water temp questions

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May 11, 2011
Wilmington NC
So im just trying to rack some brains here on the causes behind my dilemma.

Finally had some nice weather and decided to take the fj40 out on the beach for a cruise.

My water temp always spikes on the beach from a constant on-road temp of (170-180) to about 200 or so. if I turn the truck into the breeze naturally it will cool down.

so what gives? what is making it rise ?
200 deg is a normal temp.

What temp thermostat are you running? Ideally, your truck should run within +/- 10% of your thermostat, so 200 deg is still normal especially when running in sand (low speed, high effort).

I have a 190 deg thermostat and my truck runs between 180-210 deg.
this sounds normal. the temperature on my truck will fluctuate depending on how much air flow the engine bay can receive.
And... If you are driving, with the wind to your back, are you driving faster than the wind speed?

If not, you won't get much air into your engine bay...

Like running, if you run, with the wind to your back, the wind will push you along.

But, unless you run faster than the wind speed, you will find that you are hotter than expected.
212° is the boiling point with no cap or antifreeze. 230° with 50/50 mix and 13 lb cap. 200° is nothing to be concerned about on its own.

Do you even have a clutch fan?
No background, no speculation here.

Direct drive or clutch?
Rad core [3/4] and age?

You've got homework.
running the stock radiator and it appears original. (just picked this truck up 6 months ago) and starting to go thru it .. its a 1973 year truck

has a new weber 38 carb, timing was just set about 3 months ago

truck is running a 50/50 mix and i have no idea on the thermostat rating.

driving in road conditions it stays at 170-180 constant and never rises even at idle

if I stop the truck and let it sit it will settle back down to the 180 mark with no issues. it has never overheated but im just trying to see if this is a normal flucuating temp range. (i have an 80 series but that guage is useless)

driving conditions are about 5-10mph. im in no rush. i have an aux fan but honestly it doesnt make much difference

on the fan clutch i will have to do my HW and report back, i dont think so... since its a 73 (but i do have double pulleys - im sorting thru)

Its just something i noticied driving and monitoring and wanted to see thoughts on this.
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yea OEM 4 blade. ( i need to do the 6 blade update). and a 12" procomp aux fan in front of the radiator as a pusher

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