I've been running 10w40 in my 8N but notice my oil pressure really drops off once it's good and warmed up. I know that a small drop is probably normal, but it starts at around 35 and drops to around 10. My engine is definitely worn, but 10 seems really low. Any suggestions on switching to a thicker oil? Would that help?
Oil Pressure in the 8N
1 - 19 of 19 Posts
Joined
·
1,421 Posts
You can run a straight 30 weight. I would not run heavier. Easiest way to increase your oil pressure is to drop the pan and replace the rod and crank bearings. You can do this in a afternoon. Be sure that your caps go back on the way they came off (imperative). Also would not hurt to get the oil pump serviced at that time. Maybe $30 cost.
Hopefully your not taching up that motor. Running high revs with a worn engine can spell disaster. Otherwise change the oil every year religiously. Sometimes I have seen on some of my past engines owned that the fresh oil can help quite a bit. Granted I am a bit of a geek and dont like running oil too long in a engine.
Running a heavier oil will give you a higher pressure sometimes, yet usually you cut down the gpm of oil delivered and worsen the situation.
Hopefully your not taching up that motor. Running high revs with a worn engine can spell disaster. Otherwise change the oil every year religiously. Sometimes I have seen on some of my past engines owned that the fresh oil can help quite a bit. Granted I am a bit of a geek and dont like running oil too long in a engine.
Running a heavier oil will give you a higher pressure sometimes, yet usually you cut down the gpm of oil delivered and worsen the situation.
G
Guest
·I've used Lucas in mine when the pressure is a little low. 30W is pretty much what we run.
To do the bearings as suggested, you do have to move the front end away from the tractor since the pan makes up the frame. You can just unhook one side and roll it away.
Good luck Sir
Also, we'd like for you to visit "Around the Campfire" and introduce yourself so others can say hello.
To do the bearings as suggested, you do have to move the front end away from the tractor since the pan makes up the frame. You can just unhook one side and roll it away.
Good luck Sir
Also, we'd like for you to visit "Around the Campfire" and introduce yourself so others can say hello.
Joined
·
906 Posts
When they were new, straight grade was the way to go (factory recomended), but with todays technology multi-grade is the way to go. I don't like to put HD (high detergent) oils in an engine that has been run for years on non-detergent oils as the detergent may cause crud to break off and clog oil passages.
I don't know normal oil pressure is for an 8-N.
I don't know normal oil pressure is for an 8-N.
Joined
·
1,421 Posts
This isnt exactly true. Detergent oils are designed to clean a engine yes. The thinner makeup of the detergent oil would actually clear passages rather than plug. This would also lower the oil pressure.bikerdave said:
The older oils used things like parafin and animal fats for lubricants. Usually this is what clogged passages. The parafin when the engine cooled after running would set up and thus clog passages.
Joined
·
2,499 Posts
here's my take... 10w40 is a bit of a junky oil when it comes to viscosity swings.. but has it's uses.
I see 4 things you could do.
1, swap in a new oil pressure gauge if it's not a newer one. old gauges can be inaccurate.. even 4 psi off is huge where you are at on pressures.
2/3, if gauge is good, you -could- go to a thicker oil.. it will up pressure a bit.. but is a bandaid. then again.. a cheap and easy bandaid too. 15w40 is a high quality oil as it is c rated... 20w50 is your other choice.
4, as said.. a quick way to up the pressure is a poor mans rebuild. drop the pan and swap in rod and main shells of the same size it already has. no need to even plastigauge them.. the old ones fit when new, and have worn from there.
that will get you some... and is fast and easy. reworking the oil pump is a great idea.. but takes more tools than the average shade tree has. bushing remaers.. etc. and if the pump needs changing.. you have to line bore as it is the front cap.... so may / may not mess with it.
If you are in that far.. might pay to pull the head, hand lap the valves,ream the ridge at the top of the sleeves, adn then put in new rings. that poor mans upper and lower will take a day, and requires no real special tools.. the ridge reamer and spring compressor can be rented at most auto parts stores..
you will get a compression bump, and a few psi oil pressure. might hant to run a brake or cyl hone into each jug up and god for a lil cross hatc for a couple seconds to helpt he new rings seal..
soundguy
I see 4 things you could do.
1, swap in a new oil pressure gauge if it's not a newer one. old gauges can be inaccurate.. even 4 psi off is huge where you are at on pressures.
2/3, if gauge is good, you -could- go to a thicker oil.. it will up pressure a bit.. but is a bandaid. then again.. a cheap and easy bandaid too. 15w40 is a high quality oil as it is c rated... 20w50 is your other choice.
