Overheating?

[Kaegi]

if the fan on backwards? sorry have to ask. also are you running a stock water pump pulley and crank shaft pulley?

[June J]

Hi Kaegi,
So stock water pump and pulley. I'm pretty sure that the fan is on the right way, it sucks a sheet of cardboard hard against the radiator when I slide it up, and I can feel a good strong draught when I'm under the hood with the engine running.

The thick boss of the fan is against the water pump pulley.
Cheers
Ian

[Adam in Wa]

Is it possible the carb is running too lean? Check the plugs, and tailpipe color. Run it with the choke partially closed to test it? Do you have another carb to swap on?

[motto]

I once purchased a Jeep that the owner could not stop from boiling soon after setting off though it would happily idle all day. The PO had the head off twice to get it crack tested and given up in disgust.
A friend played around with it to see if he could sort it out. He hadn't been at it long when he called me over and said 'have a look at this!'
Every time he revved the engine up the lower radiator hose was sucked flat completely blocking off the water flow. This is why some hoses have the coil spring inside them.
Just a thought.

David

[June J]

Running lean is a possibility, although I did check the main jet size (0.045") when I overhauled it so I think its unlikely, I will swap carbs just to be sure.

Hi Dave, the Dodge (as you know) has 2 short lengths of reinforced hose, where the Jeep had a longer moulded hose so sucking flat is again unlikely but I will certainly check this as well.

Please keep the suggestions coming.

Cheers
Ian

[Kaegi]

is the cap sealing radiator too tight? over pressurized? stock is either zero PSI cap or 2.5 lb cap. I have built custom cars and learned early on that just having too high of a PSI rad cap can cause overheating on some combinations.

[June J]

Good point. Once I get it back up and running, I will try that.
Thanks

Ian

[June J]

Well, would you believe it???? Faulty temperature gauge was the problem. I simply do not know what the issue is with the gauge, I just know I tested the gauge against a candy thermometer and against a digital multimeter type gauge and always found the vehicle gauge was 100% accurate. I can only assume there is either an air bubble in the ether, or the capiliary system has been overfilled.

Either way I am soooo relieved .
Thanks to all for your suggestions and input.

CHeers

Ian

[Kaegi]

thats good news! overheating no a topic that comes up often with these trucks. its a great system

[June J]

Hi Kaegi,
I took the gauge to the instrument technician who could not fault it. His only suggestion was that its possibly something electrical earthing through the capillary tube.

Although there are a number of earth straps between the engine and the frame/body I am going to add one specifically for the dash panel.
Here's hoping.

Stay well!

Ian

[Kaegi]

wow thats a new one. never heard of a mechanical gauge reading differently like that. ?? maybe removing it got the air bubble out of the gauge and may work when you re install it?

[Phil P]

I am reading these postings with about 6 months delay! I have electronic ignition. I set my timing (without some fiddling and what ever) at 7degrees BTDC the plug gap was 35 thou. The engine has been rebuilt. I cleaned the block out till the water ran clean. I replaced the tube in the block. The water immediately changed to filthy sludge and ran like it 10 minutes! I spent 3 hours cleaning and rodding the block until it was clean. I replaced the tube and carefully rebuilt the engine. The radiator was cleaned and refitted. Bottom line it never goes over 140. Uphill downhill 140. You wind the tick over to 250 without stumbling. The valve lash was set as stock, and set running! Not easy. Oh yes the front wheel and inner wing were off.

[June J]

Thanks Phil, appreciate the response.
When you set your valve lash, did you do so hot or cold? If you did them cold, what setting did you use? I have generally set mine with the engine cold and added 0.002" to each valve to allow for stem expansion.

Cheers

Ian

[Phil P]

Sorry for not replying earlier. I set the tapers at cold at 11 and 13 cold. I fired it up and let warm up. I then reset the gaps to approx 9 & 11 thou. Some were still noisy and so were tightened until the noise went quite.NOT went away completely. This allows for any wear in linkage. It has been 2000 miles since it was set. Take your time and it will sound perfect. Best of luck.

Phil.

[Phil P]

Ps. Check the idle speed.