Engine Cooling Systems and Components

michael mayben said:
so that part is done!

How'd the rest of the motor turn out after the head gasket work? Any other issues?
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At this time everything seems ok. I think the new head gaskets, high volume water pump, and the radiator/fan combo was exactly what was needed.

Next weekend I will test it out on the sand, if it is going to get hot that would be the place for it to happen. Maranda needs some time behind the wheel anyway, she can practice her reaction time on the beach. :cornut:
 
Just to add to this thread... Sycamore branches do not improve cooling system efficiency, at least in my own personal experience.

On another note, what is the normal "max" reading you guys notice from the factory coolant gauge in the areas that are less like a desert? Mine often climbs to the 2/3 Mark or higher, and this was before I dropped a sycamore branch into the radiator, trying to find out how much coolant I had.

Still have to find a way to get that out, too...
 
kyleandhisih said:
just to add to this thread... Sycamore branches do not improve cooling system efficiency, at least in my own personal experience.

On another note, what is the normal "max" reading you guys notice from the factory coolant gauge in the areas that are less like a desert? Mine often climbs to the 2/3 Mark or higher, and this was before I dropped a sycamore branch into the radiator, trying to find out how much coolant I had.

Still have to find a way to get that out, too...
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Well, there can be variations in stock gauges (or any gauge for that matter)...

On my t/a with a 180 thermostat, normal operating temperature was the needle at the left side of the horizontal line in the gauge.

Running hard going uphill over passes (CA), it would get close to 1/2. But, it would quickly come down going down the other side.

The only time it got to 2/3 on the gauge was when the thermostat "stuck"...

Think you should check the thermostat assuming everything else (radiator / water pump) is in good shape... Do you still have the shroud?
 
robertc said:
well, there can be variations in stock gauges (or any gauge for that matter)...

On my t/a with a 180 thermostat, normal operating temperature was the needle at the left side of the horizontal line in the gauge.

Running hard going uphill over passes (CA), it would get close to 1/2. But, it would quickly come down going down the other side.

The only time it got to 2/3 on the gauge was when the thermostat "stuck"...

Think you should check the thermostat assuming everything else (radiator / water pump) is in good shape... Do you still have the shroud?
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I have replaced the thermostat, and after I discovered this place I made sure to crack it back open and verify correct part, as well as operation in electronically monitored hardboil scenario.

Pump has also been replaced, mostly due to my Dad's opinion that "it's running hot" (underhood), but then again he's experienced with the big3, and it still gets just as warm underhood. It was the stamped version, and no thought at all was given to the impeller-to-housing running clearance.

The shroud is there, the oem fan appears to be there, the radiator was removed for a recore and came back with a fin pitch of ~8/inch (which I thought I read was "factory").

To tell the truth, it's always read at about the 2/3 area when the coolant reaches temp - as far as I can remember. It will drop some on the interstate at 65, but it's back to the 2/3 Mark any time I'm cruising at 55 or less. We don't really have any serious grades to test around here, save for one on the interstate north of benton... And it's a whole 20+ mile round trip back to benton unless I tackle the median fencing/emergency vehicle access cuts. Poor people can't make many miles in these vehicles without a spare 5gal can full!

I've not really worried about it after I take my eyes off the gauge, and I guess discrepancy in the ever-so-accurate factory device is the most likely explanation. I should probably go buy an ir gun anyway, and maybe apply at the local o'reilley's or something beforehand in favor of an employee discount.

...and maybe I can find out if the tank with the limb in it has an odd heat signature?

:icon_rotate:
 
As long as the "displayed" temp goes up and down (slightly) with increased/decreased engine load, then everything is working correctly kyle!

The oem gauge display is a visual indicator of cooling system functionality...not a definitive instrument as you know. Your idea about snaking the inexpensive infrared tool from hf is perfect, those items are very accurate and serve the purpose very well for "mapping" cooling system performance.

Ya can't make a direct comparison of typical actual cooling system temps between pickalls and the Scout II due to a 20% lower radiator capacity/efficiency for the sii package. A pickall is actually somewhat "over-capacity" which is certainly not a negative...but a Scout II in oem form is barely adequate, even the so-called "increased cooling" option package...big difference.

Underhood temperature really means nothing as far as the engine is concerned. "feel" is subjective and everyone "feels" temperature differently.

Underhood air temperature does affect engine performance however if the motor is tuned for performance with a performance fuel system (not smogerator).

I have observed many times...the liquid in the windshield washer tank boiling when the hood was popped open on many vehicles while the engine cooling system at idle (and the a/c system) was perfectly normal at an ambient air temp of 165f in dealership parking lots in las vegas in August! That is an ambient temp measure at two inches away from the vehicle grille, dead center with the radiator package, that is the air the radiator sees, not the temperature that the four hour old "weather report" gives on the radio. The difference between the ambient temp taken at three feet above a green grass lawn, and twenty feet away at the same height in a line of stop-and-go traffic clogging las vegas blvd. At 2:30pm on a typical August day can be as much as 60f!!

Ambient air temperature (what we refer to as the "air-on" that the heat exchanger sees) has little to do with actual cooling system performance no matter what variation in "load" the engine has to deal with. Whether the ambient is 50f or 115f makes little difference. If the heat exchanger is properly sized, if the flow rate/volume of the water pump is correct, and if the thermostat is functioning properly, then the heat exchanger deals with increasing/decreasing coolant temperature in a near transparent manner. Displayed engine temp will increase with load and also decrease once the load is reduced and again stabilize at whatever value the thermostat can regulate within tolerance! This goes on in the motor vehicle engine cooling system constantly because unlike marine engines and aircraft engines, motor vehicles operate at continuously variable loads that are imperceptible to the driver except when going up a grade and coming down a grade. Same for adding a trailer to the "load" which is a constant that must be compensated for.

A properly operating thermo-control viscous fan clutch (or no fan clutch at all) and a fan shroud is imperative for proper functionality of the Scout II cooling system or any vehicle cooling system! Without a fan shroud, heat exchange efficiency of the package is cut by about 1/3 at road speeds under 35mph (ram air effect).
 
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I run the 195f stat in all my ihc vehicles except one, the Travelall gets a 190f 'cause I had one!

If you read through all the current and former literature produced by ihc, you will see the thermostat setpoint is actually called out all over the place. I simply like the way the 195f unit works in this stuff, no other reason!

It will allow the temp gauge to work in the lower one-third of it's reading in normal operation. That would be the "first" third of it's mid-range process and move up to one half of it's range at around 205f.
 
michael mayben said:
I run the 195f stat in all my ihc vehicles except one, the Travelall gets a 190f 'cause I had one!

If you read through all the current and former literature produced by ihc, you will see the thermostat setpoint is actually called out all over the place. I simply like the way the 195f unit works in this stuff, no other reason!

It will allow the temp gauge to work in the lower one-third of it's reading in normal operation. That would be the "first" third of it's mid-range process and move up to one half of it's range at around 205f.
Click to expand...

Sounds good, just need a confirmation that the above link is the correct item for a i4?
 
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