MD sleeves

sven · Jan 1, 2011

I have an MD that has poor compression. I took the head off today and it found the engine has very few hours on it since it was rebuilt last. The sleeves have no lip and everything looks new. I noticed that both the block and the head appear to have been milled. The sleeves stick up above the surface of the block by a few thousands of an inch. I assume they should be flush with the block and only stick up because the block was milled. Is this going to cause problems if i put it back together the way it is. Any ideas why all the clyinders would have low compression even though the rebuilt engine does not have much time on it.
Thanks

Andrew Z · Jan 1, 2011

They are supposed to be up a few thousadths. Either the rings became stuck or you have valve issues. Check to see if they are stuck to the piston and check the end gap of the ring in the cylinder and see what you get. Also a I/T manual would be of some help as well.

Andrew

D Slater · Jan 1, 2011

Did you check compression at the injector holes?
If not the compression will be low.

sven · Jan 1, 2011

The compression was checked at the injector holes. The engine will not run nice for the first 15 minutes or so when the block gets real warm, so I assume the compression is to blame for the hard starting.

Andrew Z · Jan 1, 2011

In gas mode you should be atleast 120psi or better.

Andrw

rustred · Jan 1, 2011

would be nice to post the compression results so we have something to go by. a real quick test on the small gas valves is to just remove the spark plugs when its running on diesel and see if there's a diesel compression leak . the starting valve mechanism needs to be adjusted correctly also.need .060-.080 clearance between starting valve and cam. lots of other things to check before pulling it apart. did the tractor get worked under load after o/h to seat the rings?

rustred · Jan 1, 2011

just thought of another important thing, did you check the valve lash gap? should be 0.017 hot. very easy to mess this up when not experienced for the job at hand. now that the head is off best to remove valves and look to see if they were seating good.when you checked compression at injectors was it set on deisel? you may also have problems in the fuel injection system, example injectors.

sven · Jan 1, 2011

I recently bought this tractor, i am not the one who rebuilt it. I had a to a repair shop where they checked the injectors and compression. The injectors were good but the compression was around 160 psi on the diesel side. The mechanic suggested taking the head off and thats what I did becuase I can't pay him to do everything or I'd go broke. Like i said, this tractor sounds great after it runs for 15 minutes but it sounds terrible unitl it gets warm.

sflem849 · Jan 1, 2011

Like i said, this tractor sounds great after it runs for 15 minutes but it sounds terrible unitl it gets warm.

Sounds like a lot of them I have heard. I would only give them 5 min, but for how much the rattle it feels like 15.

rustred · Jan 1, 2011

something sure sounds fishy here. with only 160psi i dont think it would run on diesel. need around 400 or higher psi. did he check on valve adjustment?

nosih · Jan 1, 2011

if you have sleeves that project approx 0.047 above the block (going from memory), you need to have a head gasket that goes around the od of the flange, to seal the head to block with the sleeve projection setting the crush of the gasket. If your sleeves fit tight to the block (no Projection), you need a special head gasket that fits on top of the sleeve to hold it into place, and provide the proper gasket crush at the same time.

D Slater · Jan 1, 2011

Compression that low makes me suspect the test.
Makes me wonder if they left it in gas mode or intake blocked when testing. Also if all 4 were that low. Think IH published compression numbers were for a RPM around 1000.

Janicholson · Jan 2, 2011

The valve job may have an effect if the seats were ground down into the head, and the old valves are reused (thin margins), the total compression can be dramatically reduced. Poor injector break pressure, pattern, or Prechamber installation all have starting and warm up issues that are far more probable than the poor compression you mention. I also do not believe it would run with compression that low.
Another issue is if it is running on all cylinders when running on gas. if it is not, or you are pulling it to start it, it is not broken, it just needs the 2 minutes of gasoline running on all cylinders, or 3to5 minutes when colder than 30 degrees. Jim

sven · Jan 2, 2011

Maybe while the head is off I will have the injectors looked at again. Do you know what a good injector break pressure is for these engines? Also could there be a problem with the timing on the diesel side?

DGK · Jan 2, 2011

Could be the rings had not seated in yet. I had a terrible time geting mine to seat in, finally worked it for a couple hours before blowby cleared up and runs good now. Doug

Janicholson · Jan 2, 2011

The Injector shop will know, I do not off hand.
Do be careful with the valve issue I mentioned below. The depth the valves operate in is a critical dimension. Jim.

rustred · Jan 2, 2011

injectors.
opening pressure new...740-750 psi
opening pressure used..690-710
no leakage below ......400
injection pump timing..0 degrees.

MD sleeves

sven

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Andrew Z

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D Slater

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sven

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Andrew Z

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rustred

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rustred

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sven

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sflem849

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rustred

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nosih

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Janicholson

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sven

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