Full Oil Filter for Flathead

Hey Guys, I rebuilt my flathead and installed the full oil filter system that Motor City Flatheads designed years back. 1st time I fired it up I had 75 lbs oil pressure and the motor locked up. The machinest opened the tolerance up a bit more and I meticulously put it back together. I got it going again and have just about 500 miles on it and the oil pressure has dropped. I have a low end knock under load which tells me the mains are out. Everything on the block was checked, line hoaned, crank turned, balanced etc. The machinist has been doing motors for over 40 years and has worked on countless flatheads. We are both scratching our heads and now somewhat pointing to the only change, that being the oil pump/filter system. Anyone have any experience with this system good bad or otherwise? Other suggestions?
Thanks.

 

Wow man that sucks. I've been thinking of adding a full filter system to the '49 Merc Flattie in my '32. Now I'm thinking that's not such a good idea. Wish I had some words of wisdom for you. Please let us know what you find out. Good luck.

 

Sounds like maybe the mains are not getting full pressure now? Why did it "lock up" the first time?
I thought about doing that mod on mine, but decided not to.
The partial flow setup (stock) seems to be working fine for me....Oil stays really clean for about 1500 miles. I change it at 2k miles. Motor is pretty stock though....
Let us know what you find.

 

I guess they did some drilling near the oil hole back of block.
I think you may want to remove what ever was done, and block any holes and run with no filter.You only hear of the failures with this setup.

 

Not sure why you would fault the MCF system with 75psi. I've got thousands of miles on my MCF filtration system, along with hundreds of others, with no problems.
The question was asked, what was the cause of the initial lock up? If bearing related, were new bearings installed?

 

Humm bad filter?, something blocking the return from the filter to the block, put a gauge on both sides of the filter and see what you have.........

I personally like the 95% filtration always worked for me

 

Both times I installed new Clevlite 77 bearings, crank turned, and on the second time around it did not lock up it has gone 500 miles and is now knocking. I am not blaming the MCF filtration system as I know someone that has it successfully but it is the only change to the motor that both the machinist and myself can suspect. I am looking for feedback good and bad and any advise/experience in this.

 

I have been running this setup for 8+ years with a slightly modded flatty. Run on the hiway at 2500-2900 RPM no problems. Oil stays clean, pressure stays around 30lbs. 75 pounds sounds high? Sounds like a restriction somewhere.. I remember something about drilling, tapping and plugging the fuel pump rod hole at the rear of the block if you run an electric pump, but thought the result if you didn't do this was no oil pressure...

 

you should check the plug in the crossover to make sure that it is not blocking the passage where the filtered oil goes back into the block.

If the crossover is blocking that passage it would show high oil pressure at the sending unit but little or no oil would actually be getting back into the bottom end.

 

I ran my flathead for several years with not even a bypass filter on it...I changed the oil when it turned black and I had absolutely no issues whatsoever....I drove about 25,000 miles this way and when I pulled out the flathead, my pal and I put it into his 35 Ford pickup...I ran the flathead in my 52 1/2 ton, which is now powered by a baby Dodge Hemi 1955 vintage....BTW the flattie has twin 97s on an Edelbrock vintage manifold and Sanderson Headers.

 

I have a block in the shop for boring right now. I have already modified the block for the filter. I plan on running an electric fuel pump, thus no pump push rod. After much reading I understand if you leave the bushing the oil flow out the bushing hole is neglibile. Without the bushing you need to drive a welch plug into the opening blocking off the oil hole. It sounds like you will at least have to pull the bottom end to address the knock. I would attach a pressurized source of oil to the system to ensure the bottom end is oiling. I will be paying attention to your post.
good luck,

 

The MCF full flow system does not require the crossover plug (or any block machining), only a hole drilled into the oil pan.

 

Oooops.

 

Does your by pass look like this. veyr poor art work

 

It is easy to get the pipe threads too deep and block the passage when the fitting is screwed in. I would suspect the fitting in the red box in the post above. Look down the passage and check for blockage.I did this and had to shorten all my fittings as the went in too far.

 

I've had over a dozen Flatheads in my time, most without filters, 1 with MCF oil system in the early days, No oil pressure I had it replaced and found out that the drive gear on the back of the cam had cracked and would spin on the shaft, put on a new gear making sure the FLAT spot on the gear was in the right place...Worked fine, with my present Flathead I run with NO filter and change it often like the above quote..
Jim

 

With the quality oils available these days,...<just add zinc> I stuck with the factory oil filter plumbing, only with a spin on unit; It's still a "partial" system, but eventually all the oil will pass thru the filter. 3,000 mile changes....

4TTRUK

 

ps; Just add zinc !

4TTRUK

 

doing some testing on this as we speek. I'll keep you all posted >>>>.

 

I'm learning here! Can I just ditch the filter on my 8ba and plug the two holes that feed and return the oil to the filter? Or do I need to put a line between the feed at the rear and the return down by the pan? I don't mind changing the oil but i do think the passive filter is pretty useless and ugly to boot.

 

On the stock 8BA canister style yes, you can just plug the feed and return. The filter system they are talking about here is a full flow filter thats not stock.

 

Excellent. I understand what this thread is covering. There are several systems that provide full or near full filtering. I was just wondering because of the discussion with the plugs closing of certain bores if I could do away with it altogether. Thanks for the info!

 

Maybe it's not the filter system at all did the plugs in the crank get removed and the oil passage inside the crank get cleaned out it could explain high oil pressure and why your main bearings are shot ? good luck

 

I use a spin on, with adapter, plumbed into the factory 8BA connections. Works great. Even though it is a "partial flow" system,..at some point, all of that oil will be run thru the filter.
As mentioned,..the oils we have today were never even dreamed of, when our Flatmotors were brand new, as well as changing at 3,000 miles. When I was an apprentice, (mid 50's) it was still the custom to change oil at 1,000 miles, and filters every 5,000 miles. Hooray for the research and resulting products we have !!!!!
Now,..put the zinc back it it !!!!!!!!!!!!!

4TTRUK

 

after my flathead was rebuilt i ran the break in period and changed the oil, ran for 200 miles and changed again, after that i have changed the oil every 1000 miles, all this and no filter.....no problems after 3 years and lots of miles.

 

8ba or 59a??

Where are your lines going to on the filter adapter. You may have them reversed! That will lead to a problem..

T

 

NOOOOOOOOOOOOOOOOOO do not plug the holes

 

If it is the old style that dumps back to the pan, you can just remove and plug. If it is a modern full flow, there is a plug in the passage between the lines. You must remove the plug or no oil will flow to most of the engine.

 

The testing I mentioned is complete. I had a customer that claimed his engine had 0 to 4 lbs of oil pressure and literaly no pressure when revved up. After 3 months of haggeling I tear the engine completly down for a complete check up and find no problems. I put the engine back together with new gaskets only. I then leave the add-on oilfilter off of the engine, plug the oil feed to the filter. I then start the engine on the run stand and bingo 17 lbs at idle, 47 lbs at 2500, and 88 lbs at 4500. I had voiced my opinion on the pressure that the add-on filter was robbing from the engine all along but the customer said back in the day they always used the add-on filters !! Then to top it all off Street Rodder Magazine print a 6 page article supporting my exact thoughts and proven theory on the same problems !!! >>>>.

 

Maybe the oil pump doesn't have the volume needed.

Or if the filter is connected backwards it won't flow well, or not at all. They have check valves in them.