Vehicle running warm 360 la

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Dillon Crowell

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My 360 la has been running hot lately it gets up around 220. I have a 26in aluminum radiator and 2 electric fans with a 180 thermostat. It has some bubbling in the radiator when I take off the fill cap so I’ve been thinking that maybe the head gasket is leaking exhaust into coolant. When I start the car up warm the temperature will be around 210-220 and will drop down to the 180 like the thermostat but will quickly then go back up to 195+. The temperature will go down to 185-195 when I’m doing steady driving. But anytime I stop the temperature hits 200+ quickly. It used to just sit at or right around 180 at all time. I recently had a vintage air ac and heater installed and it doesn’t blow hot so I’m assuming I have something wrong I’m my coolant system.
 
My 360 la has been running hot lately it gets up around 220. I have a 26in aluminum radiator and 2 electric fans with a 180 thermostat. It has some bubbling in the radiator when I take off the fill cap so I’ve been thinking that maybe the head gasket is leaking exhaust into coolant. When I start the car up warm the temperature will be around 210-220 and will drop down to the 180 like the thermostat but will quickly then go back up to 195+. The temperature will go down to 185-195 when I’m doing steady driving. But anytime I stop the temperature hits 200+ quickly. It used to just sit at or right around 180 at all time. I recently had a vintage air ac and heater installed and it doesn’t blow hot so I’m assuming I have something wrong I’m my coolant system.
Ever had a water pump impeller come loose from the shaft?
Getting hot when it didn’t before and no heat could be low or no coolant circulation.

A head gasket would cause it to push coolant out on the hiway too, and not just at idle or low speeds.
 
My plan is to change the thermostat for a new 180 just to see what happens. Ive been thinking about changing the water pump for a high flow one but havent done it yet. The heater not working and the bubbling I see from the radiator fill make me think air is getting into the system
 
First start at the beginning...

You did work on the cooling system.

Your troubles started after the work.

Go back and review your work

Many times after draining the rad it takes time to get the air out of the system.
 
Did you get the full 4 gallons of coolant back into the system when you refilled it after working on it?

Or did you only get 3 gallons in it and there is still air trapped in the block?

Air bleed thermostat:

Screenshot_20220430-164813_Gallery.jpg
 
My plan is to change the thermostat for a new 180 just to see what happens. Ive been thinking about changing the water pump for a high flow one but havent done it yet. The heater not working and the bubbling I see from the radiator fill make me think air is getting into the system
I always recommend a high flow 160 in anything above stock.
 
Once the air is worked out of the system, tune can cause overheating as well. Maybe add a bit more fuel at Idle. What cam? More timing can help. If those electric fans are aftermarket (i.e. not an OEM setup), they likely will be marginal at best for moving enough air. The aluminum shrounds some aluminum radiator retailers sell are known to be restrictive.
 
Did you get the full 4 gallons of coolant back into the system when you refilled it after working on it?

Or did you only get 3 gallons in it and there is still air trapped in the block?

Air bleed thermostat:

View attachment 1716026781
Just drill an 1/8" hole like in pic. I will bled out air before t-stat opens. I put a new Stant t-stat in my hardtop when I 1st built it and it ran hot. Thought it might be radiator. Turns out it was a bad (new) t-stat.
 

Heater not getting hot means you need a new heater core.
180 thermostat is just fine.
In regards to the new AC. Did the car already have factory AC ?
Reason being, AC cars, and Non AC cars use different pulleys and water pumps.
 
You could try flushing your heater core just be careful how much pressure you use. Flush both ways and see if anything comes out.Low coolant the heater will get cold 1st.
 
All that the thermostat does is set the low temp minimum.

160 sets the low temp to 160, 185 sets it to 185, etc.


Once the temp is above a particular temp the thermostat is fully open and the temperature is set by the rad, air flow, pump, pulleys, tune etc.

The cooling system is a SYSTEM, all the componants have to matched correctly to function properly.
 
All that the thermostat does is set the low temp minimum.

160 sets the low temp to 160, 185 sets it to 185, etc.


Once the temp is above a particular temp the thermostat is fully open and the temperature is set by the rad, air flow, pump, pulleys, tune etc.

The cooling system is a SYSTEM, all the componants have to matched correctly to function properly.
Correct, however the cooling system is all about getting the water out of the hot engine as quickly as possible. The sooner the thermostat opens, the sooner that water is on its way out and into the radiator so the radiator can do its job. The sooner you get the water into the radiator, the sooner the radiator can cool it off. I also wouldn't use anything but a high flow thermostat. Everyone put high performance this and that on their engines, but when you start making recommendations for a high performance cooling system, they wince up and say "that's not how you're supposed to do it". I KNOW what worked for mine and it never, ever runs hot now.
 
Heater not getting hot means you need a new heater core.
180 thermostat is just fine.
In regards to the new AC. Did the car already have factory AC ?
Reason being, AC cars, and Non AC cars use different pulleys and water pumps.
It had factory ac,I don’t know for sure about the 360 that was swapped in though. I have new pulleys but not the pump.
 
Another thing is when I have the radiator cap off and I squeeze the upper coolant tube to let any air out the heat will be warmer for a while and the engine seems to run cooler. But after a while driving it goes back to before.
 
