low oil pressure after engine rebuild

kcraigmile · Post by **kcraigmile** » Sun Oct 24, 2010 1:50 pm

Hi, looking for some assistance with the above if anyone can help.

Tractor is a 1964 Super Major

We have rebuilt the engine using new shells and gaskets and a new oil pump.

When engine is started from cold at about half revs oil pressure reads 25psi

When the engine gets hots and is ticking over at idle pressure drops to 5psi and the light is flickering, at about half revs the oil pressure goes up to about 15psi

Tried other oil filter and housing, tried 20/50 engine oil and still the same

Put oil pressure guage to check that reading is correct and it reads the same

Any advice or assistance would be greatly appreciated

Thanks

Keith

Post by **Brian** » Sun Oct 24, 2010 2:17 pm

Welcome to the board.

Did you re-grind or replace the crank?
Did you check the new oil pump?
Did you check condition of camshaft bearings?

These are the most likely areas. Majors are not normally high on oil pressure but you should have more than that.

kcraigmile · Post by **kcraigmile** » Sun Oct 24, 2010 6:48 pm

Hi, thanks for the reply

I have tried a couple of oil pumps, the original and then the new one so think the oil pump is probably ok

We are going to have the crank measured in the next couple of days and see if that reveals anything

The engine is a fairly low hour engine so hoping the camshaft bearings are ok although thats something else that we can check

Will post back in a day or so after the examination of the crank with the results of that

thanks for the suggestions, very helpful

Cheers

Keith

JohnnyBoy · Post by **JohnnyBoy** » Mon Oct 25, 2010 11:13 pm

I’ve not been into my FMD engine and at the moment can’t see any reason to because it runs so well…

…BUT having rebuilt a Ferguson engine that was seized on the main bearings, I was warned at the time about the camshaft bearings. Fortunately mine were okay having been line bored and re-bushed in a previous re-build.

Dandy Dave · Post by **Dandy Dave** » Tue Oct 26, 2010 2:22 am

Never do an engine job with out micing the crank and cam bearings. Look in the shop manual for correct dimesions. Dandy Dave!

JohnnyBoy · Post by **JohnnyBoy** » Tue Oct 26, 2010 7:55 pm

Dandy Dave wrote:Never do an engine job with out micing the crank and cam bearings. Look in the shop manual for correct dimesions. Dandy Dave!

Yep you’re right DD. The Ferguson rebuild I mentioned had a crankshaft that had been machined to 0.013” undersize on all the journals when it was checked… Maybe the guy who did the first crank grind should have calibrated his micrometer. The guy who did my machining took the crankshaft journals down to 0.020” undersize.

kcraigmile · Post by **kcraigmile** » Wed Oct 27, 2010 9:56 pm

Thanks for the replies so far guys,

checked the crankshaft and the measurements of the crankshaft are spot on

we had 2 different gaskets sent to us for between the engine mounting plate and the engine and we think we may have put the wrong one on although not sure if it would make a difference

the one that came off the engine is the one below

and the one which we put on is the one pictured below

would this cause the low oil pressure, there are no leakages

cheers

Keith

Supermanuel · Post by **Supermanuel** » Fri Oct 29, 2010 11:35 pm

Whats the motor serial no. ?

JohnnyBoy · Post by **JohnnyBoy** » Sat Oct 30, 2010 12:28 am

I really don’t see how a gasket in this case can cause a loss in oil pressure, maybe if you’d fitted this one with the cut out as shown then that could cause oil to escape back into the crankcase.

However, I’ve never had a Fordson engine in bits so I don’t recognise this gasket or what it does but I’m very certain an engine designer would not allow a cut out in a gasket to act as an oil supply.

What was the oil pressure like before the rebuild? What about the oil pressure relief valve? Have you checked the oil pump? Are the camshaft bearings okay?

Post by **Brian** » Sat Oct 30, 2010 8:04 am

The difference in the gaskets is one is for a three bolt fixing cam shaft and the other for a single bolt fixing cam shaft. Neither will make any difference to the oil pressure.

