Oil Pressure

John Kamerer

New User
I just restored a 46 2N motor. Runs great, BUT after it warms up the oild pressure drops to 1 maybe 2 lbs. Starts out at 35 - 40 lbs. What gives? is the spring tension on the pressure thingy bobby up front weak?
 
(quoted from post at 18:47:42 01/09/13) I just restored a 46 2N motor. Runs great, BUT after it warms up the oild pressure drops to 1 maybe 2 lbs. Starts out at 35 - 40 lbs. What gives? is the spring tension on the pressure thingy bobby up front weak?
id you do any oil pump work? Did you verify all main, rod, and cam bearing clearances?
 
The original oil pump had a striped gear to the crank. a new one was installed during the over haul. Yes all clearances were checked. I do get good oil pressure for the first 10 minutes.
 
(quoted from post at 19:10:44 01/09/13) The original oil pump had a striped gear to the crank. a new one was installed during the over haul. Yes all clearances were checked. I do get good oil pressure for the first 10 minutes.
a new one was installed during the over haul" new pump or new gear?
 
(quoted from post at 19:19:28 01/09/13) just a new drive gear the impellers were in good shape
learance from the gear surfaces to surfaces they run against and shaft to bore clearances as well as face to face are all critical. "Look good" isn't good enough. If bearings plasti-gauged good & good cam bearing clearances were verified, I would be suspect of oil pump.
 
(quoted from post at 18:47:42 01/09/13) I just restored a 46 2N motor. Runs great, BUT after it warms up the oild pressure drops to 1 maybe 2 lbs. Starts out at 35 - 40 lbs. What gives? is the spring tension on the pressure thingy bobby up front weak?

If you have 35-40 PSI at startup the "spring thingy bobby" is producing at least 35-40 PSI of cracking pressure. The "spring thingy bobby" doesn't know or care whether the oil is hot or cold just how much pressure it is holding back. Your problem is elsewhere.

Loss of pressure when the oil gets hot says you have overly wide clearances or a leak somwhere in the oil system. First thought would be to verify the cover plate on the pump is sealed good and tight. Any leak there will kill pump pressure.

TOH
 

Looks like i need to drop the pan and check the nuts on the oil pump.. I remember tighting these as i wire the nuts. the oil filter line on the bottom goes arround the back of the block and enter the inspection cover for the valve adjusters. inside it sprays out the the valves. I thought this was letting to much oil pass thru. So, I installed a shut off valve in the line and as i close the valve I can get oil pressure up to 10 lbs but then I hear increasing valve noise.
 
(quoted from post at 19:45:04 01/09/13)
Looks like i need to drop the pan and check the nuts on the oil pump.. I remember tighting these as i wire the nuts. the oil filter line on the bottom goes arround the back of the block and enter the inspection cover for the valve adjusters. inside it sprays out the the valves. I thought this was letting to much oil pass thru. So, I installed a shut off valve in the line and as i close the valve I can get oil pressure up to 10 lbs but then I hear increasing valve noise.
the oil filter line on the bottom goes arround the back of the block and enter the inspection cover for the valve adjusters. inside it sprays out the the valves."...........sorry, but not on an N tractor!
oil_ckts_filter_2.jpg
 
Yep it's what it does. I've not seen this before either. But, who knows what some users do when they try to fix things. The govenor does not have a oil inlet. Do I need to install one and run the oil line there? The casting on the block shows B116 which I think means a Feb 11, 1946 engine. I got this out of Kamloops BC for $500 and it had almost new tires all around. but the engine was siezed up. I restored an 8N 3 yrs back with all your help on the forum.
 
(quoted from post at 20:20:40 01/09/13) Yep it's what it does. I've not seen this before either. But, who knows what some users do when they try to fix things. The govenor does not have a oil inlet. Do I need to install one and run the oil line there? The casting on the block shows B116 which I think means a Feb 11, 1946 engine. I got this out of Kamloops BC for $500 and it had almost new tires all around. but the engine was siezed up. I restored an 8N 3 yrs back with all your help on the forum.

