The Stovebolt Site Forums The Shop Area Engine Shop Running hot, what's too hot?

I've got a freshly rebuilt '54 235 that's running hot, and I'm looking for some help.

I did a 20 minute 2000 RPM break-in on first startup, no problems.

When driving the truck (1/2 ton) around, the temp will get as high as 220. New radiator. Everything on engine stock. 180 thermostat. No fan shroud. I have a fancy IR temp sensor I can use to pin-point different spots on the engine. Here's the recording I see after driving around for some time, and then measuring at idle:

bottom of radiator: 190
top of radiator: 210
top of thermostat housing: 215
left side of head, near temp sensor: 230
right side of head: 210

When I shut engine off, I'll loose fluid out the radiator overflow.

I don't have heater installed, so I've made a 3 ft. loop with the heater line.

It's a '56 head with a '54 block.

Motor doesn't have tons of power, so maybe I'm off on timing. I timed it with timing light and I have the BB right at the pointer. Sometime when stopping motor, it'll backfire thru carb and or turn backwards.

Any ideas what might be going wrong? I'm assuming these temps are too high.