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"

[PA-Kubota]

you got screwed... he's feeding you a line of BS

 

[Barker806]

Just throwing this out there ... Valve guide seals will do the same thing. He may not have put any on the valve stems. I had a JD 5205 that had a bad set of valve guide seals and it looked like a crime scene when you ran it. Smoke and oil everywhere! I lapped the valves and changed the seals and it has been fine for 10 years.

 

[Big-Foot]

Hi guys…
I’ve built many engines and was an Engineman (diesel mechanic) in the Navy. I agree with what a number of the other wrenches here had to say in regard to proper break-in under load & oil pressure. A couple things I have to add are -
1) We have no idea how much assembly lubricant is trapped in the oil filter. Since the engine is not getting hot enough to dissolve the assembly lube trapped there, it is likely causing a restriction. Swap to a fresh oil filter and after a couple hours of proper break-in, dump the oil and filter again and put in your favorite 15w40.
2) Don’t idle that engine anymore. You may have already damaged the rings and bores by not putting enough cylinder pressure in those bores to seat the rings. The rings may have been “rocking” in their grooves. That will take the edge off of them.
—
Finally - after 10 hours, if she’s still smoking, I would do a proper leakdown test to see if the rings are the issue..

Regards - Randy

P.S. Most all oil pressure gauges are connected downstream of the filter, which is why you may have a low oil pressure reading at idle If the filter media is loaded with assembly lube.

 

[daleb]

I recently rebuilt a 350 Chevy engine (my 4th engine rebuild). Machine shop advised me that rings aren't seated by RPM or miles any more, but heat (cast iron vs. chrome moly?). I was told to run it at 2000 to 2500 rpm and let it get hot (hotter than normal run temp) for about 15 minutes

 

[deezler]

You got issues. Sorry to say but a full rebuild is probably in order again.

No thermostat? get the F$%^ out of here with that nonsense.

I see a lot of old school thinking about "seating the rings". Mostly a wives tail here in 2023. The only thing a poor break-in will do is lead to gradual oil consumption issues over time, not really a big deal. And has nothing to do with your oil pressure issue. Your engine is smoking because it's burning a lot of oil in cylinder - most likely from the valves, not a piston ring issue. It'll probably get worse, not better.

Rebuild, with a different mechanic. Sorry.

 

[boatmoter]

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.

when I was building & repairing diesels for a used tractor dealer I used to use comet or ajax and put a half handful down the intake while running,it lightly sands and seats in the rings on new builds, do it 3-4 times

 

[oneal hicks]

The Mechanic needs to lick this calf over smoke is a bad problem (may not have oraneted the rings correctly) however the oil pressure drop you can't live with for long.The repairs should be at his expense!

 

[pmsmechanic]

when I was building & repairing diesels for a used tractor dealer I used to use comet or ajax and put a half handful down the intake while running,it lightly sands and seats in the rings on new builds, do it 3-4 times

When I went to school I was told to only do this is you can't get the rings to seat.

 

[rocco611]

You can run it for a while and see if the rings come in, but the oil pressure issue is not going to change with break in. Normal oil pressure cold but low at warm idle usually indicates too much clearance somewhere in the engine. As the engine warms up the clearances increase and the oil gets thinner, pressure drops. You could pull the exhaust manifold, you will find oil in the exhaust port or ports of the cylinder or cylinders that are passing oil, you could pull the pan, check the bearings and the crank. pull the head check the valve guides and seals, pull the piston or pistons check ring gap, cylinder condition. If your not a mechanic and have to pay someone to do all this, you may be throwing good money after bad. In that case I would pull the engine and have a competent shop to go through it.

 

[aherring]

Interestingly enough I rebuilt this engine on a 7610 almost a year ago for a friend of mine. Most of these engines have been sleeved, as was the case with ours (and yours too it looks like). I'll spare you all the details, but in the end we found out the hard way that the sleeves were causing problems. After cutting down the block for a sleeve, there isn't much material left in that cylinder wall. This thin wall was also suffering from pitting caused by old coolant, and was allowing coolant and oil to mix. I am including a picture of the block below, showing (in pen marks) where the separation was. It is a thin gap, but this was causing it to throw black oil/coolant out the exhaust pipe, very similar to what you have going on.

We sourced a completely new bottom end (block/crank/pistons) from the UK as we could not find a block in our area that was in decent shape to use.