To Filter or Not to Filter

[Dick Deegan]

That is the question.

I currenly hbave a "full flow" filter with the filter itself mounted on the valve cover and have had it installed for several years. I am currenlty adjusting valves and have the valve cover off (obviously).

My engine is stock Model A with a Snyder's 5.5 head. I use a high quality oil 10W30.

I have often wondered whether I am doing more harm than good with this filter. Oil pressures are very high when the engine is cold (15 - 20 psi) at very moderate speeds (water temperature is in the "driving range') and I wonder if I am restricting flow into the galley and thus reducing the oil at the mains and elswhere and causing excess wear on the main bearings etc. It does take about 20 minutes or so for the pressure to go down into the 2 - 3 psi range where I like to see it, indicating the the oil is finally starting to warm up.

Should I go with no filter or stay with what I have?

What do you think?

Dick

 

[Al Bass]

I dont have a filter and my oil pressure pegs the needle til it warms up. am installing a filter next week, daily driver.

 

[Dave in MN]

To Filter or Not to Filter that is the question!

Should I go with no filter or stay with what I have?

What do you think?

Dick

Hi Dick,



I am assuming you are using the kit shown in the picture above.

The Model A pump is an unregulated pump as to pressure. I would call it a positive displacement pump. As long as it is turning it is delivering oil. The flow of the oil from the pump is not changed much with increased pressure. The amount of reduced oil pumped with a bit of back-pressure would be directly related to the clearances (wear) within your oil pump. The oil flow from the pump passes by the center cam journal and gear. The amount of oil moving out and around the center journal of the cam on its way to the valve chamber would also be related to the back-pressure the filter kit places on the system. What I am trying to explain is that you will loose a bit of oil flow to the valve chamber when you pass it through the filter kit because of the losses due to pump wear and and wear at the center cam journal. IMO: But not much!

If you do not mind the "look" of the filter kit, I would keep it in the system. I have started about 50 engines in the past couple years after rebuilding them. Even though I install a oil pressure gauge in the oil passage hole (slotted pump hole plug) I often loosen the lower bolt on the return oil pipe to verify oil flow from the valve chamber to the oil pan/dipper tray. I have not noted any reduction in the time it takes to note oil flow if the engine has a full flow filter kit.

In my driver, I like clean oil!
I have a full flow filter on the inserted engine of my driver (Phaeton). This engine has over 50K miles on it and I drive/push this engine hard. I also note the increased pressure during warm-up. I am not the least bit concerned about reduced oil flow.
I do not have a filter kit on my "Stock" pickup engine. I don't put many miles on the pickup and I want it to look as Henry built it.

Now the counter: I spoke to Ron Kelly (well known engine builder from Texas) years ago and he stated at the time that the Model A engine has the ability to "self filter" the oil pumped to the valve chamber because of the valve chamber dams in the block. The heavy particles are often settled to the floor of the dammed areas and do not make it to the bearings. At the time I spoke to Mr. Kelly, he did not think it necessary to use a filter.
Observation: The next time you have an engine open, look at the openings within the valve chamber that feed oil to the main bearings and camshaft. You will find that all three of the main bearing openings are elevated above the floor of the valve chamber. The lowest opening in the floor of the valve chamber is the oil feed to the rear journal of the camshaft. It is at the rear of the rear section of the chamber and close to if not the lowest elevation in the valve chamber. This opening would be the most likely to pick up heavy contaminants from the chamber floor and damage the rear journal. But I never see the rear journal of a camshaft worn more than the center or front journal. I think Henry and his engineers had it figured out...the engines worked well without filters and non-detergent oils. The settling in the pan and valve chamber kept the engines working. For my own satisfaction, I will start scraping some of the sludge from the valve chamber in old engines and check it for particles before I put them in the cleaning solution.

So in the end, I like to filter the oil but it probably won't make much difference as long as you change your oil often.

