Flathead filter
 

Hi. Is it OK to run a flathead without an oil filter?
Thanks

Re: Flathead filter
 

No more or no less OK than any other engine. I wouldn't, but you may get differing opinions.

Bob

Re: Flathead filter
 

I think if you use Fords stock filter you pretty much are running it without one ,being a partial filtration system.I use the stock filter and just change my oil every 1500 miles and oil still looks pretty clean.

Re: Flathead filter
 

Fords of 32-35 did not have an oil filter and Ford did not offer one as an accessory until 1936. From 36 until the war the filter was not installed on the car unless the accessory filter was purchased. Many flatheads have never seen a filter and the filters are only a "partial flow" design which means that Not all the oil was passed through the filter every time around. Go ahead and run without the filter.

Re: Flathead filter
 

My 46 doesn't use a filter and she has done just fine however I do change the oil every 1000-1500 miles. You should be ok. Steve

Re: Flathead filter
 

i don't run one on my 35 21 stud motor

Re: Flathead filter
 

If you feel you must run a filter, my suggestion would be the method shown in the attached picture. This is usually best done during a rebuild. Otherwise, I would go filter-less and change oil frequently. Today's oils do a good job of keeping the inside of an engine clean. JMO

This larger picture may help those who can't see the attachment that well.

http://i39.photobucket.com/albums/e1...FlowOilSys.jpg

Re: Flathead filter
 

I think Ford offered the oil filter as a marketing ploy because as others have stated here, it is a bypass/partial oil system that returns the filtered oil to the pan, not into the system to be used right away. I'm wondering now if a PCV is more important than an oil filter because apparently Ford's breather system without one is what allows sludge build up from moisture condensation. Frequent oil changes will prevent that, too, of course.

Re: Flathead filter
 

I can't read what the "thing" is that is inserted into the "connecting "oil passage. Please let me know. Thanks, JIM

Re: Flathead filter
 

The oil filter shown in the sketch above is payyerned after the filter system used in WWII and kept by the Canadian engines after the war. I started using this system back in the 60's on the stockcar to save barings from flaking. The oil comes out of the pump where the oil pressure sending unit is and is 1/4" pipe. I redrill this to 3/8. Then about 2" up the rear of the block I drill another hole (3/8NPT) for the return oil. the passage way between them is plug usually with a 7/16 set screw. Every eng that leaves my shop has this mod. This filters 2/3 of the oil going to the main bearings and 3/4 of the oil to the rods. If you use a dual remote filter with cooling fins it will reduce the oil temp. I'm using this system on my grand sons engine with 5-20 synthetic oil. The thinner oil runs cooler. Hope it works.

Re: Flathead filter
 

I can't read that either but as Ol' Ron said, it is a plug (set screw) that is threaded in place between the two passageways.

Re: Flathead filter
 

I've been running my '40 without a filter but am planning to try what Ol'Ron is describing asap.
Even though I change my oil regularly and am probably ok, I still feel weird not running a filter of some sort. ...not that good kind of weird either...

Re: Flathead filter
 

And I too suspect that PCV is about as important as a filter...how many gallons of sludge have all of us dipped and scraped out of flatheads?? PCV plus thermostats to keep engine warm enough to cook off the combustion water and mystery chemicals.
Remember, Ford put PCV's on the same military engines that got the filter arrangement shown above. They were used in armored Bren carriers, artillery tractors, and severe use applications like that.
Lots of people worry about the "3/4 filtering" not passing the oil to the rear main.
This is the way oil is routed in all small block Chevys that have the built in full flow filter, all made since '57 or '59 or so. See lots of them sitting by the road with smoked rear mains, don't we??
Interestingly, the SBC oil system is virtually identical to the system shown here except for having the passages cast into the block and having extra galleries to feed those hydraulic lifters and rockers we don't need to worry about here.
If you don't think Knudsen had a few flatheads sitting on the workbench when designing the SBC, have a look at the way the pump/dist drive seals the oil gallery and look at the top of a flathead or Lincoln pump...coincidence?? Yeah.

By the way, the stock filters used '40-53 bypass systems allow finer filtering than is practical in full flow...and expensive heavy duty engines, big $$ large stuff, puts this idea to work by running 2 filters, a full flow plus a bypass one that gives the oil a good screening for the finer crud. Might be interesting to try.

