Too Hot???

[MattPSU]

I'm trying to figure out if my truck is running too hot.

1972 - 350 auto, 180* thermostat - it's also about 85+ in SC today.

Took it for about a 20 minute drive tonight - the second short drive after having everything apart - and it seemed really hot when I got back. The temp gauge was about 1/3 of the way up - creeping towards straight up. When I got back the hoses were nearly too hot to touch and solid as can be. It's the original radiator, but all new hoses. I did shave my heater, and I have a hose in it's place (running from the intake into the water pump).

The first drive last week heat stained my intake. It was suggested that I add the heat riser plates (?) which I did this past week. While at it, I also switched from the 195* thermostat to a 180* (I also drilled 3 holes in it).

After today's drive, the stain is starting to show back up and it seems to be really hot to the touch. I never noticed how hot it was before I tore it all down, but I think I would have noticed it being this hot.

It also shook when I came to a stop and it stalled when I finally did stop. Not sure if this is related or not.

Is it too hot? Or is there another problem? Suggestions?

Thanks - Matt

[GASoline71]

What do you mean by "heat stained"? If it's a cast iron intake that has been painted... the middle of both sides will discolor from the heat of the exhaust riser below the carb.

It actually sounds like it's probably running okay. But, Might be time for a new radiator. Or at least a rod out or recore. The 40 year old rad just might not be up to the task.

Gary

[Lee H]

You need to figure out the actual temp. A good old thermometer, an IR gun, maybe a known good mechanical gauge. Find out the real temp and go from there.
Posted via Mobile Device

[MattPSU]

Here's a picture of the "heat stain" from last week. I repainted while I had it apart and you can see it coming back. Paint's supposed to be for intakes 500+ degrees. - Matt

[GASoline71]

That's exhaust heat doing that, and is completely normal unless you block off the croos flow of exhaust under the carb..

Gary

[D.PASSMORE]

If you have the correct thermostat for the motor ie - 180, 165... the temp and guage stays nearly in the same spot when operating. I played with mine on my K20 because when I towed or ran high RPMs for a distance it would creep up. For Florida and the way I was running the truck I settled on a 180. After a few years it started creeping again and figured out I had a head gasket leaking. Replaced the gaskets and back to normal.

On the exahaust, If your truck is running on the lean side, it causes the heat to increase around the cylinders and on the crossover. I wasted a set of mufflers and tips trying to run lean to save gas. Oh yeah and burnt a valve too. Keep your eye on that.