Back to the "slow to oil pressurre" N

Lynn Patrick

Well-known Member
Finally got the rider mower done & out of the way, so I tore into the '44 2N this morning (the one that dropped #1 sleeve). I have the oil pump out and on the bench and can see scratches (one might possibly be a hairline crack) and small nicks on the pick up tube. None seem to go all the way thru, but it's really hard to tell. Now I need more from the experience here. Is there any way to pressure check the tube? Do I solder everything I see & hope to fix it? Would JWeld be better? Brazing???? I need to order a new pan gasket so I have some time to try & get it right.
Thanks for any help anyone can give.
Lynn
 
(quoted from post at 14:05:31 03/20/13) Finally got the rider mower done & out of the way, so I tore into the '44 2N this morning (the one that dropped #1 sleeve). I have the oil pump out and on the bench and can see scratches (one might possibly be a hairline crack) and small nicks on the pick up tube. None seem to go all the way thru, but it's really hard to tell. Now I need more from the experience here. Is there any way to pressure check the tube? Do I solder everything I see & hope to fix it? Would JWeld be better? Brazing???? I need to order a new pan gasket so I have some time to try & get it right.
Thanks for any help anyone can give.
Lynn

My solution to the "I wonder if it's fixed now" conundrum. Not quite ready for prime time but very close.....

TOH

IMG_1852.jpg


IMG_1851.jpg
 
(quoted from post at 14:25:28 03/20/13) Interesting! What do you use to turn it up to speed?

That's the part that isn't done ;-) I have another drive gear that I'll chuck in a 3/8" VSR drill and use that to spin it. Got to cobble up some sort of coupling sleeve and it'll be "fire in the hole" time. I was working on that last night but got interrupted. My intent is to be able to test rebult oil pumps BEFORE they go in teh tractor. I also want to get some real quantification of oil pump performance by testing a known good pump with various grades of oil - hot and cold.

TOH
 
LP I did this this repair a while back. I just bought a new oil pump and pickup tube. New pan gasket and dont forget a new front crank seal. The other option is to rebuild your pump as long as it is out now.You can take the pickup tube off the pump and plug one end and apply air to it and check for leaks and or cracks but the cracks and leaks are either in the pump or where the pump is attached to the tube.When you decide what you are going to do post back for more info. Also before you decide how to proceed wait for more replies on this as there may be other who have a better fix. On your first post on this problem I think you have a "very small leak" somewhere.
 
(quoted from post at 22:05:31 03/20/13) Finally got the rider mower done & out of the way, so I tore into the '44 2N this morning (the one that dropped #1 sleeve). I have the oil pump out and on the bench and can see scratches (one might possibly be a hairline crack) and small nicks on the pick up tube. None seem to go all the way thru, but it's really hard to tell. Now I need more from the experience here. Is there any way to pressure check the tube? Do I solder everything I see & hope to fix it? Would JWeld be better? Brazing???? I need to order a new pan gasket so I have some time to try & get it right.
Thanks for any help anyone can give.
Lynn

One test that has never let me down is to install a vacuum gauge on the end of the pick up tube... My finger even works as a tool to check the ability of the pump to suck... If it will not pull a good vacuum are suck off the starter alone its the pump are pick-up tube no matter what is going on up hill of the pump...

If one answer would fix'em all I would be a zillion air
Its a tuff issue to go after but anytime I go after a pump """" ALL """ the bearings get inspected and changed if need B,,, not just the EZ ones to check """ ALL """ all of'em.... I have been bit by NOT doing a throw inspection but never again...
 
(quoted from post at 16:00:56 03/20/13) 'Maybe' just a tad optimistic with that guage !!

Maybe - maybe not high enough :shock: Notice there is needle valve in the output line that can be used to totally shut off the output flow. What do you think the maximum pressure is on a deadheaded N-series oil pump? That is one of the things I intend to find out - at least to the maximum extent my little drill is able to spin the loaded pump. My guess is it's considerably higher then the maximum number on the OEM dash gauge - I'm confident Henry didn't let his engineers put an oil over pressure relief valve in the engine if it wasn't needed :roll:

TOH
 
(quoted from post at 06:06:04 03/21/13)
(quoted from post at 16:00:56 03/20/13) 'Maybe' just a tad optimistic with that guage !!

Maybe - maybe not high enough :shock: Notice there is needle valve in the output line that can be used to totally shut off the output flow. What do you think the maximum pressure is on a deadheaded N-series oil pump? That is one of the things I intend to find out - at least to the maximum extent my little drill is able to spin the loaded pump. My guess is it's considerably higher then the maximum number on the OEM dash gauge - I'm confident Henry didn't let his engineers put an oil over pressure relief valve in the engine if it wasn't needed :roll:

TOH

What if in addition to the needle valve you made a pressure relief valve using original spring and plunger? What got me thinking is I have no idea of how much oil is actually going to the bearings. I know it would depend on the bearing cleaances.
 
(quoted from post at 18:47:12 03/20/13)
(quoted from post at 06:06:04 03/21/13)
(quoted from post at 16:00:56 03/20/13) 'Maybe' just a tad optimistic with that guage !!

Maybe - maybe not high enough :shock: Notice there is needle valve in the output line that can be used to totally shut off the output flow. What do you think the maximum pressure is on a deadheaded N-series oil pump? That is one of the things I intend to find out - at least to the maximum extent my little drill is able to spin the loaded pump. My guess is it's considerably higher then the maximum number on the OEM dash gauge - I'm confident Henry didn't let his engineers put an oil over pressure relief valve in the engine if it wasn't needed :roll:

TOH

What if in addition to the needle valve you made a pressure relief valve using original spring and plunger? What got me thinking is I have no idea of how much oil is actually going to the bearings. I know it would depend on the bearing cleaances.
What got me thinking is I have no idea of how much oil is actually going to the bearings." I would say all but a drip, unless your pressure it high enough to open the relief valve, which is a pressure that has been published.
 