Dandy Dave · Post by **Dandy Dave** » Fri Nov 05, 2010 2:05 pm

Worked on a track loader engine for a fellow a bunch of years ago with a similar problem. The engine was replaced with a factory rebuild short block which did not include a new oil pump. The bloke that put the engine in never checked the oil pump as when I pulled the pan down and pulled it out there was some metal filings stuck under the relieve valve. I cleaned them out and put it back together. Oil presure was perfect after that. Luckily the filings did not go though the engine as it has been running for around 20 years now. Just another thought. Dandy Dave!

Kav · Post by **Kav** » Fri Nov 05, 2010 2:21 pm

Years ago I had the same trouble with a 1954 Diesel Major. After I put new slipper bearings in , the oil pressure did not increase. I eventually found that the relief valve was not seating properly and at about 15-20 psi, most of the oil was going through the valve. I changed the relief valve and got good pressure straight away. Best regards - Michael

kcraigmile · Post by **kcraigmile** » Sat Nov 06, 2010 8:56 pm

Think we may have found the problem, it looks like it's the shells.

The new shells that we installed were standard but we have now noticed that the old ones that came out were 0.015 oversized on the housing

Have ordered new shells so will report back once they are installed

thanks for all your help so far guys

cheers

Keith

Dandy Dave · Post by **Dandy Dave** » Sun Nov 07, 2010 2:48 pm

Should be .015 under size. That would cause your problem, and another reason that you should always mic the shaft. Kind of odd being .015 as bearings usually come in .010, .020, and .040 under size. Anything is possible. Dandy Dave!

Grani · Post by **Grani** » Sun Nov 07, 2010 3:00 pm

I think he means the bearing bores. Standard are 3,167 and oversize are 3,182 that is 0,15 bigger.

BearCreek Majors · Post by **BearCreek Majors** » Sun Nov 07, 2010 7:17 pm

Keith, you may have a reconditioned block, if it has cam bearings in it you can bet the block has been bored to take .015 OD oversize crank bearings as well. The blocks came without cam bearings unless the block had been reconditioned/reworked at a shop or at the factory, they also line board the crank holes when needed and used the bearings with the .015 oversize outside diameter. If you can get these bearings let us all know as these and the cam bearings seem to no longer exist anywhere on the planet.
Check out my posting for “A fix for .015 O.D. bearings”

Pat

Dandy Dave · Post by **Dandy Dave** » Mon Nov 08, 2010 1:28 pm

BearCreek Majors wrote:Keith, you may have a reconditioned block, if it has cam bearings in it you can bet the block has been bored to take .015 OD oversize crank bearings as well. The blocks came without cam bearings unless the block had been reconditioned/reworked at a shop or at the factory, they also line board the crank holes when needed and used the bearings with the .015 oversize outside diameter. If you can get these bearings let us all know as these and the cam bearings seem to no longer exist anywhere on the planet.
Check out my posting for “A fix for .015 O.D. bearings”

Pat

That makes more sense. Line bored and a thicker bearing installed to correct a main that may have spun at one time. I take it that with this fix you could install a standard crank then. Dandy Dave!

Post by **Brian** » Mon Nov 08, 2010 3:44 pm

Think he means the size stamped on the bearing said 0.015" u/s which would be correct if the crank was ground to that.

If the block had been line bored the standard bearing would have been floating around in there and really noticable.

YorkshireDextaMan · Post by **YorkshireDextaMan** » Tue Nov 09, 2010 12:01 am

Dandy Dave wrote:
BearCreek Majors wrote:Keith, you may have a reconditioned block, if it has cam bearings in it you can bet the block has been bored to take .015 OD oversize crank bearings as well. The blocks came without cam bearings unless the block had been reconditioned/reworked at a shop or at the factory, they also line board the crank holes when needed and used the bearings with the .015 oversize outside diameter. If you can get these bearings let us all know as these and the cam bearings seem to no longer exist anywhere on the planet.
Check out my posting for “A fix for .015 O.D. bearings”

Pat
That makes more sense. Line bored and a thicker bearing installed to correct a main that may have spun at one time. I take it that with this fix you could install a standard crank then. Dandy Dave!

