Fhead Overheating

Build a tub around the engine you can fill with ice water?

Seriously though changing the radiator can't hurt. It might be pretty restricted.

 

I believe so but not certain.

I needed a good laugh. Yep, 3 core aluminum radiator meant for a v8 can't hurt.

Not enough to offset where the PS belt runs. Yessir, It's a Mopar RV2 compressor for OBA.

 

Water boils at 212*, but he said he was using 50/50 mix.
I say water pump. Or a plugged radiator.

 

Agree, but coolant should be flowing fairly aggressive with new water pump and clean rad. Unless the block is partially stopped up.

 

They were supposed to. I know they patched and painted it. I took off the upper radiator hose and observed the water flowing out of it at different rpms. Water flow increased as the engine speed did.

 

What temp does it run at idle?

 

Im leaning towards shroud. I'm no aerodynamics expert, so I don't know what air flowing at higher speeds on a 3B does, but a shroud on a fan does create the pull of air required for proper cooling.

What I'm getting at is, I don't know how much air actually pushes through the radiator at different speeds.

You could remove the stock fan and go electric. Removing the parasitic load of a fan helps with hp on these small engines.

 

I wouldn't think the shroud would have much effect at speed. Normally more benefit at a snails pace.

 

It ran up to 210 this evening and ambient temperature was 80 something. Normally it sits around 180-200.

I like the noise it makes and mechanical fans.

 

I took the cap off while it was hot and watched and I watched while it warmed up. I took the upper hose off the thermostat housing with the engine running and watched as the thermostat opened. I cut off the engine and I could see the thermostat was in fact open.

I'll buy a better quality mechanical gauge and test it in a pot of boiling water and Wednesday my new radiator should arrive. I'll give another update then.

 

An electric fan is still a "parasitic load" in some sense. The energy to run it has to come from somewhere, ultimately the engine. Some power saving might come from not having it run constantly the way a mechanical fan does without a thermal clutch.

 

Hopefully your new radiator solves your issue. I don't know how old your current radiator is, but if it's original or of that vintage and the radiator shop didn't recore it i'd be suspicious of how well it's cooling.

 

It was in the jeep when I got it and I threw it under the scrap pile and it sat there under a few hundred pounds of junk for two years until a few months ago. It was a wreck. I have no idea if the shop rodded the radiator. I know they didn't recore it. I was told the radiator had a few dozen holes and the man told me "like to never get it all patched up" because new leaks kept appearing. Should've left it where it was.

 

I think you may have come full circle. I would be suspecting (coolant not moving) a blockage in the system or water pump issue.
I know it looks correct in the picture, but could the pump be rotating in the wrong direction (This is an issue on the 258 due to two different belt systems being used)? Maybe check the impeller.