the pipe thread size.  1/2" OD steel (7/16 ID) where most use 3/8 hose..  That's one of the reasons it's not done yet, they are a royal b..... to get shaped right.

[desoto1939]

I use the bypass filter system with the AC metal canister and use the NAPA 1010Gold filter.  I have been running this for 35 Years and my oil pressure is good the filter has worked this long for me.  I change every couple of years.  The original PB1/2 throwaway filter type were good for 8000 miles becasue of being a bypass filter.

 

So i am going to stay with what i have and may car came from the factory with the PB1/2 filtering system and now has almost 100k 

 

Rich Hartung

desoto1939

 

[Sniper]

Wix 51010, same as the Napa 1010, has the worse micron rating of all the filters mentioned in this thread. 

 

Nominal Micron Rating 32

 

https://www.wixfilters.com/Lookup/PartDetails.aspx?Part=146023

 

I wonder if that 100k miles is on an unrebuilt engine?

 

 

[Bryan]

My question would be how much dirt is getting into the engine and how does it get there, how to control that?   

[desoto1939]

  On 6/26/2021 at 1:28 AM, Sniper said:

Wix 51010, same as the Napa 1010, has the worse micron rating of all the filters mentioned in this thread. 

 

Nominal Micron Rating 32

 

https://www.wixfilters.com/Lookup/PartDetails.aspx?Part=146023

 

I wonder if that 100k miles is on an unrebuilt engine?

 

 

Expand  

Yes this is a rebuilt engine but the car originally came with the PB1/2 filter installed on the car.

 

Rich Hartung