The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work"

   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work" #1  

TomSam

Member
Joined
Sep 1, 2023
Messages
43
Location
Tampa
Tractor
Kubota 5800
The engine only has about 30 or 45 minutes of runtime on it right now and that is basically been slow and fast idle. It is boiling black oil out of the exhaust manifold that runs down the engine. He said since it is Florida that it is not necessary to put a thermostat in it. I noticed that it never warmed up more than 110 or 120°. I put the thermostat in it and let it warm up to normal operating temperatures. When it warms up to normal temperatures the low oil pressure alarm goes off when the idle goes below 1000 RPMs. This coincides with a manual oil pressure gauge that I put on the side of the engine. We trailered it over to his shop and he said that the oil pressure is normal that it should be about 10 psi per 1000 RPMs. So at 1000 RPMs an oil pressure of 10 psi would be OK. He suggested using Lucas oil treatment and thicker oil. It currently has 15 W 40 oil in it. In his defense he ran the tractor around the property for a short time while riding the brakes to put some stress on the engine and it did seem like it was smoking less. The oil pressure issue remains the same. So my question is what is a good oil pressure at an idle on a brand new engine. I understand that a new engine will smoke when it is first started. How much is too much how long before it should stop or go down to the minimum. I am certainly not an engine rebuilder but I have done everything on this tractor except for actually assembling the internals of the engine. I feel a little bit uncomfortable about putting a big bush hog on it and running it for a couple hours without checking with someone else to see how they feel. What do you think. Thanks for your time and attention. OK



Sorry I should have included that information from the beginning.
-Bored 040 over
-Machined Crank
-New Pistons all
-New Rods all (one was bent)
-New Rings
-New Injectors
-New Valves
-New Guides
-New Oil Pump
-New Cam Bearings
-Lifters looked perfect just cleaned
-Push rods checked and re-used
-New Idler timing Gear
-New Water Pump
-New Radiator



I dealt with the machine shop dropped and picked up. The machine shop got the Reliant rebuild kit and did the cam bearings, the rings were installed when I got the pistons in the boxes. They said everything was correct and ready for assembly. I have done mechanical work since I can remember and do pretty well on any project BUT, I wanted an experience builder to actually put it together. I have put engines together but I am NOT "The Engine Guy"

The guy that put the internals together came to my shop with his father and put it together. I had everything cleaned, labeled, and laid out on a table like a surgery before the doctor gets there. I watched them and waited on his every request (tools, bolts, supplies...etc). He seemed to know what he was doing. No big red flags on the build.
 

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   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work"
  • Thread Starter
#2  
Ol Smokey
 

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   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work" #3  
Doesn't sound right to me, but I've never done it myself. Just watched videos of rebuilt other engines are they are looking for at least 40psi of oil at cranking speed before they'll turn the fuel on and try to start it.
 
   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work" #4  
Do you have a list of everything that was done to the engine?

Bored? Honed? New Sleeves? New Pistons? New Rings? New (or rebuilt) injectors? Valves? Valve Guides? etc.

The photo you included of the cylinders looks like it has some rust spots, and I'd be most comfortable if those were bored or honed out.
 
   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work" #5  
I've never seen a properly rebuilt engine burn oil like that before.

He said since it is Florida that it is not necessary to put a thermostat in it. I noticed that it never warmed up more than 110 or 120°.
I'd call bs on that one for sure.

When it warms up to normal temperatures the low oil pressure alarm goes off when the idle goes below 1000 RPMs
New rod and main bearings? Oil pump?
 
   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work" #6  
The engine only has about 30 or 45 minutes of runtime on it right now and that is basically been slow and fast idle. It is boiling black oil out of the exhaust manifold that runs down the engine. So my question is what is a good oil pressure at an idle on a brand new engine. I understand that a new engine will smoke when it is first started. How much is too much how long before it should stop or go down to the minimum. I am certainly not an engine rebuilder but I have done everything on this tractor except for actually assembling the internals of the engine. I feel a little bit uncomfortable about putting a big bush hog on it and running it for a couple hours without checking with someone else to see how they feel. What do you think. Thanks for your time and attention. OK
It is boiling black oil? I’m not sure what you’re saying here. How much oil? Oil leaking out of the exhaust manifold would indicate A) exhaust manifold gasket is bad B) Blowby in the piston rings or head assembly 0 need for magical additives if the rebuild was done correctly.
10 psi oil pressure / 1000 rpm is a rule of thumb.

IMO, as long as the oil is leaking into the exhaust manifold it will continue to smoke. How much and where from is what I’d be looking into.
 
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   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work" #7  
The builder may have broken a ring putting them in. Were the cylinders honed? In that photo, they look like crap. Oil in the exhaust can only come from a poor ring job.
 
   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work" #8  
Also breaking in an engine goes not mean taking it easy on the engine. It means warming it up slowly and cooling it off slowly under a moderate to a heavier load at first, say for half an hour. Then onto a more full load. The engine needs to work to seat the rings.

I agree with you on the thermostat. I would also hang a garbage bag over the grill and adjust that as you're working the engine to keep the engine temperatures well into operating range. That means you are the thermostat and you need to keep an eye on the temperature gauge.

I used to rebuild pumping units for irrigation. We would warm them up for a few minutes and then apply the load. There is no such thing as a partial load running a center pivot. It was kind of neat to watch. You could slowly over half an hour give less throttle as the engine broke in. After a day change the oil and put it to work for the season.
 
   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work" #9  
What do you guys think about driving it around with the brakes depressed to load the engine? Don't think I'd appreciate that on my tractor.

I grimace every time that I ACCIDENTALLY drive off with my brake engaged . . .
 
   / The guy that put the engine internals together says "The rings are not seated yet end the smoking is normal. Just give it a couple hours of work"
  • Thread Starter
#10  
Doesn't sound right to me, but I've never done it myself. Just watched videos of rebuilt other engines are they are looking for at least 40psi of oil at cranking speed before they'll turn the fuel on and try to start it.
Doesn't sound right to me, but I've never done it myself. Just watched videos of rebuilt other engines are they are looking for at least 40psi of oil at cranking speed before they'll turn the fuel on and try to start it.
The Oil is great until it gets up to operating Temperature. 60psi at cold start up then 45psi after it is warms to 140F as long as the RPMs above 1200. Then it gets weird....oil pressure drops radically below 1000 rpm to below 16psi at 800rpms (per low pressure alarm I added to build) the gage coincides to around 10psi. Thanks for your time.
 

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