HOT, HOT, Hot, Hot

[Herman]

Need advice.

Have a 48 flathead, newly rebuilt less than 150 miles on engine and it seems to run very, very hot, pegs the needle on gauge.

Rebuilt, water pump, pressure tested and boiled our radiator, new 180 degree thermostat, new 6V temperature sending unit, no teflon on threads.  9# radiator cap..new hoses top and bottom and not collapsing... Engine with infra-red sensor seems to run 195 to 210 degrees F and does not seem to cool when driving.

What are we missing?  What is the normal operating temperature for these engines?  Any suggestions will be greatly appreciated.

Herman

[Robert Meyers]

Just a thought...

Is timing set correctly? Had a similar situation with rebuilt engine on 49-6269. Just plunked in distributer when first trying engine. Heated up very quickly until timing adjusted correctly.

Best of luck to you

[Bill Ingler #7799]

Hi Herman- I would say you have a circulation problem after reading what you have checked on your engine.What is normal operating range temps on the engine? I think the operators manual that came with the car will say the temp needle for normal should be in the middle of the gage. Normal I defined for myself as 75 outside temp and driving down the road at 50mph. Both my 41 and 47 will have the gage needle about in the middle. This also on my 41 means 175 temp and the shutters wide open. Now put in another 10 or 20 degrees hotter and your temp needle will ride between the middle and the H in the gage. I have had both car needles on the O in Hot and no boil. You will get higher reading in hot weather if climing or idleing at a light. I would take out the thermostat in your car and then check to see if the car ran cooler. If it did then your problem could be your radiator is partly plugged. I have been through the scenerio with the radiator shop saying Yes I boiled it out and it has good flow.I went through this with both cars on running hot and both times when the top tank on the radiator was pulled off, both 50+years old cores were more then 50percent plugged.I know that what I say next could be after the fact since you have rebuilt your engine but was the block and heads de-rusted when you did the engine. This really should be a must on any rebuild. American Metal Cleaning in Toledo did my 47 several years ago and it was like a new block and heads when they finished.