How hot is too hot?

[khryslerkid]

I knew it was just a matter of time before the myth about an engine overheating without a thermostat would show up. This is false.

Guess I was imaging things....

 

[67 B-body]

Guess I was imaging things....

Me too considering I would purchase different sized coolant restrictors specifically to adjust engine temps in our Late Model dirt track cars engines..... If you went to far in either direction, the engine temps would raise..... I'm as certain about this as others here who would refer to it as a myth! This is a FACT!!!!! Not some discussion point among cyber buddies!
Sorry to call anyone out on this,,, but I have the right to be sure about something too,,, even if it doesn't support someone else views.....
BTW,,, the restrictors are just fancy washers with different sized holes punch through the middle and are used in lieu of a thermostat.....
Now before you go and dig up some old car craft magazine article supporting a different opinion that closely matches yours I can tell you that I simply don't care....... I have my own FIRST HAND practical experience utilizing different restrictors on Alcohol burning 700+hp race car engines. It was most definitely one of the tools commonly used when tuning these engines to keep with the competition.
I'm done now,,,,,
Sorry for the Semi-Rant!!!!! And sorry for any offence.......:eusa_think:

 

[snakeoil24]

Everyone asks about what is the right temperature for an engine to run. Another way to look at this is. To think what it takes to keep the engine from producing excessive steam during operation. A few things have to happen for best running Temperature.
1. The engine has to ignite the fuel when the least amount of cylinder wall is exposed to the combustion. Once the exhaust valve opens heat is transferred very quickly out the exhaust. if you ignite the fuel to early then the cylinder walls have to absorb excess heat. Engines where designed to ignite fuel when this area is very small. This allows the Cylinder head, Piston top and exhaust in conjuntion with valve overlap to cool the chamber very quickly.
2. the same can happen with late firing of the fuel once the cylinder begins its downward stroke, just not as bad. On later smog engines used EGR to help cool combustion chamber temperatures to allow the fuel that was unburnt to be cooled and reduce emissions and still burn as it entered the exhaust manifolds.
3. Proper ratios of fuel can make an engine miserable if it is too lean.
4. At sea level water boils at 212 F, at 16 PSI pressure it boils at 230 degrees. What you need to be concerned about is the rate of steam production is controlled in the cylinder head. all cylinder heads produce small amounts of steam when the engine is running normally. This release of steam takes place in the top of the cylinder head in the form of very tiny steam bubbles. This releases heat. When you get in trouble is when these bubbles get out of control. Bad water pump, clogged radiator, bad timing, cracked head or leaking head gasket. If an engine runs to cool rust on cylinder walls takes place and like the other guy said it doesn't burn off moisture in the oil. Running an engine at 220 F under pressure is fine if pressure is maintained in the radiator.

 

[500stroker]

Listen we are talking old school engines here.
Save your money on snake oil and fancy electric junk that does not work.
Go and get a direct fit Griffin 2x1.5 inch aluminum radiator run it with a hi flow t-stat and water pump and you can run in any conditions and not be concerned about engine temps. I also added a recirculating tank and a 6 blade belt driven fan. I have seen this cooling combo work here in MO in 100 degree heat with no problems, never gets above 190 cooling a stroked 440 w/ 727

 

[snakeoil24]

sounds good

Listen we are talking old school engines here.
Save your money on snake oil and fancy electric junk that does not work.
Go and get a direct fit Griffin 2x1.5 inch aluminum radiator run it with a hi flow t-stat and water pump and you can run in any conditions and not be concerned about engine temps. I also added a recirculating tank and a 6 blade belt driven fan. I have seen this cooling combo work here in MO in 100 degree heat with no problems, never gets above 190 cooling a stroked 440 w/ 727

I dont see any snakeoil here either!

 

[Hemi Rebel]

The myth is that the speed of the coolant through the radiator is the problem. Its not some car craft article. Its physics and thermodynamics. Restrictors are not used to change the speed of the flow of coolant, they create a dynamic pressure in the engine above what the static pressure is set by the cap. Running a higher pressure cap with no restrictor will have the same effect. The point being that it is not the speed of the coolant, but the pressure its under. Which brings us back to the matter at hand, how is the cap on the car in question?

 

[67 B-body]

"Restrictors are not used to change the speed of the flow of coolant, they create a dynamic pressure in the engine above what the static pressure is set by the cap."
Well now I've heard it all... LOL
What Engineering school did you go to???? I'll compare Degrees with ya....
Sorry, maybe that wasn't nice,,, but that's one of the largest piles of Bull I have ever heard...

Lets move on to the OP of "what's too hot".......

 

[khryslerkid]

:iamwithstupid:

 

[mjb765]

I might have missed this since I read through the thread quickly...but did anybody ask how old the radiator is and what condition it's in?? Has it been boiled out?? There is a good possibility that it is not flowing properly which could be the entire problem.