That's what I think!
Good Day!

www.durableperformance.net

 

[raprice]

My car wouldn't know what to do with an oil filter.
Rog

 

[ford1]

oil filters were made to increase the milage between changes, oil doesnt wear out, just gets dirty from contaminates and dirt(basically the same stuff) the filter traps a lot of junk and holds it in the filter instead of let it returning to the oil pan, so it boils down to how often you want to change your oil, every 500 miles, or ever 1500 miles, new car manufactors say change it ever 5000 miles, and the warrantee the engine for 100,000 miles, and the new engines develop 5 times the horse power and turn twice the rpm's of the model a engine, so i guess they should know if a filter is needed, if they didnt they wouldnt spend the money to install them

 

[Paul_nz]

[FONT=&quot]Engine oil seems so simple, it is slippery, it keeps metal parts from fusing together. It's messy, especially when it has been squeezed, slung, and sprayed around the inside of a hot engine for thousands of miles. And after it has been inside an engine for a few thousand miles, it seems dirty, worn out, and ready for disposal. But engine oil never wears out, it gets contaminated from combustion byproducts and it loses its additives to heat and pressure, which is why it must be changed from time to time. Otherwise, oil lasts virtually forever, so we have two options change the oil every 500 miles, or filter it to clean the oil of contaminants. [/FONT]

 

[steve s]

When I worked as a summer intern of sorts at the GM Tech Center, one of our "classes" featured one of their lubricants specialists. He explained to us that in modern engine oils, the "oil" is just a carrier for the various additives, WHICH DO THE REAL LUBRICATION. And, those additives do wear out: Anti-oxidants get sacrificially oxidized. Detergent molecules get titrated away by the dirt. High molecular weight viscosity regulators get sheared down to smaller, ineffective molecules. It's really not as simple as just the oil getting dirty, but that is going on and to that extent a filter is a good thing.
Steve

 

[Tom Endy]

I have used the kit shown in the post above in four Model A's I have owned in the past 25 years. I believe they are still called an A-Fordable filter kit.

I have put over 40,000 miles on my Victoria since 1994 switching two engines in an out for various reasons. I have never found any sludge build up in either engine and everything inside looks clean. My oil change schedule is at about 1,000 miles, but a number of times it has run to 1,500 on a tour before I could get to somewhere for an oil change.

One bit of advice is to paint the filter Ford engine green as the orange or white filter will leap right out through the louvers and be plainly noticeable.

Tom Endy

 

[Dick Deegan]

Thanks to everyone who responded. I really appreciate the information and the different perspectives on this. Yes, the setup I have is the same as the one pictured by Dave in MN.

After reading all the posts I will stay with my setup and re install the filter kit.

Thanks again. Great info.

Dick

 

[Bobs29ModelA]

I installed the type of oil filter kit where the camshaft-gear inspection cover is removed, and then replaced with a new (well-made) piece that also includes a segment to screw-on a large spin-on oil filter. The oil is fed to it from a fitting that is placed into where the oil pump plug originally is; then pressurized oil runs through a copper pipe into the filter (through the new inspection cover), then it is forced to drain back into the camshaft gear area, thus returning it into the oiling system (and squirting onto the cam-gears at the same time).

I chose this type of system over the type being discussed here because it seemed to make sense to have the filter being fed with a pressurized line. All I know is that, when you remove the filter during an oil change, a lot of dirty oil comes out of it! Anyway, here is a photo of the installation.

 

[Roger V]

I use the type Dave shows on both of my drivers. The coupe had the timing gear cover type that Bob describes, when I bought it. I removed it as all of the oil wasn't necessarily going through the filter as it had two directions to go. Also, there was no practical way to know how much, or if enough made it up to the valve chamber plus x amount was headed to the timing gear. I suppose enough "may" end up in the valve chamber with that one. I like knowing the discharge tube from the oil pump delivers all (except for minor leakage) to the filter which dumps it back into the valve chamber on Dave's type.

 

[Bobs29ModelA]

Roger, could you please explain to me how the other type actually works? Is the valve-chamber (meaning everything behind the side cover) actually somehow pressurized, in that it will then pump oil through a filter mounted on the side cover? If so, then how does the oil get back where it needs to go? I'm not fully understanding of the process with that type of approach, so if you can shed any light on it for me, it'd be much appreciated!

 

[CarlG]

Re: To Filter or Not to Filter that is the question!

I spoke to Ron Kelly (well known engine builder from Texas) years ago and he stated at the time that the Model A engine has the ability to "self filter" the oil pumped to the valve chamber because of the dams in the block. The heavy particles are often settled to the floor of the dammed areas and do not make it to the bearings. At the time I spoke to Mr. Kelly, he did not think it necessary to use a filter.