4, as said.. a quick way to up the pressure is a poor mans rebuild. drop the pan and swap in rod and main shells of the same size it already has. no need to even plastigauge them.. the old ones fit when new, and have worn from there.
that will get you some... and is fast and easy. reworking the oil pump is a great idea.. but takes more tools than the average shade tree has. bushing remaers.. etc. and if the pump needs changing.. you have to line bore as it is the front cap.... so may / may not mess with it.
If you are in that far.. might pay to pull the head, hand lap the valves,ream the ridge at the top of the sleeves, adn then put in new rings. that poor mans upper and lower will take a day, and requires no real special tools.. the ridge reamer and spring compressor can be rented at most auto parts stores..
you will get a compression bump, and a few psi oil pressure. might hant to run a brake or cyl hone into each jug up and god for a lil cross hatc for a couple seconds to helpt he new rings seal..
soundguy
Thanks for all the advice, folks! I looked for bearings at just8ns.com and saw they have several choices for both rod and main bearings.....any suggestions on if I should stick with the standard width, or go undersized? And if undersized, how much?Lovesthedrive said:
G
Guest
·soundguy said:
So I should be able to still see the marks on them? Figured they'd be long gone...soundguy said:wncfarmer said:
IMPOSSIBLE
you must pull the old ones and see what they are marked and buy those again. can't practically go to an OS bearing unless you have the crank turned to match.
Joined
·
63 Posts
most often size is visible on back of bearing - noted as STD .010 .020 etcwncfarmer said:So I should be able to still see the marks on them? Figured they'd be long gone...soundguy said:wncfarmer said:
IMPOSSIBLE
you must pull the old ones and see what they are marked and buy those again. can't practically go to an OS bearing unless you have the crank turned to match.
unless crank is being machined put back in what comes out -
on using thicker oils - be careful as too thick will accerate wear at start up, take longer to flow when cold
on automotive style engines a general rule of thumb is 10 psi per 1000 RPM is generally considered adequate at operating temp
Joined
·
2,499 Posts
on these engines, even lower.. figure 6psi per 1000 is safe.. and I've seen much lass 
ditto on the bearing size ont he rear of the shell. unless it has spun.. it should be tere.
as for heavy oils.. ditto.. if I went to a heavy oil.. it would have to be multi vis.. .. not straight weight. ie.. 20w50 vs 50w
soundguy
ditto on the bearing size ont he rear of the shell. unless it has spun.. it should be tere.
as for heavy oils.. ditto.. if I went to a heavy oil.. it would have to be multi vis.. .. not straight weight. ie.. 20w50 vs 50w
soundguy
You need to know if you crank has been turned to decide under, over etc for bearings. I am not sure if there are markings or if you have to micrometer the crank itself. I remember plastigauging a crank in school but I don't remember if it was the mains or the connecting rods or both. It was easy to do, remove the cap, lay the plastigauge strip, looked like a string , on the machined crank from side to side, replace and torque the cap and then remove the cap and use the built in scale on the plastigauge container to measure how squished it was. This told you if your bushings were within tolerances. I think I would take the old bushings off and look for spec numbers on them before ordering. Shouldn't go wrong then. As said, don't mix up the caps and they probably have a number on the cap that matches the rod on the same side. If not use a prick punch before disassembly to put one mark on #1 two on #2 etc. Always mark the same side and both the cap and rod to keep things sorted.
Joined
·
63 Posts
plastigage can be used on any 2 pc bearing shell to indicate clearance - will not give bearing size or diameter
quality oils will not cause a problem, if sludge and buildup clog passages, detergents in modern oil will dissolve more readily and help keep from settling in galleries or gelling in pick up
changing filters is crucial, on some hiway truck engines a filter change without oil change can increase life of the oil by half.
modern oils do not wear out, but rather just get over contaminated
quality oils will not cause a problem, if sludge and buildup clog passages, detergents in modern oil will dissolve more readily and help keep from settling in galleries or gelling in pick up
changing filters is crucial, on some hiway truck engines a filter change without oil change can increase life of the oil by half.
modern oils do not wear out, but rather just get over contaminated
I would not just pick out an undersize bearing. You need to use an outside micrometer to measure actual journal diameter. From there you can determine the amount of undersize. You need to keep in mind oil clearance is .001-.003. As long as the undersize keeps you in that range you should be ok. Remember also to mark caps with a number and an arrow to make certain they go back on in the same position and direction. They are align bored and honed for a perfect circle and centerline. Gerardwncfarmer said:
1 - 19 of 19 Posts
