motor city oil system

[52merc]

my buddy has one of these fitted to his 59a engine he is having problems with oil pressure,,at idle hot 40ibs crusing at 50/55 20 lbs 60 mph 70 lbs pressure any ideas on his problem by the way this is a new engine {recon} he dont have a puter so asked me to put on barn thanks guys

[Old Henry]

I would tell your friend that he doesn't have a problem. All of those pressures are plenty high to move the oil through where it needs to be. Lubrication is not by pressure but by flow. IMHO any flow is sufficient so all of his pressures are more than sufficient. I think there may even be some that would say that they are excessive. Normal pressures for a 59A are 20-30 psi at highway speeds and 5-10 psi at idle speeds warmed up. A little higher when cold but not over 30 psi. Again, you don't need pressure to lubricate, just flow to get the oil where it needs to be.

[flatjack9]

Don't you have the idle and 50 mph pressures reversed?

[52merc]

no they are not thats the problem

[52merc]

btt

[Walt Dupont--Me.]

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I did a 59AB that had one of those Mark Kurby full flow systems on it. I'd never use another one. All that monkey motion with flex pipe inside the pan and fittings through the side of the pan. Nothing but trouble in my opinon. Walt

[flatjack9]

I've had one in my engine for 20 years and 50,000 miles. 52 Merc: how is your buddy measuring the oil pressure?

[woodypecker]

The only thing I could think of is if he has an over drive transmission that causes the RPM to be higher at idle than at 55 cruise. Any chance this is possible?

[52merc]

well yes he does have a mitchell 36% i think he also has a modern oil gauge

[Cecil/WV]

Originally Posted by woodypecker

The only thing I could think of is if he has an over drive transmission that causes the RPM to be higher at idle than at 55 cruise. Any chance this is possible?

Seems to me that it would be a real fast idle or an unusual ratio overdrive that would cruise at a lower rpm than at idle?

[Seth Swoboda]

I have to agree with Walt. Those full flow oil systems aren't worth the cost and aggravation. I'd get rid of it.

[side_valve]

I would check the hose inside the oil pan. It can easliy get twisted when tighting the fittings on the pan resulting in low pressure and flow. I wouldn't run your engine until you check that - I had that problem and it wasn't good.

[Tom Walker]

Sticking blow-off valves can produce wierd readings. Just a thought.

[JM 35 Sedan]

Originally Posted by side_valve

I would check the hose inside the oil pan. It can easliy get twisted when tighting the fittings on the pan resulting in low pressure and flow. I wouldn't run your engine until you check that - I had that problem and it wasn't good.

I had the same issue when I installed the MCF full flow oil filter system on a rebuilt '35 21 stud engine. However, as aggravated as I was at the time, I have to admit twisting that internal hose was my own fault. If I had followed directions more carefully, it probably would not have happened. After the pain of having to pull the engine to fix this, I have not had any other problem with this system in the last 12,000 to 13,000 miles. Of course Mark Kirby no long sells this system but it is still available from another source.

[FlatheadTed]

One thing about the conventional oiling system is that it supply's full pressure right off the pump to the the rear main cushioning the heavy fly wheel.
.I like That John I think he got the idea from Edison ,nothings imposable .When Henry Ford decided to produce his famous V-8 motor, he chose to build an engine with the entire eight cylinders cast in one block, and instructed his engineers to produce a design for the engine. The design was placed on paper, but the engineers agreed, to a man, that it was simply impossible to cast an eight-cylinder engine-block in one piece.

Ford replied,''Produce it anyway.” ― Henry Ford

[GOSFAST]

We've never used the oil system modification mentioned here (motor city) but we've now done a few with the "95%" deal, it works excellent with a remote filter setup!

Not all that hard to machine but it really does require a "Bridgeport" type mill, makes it much easier!

The builds run with a nominal 30# idle pressure and 55#/60# "cruise", around 3000 RPM.

Thanks, Gary in N.Y.

P.S. Would not hesitate for a moment recommending this procedure to anyone building a Flathead!!

[Walt Dupont--Me.]

Gary, nice looking job drilling that top hole straight down in a Bridgport. I see you use the stock 1/4in. pipe thread. I've always drill and tapped to 3/8pipe bit I don't think it's nessarry. The canadan millitary blocks just use the 1/4in. pipe. I'm building one right now and useing the grub plug that a guy in canada makes. I cain't remember his name but someone on the barn gave it to me a couple of month ago. If thay don't jump in I may be able to find his name. What do you use for a plug? Walt

[GOSFAST]

Originally Posted by Walt Dupont--Me.

Gary, nice looking job drilling that top hole straight down in a Bridgport. I see you use the stock 1/4in. pipe thread. I've always drill and tapped to 3/8pipe bit I don't think it's nessarry. The canadan millitary blocks just use the 1/4in. pipe. I'm building one right now and useing the grub plug that a guy in canada makes. I cain't remember his name but someone on the barn gave it to me a couple of month ago. If thay don't jump in I may be able to find his name. What do you use for a plug? Walt

Thanks, Walt. Like I stated, the Bridgeport makes it all easy (those are 3/8" pipe, they only look smaller in the photo)!

By using the 3/8" pipe size we can maintain the 3/8" I.D. for the oil feed through the block AND through the filter lines. There is no "step" down anywhere on the internal lines!

If you look closely you can see we start with a nice sized flat counterbored section (on the inner line) to enable tightening the fitting with a conventional socket! The first thing we did was measure the socket O.D. required to adequately tighten the fitting and then machined that land! Then it's drilled and tapped for the 3/8" pipe!

We took a long hard look at the very first unit we did and before we did any machining, decided on keeping ALL the internal lines consistent for size. As I said, this is the main reason for the larger pipe thread size! It also makes tapping the "crossover" easy for the size. I won't use 1/4" pipe, it complicates the entire machining procedure!

Thanks, Gary in N.Y.

P.S. The "plug" used to direct the oil to the filter is a 7/16"-14 set screw about a 1/2" long. The original passageway is already 3/8" I.D. so we merely tap that for the correct size. We stop the threads "short" and after we dyno the build we install that set screw with some "Loctite", at the same time letting it "bottom" into the threads. It gets delivered, and the customer simply hooks up the filter. With this procedure there's no need for a "special" grub plug!

[51 MERC-CT]

Originally Posted by GOSFAST

Not all that hard to machine but it really does require a "Bridgeport" type mill, makes it much easier!
Thanks, Gary in N.Y.P.S.
Would not hesitate for a moment recommending this procedure to anyone building a Flathead!!

Does not really require a 'Bridgeport', I did mine using a benchtop drill press bolted to the intake suface of the block.

[BILL WZOREK]

51 MERC CT
What is that Chain going to the bolt,in the 1st & 2nd Picturewsed for?

BILL W