Motor Runs Hot

[Ron H]

This is part of a long saga as I posted about this a few months ago on my built up poly on my '63 Fury. I added a 7-blade and found an old OEM shroud I refurbished and installed. I'd say that dropped the temp around 10-degrees. Doesn't seem to be enough yet as after some highway running the temp still pops out at the T of 210-215. Radiator was boiled/flushed, new 160 thermo installed. The rad is original two-core and wonder if adding an electric fan in front would do the chore or if I need to look at a larger rad? Part of the issue could be I have the heater core bypassed as I've had for 20 years. Any advice? Thanks.

 

[mopar 3 B]

Why the 160 thermo? It is not normal operating temp even for a poly and does absolutely nothing for cooling.
As for the heater bypass did you cap the pump ports or just run a connector hose?
Hope this is a non-ac car or the next thing will be the ac doesnt work.

 

[Cranky]

Might try something simple and throw in a 180 T stat and see what it does. Is the radiator a stock unit? 4 core radiators usually don't cool any better than one with larger tube 2 core rads do.....

 

[oldbee]

Also, is the block itself clean or corroded internally? W/pump impeller not slipping on the shaft?

 

[mopar 3 B]

In all the time I had a poly over heating was never a problem. Open wheel well 383s and 440 on 22" poly radator with no problems even with a 6 blade fan.

Go back to the proper 180 thermo and figure out what is restricting air flow.

 

[Dennis H]

180 Stant Superstat. Did they come with the thermal fans?

 

[moparedtn]

Thermostats only affect warm up time; given two thermostats of equal orifice but different temps (say, 160 and 180), the engine is going to reach whatever operating temperature it's going to regardless of thermostat rated opening temperature.
Been through all this hell recently and arrived at the "overkill" level finally with mine.
Keep in mind - more horsepower means more cooling system needed usually.

You start with the basics:
1. Does the thermostat open at all? A Superstat is always a good idea.
2. Are all parts of the cooling system clean & unobstructed? Have you flushed hell out of it?
3. Is your coolant at least a 50/50 mix (if not a little weaker than that)? Water cools better than antifreeze, remember.
4. Heater core being hooked up or not doesn't matter. Hopefully you simply plugged off the outlets at the pump housing?
A hose looped between the two is a bad idea, creates turbulence in there.
5. Timing and fuel mixture both affect temperature, too. Just a heads up there, that's a whole subject by itself.
6. Are either of your radiator hoses collapsing? Seriously, it happens - especially the lower one. Watch it while the engine is running
and warmed up. Goose the throttle a few times and watch the lower hose - you'll see it collapsing if it's being cavitated.
(Some of us have installed springs in ours to prevent this).
7. If everything checks out as good, time to look at your radiator not having sufficient capacity.
(Personal recommendation here - as advised by Rick Ehrenberg himself, I bought a Griffin. Best move I ever made. Thing is a cooling BEAST).

Good luck and report back.

 

[Ranger16]

Thermostats only affect warm up time; given two thermostats of equal orifice but different temps (say, 160 and 180), the engine is going to reach whatever operating temperature it's going to regardless of thermostat rated opening temperature.

Here we go again. Why in the world would anyone want to lengthen the warm up time?
Do a little research. Thermostat operation is not rocket science nor a big secret.

 

[Ranger16]

wonder if adding an electric fan in front would do the chore

I can't say it would or wouldn't, BUT it may block some air flow at cruise. Just something to consider.

 

[moparedtn]

Here we go again. Why in the world would anyone want to lengthen the warm up time?
Do a little research. Thermostat operation is not rocket science nor a big secret.

Who proposed to do that, exactly? Wasn't me obviously.
Do a little reading comprehension.

 

[mopar 3 B]

These things were not designed to over heat. There is no reason to redesign the cooling system unless the poly has been taken to extremes.
The problem could be as simple as a dirty air filter, one thats to small or simply of poor quality.
Or just remove the piece of cardboard put infront of the radiator last winter because it would not warm up with that 160° thermostat.
Cooling system could even have a leak. It needs coolant to cool.

 

[Car Nut]

What temp. gauge are you using, don’t trust the factory one. Get yourself a infrared temperature gauge and check it that way. These cars were designed to run a little hot so 200 to 210 is not too bad.

 

[moparedtn]

180 was the norm in thermostat temps until the advent of emissions and fuel economy pinches in the 1970's.
I'd be concerned if a fairly stock 60's poly was running routinely over 200F.

 

[Ron H]

Well it's never been run in winter...and core is bypassed anyway...ahh no cardboard I might a left in there. I had a 180 T in and no diff. The T of course at 160 gets coolant into the rad sooner for it to do its job so the idea of a 160 made sense as an easier exploration as some had suggested. I just tossed out the popular electric fans as a query for anyone having done this...before I have to think larger rad. Significant but not radical build up was done including bore .060, a bit hotter cam, mech lift. Part of the equation was going to higher rear gearing (3:23 to 3:55). I agree, as posted thanks, that an el fan thrown in could create other problems such as blocking air flow. I have an IR temp gun that's what I used to check; it's pretty close to my dash gauge. Another check I have to make as I forgot (as was posted in another post) is lower rad hose possibly collapsing. I'll try to do that today if I can go for a ride.

