Now that it's good & hot I'm thinking the 195 degree thermostat (that apparently the 390 calls for) is a little too warm for afternoon traffic. My temp gauge approaches 210 while stopped at long lights. I'd like to replace with 160 t-stat. What do you guys run in summer on your FE's?

 

I run a 180° t-stat 365 and 24/7.

 

2x Hio,
I think 180* is about the best all round stat used in warmer climates.

But every thing depends on how clean your cooling system is Right!

The thing about a radiator cooling system is they first start clogging up in the lower tank tubes where one can't see. Everyone just looks in the top tank to see how dirty or if the tubes look clogged closed over..
Orich

 

Just some suggestions...

Thoroughly flush the engine block. Pull the pipe plugs on each side of the block and watch the yuck flow out...... I pulled them from my 70's FE and nothing came out... then I poked the hole with a scribe and was greeted with a torrent of rusty, scaly muck. There was at least a quart of residual coolant on each side.

Refill with a 50/50 mix...Here's how:

1. Buy two, one-gallon jugs of coolant. Pour in one gallon and then refill the now empty jug and pour it in.

2. Take the still-full jug and refill the empty jug but only half-full. Now fill both jugs with water... both now have a 50/50 mix, right? Right!

3. Top off the system. Done.

..... don't forget to open the heater valve to "hot".

 

I run a 160 in all 3 of my old vehicles, my 69 F100 my 66 Mustang and my 55 Chebby. One word of caution though; avoid those "fail safe" t-stats. Every one I have used has gotten hot and locked itself "open" meaning no heat in the winter!

 

Thermostats are supposed to be changed out about every 3-5 yrs when coolant is changed out. And when not they fail..

Only had one stuck closed on me was a Chevy 63 vett. 20 days after buying it. The vehicle was only 3.1/2 yrs old then.

But on the 31st day the clutch pedal went haft way to the floor and stayed on the way home..

The dealer charged free labor an a 1/3 cost on parts it seems like that's what, I remember it was. 53+ yrs ago.

I never had another that did freeze up or fail since the vett.
Orich

 

4strats I agree with HIO about using a 180 degree stat. There seems to be some confusion about the thermostat. 180 degree or whatever you run is what temp it opens at. It is not like a house thermostat regulating the air temp.

Should you be stuck in traffic without a good flowing system the temp gauge can rise. Should this occur when I'm out & about I will move the shift lever to N and rev the the engine to about 1200-1500 rpms and that seems to do the trick for me. You might drive it a bit in a lower gear to rev the engine.

I slightly disagree with his mix formula, I highly recommend using grocery store distilled water, less than a buck a gallon in NC. Some water in different parts of the country have minerals in them that you are adding to your system by using it. On the farm where I grew up using the water there caused the coolant to turn muddy looking and it thickened. I 1st noticed a difference after I moved to Durham NC and started mixing the city water with my coolant.

Then I read 20 years or so back that by using the distilled water you were not adding anything to the system. To be truthful the coolant in my 66 is much older than 5 years and still looks like it was just poured in.

I have been a Prestone brand user for nearly 50 years now, and it is still my choice. If you are concerned about overheating I would agree with the flush product and reload the system with a 50/50 mix and a 180 stat.



John

 

Y'all must have hard water I'm NC!

Concur usiing distilled water if your area has the same condition.

 

I put in a 180 years ago and a couple months ago when I removed the valve covers to put on new gaskets, there was a half inch of oil sludge that looked like grease on the inside of my valve covers. Guys here said that the build up could be the result of too cool a tstat.

 

I've have found the main cause is listed below

Tracked the causes down to a failed PCV system.

1.Mostly caused from a bad PCV rubber valve cover grommet.

2. A leaking cracked carb to valve cover PVC Hose.

3. A carb base PCV plate clogged with carbon to the point not pulling the
fumes from the valve cover.
4. And the worse is having water in the oil bad head gasket or cracked head
from over heating issues..
5. To cold of thermostat or none.
Orich

 

I agree with the distilled water. Even though it's not as important as the newer vehicles with the different color coolants it's still cheap insurance on a better working cooling system. Note, on the newer coolants in current vehicles you Must use distilled water at a 50/50 mix to keep the PH level correct in the cooling system.
And I like Hio's idea of back filling a 1/2 empty coolant jug with the water to guarantee a 50/50 mix.

 

Going with cracker on this one. Recently changed coolant, 50/50 mix, got a 160 t-stat & red line water wetter. Don't need heat, heat is for women! Thanks for discussion all
Mike

 

F/u,
Installed 160 T-stat, with water wetter, & coolant I just changed. Let run in driveway until T-stat opened plus 40 minutes. Temp gauge (Sunpro, not stock) never got above 170. When it gets cold, I'll put 195 T-stat back in, only a 30 minute change, no big deal. And coolant will need changed anyway. I'm sure my C-6 will be happy now...yes it has a cooler, in front of Rad, the good ones.
Thanks all,
Mike

 

I still get plenty enough warmth from the heater with a 160 in the winter. You must live in a much colder climate than NC!

 

I replied to the wrong forum. Should have been in the Superduty forum.