Operating temperature for New Holland TN 70

[rScotty]

I don't have access to my service manual. However, I think it is binary; below a coolant temperature of 120°F, the timing is retarded 2°. Above a coolant temperature of 120°F, it is advanced by 2° back to design timing.

It is done internally to the hydromechanical Bosch Injection Pump. (As I said, I don't have access to the service manual. It's in our storage container since we moved to Idaho.) If I were designing the actuator I would have it fail to normal timing. 2° timing change is miniscule since I think this is just a "rule beater" to satisfy the EPA. during Tier II certification. I notice no difference in performance and the exhaust is invisible after startup.

That's interesting about the "invisible exhaust" on your TD95D. I think you are saying it runs very clean. So does the old tier II motor on our JD310. Those Tier 2 engines only had to meet minor EPA standards at the time, but ours has a natually has clean exhaust - and it is very economical to run in spite of it being 90 hp.

It makes quite a contrast to our 2008 Kubota with the emission equipment designed for the Interim Tier 4 regs - which are NOT the same as the final Tier 4 regs. Nobody would call that exhaust invisible. It's black. Interim Regs were all about NOx & not about soot.
That engine has horrid exhaust & less HP than the JD but uses twice the fuel. Getting a whiff of its exhaust will make your eyes cross, but that is what the EPA standards required at the time. Still, it's been a reliable engine in spite of the dirty exhaust

Someday I'd like to find a way to study up on exactly what the "engine computer" does on our Tier 2 JD.
rScotty

 

[Jerry/MT]

That's interesting about the "invisible exhaust" on your TD95D. I think you are saying it runs very clean. So does the old tier II motor on our JD310. Those Tier 2 engines only had to meet minor EPA standards at the time, but ours has a natually has clean exhaust - and it is very economical to run in spite of it being 90 hp.

It makes quite a contrast to our 2008 Kubota with the emission equipment designed for the Interim Tier 4 regs - which are NOT the same as the final Tier 4 regs. Nobody would call that exhaust invisible. It's black. Interim Regs were all about NOx & not about soot.
That engine has horrid exhaust & less HP than the JD but uses twice the fuel. Getting a whiff of its exhaust will make your eyes cross, but that is what the EPA standards required at the time. Still, it's been a reliable engine in spite of the dirty exhaust

Someday I'd like to find a way to study up on exactly what the "engine computer" does on our Tier 2 JD.
rScotty

Unless you know somebody that worked on designing the engine controls who is willing to talk about their design, I'm afraid that stuff is considered proprietary to the engine company. However, there are some books that discuss common rail fuel systems around. Look at Alibris or Amazon, etc. for books on this subject.

One of the methods to deal with NOX in gas turbine engines was "lean burn, quick quench". Combustion chemistry is a very complex subject. The primary burning zone is air rich and the secondary burning zone is fuel rich. As I understand the principle, the lean burn generates a great deal of NOX due to high temperatures and high airflows. The quick quench zone brings in fuel to quench the tempertures and reduce the NOX. Maybe Kubota used that technology in your interim Tier IV engine. Being able to control multiple parameters based on sensor info is the reason for electronic Power Control Modules (PCM).Granted, a gas turbine is a different beast from a compression ignition engine but the mechanism for the production of NOX is the high gas temperatures so injection timing and fueling rate using a computer controlled common rail system with multiple sensors maybe the way it is done. I'm just theorizing since I have no experience with CI engine control systems. I just know the old hydro controls are the most reliable ones.

 

[inpo44]

Replacing temperature sensor for the fourth time. This time going with mechanical gauge.

Anyone know what normal operating temp. is for this tractor?

Thanks

I have the manual for cab version of that tractor(TN70da). It’s the same engine. The green range on the factory gage relates to
140 -230 F. See the pics