Overheating issue!

[NascarFastcar!]

Hello everyone. I am currently experiencing an overheating issue or temp creep, as I should say. I let my 440 run today and let the coolant system bleed. I have a 3 row dual fan aluminum radiator and a meziere electric water pump. Currently I have a Mr gasket 4364 180 thermostat. The car will reach temp gradually then under load at 180 degrees it will climb to 205-210 before I shut it down to be safe. Are these Mr gasket “hi flow” thermostats junk. Is that my issue?

 

[Kern Dog]

210 is nothing to be worried about. Water boils at 212 in a system with no pressure.

Plain water in a radiator with even a wimpy 12 PSI cap boils at 242. Do you run anti-freeze? Read the chart. A 50-50 mix with a 12 PSI cap boils at 259 degrees.
Now, I'm not fond of running 240 degrees but people worry about 210 as if it is death knocking on your door. It is not even close.

 

[#41]

If you suspect the thermostat you can test the unit by boiling it on the stove. Otherwise, you can also take it out, run the car, and see if the temps come down with no thermostat.

Otherwise, overheating issues are a process of elimination. You didn't mention if the problem is while sitting idle or with the car moving which is often the best clue as to where to start looking.

 

[Dennis H]

Shroud? Opportunity to run brief freeway speed at 210 to see results from there?

 

[Geoff 2]

I would not be happy either with that sort of temp creep. Do NOT run without a stat or washer of equivalent opening size. The stat is a purposeful restriction in the system to build up pressure & suppress local hot spots where boiling may take place; boiling water has air bubbles in it & air is a poor conductor of heat.
Looking at the Mez water pump, it looks like the impeller size is smaller than stock. All else being equal, a bigger impeller pumps more water; so does using a smaller pump pulley with a stock type pump. Then there is the elec fans....
Not enough ign advance [ timing at idle ] will also cause hot running, especially with big-ger cams. What cam? What ign timing?
More info here: www.stewartcomponents.com

 

[gtxdana]

Hello everyone. I am currently experiencing an overheating issue or temp creep, as I should say. I let my 440 run today and let the coolant system bleed. I have a 3 row dual fan aluminum radiator and a meziere electric water pump. Currently I have a Mr gasket 4364 180 thermostat. The car will reach temp gradually then under load at 180 degrees it will climb to 205-210 before I shut it down to be safe. Are these Mr gasket “hi flow” thermostats junk. Is that my issue?

Those Mr. Gasket thermostats are Made in China Robert Shaw knockoffs now and are junk. Of course, it may, or may not, be your problem. Electric water pumps on the street are always suspect. Three row aluminum radiators don't cool as well as a one or two row. 205-210 sitting or driving down the road? Lots of things to check.

 

[pnora]

Lots to consider. Is the fan a pusher or puller? Is it moving air across all the fins. What is the timing set at? Post some pics of what you have.

 

[NascarFastcar!]

If you suspect the thermostat you can test the unit by boiling it on the stove. Otherwise, you can also take it out, run the car, and see if the temps come down with no thermostat.

Otherwise, overheating issues are a process of elimination. You didn't mention if the problem is while sitting idle or with the car moving which is often the best clue as to where to start looking.

210 is nothing to be worried about. Water boils at 212 in a system with no pressure.

View attachment 2012866

Plain water in a radiator with even a wimpy 12 PSI cap boils at 242. Do you run anti-freeze? Read the chart. A 50-50 mix with a 12 PSI cap boils at 259 degrees.
Now, I'm not fond of running 240 degrees but people worry about 210 as if it is death knocking on your door. It is not even close.

For my sanity I like to see 190-200 range especially on this built engine haha

 

[NascarFastcar!]

If you suspect the thermostat you can test the unit by boiling it on the stove. Otherwise, you can also take it out, run the car, and see if the temps come down with no thermostat.

Otherwise, overheating issues are a process of elimination. You didn't mention if the problem is while sitting idle or with the car moving which is often the best clue as to where to start looking.

The problem occurs unfelt load. I’m starting to suspect the thermostat being a restriction to my cooling system.

 

[NascarFastcar!]

Those Mr. Gasket thermostats are Made in China Robert Shaw knockoffs now and are junk. Of course, it may, or may not, be your problem. Electric water pumps on the street are always suspect. Three row aluminum radiators don't cool as well as a one or two row. 205-210 sitting or driving down the road? Lots of things to check.

I will swap out the thermostat. I’ve heard many people have had flowing issues with these Mr gasket thermostats. I’ll be switching over to a Robert Shaw emp 301

 

[NascarFastcar!]

Lots to consider. Is the fan a pusher or puller? Is it moving air across all the fins. What is the timing set at? Post some pics of what you have.

 

[Dennis H]

I got a buck that says it’s not the thermostat. I run the old 180 Napa Superstat from days of yore.
Maybe I don’t understand “under load. Was it extended idle? Did it drop at all when moving off. Mine creeps too under certain conditions the settles down when moving.