A farmerization that probably breaks things and possibly why you had a siezed engine. That oil line flow is inline with the mains/rods and is sucking off pressure. Remove that kludge - the valves do not need it and it only confuses the issue.

TOH
 
(quoted from post at 17:29:10 01/09/13)
(quoted from post at 20:20:40 01/09/13) Yep it's what it does. I've not seen this before either. But, who knows what some users do when they try to fix things. The govenor does not have a oil inlet. Do I need to install one and run the oil line there? The casting on the block shows B116 which I think means a Feb 11, 1946 engine. I got this out of Kamloops BC for $500 and it had almost new tires all around. but the engine was siezed up. I restored an 8N 3 yrs back with all your help on the forum.

A farmerization that probably breaks things and possibly why you had a siezed engine. That oil line flow is inline with the mains/rods and is sucking off pressure. Remove that kludge - the valves do not need it and it only confuses the issue.


I'll drill and tap a 1/8th NPT in the governor and move the line there. The oil does need to return form the oil filter right?

TOH
 
(quoted from post at 20:35:04 01/09/13)
(quoted from post at 17:29:10 01/09/13)
(quoted from post at 20:20:40 01/09/13) Yep it's what it does. I've not seen this before either. But, who knows what some users do when they try to fix things. The govenor does not have a oil inlet. Do I need to install one and run the oil line there? The casting on the block shows B116 which I think means a Feb 11, 1946 engine. I got this out of Kamloops BC for $500 and it had almost new tires all around. but the engine was siezed up. I restored an 8N 3 yrs back with all your help on the forum.

A farmerization that probably breaks things and possibly why you had a siezed engine. That oil line flow is inline with the mains/rods and is sucking off pressure. Remove that kludge - the valves do not need it and it only confuses the issue.


I'll drill and tap a 1/8th NPT in the governor and move the line there. The oil does need to return form the oil filter right?

TOH
/quote]If I follow your oil line description correctly.........then what has been done is that the oil filter outlet (bottom center) has been routed into the valve cover instead of into the governor (or as before the governor oiling scheme, into the block(see pic), just below the filter. I would want it corrected, too, but I'm afraid this (where oil filter return dumps) will NOT impact your low oil pressure.
9N_filter_block_rtn.jpg
 
(quoted from post at 20:35:04 01/09/13)
(quoted from post at 17:29:10 01/09/13)
(quoted from post at 20:20:40 01/09/13) Yep it's what it does. I've not seen this before either. But, who knows what some users do when they try to fix things. The govenor does not have a oil inlet. Do I need to install one and run the oil line there? The casting on the block shows B116 which I think means a Feb 11, 1946 engine. I got this out of Kamloops BC for $500 and it had almost new tires all around. but the engine was siezed up. I restored an 8N 3 yrs back with all your help on the forum.

A farmerization that probably breaks things and possibly why you had a siezed engine. That oil line flow is inline with the mains/rods and is sucking off pressure. Remove that kludge - the valves do not need it and it only confuses the issue.


TOH
I'll drill and tap a 1/8th NPT in the governor and move the line there. The oil does need to return form the oil filter right?

Sorry - I didn't read carefully and jumped in with foot in mouth. I thought the line was off the tee at the back - not the oil filter outlet. That rerouting won't hurt anything.
 
Thanks for the pic. I'll run it to the block as shown. But I agree it won't help the oil pressure. or is there a good reason they went to the govenor?
 
(quoted from post at 21:37:34 01/09/13) Thanks for the pic. I'll run it to the block as shown. But I agree it won't help the oil pressure. or is there a good reason they went to the govenor?

Yes - the early governors were wearing out prematurely due to lack of lubrication.

