new/used/rebuilt engine needed for JD 4100

[coloradotrout]

Thank you! I'll be making that contact today. If I can find a known good condition engine in that price range, that's the solution.

Bruce had one. If this works out, that would be amazing. Thanks Darryl.

 

[Kernopelli]

Glad to assist:thumbsup: Keep us updated.

 

[coloradotrout]

Should there be noticeable compression when turning the crank by hand? I can feel one piston going to the top. There's a good bit of force applied and then released. On the other two it's not that noticeable. This is with the valve cover off, dipstick tube off, oil pan off.

 

[coloradotrout]

Sharing a bit about the project. To get the Yanmar 3TNE74 ready for the JD 4100 have to:
swap exhaust manifold
swap governor/shutoff (to add solenoid shutoff for JD)
move fuel pump
move a block plug from near the oil pressure sensor
swap oil pan, spacer block, crank cover
swap frame mounting plate, starter

 

[dfkrug]

Should there be noticeable compression when turning the crank by hand?

Yes, lots of compression, but you can not easily tell which piston is pushing and which one is pulling.

It has been 2 weeks. Does this mean you bought an engine from Bruce, and you have it already? Details, man!

 

[coloradotrout]

Got the engine from Bruce. Fast ship, but got them swapped with a guy in NE. NE guy brought mine to me on 8.22. That added 4 days. Pretty much have all the parts off the JD that need to go on the Yanmar. All parts off Yanmar. I'm ready to start installing. Thus the compression check. With the YM pan off I can see the rod action. I can feel when compression is most. Your point about a vacuum is interesting but I would think it's the tdc compression that would be very noticeable. It is for 1 cylinder. Right as it's going to top there is a big increase in torque needed to rotate the crank. That's once in 2 revolutions. I believe that should occur 3x in 2 revs. There are 2 other times but they are much less compression and I can hear air escaping. It's many hours to the end so I don't want to continue unless I'm more certain this engine is good.

The valve cover is missing and when I got it one of the push rods was out from under the rocker arm. I had to loosen the rocker to get it under. Im not sure how it's possible to come out without pretty substantial force. I need to pull the rocker off to see if there is any other damage.

 

[dfkrug]

Hmm. What did you have to pay for this motor, and do you know anything about hours or use? Warranty?

Since it is easy when the motor is out, I would pull the head and check the bores. Replace the head gasket and rings if bores look good. A compression check is also a good thing to do, but that takes a special adapter and removing the injectors is not easy.

As for the valve springs, they are so soft you can compress them with your thumbs. My guess is that the engine got bumped in handling, which knocked the rocker off the rod. I wonder what happened to the valve cover....

 

[coloradotrout]

Bruce said valve cover was damaged. But it's gone. $1475 w ship. Was told 500h. Probably from Japan so no history. I can pull head and replace rings, but now I am edging past where I expected I needed to be with this engine.

 

[dfkrug]

Bruce said valve cover was damaged. But it's gone. $1475 w ship.

That is not bad $ if it is in good shape. If you drop it off your forklift or truck and it lands on its valve cover, I will bet that
the impact can pop a rocker off its valve.

 

[coloradotrout]

Yes. Fair price for full block. Even with the parts I have to swap a fair price. But if compression is low whole new ball game.