Battling overheating new 360 build

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I will say - great fit and finish on the Champion. Very impressed. Had to modify the bottom a hair, but it sits perfect against the radiator support, no gaps. Just wish my OEM shroud would have fit.

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I'm thinking you have other issues. Like internal in the engine. I have a Champion 526 3 core with a single 16" electric fan and it cools my 416 with ease.
 
I have a block tester, I'll check it for *****. I have no coolant or oil consumption.

I have a great temp drop between the upper and lower rad hoses. About 40-50 degrees. I'm pretty stumped at this point to be honest
 
Have you actually installed a quality mechanical water temp gauge to see what number it is actually running at?
 
At the sender itself about 185 when I’m dead nuts center of the gauge, but shooting all over the manifold I’m finding temps upwards of 200. I have the sender in the port next to the water neck.
 
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185 at the sender, with the guage centered, would be about right for a 180 stat.
There are exhaust cross-over ports on the manifold that'll be way hotter than the coolant temps.

I humbly suggest that you install a mechanical guage to be sure.
With your rad dumping all that heat, I'm getting the feeling all has been normal since the new un-plugged rad.
 
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DSMRossi said:
Welp, I took car for a cruise and I have a decent drop across the rad. Top hose is around 185 coming out of radiator, lower hose is 150's. I will say that the thermometer isn't exactly the most accurate, it gives funny readings.

What I did notice was that there were a few areas on the radiator at the bottom driver's side mostly that were much cooler than the rest of the rad, like 60-70 degrees cooler. So I believe I have a compound issue that I didn't notice with my cool-running 318. It looks like a radiator upgrade is in my immediate future...

I did pull the timing back and I disconnected the vacuum advance so that part throttle cruising didn't have the added timing and that had no effect, so I don't believe I have a timing issue.
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This post indicates the cooling system at idle is doing it's job , thermostat temp(ish) coming out top hose , rad dumping enuff heat to cool at idle, pump circulating.
Now, at speed the partially plugged rad could not keep up with the added heat cuz it's effectively too small, and the temp creeps up till the faulty guage makes you uncomfortable.
If you pulled to the side of the road and left it idling it woulda cooled down.
On top of that your believing a guage you know not accurate.
Does the engine now overheat at speed ? What's the upper rad hose temp in the "overheat" condition, engine still running ?
 
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inertia said:
This post indicates the cooling system at idle is doing it's job , thermostat temp(ish) coming out top hose , rad dumping enuff heat to cool at idle, pump circulating.
Now, at speed the partial plugged rad could not keep up with the added heat cuz it's effectively too small, and the temp creeps up till the faulty guage makes you uncomfortable.
If you pulled to the side of the road it woulda cooled down.
On top of that your believing a guage you know not accurate.
Does the engine now overheat at speed ? What's the upper rad hose temp in the "overheat" condition, engine still running ?
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Engine has been overheating at speed. New rad and 8 vane pump made no change. I was saying the infrared thermometer gives off funny readings, not the dash gauge. What I did find is that the dash is saying I’m almost at H when the infrared therm is reading 200ish, so perhaps that’s where the dash gauge is calibrated from the factory?

Also, this is where my temp sender is tied into the manifold, should I be tapping in closer to the water neck?

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That's the normal place for sender.

Very long shot, run a ground wire to the sender base, see if it's getting a good ground.

Factory guages are notorious for being a "guidline".
 
inertia said:
That's the normal place for sender.

Very long shot, run a ground wire to the sender base, see if it's getting a good ground.

Factory guages are notorious for being a "guidline".
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Ground seems fine. I notice the infrared therm once it gets warm in my hand starts reading warmer than actual temps as well. It’s 31 outside and it was reading 54 degrees. Going to rig up a mech auto meter gauge I have in another car now and compare readings. I’m sure the car is running hotter than a standard low compression 1973 motor, but I’m not boiling over and starting to think that the car is most likely fine. More info to come once I get this wired up
 
Are you saying it's running hot @ 200 degrees?
Also what champion radiator? I have the cc526 and the factory shroud bolts right up.
 
dgibby said:
Are you saying it's running hot @ 200 degrees?
Also what champion radiator? I have the cc526 and the factory shroud bolts right up.
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CC2374 radiator. No, the car is pegging H on the dash and my IR therm is reading 215. I'm trying to get the temps lower, but starting to think that it's just a hot running motor. I don't have a high-flow therm in yet, that'll be next
 