 

[67 B-body]

:iamwithstupid:

:iamwithstupid:

 

[69Bee]

...4. At sea level water boils at 212 F, at 16 PSI pressure it boils at 230 degrees...

Actually, the boiling point will be raised by approximately 2 to 3 degrees per each lb of pressure. Also, a 50/50 mix of ethlyene glycol will raise the boiling point to approximately 223 degrees fahrenheit.

A 16 lb cap will raise the boiling point by 32 to 48 degrees, adding the 50/50 mix, the boiling point is raised to 255-271 degrees fahrenheit

Ethylene glycol: http://en.wikipedia.org/wiki/Ethylene_glycol

 

[67 B-body]

Does the boiling point of a coolant mixture truly dictate what the normal operating temperature should be? If I poured some other chemical into my coolant system that raised the boiling point say another 20 deg F, does that mean my engines normal operating temperature should also increase???? Other factors are to be considered in the OP's question.... For example,,,, What did the factory "designers of the car and all of its systems" deem appropriate regarding normal operating temperatures? We can answer this pretty easily by monitoring our factory instrument cluster, specifically the temp gauge.
If it's leaning clear over to the right,,, well guess what,,,, it's too damn hot.... Or, beyond or near the MAX operating temps. When something is at its MAX operating temps you have no room for normal coolant fluctuations in temp, like entering residential areas or in town traffic.....
It seems simple to me and so far many others to answer this seemingly simple question.... In summary, we don't need to think beyond the ORIGINAL FACTORY recommended operating temps in this debate, not today's engine standards.... Once again, this value is able to be monitored using factory gauges, Whatever that temp is.

 

[bigmanjbmopar]

180° stat runs up to 210 when it gets hot and then when the stat opens it's back down to 180°. Are you sure your timing is set right? that will effect the heat, with a big block you need a min of a 26" 3 row for summer nights.

I don't worry about 200-210 temps but I can feel a difference in performance when it hits 225° or higher in traffic for 30 minutes or more it is sluggish and slow to pick up even with aluminum heads

 

[terzmo]

"It seems simple to me and so far many others to answer this seemingly simple question.... In summary, we don't need to think beyond the ORIGINAL FACTORY recommended operating temps in this debate, not today's engine standards.... Once again, this value is able to be monitored using factory gauges, Whatever that temp is."

Never were truere words spoken,,,,it's not anew millemium engine or design, as I stated earlier. 210 is hot for old iron...220 is a no no.:wav:

 

[64Belvedere]

These year cars never had a 26 inch rad when they were new. There is a 3 core in it. I had the rad flushed added a bottle of water wetter and I had it out last night to a cruise night and never saw over 200 sitting in traffic. I'm happy with that compared to 250* two weeks ago. Thanks to all who posted, there is a lot of good info in this thread.

 

[RustyRatRod]

All I know is, I've been building engines a LONG time. I've had some street driven engines that were in excess of 500 HP. I never had a problem with overheating. Not once. If you use the right parts and in general factory configuration, you won't be worryin about how many steam pockets you have, what kinda pressure differential the thermostat is makin or any of that other hocus pocus theorhetical physics horse hockey. It's really not that hard to build a car that doesn't overheat. All it takes is common sense.

 

[RustyRatRod]

These year cars never had a 26 inch rad when they were new. There is a 3 core in it. I had the rad flushed added a bottle of water wetter and I had it out last night to a cruise night and never saw over 200 sitting in traffic. I'm happy with that compared to 250* two weeks ago. Thanks to all who posted, there is a lot of good info in this thread.

That's good. I am glad you got it where you're comfortable with it. Sounds like it's just about right, too.

 

[mjb765]

These year cars never had a 26 inch rad when they were new. There is a 3 core in it. I had the rad flushed added a bottle of water wetter and I had it out last night to a cruise night and never saw over 200 sitting in traffic. I'm happy with that compared to 250* two weeks ago. Thanks to all who posted, there is a lot of good info in this thread.

Perfect......the simple fixes are the best!!!

 

[snakeoil24]

Restrictor plate

The myth is that the speed of the coolant through the radiator is the problem. Its not some car craft article. Its physics and thermodynamics. Restrictors are not used to change the speed of the flow of coolant, they create a dynamic pressure in the engine above what the static pressure is set by the cap. Running a higher pressure cap with no restrictor will have the same effect. The point being that it is not the speed of the coolant, but the pressure its under. Which brings us back to the matter at hand, how is the cap on the car in question?

Restrictor plates create added velocity also keep fluid in radiator longer but that is it..

 

[snakeoil24]

It still is all about steam production control. That is the main thing about cooling systems "controlled steam production". Proper pressurized cap, proper timing, fuel ratio and good flow in radiator. also minimal air pockets in Cylinder heads. All the modern electric fans are nice but do nothing to fix a poorly pressurized and properly timed engine..