Where do you guy's '74s normally run? A PO changed mine over to an electric fan and it runs from halfway to a little under 3/4. This sounds a little hot to me, what do you think?

 

Ignore what the factory gauge says. Get a mechanical gauge on it and go from there.

 

I hate the idea of mounting anything under the dash since it's not been drilled or cut up...

Is that pretty much the norm?

 

The 302 in my '74 ran a little over half way.

 

I am with you, I don't care to see the dash all hacked up with temporary half baked ideas from the past. I use my factory guage in my 77 f150 300 I6 which runs about 1/4 up on the guage. My dads, which had a 302 ran about the same.

 

I wish there was some way to know what 1/4, 1/2 and 3/4 is temp wise. I may hook a mech gauge up under the hood and see...

 

My Brand NEW 73 F-250/390 ran on the "E" in the word TEMP. Oil ran on the "L" in OIL.
Most of my other F series did the same.

I like the Dash to be stock myself. I dont like other guages etc in there. Those stock guages were good. The only one I didnt like was the newer (80's) Oil pressure guages that was an on/off indicator.

 

If you mount the mech gauge just under the lip to the left of the ashtray you cannot see the holes whatsoever! I don't drive anything new or old without putting manual temp/oil gauges in. However, do what you will.

 

Them's the breaks. Factory gauges are not reliable, especially after 30 years.

You don't have to drill holes. I use black spring clips from Office Depot to fasten the gauges to the dash. You can't tell I put something there.

 

Get yourself a candy thermometer and take off the radiator cap. Put the thermometer into the water then start the engine and let it warm up and see just what the water temp is at that temperature gauge reading. I have had guys tell me I was nuts and to just use a laser thermometer. I have a laser thermometer and it doesn’t give an accurate of a reading of the water temperature as the candy thermometer does.

 

I like that idea, I'll give it a shot.

 

Okay, let me clear things up:

1. Do not use a thermometer in the radiator. That tells you nothing. The temperature at the fluid level in the radiator is not the same as the temperature of the coolant circulating in the block.

2. Do not use laser thermometers, "sight" thermometers, IR thermometers (whatever you prefer to call them) on engine blocks because it does not tell you the correct temperature. I have extensive experience in thermal imaging and can tell you it's not accurate in this application despite what any marketing literature will tell you. IR thermometers measure a surface temperature based on an assumed emissivity of the surface. It's not the same temperature of the coolant circulating underneath. While it can get lucky and guess in some cases, it's not what you want to use.

People, I can't say this enough. The only way to accurately monitor your motor's temperature is with a mechanical gauge because it places a transducer directly in the coolant path. Stop making excuses; if you want to know the data, you've got to buy the tools.

 

Thank you! This should be mandatory learning!

As I stated previously, you don't have to drill holes in your truck. Use clips or hang it off something...there are alternatives.

 

get a radiator cap with a guage built in

 

I knew somebody would flame me over this. I totally agree with the use of laser thermo’s. I have found them to be very inaccurate, but I will call you on putting the candy thermometer into the coolant through the radiator cap. Take a good look at where the coolant is at under the radiator cap. It is right next to the top hose. That is the hose that is connected to the thermostat that lets the water out of the engine. The thermostat is right next to the sending unit for the temperature gauge. How much closer could you get? I have made numerous measurements throughout the years and there isn’t enough difference between the coolant temperature in the top tank of the radiator and the engine block at the temperature sender to note the difference with non-laboratory equipment. The man said he didn’t want to clutter up his dash with a bunch of after market gauges, so I gave him a simple solution to find out approximately what temperature the engine was running at when the gauge was between halfway and ¾ as he asked for. He didn’t ask for a lesson in physics. All he wanted was to know was if his engine was running too hot or normal. I gave him a simple solution to find out if his truck was boiling over or running normal. He doesn’t care if his engine is running at 185 or 196.38567 degrees. He just wants to know if it is normal or boiling over, so lets not complicate the issue with a bunch of engineering lingo.