M37 exhaust temp above 500 degrees

[highfavor1004]

I am posting this for a friend. He has recently acquired and put together a fully restored M37. The motor has been completely rebuilt and everything on this truck mechanically looks brand new. He started the truck the other day oil presser was good. Now he told me that the temp was at 220 degrees. Now that seemed high to me. He has an exhaust tempt gauge. the gauge was reading 500+ degrees. he shut the truck off to stop any damage to the motor. he said when he started the truck that the exhaust was white but when it reached the temp of 500+ the exhaust was dark

He thinks that it might be getting to much fuel.

Now for me with not knowing the running temp of the M37 and in combination that everything on this truck is brand new. I would not want to make a assessment until I know all the facts.

So:
First question what is the running temp of a M37
Second would poor ventilation to through the carb cause for a increase heat temp
Third the spark plugs not having the correct gap?
Fourth the type of fuel used
Fifth quest would what about the timing advance or retard create this issue.
Final is this even a issue?

 

[T. Highway]

Thermostat should be a 180* F Stant PN 13928. Depending on ambient air temp I have seen operating temperatures of 200* F. They do reference a 160* F thermostat also but I have seen this cause allot of condensation in the crankcase from not letting the engine get warm enough to burn it off. (As in milky residue on the underside or the Oil filler cap)

I would get the idle speed set to 600 - 650 RPM to start, If you have a vacuum gauge available it would be a good time to adjust your idle mixture screw for maximum vacuum, since your adjusting your idle speed.

Forget the 2* After TDC that the service manual tells you, Optimum setting is 4* Before TDC. This means you reference the 4* mark, to the Right of DC as it's rotating clockwise.

The exhaust temperature will vary greatly depending on the location of the pyrometer probe.

I would also check block temperature from front to back with an Infrared Pyrometer. If the rear of the block is greatly hotter than the front of the block I would suspect a missing or plugged water distribution tube.

Have your buddy check out the G741.Org site for allot more information about the M37 and it variants.

Bert

 

[highfavor1004]

There is no data tag on this motor. Is there away to look up the engine numbers

 

[T. Highway]

That is the data tag (punched into the block) Its a T 214 engine out of a WW2 Dodge truck, 238 Cubic Inches.

Bert

 

[M543A2]

I agree, replace the thermostat then see how it goes.
500 degrees exhaust temp for a gas motor is no problem; you are about half way there, and yes it varies where you check it.
The water distribution tube in these motors is critical. If all other systems in the cooling system are in good order, the motor needs to be checked for the tube in place and in good shape. The suggestion about the temp check along the block front to rear will help tell you about this. Cooler in front than at the rear will show it up.
Regards Martin

 

[M543A2]

Another simple thing that makes mine run warm; is the fan belt tight enough??