DSMRossi said:
CC2374 radiator. No, the car is pegging H on the dash and my IR therm is reading 215. I'm trying to get the temps lower, but starting to think that it's just a hot running motor. I don't have a high-flow therm in yet, that'll be next
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If the shroud lines up with the mounting sides of the radiator you can drill it and run self tap screw in it.
Mine runs about 204 on the freeway, which I’m not worried about, but I thought I’d change out the thermostat with a Stewart high flow. Here’s the thread I started to show the difference between the two “high flow” t stats. Won’t be running mine for a few months to see if it changed but based on how much more it opens I’d go with it if you’re going to bother changing it.
Thermostat comparison
 
DSMRossi said:
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I might be late on this one but with the way you have those bypass hoses run you could be losing a lot of circulation through you radiator, those should be going through your heater core. In fact that big short jumper hose gets plugged in the pump and the manifold on the circle track racers i know. I,m thinking about plugging mine.
 
dgibby said:
If the shroud lines up with the mounting sides of the radiator you can drill it and run self tap screw in it.
Mine runs about 204 on the freeway, which I’m not worried about, but I thought I’d change out the thermostat with a Stewart high flow. Here’s the thread I started to show the difference between the two “high flow” t stats. Won’t be running mine for a few months to see if it changed but based on how much more it opens I’d go with it if you’re going to bother changing it.
Thermostat comparison
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Did you have the high flow in there previously, or is this the first time you’re putting one in?

I read somewhere that you’re supposed to use one when you install a high-flow pump, but I haven’t gotten that far yet
 
DSMRossi said:
Did you have the high flow in there previously, or is this the first time you’re putting one in?

I read somewhere that you’re supposed to use one when you install a high-flow pump, but I haven’t gotten that far yet
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The milodon that I showed in my post was a high flow. I was using it with a 8blade high flow pump
 
DSMRossi said:
...but starting to think that it's just a hot running motor.
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Rebuilt engines can run hot while they're breaking-in.
My rebuilt 360 ran hot too, but has returned to the same level the previous 318 was after a while.
It certainly doesn't run way hotter at speed, compared to idle.

Are you sure the cam is installed correctly/degreed properly?
How much timing does the engine get at 2000rpm (Driving rpm) w/vacuum disconnected?
How much vacuum does the engine pull at idle?
And how much when driving speady?
 
Ccas said:
I've also seen a lot of these rebuilt wp built with stamped impellers instead of cast impellers. The stamped ones appear like they would move a lot more fluid but they are bad news. They create a lot of cavitation.
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Got the same problem fresh rebuilt 360 10.5 piston, two electric fans three row rad and heats to 190 is 7 min. I think I am going to pressure test system for leaking head gasket thin check water pump. Good luck
 
DSMRossi said:
Just finished putting a rebuilt 360 in my car. The motor runs great, plugs look good, but I've been fighting an overheating issue since the motor swap that I didn't have with my 318.

When idling, the car will run all day, no problems. It's when I'm driving that the temp will work itself all the way over to the hot-side of the dummy-gauge. I have to pull over or park and within a few seconds the temp will drop back down.

I have a 22" radiator and the factory shroud. I'm not running a clutch on the fan, however I have the factory 6 blade fan installed.

One thing I did notice was that the fan was about 2 1/4" away from the radiator itself. I purchased a spacer to get it closer to 1", but I'm unsure that's going to solve my issue.

Pic of the plug, car might be running a touch lean, but nothing out of control. I am running 38 degrees all in and have the vacuum advance hooked up. Maybe I'll try running without the VA and see if a little less timing helps the issue?

I would think that a 22" radiator and shroud should be able to cool an average 360.

View attachment 1715276858
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Usually the best cooling set up is the 26" radiator and the 8 blade fan with thermal clutch. Also a 180° or 160° high flow thermostat will help alleviate the too hot issues. Also a factor that affects over heating is when a engine gets bored too much like. 60 over or more.
 
My fix was grounding to the chassis better lol - dropped my temp 40 degrees.

Make sure your engine is grounded to chassis as well as battery, and make sure they’re GOOD grounds. I chased the issue all because my own basic negligence.
 
DSMRossi said:
My fix was grounding to the chassis better lol - dropped my temp 40 degrees.

Make sure your engine is grounded to chassis as well as battery, and make sure they’re GOOD grounds. I chased the issue all because my own basic negligence.
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That's interesting. What do you attribute the reduction of heat to grounding? I'm asking by what mechanism does this occur? Electric fans or water pump not getting full power?

Very curious.
 
yellow rose said:
That's interesting. What do you attribute the reduction of heat to grounding? I'm asking by what mechanism does this occur? Electric fans or water pump not getting full power?

Very curious.
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My assumption is that any electric sender operates using heat to affect resistance, which is what you’re reading on the gauge. If the system isn’t properly grounded, then the unit will give off skewed readings.
 
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