Temperature differential

satelite

satelite

Senior Member
I was having trouble getting much heat out of the heater on my 53 PU so I decided to take some readings with my IR gun. To my surprise the passenger side was much colder than the driver side. 184 vs. 105 at the thermostat housing, 166 vs. 126 at the center of the heads and 123 vs. 93 at the center of the water pipes. At the time I built this engine I tested the 180 degree thermostats to be sure they were working and opened at the correct temperature. I know there may be some operating temperature differences between sides, but this seems excessive. What's going on here ?
Don in SC
 
I don't know how the thermostats are held down for a 53 pickup but for my 47 sedan, if they're not held down by something other than the hose they get pushed up by the water pressure under them, turn sideways, and quit working. Here's what I do to prevent it.

I pull a single strand of wire out of a piece of stranded wire,

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Cut it to 3½" length.

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and thread it through both sides of the thermostat like this.

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Then drape the wires down the side of the neck like this.

DSCN0754_zpsf2137321.jpg


Then push the hose down over it and tighten the hose clamp being sure that the clamp is at the top of the neck to grab the wires rather than at the bottom and possibly miss them.

Update: I have since refined the hold down wires. Twist each single strand around itself then drape a single wire down the head neck. Wire stays on the stat and in place better and only half the wires to cause potential leak.

DSC00519_zpsdda17c13.jpg
 
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are you measuring from the same distance with your IR gun? Depending on the 'gun' it could have a read / process area, at two feet that is several inches in diameter. Try holding the gun a few inches away on each thermostat housing and see what the reading is. I have a Fluke and it has an oval shaped zone that it reads from.
 
Then push the hose down over it and tighten the hose clamp being sure that the clamp is at the top of the neck to grab the wires rather than at the bottom and possibly miss them.[/QUOTE]

That is as simple, elegant and effective a method as I could hope to find. I'll keep this one for use when I get to final assembly of my engine. Thanks for sharing.
 
8BA's and EAB's are completely different than Henry's 59. I agree it has to be a stuck open thermostat.
 
SofaKing said:
Then push the hose down over it and tighten the hose clamp being sure that the clamp is at the top of the neck to grab the wires rather than at the bottom and possibly miss them.
Click to expand...

That is as simple, elegant and effective a method as I could hope to find. I'll keep this one for use when I get to final assembly of my engine. Thanks for sharing.[/QUOTE]

For SofaKing's benefit since apparently not relevant to this thread: I have since refined the hold down wires. Twist each single strand around itself then drape a single wire down the head neck. Wire stays on the stat and in place better and only half the wires to cause potential leak.

DSC00519_zpsdda17c13.jpg
 
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Do you have the heater valve open while doing this check? The heater acts like a radiator and dumps the cooler water back to the intake side of the pump, hence the right side is getting more cooling. Make sure the heater is closed off.
 
I removed the thermostat (it was closed) then tested it. It opened slightly at 182 degrees F but didn't open fully until over 200 degrees. It never closed even after being emersed in ice water. So it looks like the thermostat is bad. I will re-test with the IR gun after I replace it Monday
and post the results.
Don in SC
 
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