Normal temperatures

[jwhite1149]

I have a real problem with my 1937 pickup boiling over. What temperature is "NORMAL" at the top of the radiator at the hoses, at the center of the at the hoses and on the exhaust manifolds after a short drive? Thanks for the help.

[36tbird]

My simple theory is that if you have a clean system, rust and casting sand gone, then you should achieve a system temperature very close to whatever thermostat you have installed. Now, there will surely be a flurry of comments on whether or not you should run thermostats, whose water pumps you are using, fan type fan shroud, yada yada yada.

I'll just tell you that I live in the same climate as you and my '36 pickup with an 8BA that has 180* thermostats, no fan shroud but the big 19" 6 bladed fan, distilled water with water wetter is running around 180* all day long. On the new engine I am just getting to run, a 59A with 180* thermostats, 6 bladed fan mounted on the alternator with a home-made fan shroud, running it in the garage without any extra airflow it is holding around 150 on 3 mechanical temp gauges. (I am completely befuddled as to why it is running so cool.)

So, I guess I am trying to tell you, there is no easy answer to your questions but there are dozens and dozens of theories.

[flat-v8]

My 59A with original radiator and 50\50 antifreeze, right now, 98*+ never goes over 180* on the left side, the right side has a repop original style liquid gauge and is hard to read, so I don't really know exactly what the temp is off that head, it's probably real close to to the other side.

[G.M.]

Originally Posted by jwhite1149

I have a real problem with my 1937 pickup boiling over. What temperature is "NORMAL" at the top of the radiator at the hoses, at the center of the at the hoses and on the exhaust manifolds after a short drive? Thanks for the help.

The only temperature you need to take is on the head 1/2" or so below the radiator hoses. 170 to 180 is perfect and both sides should be within a few degrees of each other. G.M.

[jwhite1149]

That temp on the head below the hose is 203-208 taken with my infrared thermometer. Below that on the center of the exhaust manifold temp is 350+ is that too hot, could it be the cause for the head temps? Have new water pumps, flushed radiator/engine with 4 gals. of vinegar (ran it for four days), drained a lot of rusty vinegar out. But no improvement in temps. Help.....any ideas??

[19Fordy]

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If it's on an engine stand it may run cooler do to "no load" conditions.

[Mike in AZ]

temps same on both head outlets??.....top of radiator and bottom of radiator near hoses??....check both sides??....could be plugged radiator??....or needs to be rodded??.....maybe another run of vinegar??....what were temps before vinegar run??...Mike

[G.M.]

Originally Posted by jwhite1149

That temp on the head below the hose is 203-208 taken with my infrared thermometer. Below that on the center of the exhaust manifold temp is 350+ is that too hot, could it be the cause for the head temps? Have new water pumps, flushed radiator/engine with 4 gals. of vinegar (ran it for four days), drained a lot of rusty vinegar out. But no improvement in temps. Help.....any ideas??

Under what conditions are you getting 203 to 208 ?? The manifold temperature don't effect the water temp in this case. Most old Fords will idle at close to 200 after being driven at 170 to 180 on a hot day. The temp even raises higher when the engine is shut down. Raising the hood after shut down lets some of the heat out. These engines have poor fans so avoid heavy traffic and long idling on hot days. When driving the forced air from forward motion going through the radiator is what cools these engines. Again the only temp you need to check is on the heads 1/2" below the hose. G.M.

[jwhite1149]

G.M. Thanks for the info, I'm thinking of sending the distributor to Bubba's shop for a rebuild. My truck starts quickly and runs well, but I'm I have been told my timing may be off. How much effect can this have on the temperature of the engine, 10 or 20 degrees???? I'm in Texas, very near Dallas and it's hot, so I know that is a also factor. Could a cracked block, bad valve, I'm lost......any one.

[Mike in AZ]

don't know if you're lost, but i think you've come to the correct place for help....thermostats in the hoses??....checked for hoses collapsing when hot??....what coolant are you using??....Mike

[expavr]

If you haven't done so, pressure test your cooling system to see if it is holding pressure. Could be a seeping seam in the radiator core, weak radiator cap, blown head gasket, or a crack. I'd start there before going to a lot of expense on dealing with other parts of the engine. As far as operating temp I'm seeing an infrared reading of 175-185* on the upper hose at the tank. This was with an ambient temp of 95-105* in SoCal and in stop and go traffic. To improve the cooling situation I've found a shroud to be very helpful in getting more air through the radiator core.

[G.M.]

Originally Posted by jwhite1149

G.M. Thanks for the info, I'm thinking of sending the distributor to Bubba's shop for a rebuild. My truck starts quickly and runs well, but I'm I have been told my timing may be off. How much effect can this have on the temperature of the engine, 10 or 20 degrees???? I'm in Texas, very near Dallas and it's hot, so I know that is a also factor. Could a cracked block, bad valve, I'm lost......any one.

If your car starts good and runs well I doubt you will see any difference from changing the timing. G.M.

[FlatheadTed]

I am with GM timing .with vinegar flush 14 days min