Installing thermostat on a Jinma ty395 engine in a JM354 tractor

[Rich Waugh]

Thanks for the graphic Tommy, that was well done and easy to understand.

Thanks for verifying my understanding of diesel thermal efficiency, Bob. That's one of those bits of knowledge I have that I have no provenance for, like so many things in there. It comes from reading too much, I think. (grin)

 

[Bob Rooks]

I'm merely relating personal and hands-on experience with four different Chinese tractor brands Bob. I generally don't try to "improve" upon mechanical engineering decisions. If I take out a 75C thermostat, I replace it with a 75C or Fahrenheit equivalent. I've changed thermostats in Foton, Jinma, KAMA, TaiShan. No two thermostats were the same. In fact, the two seemingly identical JM254s I had didn't even have the same thermostat. I attributed that to them being from two different generations of the Y385 engine. As stated, the originals removed were 70/75/80/85 (centigrade). An 85C is indeed 185F, but as I said - it's at the top of the range. Hence my suggestion to BJR regarding the temperature stamp on the thermostat he removed.

//greg//

No worries Greg. My experience and education on diesel engines encompasses just about everything under the sun except Chinese tractor engines. My hands-on Chinese experience is limited to my little dozer. However, given that I have studied and worked on a myriad of heavy equipment in my 55-plus year working life thus far, I see striking similarities and certain engineering rules that are followed between equipment manufacturers of various countries. Emerging technology is a wonderful thing, and for the most part can be retro-adapted. There is nothing really wrong with a conservative approach to repairs other than you are not improving anything, and possibly propagating an undesirable/bad situation.

 

[Affordable]

Rich, that was done by Larry G a long time ago, I just keep it for reference, good info.

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[greg_g]

Therein lies the problem Bob, you only know one Chinese dozen engine. Given the ground speed of your machine, it may not even have the same engine variant as do similar vintage tractors w/the TY395 engine. Some are configured for stationary indoor operation, some stationary outdoor, some agricultural tractors, some dozers. Plus engine specs changed dramatically with each EPA edict. Don't for a minute assume that your engine is any kind of universal benchmark.

As the EPA tightened up, thermostat temp ratings had to increase to comply. The Ranch Hand tractor is a 1998, which means its got a pre-EPA engine. That's the basis for my stating that your 185F recommendation is at the upper limit. Pretty sure the pre-EPA engines used thermostats down in the 70-75C range. They were only "thermally efficient" relative to the engine generation

//greg//

 

[Bob Rooks]

Therein lies the problem Bob, you only know one Chinese dozen engine. Given the ground speed of your machine, it may not even have the same engine variant as do similar vintage tractors w/the TY395 engine. Some are configured for stationary indoor operation, some stationary outdoor, some agricultural tractors, some dozers. Plus engine specs changed dramatically with each EPA edict. Don't for a minute assume that your engine is any kind of universal benchmark.

As the EPA tightened up, thermostat temp ratings had to increase to comply. The Ranch Hand tractor is a 1998, which means its got a pre-EPA engine. That's the basis for my stating that your 185F recommendation is at the upper limit. Pretty sure the pre-EPA engines used thermostats down in the 70-75C range. They were only "thermally efficient" relative to the engine generation

//greg//

If what you say is true, then The Chinese are the ONLY engine manufacturerers that use different pistons, liners, cams, bearings, crankshafts, etc., for all those different applications. It has been my experience that the only differences in prime movers (engines) between the applications you mentioned is the flywheel, injector timing, and the governor type. Differences in types of heat exchangers expected.
Not many engineering changes are made with a bump in operating temperatures either. Thermal equilibrium is reached sooner and at a higher constant but tolerances remain the same. For example: The same Deutz air cooled diesel engines are used in trucks, tractors, generators, boats, and pumping stations in the Sahara Dessert. I guess then the Chinese engines are that unique.

 

[greg_g]

If what you say is true, then The Chinese are the ONLY engine manufacturerers that use different pistons, liners, cams, bearings, crankshafts, etc., for all those different applications.

I don't have a clue how you arrived at that conclusion from what I wrote. It's becoming clear that your view of the Chinese compact tractor world is solely through the prism of a very large diesel engines and your TY395 dozer. Of the two, only the latter is technically appropriate to use as a basis for discussion in this forum.

As it seems you need more definition, let's use the ubiquitous Y385. There's a stationary version for pumps (3000 rpm), another for generators (3600 rpm). Then there's the marine version, and the "walking tractor" version (governor speed unknown). Compact tractors got the Y385T (for tractor), which if you don't know is governed to only 2200 rpm. Of the Y385Ts, early sales in the US had the pre-EPA variants - followed by successive generations that had to conform to increasingly strict EPA regulations. Shrink the bore from 85mm to 80mm, and you have the Y380 - and all it's variants as well.

The whole Y80/85 series of engines DO share basics, varying individually by injection pump, thermostat, fuel advance angle, EGR, starting motor, et cetera - and/or any combination thereof. This is an unfortunately long way of getting around to explaining that a 185F thermostat doesn't necessarily make a 1998 Y385T engine any more "thermally efficient". I stand by my recommendation to replace the damaged thermostat with as close a heat range as possible.

//greg//

 

[Bob Rooks]

No worries Greg. But I still think a diesel by any other name is still a diesel. You are justified in your recommendation from a conservative standpoint.