3TNE84

Anonymous Poster · Jun 19, 2003

I see different HP ratings for the 3TNE84 in diff. JD tractors. 30/25 in the 790 and 32/27 in the 4310. Do they have different injectors, inj. pumps or is the pump just turned down?

_RaT_ · Jun 19, 2003

I would suspect both are different. The torque on the 4310 is considerably greater. 54.1 ft lbs vs 73.1 ft lbs both taken at rated speed of 2600 RPM.

Anonymous Poster · Jun 19, 2003

I agree, but what is the difference the motors have the same ## from Yanmar. I would bet on the pump???

If they are really otherwise the same block, cylinders, pistons, etc. on would think that the higher numbers MIGHT shorten the life of the motor that is working much closer to it's peak. AT least chnge the service intervals???

Sort of the way you can get a diesel pickup motor that puts out 300hp and the same basic setup will run at 200 hp commercially. The average Joe gets a quicker pickup and the working guy gets a longer service life (maybe).

_RaT_ · Jun 19, 2003

Well, with Kubota, the difference between the L4330 and the L4630 which use identical diesels, is the fuel injectors as my dealer told me. Perhaps a quick trip and a look under the hood might reveal a little. Rockyridge has probably crawled all around his 4310 enough to give you a part number or description of the pump and injectors. My neighbor uses a JD 790. I think for it's size, the power is very decent. The exhaust blows in your face and smells like burning BBQ fluid more then diesel, other then that, it works just great for him. I've tried talking him into redirecting the exhaust pipe if purely for his health. I removed the loader for him. He was very reluctant to have it removed fearing it would never go back on. I told him I would also put it back on. He was quite insistent that it really was not a problem mowing with it on. He now can't understand why he ever mowed with it on. Sometimes you just gotta show these old farts a few things, after all, they certainly have showed me plenty, Rat...

rockyridgefarm · Jun 19, 2003

JDParts Says they are differant.

4310
pump - AM881045
INJECTION NOZZLE - AM880545

790
pump - AM879904
INJECTION NOZZLE - AT110293

I doubt the 4310 is being over-driven...

_RaT_ · Jun 19, 2003

I'm sure Yanmar and JD work out the details pretty thoughly regarding engine performance/durability. If anything, just from a pure warranty point of view, I should think erroring on the underdriven side to be more like it. Not that you can't load it or any other engine up, but for much of the normal use, its going to last a very long time.

Anonymous Poster · Jun 19, 2003

I doubt the 4310 is being over-driven...

I didn't mean that. I was just thinking that in the lower powered configuration the thing should last a long time. It is being run well below potential which is nice, at least for longevity sake. /forums/images/graemlins/wink.gif