How much temp is too much.

[JC-jetro]

A bit more info, I did check with my Owner's manual and it rate the radiator cap @ 13 psi. I bought an OEM cap from NH and can't remember the rating. I'll check the marking next time to see if I can figure out. But the point is as Rick said 7 psi cap or 13 the following is true.

Kansas City is 800 feet above sea level with atmospheric pressure of 14.1 rather than 14.7 psia

7 psi radiator cap=14.1+7= 21.1 and water boils at temp of 230 deg F
13 psi radiator cap=14.1+13= 27.1 and water boils at temp of 243 deg F

50/50 anti freeze raises the boiling temp to 223 @ atmospheric condition and up to 275 deg F.

So even at 7 psi it seems the manufacturer has designed the engine to see water jacket temp up to 230 for the cap to pop off.

In no time I exceeded 210 T housing and top of the radiator surface temp.

JC,

 

[rayikeo2]

JC, It probably does not make any difference at all which cap you use. Because of my core plug leak, which has not sealed yet, I have been running my 1700 with the radiator cap in the 1/2 half unlocked position (first notch) and it has not made any change in the temperature gauge reading. So you are good to go. However you should keep a close eye on the guage for any changes. When my water pump went bad, the first thing I noticed was the pump shaft started to get longer and moved closer to the radiator with the only thing keeping it from a seperation was the fan belt alignment. So if yours (ever) starts rubbing the radiator coils, shut her down fast for a water pump repair. It may never happen buy just be aware of the chance. Ray

 

[JC-jetro]

JC, It probably does not make any difference at all which cap you use. Because of my core plug leak, which has not sealed yet, I have been running my 1700 with the radiator cap in the 1/2 half unlocked position (first notch) and it has not made any change in the temperature gauge reading. So you are good to go. However you should keep a close eye on the guage for any changes. When my water pump went bad, the first thing I noticed was the pump shaft started to get longer and moved closer to the radiator with the only thing keeping it from a seperation was the fan belt alignment. So if yours (ever) starts rubbing the radiator coils, shut her down fast for a water pump repair. It may never happen buy just be aware of the chance. Ray

Ray,

I actually took the belt off to inspect the water pump pulley and the shaft. There is no front to back or side play in the shaft. it appears to be solid. I don't see at all any sign of water leak. The coolant level stays unchanged so I have no loss there. I'd make sure belt is tight enough but never to the point to cause premature failure of shaft seal or the bearing. All the heat and rain we had here caused some of the brush to grow like mad. I know the lay of my land and pretty much know all the trees and what I have on ground surface. My mowing was scary as it looked like I'm running my tractor in to a wall. some of the brush was so tall where with me standing on the tractor barely could see the top of vegetation. I reckon I could make out an elephant coming out of the thick stuff but certainly not a deer. I think some kind of disk cutter would be a better choice than brush hog in really thick stuff. By the way, dry heat is one thing and heat associated with humidity is something else. The heat index here today is about 115 degrees and that effects dry heat dissipation rate from the radiator to the ambient condition.


JC,

PS. I was thinking of coming with some contraption to honk my horn in case of high temp or low oil pressure. Idea Might have some Merits...may be !! :2cents:

 

[rayikeo2]

JC, When I first moved to my 12 acres the brush was as tall as you describe or taller. At that time I had a pull type brush hog on wheels. I mowed down some stuff that the grill on the tractor had to bend over to get past and it did heat up the temp guage. The end result was nome nice walking lanes in the back 10 acres. So after clearing your hunting lanes maybe everything on the tractor will return to normal. I can now mow my paths with my JD rider lawn tractor.

 

[magicheater]

When I rototill with my B7800/5.5' tiller The temp gauge can climb so I just give it a break after a couple of hours of hard tilling. The tiller is probably a little large for the tractor so I take that into consideration, it does do a very nice job. I make sure to idle the tractor for 10 minutes or so before turning it off though. I do not trust the gauge that is on the tractor so when it climbs farther than normal I take notice. Knowing your equipment is important.

 

[JC-jetro]

JC, When I first moved to my 12 acres the brush was as tall as you describe or taller. At that time I had a pull type brush hog on wheels. I mowed down some stuff that the grill on the tractor had to bend over to get past and it did heat up the temp guage. The end result was nome nice walking lanes in the back 10 acres. So after clearing your hunting lanes maybe everything on the tractor will return to normal. I can now mow my paths with my JD rider lawn tractor.