Re: Flathead filter
 

It says "Grub Screw".

I have the by-pass filter on mine, and I was surprised at how much oil does flow through it. I could see the return squirting back into the fuel pump stand and the beehive filter was quite hot - that means to me that the hot oil was flowing through at a decent rate to make it heat up like that.. If there was no flow it would be cold, so the hotter the better - and the fins act like an oil cooler when the car is moving along.
It does have the 1/16" restrictor.

My other engine has no filter. Don't do enough miles for it to be a problem.

I might try the setup above on my next build.

One important point to make - I know this has caught someone out because I read it on one of the forums - If you are not running a filter, make sure a previous owner has not modified the block like above - likewise double check if it has any military history, because the passage where the grub screw has been fitted needs to be open to run filterless.

Mart.

Re: Flathead filter
 

Something to beware of regarding the "full flow" modification--- as the filter clogs up the flow will be reduced and eventually becomes a "no flow" oil system.

Re: Flathead filter
 

Grub screw is British and Commonwealth speak for set screw in American...
Modern engines have a bypass valve either in the filter itself or as in SBC in its attachment to bypass the filter whenever there is too much pressure differential across the thing.
According to various small block gurus: Modern disposable single filters are often running in the bypass mode because they lack sufficient flow capacity...SBC tests show bypass when cold and at high RPM, not just when dirty. Racers hence run dual filters in parallel or the gigantic truck version, and hotrod builders used to recommend swapping in the pre-1969 (also used later on Police, heavy duty applications) filter with the separate can...this actually flowed more than the nice convenient late one.

Re: Flathead filter
 

Quality filters will have a by pass built in that prevents such an occurrence.

Bob

Re: Flathead filter
 

Yes. I'm also reminded of a sad story that may have been posted on the HAMB, of a freshly rebuilt flattie with a full flow modification that they guy decided to "test run" without the filter (he capped or blocked off the filter lines). He filled it with oil and proceeded to cook his bearings & such.

Re: Flathead filter
 

Jack E/NJ

Re: Flathead filter
 

Mike, if you are going to modify a system, you need to know the system, right? Don't mean to be harsh, but c'mon. For all the others talking about bypasses not working or plugging, is anybody on these forums really talking about running an engine so long that we might plug everything up with contaminates? We go from guys not running a filter and changing their oil every 1000 to 1500 miles to guys that run filters but then worry about plugging them up but they probably do not run their oils any longer than those without filters. Am I right! WE ARE ALL MOTHER HENS OVER THESE OLD MOTORS! IT IS WHO WE ARE! RECOGNIZE IT, DEAL WITH IT!

Maybe the worst thing in a flathead to worry about is sludge buildup in the valley oil tube. Other than that, the old gals will run forever.

Re: Flathead filter
 

Nah, Lou. Sump-screen sludge is worse. 8^)

I'm still waiting for a pix of your PCV setup.

Jack E/NJ

Re: Flathead filter
 

Thank you.

Re: Flathead filter
 

I recall that story, but if recall correctly the failure was due to the fact that the owner had used a block that had been modified to have the oil diverted out to a filter and didn't realize it. He plugged the external pipe ports and the "grub screw" blocked the oil from entering the oil galley. I bet Bruce Lancaster remembers that one. I think he discovered the cause of the problem.

Bob

Re: Flathead filter
 

Will running without a filter give higher oil pressure when hot?
Thanks, Lew

Re: Flathead filter
 

or just run a hose from outlet port to inlet port of the block....and i read that post, too....Mike

Re: Flathead filter
 

I happen to run the Motor City full flow system on my engine which I built in 1993. I do not have a PCV system and the inside of my engine looks just like the day I built it. I do run 180 deg thermostats. As I have said, a PCV system is a good idea but not essential to a clean engine. Sludge build up in the old engines probably had as much to do with the oil technology at that time than anything else.

Re: Flathead filter
 

Maybe if it's a partial flow type filter that bleeds off oil and sends it to the filter. If it's a full flow, probably not.

Bob

Re: Flathead filter
 

Good call (again!), Jack. Sump screen plugged up would ruin your whole day.