Thats not quite how re-line boring a block is done.
First the engineer shop mills a few thous off the bottom of each of the five main bearing caps, refits them and then does the Line Bore.
That way the main bearing shells retain their outside diameter.

BearCreek Majors · Post by **BearCreek Majors** » Tue Nov 09, 2010 2:36 am

Sorry guys, shaving the caps and line boring is still common for machine shops but it’s not how Ford did it. Line boring oversize and then installing oversize bearings had the advantage of keeping the original crank centerline to the top of the block correct even in the event of a severely spun bearing, porosity in the block, badly shifted castings, etc. Although no longer available the parts manual list bearings that are .015 oversize.

Pat

Post by **Brian** » Tue Nov 09, 2010 7:44 am

Yes, Ford did a whole range of main bearing shells at oversized OD, from .010" right through to .030".

There are none available from anywhere. I have been looking for a set of .020" OD for four years.

Dandy Dave · Post by **Dandy Dave** » Tue Nov 09, 2010 1:41 pm

I bet you could re-babbit a set of old shells and machine them to size. As long as they are not spun, and the shells damaged. I've pored a few babbit bearings myself, and it always worked out. Of course the ones I poured were for a 1915 Buick C-36 Roadster, and a 1934 Caterpillar model 50 Bulldozer of which neither had shells. Bearing shells are steel, and then a layer of copper is electoplated, and then the babbit is last. I have read that old autos, with inserts made from unobtainium like these Fordson Bearings, Have been re-babbited for engine restoration. Dandy Dave!

Dandy Dave · Post by **Dandy Dave** » Tue Nov 09, 2010 2:01 pm

BearCreek Majors wrote:Sorry guys, shaving the caps and line boring is still common for machine shops but it’s not how Ford did it. Line boring oversize and then installing oversize bearings had the advantage of keeping the original crank centerline to the top of the block correct even in the event of a severely spun bearing, porosity in the block, badly shifted castings, etc. Although no longer available the parts manual list bearings that are .015 oversize.

Pat

Being a Diesel, and with the close tolerences of the piston and head clearence, I can see where this is a viable way to do it. A gas engine would have more room to "play with." When you are talking .015, that is about 1/64th of an inch. If this was increased to 30. It is a little less than 1/32 of an inch. Considering that that the piston and head/ valve clearence is only about 1/8 of an inch in a diesel. That would be a mile and a half too much to line bore the engine the traditional way. I can see the pistons rapping on the valves from here. Looking at it this way, it all makes perfect sense why they did it the way they did. Dandy Dave!

YorkshireDextaMan · Post by **YorkshireDextaMan** » Tue Nov 09, 2010 6:02 pm

Dandy Dave wrote:
BearCreek Majors wrote:Sorry guys, shaving the caps and line boring is still common for machine shops but it’s not how Ford did it. Line boring oversize and then installing oversize bearings had the advantage of keeping the original crank centerline to the top of the block correct even in the event of a severely spun bearing, porosity in the block, badly shifted castings, etc. Although no longer available the parts manual list bearings that are .015 oversize.

Pat
Being a Diesel, and with the close tolerences of the piston and head clearence, I can see where this is a viable way to do it. A gas engine would have more room to "play with." When you are talking .015, that is about 1/64th of an inch. If this was increased to 30. It is a little less than 1/32 of an inch. Considering that that the piston and head/ valve clearence is only about 1/8 of an inch in a diesel. That would be a mile and a half too much to line bore the engine the traditional way. I can see the pistons rapping on the valves from here. Looking at it this way, it all makes perfect sense why they did it the way they did. Dandy Dave!

.

It would not matter which ever way anyone Line Bored a block. the center go's plumb down the same center line, you can not do it any other way, and that applies to any engine including a Fordson 4D.

kcraigmile · Post by **kcraigmile** » Tue Nov 09, 2010 10:30 pm

Hi, we managed to get a set of bearings although you can only get them for the 6 cylinder so have to buy them in set of 6 rather than 4, they are the 015 oversized on the housing, you can also get them undersized on the shaft

The address details and telephone no that we got them from is below

David Falconer
Unit No 7
Blackburn Industrial Estate
Kinellar
Aberdeen
Scotland, UK

tel no 01224 790080