TOH
 
Ihate to ask, did you check the main and rod bearing wear, excessive clearance could cause this problem(don't ask how i know).Richard in Poulsbo,WA
 
I think I would replace the oil pump with a new or rebuilt one. Also, the suction tube that allows the pump to get oil from the sump reservoir may be allowing air to leak into the oil pump.....commonly the silver solder/braze joint between the suction pipe and oil pump housing fails (gets loose) and allows air into the pump. If the pump drive gear was damaged by poor pump operation or the pump sucking some metal from the sump in the engine's previous history (it was seized!),the pump is suspect.
 
1 or 2 lbs. of oil pressure when hot? That"s a lot! (Just kidding, but my "49 front-mount has for years shown absolutely no oil pressure when hot, yet continues to run well.)
 
Thanks, that's reassuring . I'm still going through a few steps to fix it. The previous owner had the oil line at the bottom of the filter going into the valve adjusting side plate to spray the lifters. I'm thinking that enough oil stayed up on that ledge to cause low oil level in the pan. It's a thought. I'm rerouting the line today to the block to,test and then I'll run it to the govener. Let everybody know the results
It is such a great help to get all that knowledge laying out there in the world of Internet .
 
(quoted from post at 09:57:03 01/10/13) Thanks, that's reassuring . I'm still going through a few steps to fix it. The previous owner had the oil line at the bottom of the filter going into the valve adjusting side plate to spray the lifters. I'm thinking that enough oil stayed up on that ledge to cause low oil level in the pan. It's a thought. I'm rerouting the line today to the block to,test and then I'll run it to the govener. Let everybody know the results
It is such a great help to get all that knowledge laying out there in the world of Internet .

Got the oil line ran to the govenor. Started up with 30 lbs of oil pressure. after 10 minutes went down to 15 and the after 15 min droped to 10. 20 mins it was down to 5. Rev it up to half throttle and it raised to 15. did this a few times. And then at idle would show 2-3 lbs. Rev it and it would come back to 10-15 Lbs. So, whats the thoughts out there?
 
(quoted from post at 19:39:38 01/10/13)
(quoted from post at 09:57:03 01/10/13) Thanks, that's reassuring . I'm still going through a few steps to fix it. The previous owner had the oil line at the bottom of the filter going into the valve adjusting side plate to spray the lifters. I'm thinking that enough oil stayed up on that ledge to cause low oil level in the pan. It's a thought. I'm rerouting the line today to the block to,test and then I'll run it to the govener. Let everybody know the results
It is such a great help to get all that knowledge laying out there in the world of Internet .

Got the oil line ran to the govenor. Started up with 30 lbs of oil pressure. after 10 minutes went down to 15 and the after 15 min droped to 10. 20 mins it was down to 5. Rev it up to half throttle and it raised to 15. did this a few times. And then at idle would show 2-3 lbs. Rev it and it would come back to 10-15 Lbs. So, whats the thoughts out there?

Same as before - you have excessive oil clearances somewhere - in the pump, in the bearings, possibly both. The 10-15 PSI will keep it running but something somewhere is in less than new condition.

TOH
 
(quoted from post at 16:39:38 01/10/13)
(quoted from post at 09:57:03 01/10/13) Thanks, that's reassuring . I'm still going through a few steps to fix it. The previous owner had the oil line at the bottom of the filter going into the valve adjusting side plate to spray the lifters. I'm thinking that enough oil stayed up on that ledge to cause low oil level in the pan. It's a thought. I'm rerouting the line today to the block to,test and then I'll run it to the govener. Let everybody know the results
It is such a great help to get all that knowledge laying out there in the world of Internet .

Got the oil line ran to the govenor. Started up with 30 lbs of oil pressure. after 10 minutes went down to 15 and the after 15 min droped to 10. 20 mins it was down to 5. Rev it up to half throttle and it raised to 15. did this a few times. And then at idle would show 2-3 lbs. Rev it and it would come back to 10-15 Lbs. So, whats the thoughts out there?
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