I remember a '39 Ford that my dad bought where we poured kerosene in the crank and ran it to loosen up the sludge to drain. I got the assignment to remove the drain plug so I was on my back expecting the usual slosh and splash of oil draining as you removed those big plugs so I did the final twist and pulled back. Even after the kerosene run, nothing came out! I stuck my finger in the hole only to feel solid sludge. I had to use a screw driver to poke a hole in the stuff to get something to finally drain out.

On my PCV set up. I've got it all mocked up and I think it will be really cool. I need to make a rear vent pipe piece, the one that goes down from the fuel pump base mount into the boss around the pump rod base. Measuring one from a '36, it is about 1.725 OD but all I could find is some 1 3/4" OD exhaust tubing. So, I will have to shave that just a little and it should fit. Anyway, with the discussion we had here on the Barn about it, I think we can say a collaborative effort was used to design a PCV setup for a 59A that will not diminish the engine's vacuum. Mine will not be completely hidden away like the ones under the manifolds, but will be very "attractively functional".

Re: Flathead filter
 

Had my engine apart last summer and as I stated it was as clean inside as the day I built it. The screen looked like new. No doubt the old oils, no themostats and lack of maintenance caused all kinds of sludge to build up. It just doesn't happen today.

Re: Flathead filter
 

Re: Flathead filter
 

You drill the passage in order to install plugs. You are directing the oil up the vertical shaft from the oil pump to the filter. The oil comes out of the filter and returns to the existing passage via the new hole drilled upstream. You install a plug in the horizontal passage way between where the vertical oil passage from the pump intersects and the new hole downstream to keep the oil going to the filter from mixing with the oil that has come out of the filter.

Re: Flathead filter
 

The new passage needs to be drilled to allow the full flow from the pump, through the filter, back to the new port so the full flow of filtered, pressurized oil is on it's way to the bearings. The partial flow system diverts part of the pressurized oil from the pump, through the filter and back to the pan. By the way, the disasters associated with leaving the grub screw in place without the filter and lines was eliminated in the Ford Canada full flow system by using a special outlet fitting that used a thinwall extension tube from the bottom to project down past the horizontal connecting passage. This tube effectively blocks the "out" passage from the "in" passage in full flow mode, and removing the hose fitting from the block removes the separation and allows use without filter system of any kind, or a partial flow filter. ..B.

Re: Flathead filter
 

I agree with most:

"The oil comes out of the filter and returns to the existing passage via the new hole drilled upstream."

but why not just direct the oil coming out of the filter back to the hole in the block above the oil pan? It just doesn't seem to be a need to drill the new hole if the only purpose is to have the oil from the filter return there rather that back through the original hole in the lower block?

Re: Flathead filter
 

Barlea:

Thank you for the reason and explanation for the new hole...I take it that you just plug the hole in the lower block?

Re: Flathead filter
 

If you run all the oil through the filter and back into the pan there will be no pressurized oil to the bearings. Also, I didn't mention in my previous post that the inboard oil port is already drilled and tapped on Ford Canada flatheads. ..B.

Re: Flathead filter
 

you only do the drilling, tapping, plugging, etc. if you are going to the "full-flow" filtering system as shown in the diagram....what you have is the original filtering which only filtered a small portion of the time at a time, where the "full-flow" filtering system will filter most of the oil at a time.....Mike

Re: Flathead filter
 

As I look at that drawing it is NOT a full flow oil system, because unless I am wrong the rear main is still recieving unfiltered oil.........right?

Re: Flathead filter
 

Yep. Same as a Small block Chevy...

Re: Flathead filter
 

37, you can direct filtered oil to the rear main but it involves drilling holes to the oil passages at the back of the block inside of the flywheel. I did this to the 8ba that currently resides in my '36 p/u. Everything seems to be fine but I always worry about that plumbing coming loose and dumping all of my oil in a few seconds. If I had it to do over again, I would not. As Bruce points out, there are millions of SBC's running around that do not have filtered oil going to their rear mains.

Re: Flathead filter
 

I know exactly....what you did, I thought that as the thread was going it began to sound like people believed that the diagram was a full flow system. I know of only two ways to completely filter the oil.......the MCF oil pump method or Red Hamilton..aka Red's Headers method. I was a little nervous when I installed Reds method, but its been in the car about 6 years with no problem. I also run the High Volume pump with it, I thought it would be better to use it knowing all the oil was pushed through the filter medium.