 

[WileERobby]

You mentioned getting hot after highway driving. What about during highway driving ? What about when idling for a while ?

 

[Ron H]

Seems like it could idle all day or low speeds no problem its when out on the highway for a time that does it. That's why reckon the higher gears cranking upper 2,000's after 30 or so miles is too much for cooling system to handle.

 

[Ranger16]

Who proposed to do that, exactly? Wasn't me obviously.
Do a little reading comprehension.

You said "Thermostats only affect warm up time". IF that were true, what is the purpose of using a 160, 180 or a 190? The only reason for changing thermostats would have to be to chang the warm up time. The idea is to reach operating temperature as quick as possible. Comprehension?

See if you can comprehend this (from Stant). It's really not that hard to understand. I doubt you'll find anyone here that will agree with you.

FREQUENTLY Asked QUESTIONS - Thermostats

• What is a thermostat? What purpose does it serve?
• How does a thermostat work?
• How often does a thermostat need to be changed?
• When does a thermostat start to open?
• When is a thermostat fully open?
• Does Stant have a high flow thermostat?
• Why does my engine overheat?
• Why doesn't the passenger compartment in my car heat up?
• Does Stant have a fail safe thermostat?
• What does a jiggle pin do?
• My thermostat has a jiggle pin but the Stant thermostat doesn't. Will a Stant thermostat still work?

What is a thermostat? What purpose does it serve?
The thermostat has two important jobs to perform; to accelerate engine warm-up and to regulate the engine's operating temperature. A quality thermostat ensures excellent fuel economy, reduces engine wear, diminishes emissions and blow-by, improves cold weather drivability, provides adequate heater output, and detours overheating. This is accomplished by blocking the circulation of coolant between the engine and radiator until the engine has reached its predetermined temperature. The thermostat then opens as required in response to changes in coolant temperature to keep the engine's temperature within the desired operating range.
How does a thermostat work?
"Usually located within a metal or plastic housing where the upper radiator hose connects to the engine, most of today’s thermostats utilize the "reverse poppet" design, which opens against the flow of the coolant. Thermostats have a wax filled copper housing or cup called a "heat motor" that pushes the thermostat open against spring pressure.

As the engine's coolant warms up, the increase in heat causes the wax to melt and expand. The wax pushes against a piston inside a rubber boot. This forces the piston outward to open the thermostat. Within 3 or 4 degrees F. of the thermostat preset/rated temperature which is usually marked on the thermostat, the thermostat begins to unseat so coolant can start to circulate between the engine and radiator. It continues to open until engine cooling requirements are satisfied. It is fully open about 15-20 degrees above its rated temperature. If the temperature of the circulating coolant begins to drop, the wax element contracts, allowing spring tension to close the thermostat, thus decreasing coolant flow through the radiator. "

 

[MOPOWER871]

one other possible, head gasket. might be leaking combustion gases into the cooling system and causing a air pocket and hot spots in one of the cylinder heads. happened to me. drove me crazy nothing in the cylinders , new rad, shroud, clean block... confirmed it with a combustion gas leak detector. just a thought.
www.handsontools.com/Lisle-75500-Combustion-Leak-Detector_p_5124.html?gclid=Cj0KCQjw0a7YBRDnARIsAJgsF3PJz1smVTyJYbyoOW4Tc4D18PQWv-sl_InqQxaaX4u4-_jJbJWXVwgaAuCEEALw_wcB

 

[HEMI-ITIS]

Thermostats only affect warm up time; given two thermostats of equal orifice but different temps (say, 160 and 180), the engine is going to reach whatever operating temperature it's going to regardless of thermostat rated opening temperature.
Been through all this hell recently and arrived at the "overkill" level finally with mine.
Keep in mind - more horsepower means more cooling system needed usually.

You start with the basics:
1. Does the thermostat open at all? A Superstat is always a good idea.
2. Are all parts of the cooling system clean & unobstructed? Have you flushed hell out of it?
3. Is your coolant at least a 50/50 mix (if not a little weaker than that)? Water cools better than antifreeze, remember.
4. Heater core being hooked up or not doesn't matter. Hopefully you simply plugged off the outlets at the pump housing?
A hose looped between the two is a bad idea, creates turbulence in there.
5. Timing and fuel mixture both affect temperature, too. Just a heads up there, that's a whole subject by itself.
6. Are either of your radiator hoses collapsing? Seriously, it happens - especially the lower one. Watch it while the engine is running
and warmed up. Goose the throttle a few times and watch the lower hose - you'll see it collapsing if it's being cavitated.
(Some of us have installed springs in ours to prevent this).
7. If everything checks out as good, time to look at your radiator not having sufficient capacity.
(Personal recommendation here - as advised by Rick Ehrenberg himself, I bought a Griffin. Best move I ever made. Thing is a cooling BEAST).

Good luck and report back.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
There is the punch list right there! I will add that all I use on my 9:1 blown 545 inch hemi is an aluminum Afco 2 row with 1 inch tubes and had to be a 3 pass for the inlet/outlet locations. Single spal 16 inch pusher fan because there is NO room between the blower belt & WP pulley.Will idle at 175/180 all day and goes up to 185 to 190 depending on how bad I'm beating it up! LMOL

 

[Hanover Mopar]

Side note. How much heat should a radiator take out of an engine or is it too variable to guess.