I would think that this would require "frequent" cleaning out of the valve chamber (as well as the oil pan itself) if that were the case

One bit of advice is to paint the filter Ford engine green as the orange or white filter will leap right out through the louvers and be plainly noticeable.

I took someone's advice on here some time ago and got Wix filters that are black with a peel-off label. Takes care of the bright orange, white or whatever that tend to shine thru the louvers. I also put on a 90 degree adapter on it so that the filter is tucked in closer to the engine. And painted the adapter engine green.

...could you please explain to me how the other type actually works? Is the valve-chamber (meaning everything behind the side cover) actually somehow pressurized, in that it will then pump oil through a filter mounted on the side cover? If so, then how does the oil get back where it needs to go? I'm not fully understanding of the process with that type of approach, so if you can shed any light on it for me, it'd be much appreciated!

The oil is diverted via a copper tube (that U shaped piece in Dave's picture) directly to the filter, then everything coming out of the filter is dumped back into the valve chamber where it was headed before the filter was installed.

 

[Roger V]

Roger, could you please explain to me how the other type actually works? Is the valve-chamber (meaning everything behind the side cover) actually somehow pressurized, in that it will then pump oil through a filter mounted on the side cover? If so, then how does the oil get back where it needs to go? I'm not fully understanding of the process with that type of approach, so if you can shed any light on it for me, it'd be much appreciated!

To add to Carl's explanation, that copper tube going to the oil filter on the inside of the new valve cover has the input end slipped into the factory steel tube that is horizontal in the bottom of the valve chamber fed from the oil pump.

 

[Dave in MN]

Re: To Filter or Not to Filter that is the question!

I would think that this would require "frequent" cleaning out of the valve chamber (as well as the oil pan itself) if that were the case

CarlG, "require "frequent" cleaning..." No, I think you missunderstood or I was not clear in my statement. The point I was making is that the original un-filtered system did not require frequent cleaning and that was the opinion of Ron Kelly. Engines were run for years with non detergent oils and sludge built up on the floor of the valve chamber and the base of the pan. This sludge held much of the "debris" that accumilated in the system as the "heavy" stuff would settle out.

CarlG and Roger V explained the function of the A-Ford-Able filter well.

Bobs29ModelA, The side timing cover filter you have installed actually robs (diverts) a percentage of the oil being pumped and sends it to the filter which then dumps it over the fiber gear. So oil flow to the valve chamber is less with this type of system. (I don't know that it probably matters because the pump moves lots of oil.) What concerns me is that with the side timing gear system only a small percentage of the oil flow is filtered with each cycle through the pump. My concern prompted me to change from the side timing gear cover system to the A-Ford-Able system.
Good Day All!
An early wish for a Happy New Year!

 

[Jim Brierley]

Why would anyone not filter their oil??? It is especially important with modern oils, the old non-detergent oils let any particles settle to the bottom of the pan and stay there. Modern oils keep the stuff in suspension.

 

[Lawrie]

On my eng I enlarged the little hole on the block where the oil comes up, to 3/8 npt,then machined a collar to block off the channel around the dist drive shaft boss,then all the pump oil comes out through the 3/8 hole,into a full flow filter and back into the side cover just above the old original oil discharge tube.
80000klms on the same bearings.
I will find out how good they are this week as I,m pulling the eng to fit a 5.5 head and fix a few leaks.
Lawrie

 

[mrtexas]

The question I have of you is: where do you want the sludge to build up, in your filter or in all the horizontal areas of the engine like the valve chamber and bottom of the pan?

 

[Bobs29ModelA]

OK, my thanks to all who tried to explain how the other system works. I do know, however, that when running non-detergent oils, sludge forms... as I had to clean a lot of it out of the valve-cover area, as well as from the oil pump screen, when I went through a previous engine to replace all of the leaking gaskets. However, now that we can run today's modern oils, (and everything is kept in suspension), I would rather be able to filter some, if not all, of the oil, and trap the contaminates in the filter, instead of letting it continue to circulate throughout the engine. This has got to be a better way to address the issue, than how it was done in the "old days".

 

[Al Bass]

Installed my filter today. an easy two hour job.