Correct, however the cooling system is all about getting the water out of the hot engine as quickly as possible. The sooner the thermostat opens, the sooner that water is on its way out and into the radiator so the radiator can do its job. The sooner you get the water into the radiator, the sooner the radiator can cool it off
Correct BUT after the temp the thermostat is fully open it makes no difference. So if it took 2 minutes to get to 160 vs 3 minutes to 185, at minute 4 it is 195 and both thermostats are fully open
 
Another thing is when I have the radiator cap off and I squeeze the upper coolant tube to let any air out the heat will be warmer for a while and the engine seems to run cooler. But after a while driving it goes back to before.
Replace your water pump with a Flow Kooler type unit.
 
If your heater core is blocked from sediment, the radiator could be also. Cross flow rads are the worst for this, not sure what model uses.
 
Correct BUT after the temp the thermostat is fully open it makes no difference. So if it took 2 minutes to get to 160 vs 3 minutes to 185, at minute 4 it is 195 and both thermostats are fully open
Well sure, but the 160 is still open sooner. It makes a difference. I've seen it first hand.
 
I always recommend a high flow 160 in anything above stock.
Just a question rusty will a 160 t stat be sufficient to prevent engine wear? In other words will engine get hot enough to not wear parts for running too cool? I hope I make sense in what I ask.
 
Here is a plan "B" for the guys that are overheating.

Not sure what your electric fans and flat shroud setup is? Those shrouds can actually block air flow through the radiator.

Screenshot_20221022-095723_Gallery.jpg


This worked on a performance 440 that was overheating with an electric fan and flat shroud.

Running Cool now.

☆☆☆☆☆
 
Post #2 says it .
But I'll add that you need to make sure that your vacuum advance is working and pulling in at least mid-teens.
However;
I had one engine that did not respond properly no matter what I did.
I tore it down, put another .001 skirt clearance into her and opened up the ring gaps several thousandths, badaboom problem solved. So much so that , that I undid some of the previous mods that I had done in an effort to run cooler. I even installed a 195 Hi-flo, and reset the max Temp to 207*F, and that is what she has run ever since.
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Also; check your ignition timing. If the timing is overly-retarded, the heat of combustion will go into the cylinder walls as the piston is going down, and guess what is on the outside of the walls, lol.. Plus at certain times, the mixture may not finish burning in the chamber on the power stroke, and the piston may push the still burning mixture into the exhaust system. On it's way out, it heats the ports...... which are surrounded by water, so there goes more heat into the cooling system.
>>At idle, the timing is always retarded. It doesn't matter what you set it too, it will always be retarded. How much? well here's how you figure out what she wants. Set the idle to 750, then pull in some timing, say 5 degrees. Reset the idle to 750. Repeat until the idle rpm no longer increases, them back the timing off a couple . Now, read the timing. Whatever you get is what she wants. Don't be surprised to see a number at or over 30*.
Now, set your rpm to 2400, and again pull in timing/reset the rpm as before. When the rpm no longer rises, back it off a tad. Whatever you get is what the engine wants at that 2400rpm with no load on it. Don't be surprised to see a number over 50*.
Obviously, you cannot put a load on an engine set up like that, lest it detonate itself to pieces. So put it back where it started from. Then think about what you just learned and how to make use of the lesson.
At WOT/full load and not detonation limited , the 360 LA will like about 35* of timing after about 3600 rpm., plus/minus 1 or maybe 2 degrees. Unless you have alloy heads and on the street, then I recommend 34* . These numbers are pretty much set in stone so don't mess with them. But how you get there is entirely up to the engine, and the load on it. I highly recommend to start at around 12 to 16 degrees depending on where that puts the Transfer-slot to mixture screw synchronization, which is also more or less written in stone, at an exposure of square to slightly taller than wide. Once you set that, then you control the idle speed with timing and or idle-air bypass.
The point of all this, is that you get the combustion process contained in the chamber/and top of the cylinder, and all of the fuel burned up before it exits the cylinders. Thus you get maximum energy transferred to the crank, and minimum energy transferred into the cooling system. With electric fans, you cannot afford to get too far out of the groove.
My best advice, I don't care about anyone else's opinion, is to over-engineer your cooling system using; a 7-blade, hi-attack angle, all-steel fan; and then put a thermostatic clutch on the fan to control the temp within a very narrow range.
BTW; when you do this right, you don't need a mega-dollar rad. My rad is factory circa 1973, off a 318 Dart with A/C. Nor do you need to run the pump in overdrive. Granted my engine, by it's trapspeed, is only putting out about 430hp crank.
>>If you think the 7-blade fan is a power-hungry monster that certain Performance magazines say it is; lemmee ease your pain. What's more important to you; a few horsepower at WOT, or keeping your engine from melting down? With the T-clutch I can almost guarantee you that both you and your engine will hardly know it's on there. It will do all it's work at speeds under about 30/35 mph , then more or less freewheel, unless maybe you are working a roadcourse. And I gotta tell you, seeing the gauge at the same old spot EVERY time I look at it, no matter what lunacy I have just been doing, is worth every single horsepower it might rob from the crank.
Am I recommending you swap off those electric fans?
Well no, but;
sooner or later, you are probably gonna anyway.........., and when you do, pay attention; a clutched fan, on the street, is not the monster that some people will try to make you believe it to be. I'm not talking about FABO people; they're a good bunch.
 
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