no oil pressure

LisaK

Member
Pulled a "project" 48 8n into the shop this evening. When it was last run I don't know. Couple years ago. Did compression test dry was 25-100-100-50 and wet range from 100-110-110-125 wet. No spark big shock..next was to verify op...Primed the oil pump...Yes I know how and I used 80/90 gear lube. Spun it over plugs out (not that that matters) no movement on gauge, Disconnected the line from the back of the gauge, no oil. Took the line off the junction block, Primed pump again, no oil. Dropped the oil, pick up tube not loose one tiny bit. Decided to call it a night and go home.
 
Great. I even tried piming it with
assembly lube last night. I'll try again
when i get out there in a bit but am I
looking at the oil pump is bad? I dumped
the oil last night to check the tube maybe
I should put some cheap oil back in
instead of the rotella if I will end up
dumping it right away?
 
(quoted from post at 10:40:42 11/02/14) Great. I even tried piming it with
assembly lube last night. I'll try again
when i get out there in a bit but am I
looking at the oil pump is bad? I dumped
the oil last night to check the tube maybe
I should put some cheap oil back in
instead of the rotella if I will end up
dumping it right away?

Your symptom is no flow at the end of the main oil galley. That might be any number of things - bad pump, a leak or blockage in the pickup, or a blockage in the oil pipe. You have an engine with no documented history so it's a real pig-n-a-poke.

Aside form getting an oil flow what is your long term goal? Do you expect to get it running and "in teh field" without doing engine work? You already have two bad cylinders.

In any event I would be using the cheapest stuff I could pour into it I had something more to evaluate.

TOH

PS> If you want to see oil out the back of the block remove the pressure relief and hit it with some shop air. That would eliminate the blocked pipe possibility. You could also try that on the end of the oil pickup tube
 
The goal with this one was to see how it
ran and if it ran good paint it and keep
it. Its got a step up tranny and near
perfect tin and almost new tires. Even
with the 2 cylinders that had low
compression but came up to normal wouldn't
that indicate the rings were stuck? I
hadn't really hoped to tear the engine
apart but that's the crap shoot ya take
buying a non runner. Been there done that
once already. So I will blow some air
through both places.
 
(quoted from post at 11:27:34 11/02/14) The goal with this one was to see how it
ran and if it ran good paint it and keep
it. Its got a step up tranny and near
perfect tin and almost new tires. Even
with the 2 cylinders that had low
compression but came up to normal wouldn't
that indicate the rings were stuck? I
hadn't really hoped to tear the engine
apart but that's the crap shoot ya take
buying a non runner. Been there done that
once already. So I will blow some air
through both places.

Compression test looks like ring blow-by - maybe stuck maybe not. Since you had/have the oil pan off I'd certainly have a hands-on look at the pump and some if not all of the bearings. Especially since you are having oil pressure issues. You've been to enough of these dances enough to know what to look for.

Good luck.

TOH
 
You may have a disconnected oil tube,a bad gasket,a bad oil pump,or a litany of related problems. ATF,put in the cylinders may unstick the rings. As you probably know,there can be many problems that show up as no or low oil pressure. I'd try the things listed if you only want a runner. It may start up with oil pressure and go on to be a good one. lha
 
Those wet readings came up pretty good. If it were mine, and not knowing the quantity of oil you pre-lubed it with, I would try pre-lubing with a pressure tank with at least 3-4 quarts. I have known diesel techs that run separate lines to another engine to pre-lube under pressure from the running engine. Cranking with no lube on main and rod bearings can ruin the clearances in a hurry. During cranking the bearings only have "boundary lubrication" at best. Hope this helps. Gerard
 
I don't have the pan off. I put a new
spring on the plunger. Put new oil in it.
Left the plugs out spun it over and on
about the 5th revolution it noticibly spun
over easier leading me to think oil
started moving. It took me a bit to get
the plunger back in and there was new oil
on it so leads me to think the gears are
holding oil. I did not prime it again. In
any case whether its right or wrong I just
cleaned the points on the dizzy and set
the. I'll throw some new plug wires on
and new plugs add some gas and see what
happens. If I'm going to have to tear into
it at all it will be a full rebuild
regardless if just the pump needs work.
For now I'm going to shoot my rifle for a
bit
 
Success! It runs and has good op! Has a bad exhaust leak on #4 and the clamp. Pull started it with my 51. I'll try upload the video when I get home
 
Thanks Colin! Cant wait to get it apart and paint it. Reason for the pull start was #1 wanted to see if the op would come up...and it did #2 the carb needs an overhaul (gas drips out of it) so 2x down the drive way was able to drive it around the yard a bit and clear some of the oil out of the cylinders we dumped in. The 3pt lift arms are missing so after we get a new manifold gasket on and do the carb we'll test that out to know if we need to take that apart.
First run
 
Good deal. I've never been able to get much cranking an engine. With distributed engines we use a drill and made several shafts to fit the different oil pumps. Hot idle oil pressure is the key here. Nice job.
 
Thank you. That's what we kinda thought that the 6v cranking wasn't enough. We compared it to my 51 and that takes a few seconds to register on the guage when starting and its 12v. He put the Sherman in high and tractor in 4th I pulled him in 1st wot. Now I know for the next one.
 
I think the pump did prime but the engine just needed to spin faster to get the oil through the lines. I don't think i pulled it 20ft and the pressure came up on the guage. Sure glad I didn't drop the pan.
 

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