961 getting warm while brush hogging

ModMech · Jul 30, 2011

LP engines run a LOT hotter than their gasoline consuming counterparts, especially if the fuel mixture and timing are not spot-on.

After ALL this time, one can be assured that the timing has drifted to the retarded side and the fuel mix is lean, BOTH will cause overheating by themselves, combined they can spell dealth for an engine.

Now, the caveat is, I am not familiar with Ford LP systems on older tractors but the physics of the combustion process remains the same over the years.

Soundguy · Jul 31, 2011

ModMech said:
After ALL this time, one can be assured that the timing has drifted to the retarded side and the fuel mix is lean,.

If that's true.. couldn't we also assume that timing has been reset and points gap set and checked?

hard to ***-ume anything on these.

soundguy

wmonroe · Jul 31, 2011

ModMech said:
LP engines run a LOT hotter than their gasoline consuming counterparts, especially if the fuel mixture and timing are not spot-on.

After ALL this time, one can be assured that the timing has drifted to the retarded side and the fuel mix is lean, BOTH will cause overheating by themselves, combined they can spell dealth for an engine.

Now, the caveat is, I am not familiar with Ford LP systems on older tractors but the physics of the combustion process remains the same over the years.

By a lot hotter do you mean coolant temps or combustion temps? Coolant temps when running hard are about 160* +/-, checked with an infrared temp gun. Do the gasoline versions really run cooler than 160*?

ModMech · Aug 2, 2011

If your actual temps are in the 160*F range under load, there is no overheating or running hot condition.

Combustion, cylinder, exhaust and coolant temps all run hotter with LP than gasoline or diesel. Older equipment was generally WAY over-designed for cooling so you rarely see any significant difference in coolant temps from gasoline to LP because the radiator is just so large. If you measured the BTU rejection, which is the definition of "running hotter", LP engines dump more BTUs into the cooling package than gasoline engines do.

Cooling is a matter of delta T and flow, for the same coolant temperature you can remove a lot more BTUs simply by having the thermostat open even a little more increasing the flow the the radiator.

Soundguy · Aug 2, 2011

considering the 160' thermostat is kinda 'cold' and many people run a 180' tstap.. I doubt he will have an issue.. especially since it was a factory setup that ford used. As you surmised.. ford rads of that era were quite a bit overdesigned for the heat disipation they needed to provide.

soundguy

Oldstuff · Aug 2, 2011

I have a similar tractor and since I am somewhat new (1 1/2 years) to tractors I really do not know what temps are normal. Mine is a 1963 Ford 2000 gas engine and in cool and hot weather it runs at 130 degrees. However, when I cut knee deep weeds or taller on a 90 degree day it runs at 180-190. I assume this is normal, these are also the degrees the previous owner told me to expect? Does this sound OK?

Thanks- Oldstuff

Soundguy · Aug 2, 2011

yep...

soundguy

Oldstuff · Aug 2, 2011

Thanks Soundguy,

Oldstuff

wmonroe · Aug 3, 2011

Thats about how mine runs also. If its not working it doesn't make much heat, not until its loaded and working hard does it really run a consistent 'normal' temperature.