(quoted from post at 19:10:00 03/20/13)
(quoted from post at 18:47:12 03/20/13)
(quoted from post at 06:06:04 03/21/13)
(quoted from post at 16:00:56 03/20/13) 'Maybe' just a tad optimistic with that guage !!

Maybe - maybe not high enough :shock: Notice there is needle valve in the output line that can be used to totally shut off the output flow. What do you think the maximum pressure is on a deadheaded N-series oil pump? That is one of the things I intend to find out - at least to the maximum extent my little drill is able to spin the loaded pump. My guess is it's considerably higher then the maximum number on the OEM dash gauge - I'm confident Henry didn't let his engineers put an oil over pressure relief valve in the engine if it wasn't needed :roll:

TOH

What if in addition to the needle valve you made a pressure relief valve using original spring and plunger? What got me thinking is I have no idea of how much oil is actually going to the bearings. I know it would depend on the bearing cleaances.
What got me thinking is I have no idea of how much oil is actually going to the bearings." I would say all but a drip, unless your pressure it high enough to open the relief valve, which is a pressure that has been published.

Also hsome squirt holes but they are probaly dwarfed by the bearing clearances. We could do the math ;-)

TOH
 
OK TOH. You inspired me! I put together a way to bench pressure test my pump. If I can figure out again how to post a picture I'll include it, but I mounted the pump on a heavy angle iron w/cork gasket, plugged the tube end w/a rubber hose & plug, tapped a air connector into it, hooked the whole thing up to my small air compressor so I had a small air supply, pumped up 20# pressure, then sprayed the whole pump & tube w/water & soap mixture (like testing inner tubes!). The good news/bad news is - no air leaks/now what? The pump is out so do I rebuild/replace it?
15965.jpg
 
(quoted from post at 11:37:46 03/20/13)
(quoted from post at 14:25:28 03/20/13) Interesting! What do you use to turn it up to speed?

That's the part that isn't done ;-) I have another drive gear that I'll chuck in a 3/8" VSR drill and use that to spin it. Got to cobble up some sort of coupling sleeve and it'll be "fire in the hole" time. I was working on that last night but got interrupted. My intent is to be able to test rebult oil pumps BEFORE they go in teh tractor. I also want to get some real quantification of oil pump performance by testing a known good pump with various grades of oil - hot and cold.

TOH

I don't know how much power it takes to get that pump up to speed but how about a heavy rare earth magnet stuck to the face of that gear?

Looks like you could even rig up some kind of pilot to center it on that gear and a shaft on the other side of it for a drill motor. Just a thought.
 
(quoted from post at 13:05:39 03/21/13)
(quoted from post at 11:37:46 03/20/13)
(quoted from post at 14:25:28 03/20/13) Interesting! What do you use to turn it up to speed?

That's the part that isn't done ;-) I have another drive gear that I'll chuck in a 3/8" VSR drill and use that to spin it. Got to cobble up some sort of coupling sleeve and it'll be "fire in the hole" time. I was working on that last night but got interrupted. My intent is to be able to test rebult oil pumps BEFORE they go in teh tractor. I also want to get some real quantification of oil pump performance by testing a known good pump with various grades of oil - hot and cold.

TOH

I don't know how much power it takes to get that pump up to speed but how about a heavy rare earth magnet stuck to the face of that gear?

Looks like you could even rig up some kind of pilot to center it on that gear and a shaft on the other side of it for a drill motor. Just a thought.

Gear is aluminum. I have another gear and my plan is to couple them face to face with a close fitting sleeve around the circumference to keep them concentric. The shaft on teh second gear is perfect for the drill motor. Just got to do it....

TOH
 
I removed the timing gear from the crank, had a friend with a 3D printer print a drive adapter for the pump, suspended the pan on long bolts, and installed just the timing cover so I could run the whole system oil circulating system with my cordless drill.

The camshaft has to be clocked in the right position or the oil flows out the grooves in the cam bearings and you will never get pressure. With everything set right you can watch the pressure change with pump speed. The poppet valve open/close can be observed too, and the influence of stretching the spring to increase the pressure is easily demonstrated.

I have videos (.MOV files) if someone wants to host them...
a107932.jpg
 
If you prove the pump and pick-up are not the issue and it looks like you are doing that... It looks like you are going to have to take a look into the engine after the pump...

A delay in pressure could be from clearance way out of spec pump connection to block,cam/crank etc that a good pump can over come once it overcomes the clearance with oil pressure/volume...

Y'all are going way over kill for me but I commend Y'all going the extra mile...

I check the suction side of the pump (with out removing the pan on a N) if its good move on to the other side of the pump (pan removed)....
 
I see this same thing when any old engine sit awhile. Oil drains back & it takes a bit for it to pick up & show pressure again. Probably worn/too large clearances in oil pump when it is not a leak in suction tube. Just my opinion. Personally, even though a bit alarming, it seems to be "all is well".
 
(quoted from post at 08:11:18 03/22/13) Picture of the 3D printed socket-to-oil pump gear adapter I used. If you want I can send it your way.

Very cool. I understand the 3D printing process but what exactly is the material it prints with and how strong is it?
 
This process is called (FDM Fused Deposition Modeling) where a thread of molten plastic builds the object layer by layer. A MakerBot was used to make this piece. I modeled the part in 3D CAD, and my friend printed it on his MakerBot.

The plastic is ABS like Lego building blocks. It isn"t quite that strong due to the multiple layer build instead of a solid casting. It worked fine in this application.
MakerBot
 

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