new/used/rebuilt engine needed for JD 4100

[coloradotrout]

That agrees with tech manual. Cannot remove oil pan though; still need to remove engine from front half to get to it, but at this point it needs bored. The tech manual says .25 and .5 but I have not checked yet.

Any suggestions for parts? JD will likely make this not feasible unless a full engine replacement is reasonable. It's a yanmar. Surely there are non JD parts out there.

 

[dfkrug]

Any suggestions for parts? JD will likely make this not feasible unless a full engine replacement is reasonable. It's a yanmar. Surely there are non JD parts out there.

When I did my last JD4300 years ago, I was still able to get .25mm O/S pistons from a JD dealer in IL or PA. JD did not sell a .5mm. The xx00 tractors are old enough now that I would not be surprised if you can not get the pistons from JD anymore. I would be looking for Yanmar pistons meeting the same spec. I buy directly from JD dealers and eBay sellers.

 

[coloradotrout]

One JD parts person here was not too helpful. Could only see individual parts or block and crankshaft assembly. But that's 4K and nothing in the holes yet!

 

[dfkrug]

The Yanmar 3TNE74 engine is used in a lot of equipment, including machines from China. I see a Yannel set of 0.5mm o/s pistons and rings on eBay from China, for $445 + sales tax. You might also check on Alibaba, and from some Yanmar dealers.

 

[coloradotrout]

Is it possible to overbore and add a liner (New Overhaul Rebuild Kit for Yanmar 3D74E 3TNE74C 3TNE74 Engine Parts | eBay) ?

My block does not have a liner, but could it be overbored and then add?

 

[dfkrug]

My block does not have a liner, but could it be overbored and then add?

Interesting kit, reasonably priced.

I have never had the machine shop install liners, but it was suggested to me once by a shop. It was my only option if boring the block 0.25mm O/S did not remove all the scoring I had. I could not get a .5mm O/S piston for that engine.

Ask your machine shop what they will do and for how much.

 

[coloradotrout]

Interesting kit, reasonably priced.

I have never had the machine shop install liners, but it was suggested to me once by a shop. It was my only option if boring the block 0.25mm O/S did not remove all the scoring I had. I could not get a .5mm O/S piston for that engine.

Ask your machine shop what they will do and for how much.

I still have the engine in the chassis, and the shop will probably want only the block which means I have some teardown to do. (And having never gone this deep, I'm also looking for engines, aka "an easy way out". lol.) If I get JD parts, this is too expensive, but if those ebay parts are good, then it gets promising. The shop quoted me $220 for 3 bores (but I didn't ask about liners). I might only need the center cylinder. If I could leave some parts on the block it would save some effort. Are liners just pressed in?

 

[coloradotrout]

Interesting kit, reasonably priced.

I have never had the machine shop install liners, but it was suggested to me once by a shop. It was my only option if boring the block 0.25mm O/S did not remove all the scoring I had. I could not get a .5mm O/S piston for that engine.

Ask your machine shop what they will do and for how much.

Appreciate the feedback. I cannot find .5mm pistons either. Not sure the .25mm will be enough, thus the curiosity in the liners. I have zero experience at this level, so I'm assessing how much further to go. Do I need a rod for that cylinder? Do I need to do the other two cylinders? Do I need to replace crank bearings? And other stuff that I don't know/understand. Any guidance appreciated.

 

[dfkrug]

Well, first thing to do is fully remove the engine and assess what you need. Maybe the conn rod is bad, as you say. Crank bearings may be OK, but that kit includes them and costs about the same as just a set of 3 pistons/rings alone.

Liners are pressed in, but it will be a tight fit that requires accurate machining and a proper press. A good machine shop will know how.

As for doing only one cylinder, you may be able to get away with that, despite the slight imbalance. Not the optimal way to go.

 

[coloradotrout]

Well, first thing to do is fully remove the engine and assess what you need. Maybe the conn rod is bad, as you say. Crank bearings may be OK, but that kit includes them and costs about the same as just a set of 3 pistons/rings alone.

Liners are pressed in, but it will be a tight fit that requires accurate machining and a proper press. A good machine shop will know how.

As for doing only one cylinder, you may be able to get away with that, despite the slight imbalance. Not the optimal way to go.

So 15 years ago I was concerned about pulling off the head and oil pan and doing an in-place ring job. Today, I'm onto a complete engine tear down. I think that is what "an ounce of prevention is worth of pound of cure" means! I may be in over my head this time.