Hi Ray,

I was there this morning and cut about 2 acres of brush. Pic below shows what my little 1700 was up against.

JC,

 

[JC-jetro]

I say that your gauge and sender are well calibrated, and your tractor is performing well. If and when the gauge gets to the overheating mark, the engine will in fact be overheating or very close to it. With a 7psi or so radiator cap, at 1/8" to the left of the overheat mark, your tractor is running at its maximum thermal efficiency. Diesels do not run well or efficiently while cold or even warm.

Rick,

I was on my place to cut some of the thick brush. I'm not worked up too much about where the needle rests. There is a mark left of "H". I suppose that is not to exceed limit although I was not able to corroborate that from owner's manual. At where you see the gauge shows, the T housing temp was 212 and the top of radiator was 210. The ambient was pretty high with good heat index 110+. Do you know what maximum not to exceed head/ coolant temp for that vintage diesel engine is? I was not able to find a definitive number anywhere. There was no boil over and not slightest amount of burned oil or gasket smell.

Thanks,

JC,

Has anyone else has an opinion or experience with max not to exceed temp for diesel?

 

[RickB]

Rick,

I was on my place to cut some of the thick brush. I'm not worked up too much about where the needle rests. There is a mark left of "H". I suppose that is not to exceed limit although I was not able to corroborate that from owner's manual. At where you see the gauge shows, the T housing temp was 212 and the top of radiator was 210. The ambient was pretty high with good heat index 110+. Do you know what maximum not to exceed head/ coolant temp for that vintage diesel engine is? I was not able to find a definitive number anywhere. There was no boil over and not slightest amount of burned oil or gasket smell.

Thanks,

JC,

Has anyone else has an opinion or experience with max not to exceed temp for diesel?

Maximum operating temperatures vary, but generally are in the 190-210 range.

When the coolant reaches the boiling point, however altered by a pressure cap and antifreeze mixture, the boiling will begin in the cylinder head. When coolant liquid boils away from the head casting, the casting rapidly overheats (because gasses can't transfer heat from cast iron as fast as liquids) warpage/ gasket failure/ cracking can occur. If you have any appreciable amount of antifreeze in the coolant mix, or if your cooling system has sufficient integrity to contain a few pounds of pressure, and your pump has the ability to circulate coolant, your tractor is not about to overheat at the described temperatures. Your tractor is running near peak thermal efficiency. If it has sufficient coolant at startup and is not puking from the overflow, you are OK. Running it another 10 degrees hotter may change things.
FWIW, I would not want a 25 year old radiator to have to keep 13 PSI bottled up over the long haul. Regardless of the application, I would probably install a 7psi cap rather than the specified 13 psi cap if a replacement is needed.

 

[JC-jetro]

Maximum operating temperatures vary, but generally are in the 190-210 range.

When the coolant reaches the boiling point, however altered by a pressure cap and antifreeze mixture, the boiling will begin in the cylinder head. When coolant liquid boils away from the head casting, the casting rapidly overheats (because gasses can't transfer heat from cast iron as fast as liquids) warpage/ gasket failure/ cracking can occur. If you have any appreciable amount of antifreeze in the coolant mix, or if your cooling system has sufficient integrity to contain a few pounds of pressure, and your pump has the ability to circulate coolant, your tractor is not about to overheat at the described temperatures. Your tractor is running near peak thermal efficiency. If it has sufficient coolant at startup and is not puking from the overflow, you are OK. Running it another 10 degrees hotter may change things.
FWIW, I would not want a 25 year old radiator to have to keep 13 PSI bottled up over the long haul. Regardless of the application, I would probably install a 7psi cap rather than the specified 13 psi cap if a replacement is needed.

Thanks Rick,

Picked up the number off the radiator cap and will contact my NH dealer to verify the pressure. I too do not want to force cooling system to 13 psi above atmospheric pressure. I don't have my charts here at home but I thought the the temp would jump to 230 at 13 psi above atmospheric. It never puked once either. This is by far the tallest and thickest weed and highest temp I operated my tractor. I slowed down a bit here and there but kept on mowing for 2 1/2 hrs. Thanks for the insight.

JC,

 

[Hooked_on_HP]

JC, I was also concerned about my 1900 running around the mark below hot. Like you I checked it with the IR temp gun and found out this is arround 200 deg. I keep saying I am going to put in a temp guage with numbers but never seem to get to it. As RickB said 210 is where must manufactures want there engines to run.
Bill