L-Head Temperature Questions

I have a 1946 L-Head in my 1966 CJ6 that was installed by the previous owner. It runs well and was supposedly rebuilt about 13,000 miles ago. All winter I noticed that the temperature level was about 3/4 to 7/8 up on the gauge. So this spring I pulled out the thermostat, wondering if it was the hotter 180 degree thermostat that was in there, and wondering if it would run cooler without one. If it still ran hot, then perhaps it would be the temperature sending unit, or waterpump.
We'll, it did run cooler, at about half on the temp gauge. The thermostat was the 180 degree one too. So my question is would it hurt the engine to run it for the summer without a thermostat since I just put it all back together? A guy at Autozone said it would warp the head and a bunch of others bad things if I ran it without a thermostat. Also, if I need to put a thermostat back in, and if I put the cooler 160 degree thermostat in, will it run at halfway on the temp gauge, where it seems it should run?
As always, thanks for the input and advice.
Dave

 

Bad for the oil to run w/o a thermostat - water condensation in the sump never gets burned off. I would use a 160º or 165ºF unit, based on F-head experience, but check the FSM.

Check your gauge too - are you sure it's true?

 

I agree . you should run thermostat , it controls the cooling cycle in coolant passing through radiator . are you sure radiator has flow . and yes could be faulty gauge . do you have a hand held temperature gun , they really help . when a gauge is in question . no need to remove cap to test temperature

 

Thanks for the replies. Any idea what a cross reference might be for a 160 degree thermostat for an L-Head? When you mention anything at any parts store that they can't punch in their computers, they kinda give you the deer in the headlights look. I think their computers only go back to 1969 or so for Jeep.

 

Computers? Find the parts store with the old guys up front and paper parts books still kept in the back.

The place where they will have the part number in their head.

 

Not an expert on L-head, but I think you can run a F-head thermostat using an adaptor sleeve. Maybe you already have that?

 

No adapter sleeve that I saw. Just a really rusty piece of metal that I found out was a thermostat housing retainer. There is an old Napa store here in town that uses old books. I remember now buying an oil filter from them for a 1942 Ford N tractor I had. I was really surprised that they had it. Thanks for jogging my memory!

 

Walck's

http://walcks4wd.com/cooling-system/thermostat.html