 

[NascarFastcar!]

I got a buck that says it’s not the thermostat. I run the old 180 Napa Superstat from days of yore.
Maybe I don’t understand “under load. Was it extended idle? Did it drop at all when moving off. Mine creeps too under certain conditions the settles down when moving.

well to be specific, when it reaches the 190 mark and I step on it, it will rapidly climb and I have to shut it down. It will not settle down. I suspect the thermostat for two reasons. The car cools down very quickly when I switch the key and let the pump and fans run with the car off. Another reason is before, when I ran it with an open thermostat, I would open the radiator cap and I could see the coolant flowing fast which makes sense… now with the Mr. gasket thermostat the coolant barely moves, it’s almost at a stand still. That for me is a concern. Obviously with a thermostat in there’s bound to be some loss in circulation but this seems choked off. It’s not allowing coolant to flow.

 

[Kern Dog]

For my sanity I like to see 190-200 range especially on this built engine haha

I do too but 210 is not a death sentence.
The following is not meant to offend anyone, it is just an observation....
WHY do people seem to think that an electric fan is a good idea? I'm no purist but NOTHING pulls more air through a radiator than a proper belt driven fan and a well fitting shroud. Most of the times I see threads about overheating, the OP has an electric fan that pulls less air than a stock 7 blade fan.
I can take a piece of cardboard and put it against my radiator at idle and the suction of the fan will keep it there.
Can you say the same about the electric fan? I doubt it.
Electric fans do look more modern, I'll admit but belt driven fans are still used on pickup trucks where they are under a load when towing and hauling even at low road speeds. That is because the belt driven fans draw in the most air.

 

[RemCharger]

As stated , pull the thermostat and try it.
One of 3 things will happen; it's better, worse , or the same.
Luckily you have the bolt in electric pump. Easy to switch back to mechanical. That would be preferred for the street.

 

[Michael_]

Otherwise, you can also take it out, run the car, and see if the temps come down with no thermostat.

I was going to suggest this too. If it does fix your problem get a real Robert Shaw Thermostat instead.

Unfortunately your aluminum radiator, electric fans and electric water pump could all be the problem too.
Of course it could also be something not cooling system related like the ignition timing. (You said the temperature shoots up under load)

I would start by taking out the thermostat since this is easy and it also costs nothing.

 

[NascarFastcar!]

I do too but 210 is not a death sentence.
The following is not meant to offend anyone, it is just an observation....
WHY do people seem to think that an electric fan is a good idea? I'm no purist but NOTHING pulls more air through a radiator than a proper belt driven fan and a well fitting shroud. Most of the times I see threads about overheating, the OP has an electric fan that pulls less air than a stock 7 blade fan.
I can take a piece of cardboard and put it against my radiator at idle and the suction of the fan will keep it there.
Can you say the same about the electric fan? I doubt it.
Electric fans do look more modern, I'll admit but belt driven fans are still used on pickup trucks where they are under a load when towing and hauling even at low road speeds. That is because the belt driven fans draw in the most air.

I think it all comes down to accessibility and how much you want to spend. This car didn’t come with the original radiator nor did it come with an engine nor the engine brackets. I kind of had to start with nothing and I had a budget so I did what would kind of work best for me and to be quite honest some of it is partially for the aesthetic.

 

[NascarFastcar!]

I’ll check back in. Hopefully with a better flowing thermostat that fixes my issue

 

[Rebelrouser]

Hello everyone. I am currently experiencing an overheating issue or temp creep, as I should say. I let my 440 run today and let the coolant system bleed. I have a 3 row dual fan aluminum radiator and a meziere electric water pump. Currently I have a Mr gasket 4364 180 thermostat. The car will reach temp gradually then under load at 180 degrees it will climb to 205-210 before I shut it down to be safe. Are these Mr gasket “hi flow” thermostats junk. Is that my issue?

A meziere electric pump will not flow enough on the street. 1/4 mile and cool off in the pits OK but no on the street seen too many guys try including me. While the electric pump is rated at about the same as a stock pump 50 gph I believe that is free flow, engine block etc. get in the way. I usually use a stock a/c water pump and change the pulleys so it spins a little faster and flows more water. And from my experience a big two core radiator will flow more water that a big three core. And remember HP is heat that is just physics, the more HP the more heat you have to deal with. For the street I like a belt driven fan with good shrouds. I use electric fans for A/C use and to help out at slow speeds. The couple times I had issues with a car like yours I simply pushed water out of the hose into a 55 gallon drum for a time and then calculated the flow, big difference sometimes than published numbers.

 

[Charlie Brown]

If you really want to dive deeper, this link will expand your knowledge. It's also a rabbit hole thing. Very interesting read. Start at post #191. Overheating issue resolved....interesting read ! - Page 8