Re: how hot is too hot of an operating temp?
[Re: 360view]
#894195
01/06/11 01:22 PM
01/06/11 01:22 PM
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Joined: Mar 2005
Posts: 2,060 Pendleton NY
terzmo
top fuel
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top fuel
Joined: Mar 2005
Posts: 2,060
Pendleton NY
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Quote:
195 degree ..... 18.00 MPG 175 degree ..... 17.91 MPG 155 degree ..... 17.82 MPG 135 degree ..... 17.74 MPG
For whatever it is worth the above is what Kevin Gertgen's 'Fuel Economy Calculator' program
http://performancetrends.com/fuel_economy_calculator.htm predicts for a stock 1995 2wd 5.9 V8 46RH auto Ram pickup with 3.55 diff, travelling down a level concrete highway at a steady 70 mph on a windless 42 degree F day
The program does not allow thermostat temps above 195, but one might speculate that each 20 degrees of coolant temperature increase might be worth 0.1 MPG
I know that if you idle a 1995 Ram for ten or so minutes with the factory radiator fan removed, but with Evans NPG coolant to prevent boil over, the coolant temperature goes up from 193 to 240, the idle smoothness noticeably improves, and the fuel consumption drops from 0.66 gallons per hour to 0.60
When at speed on a highway, if you raise the coolant temperature by blocking airflow through the radiator, rather than by thermostat action, you might get an even better MPG gain, because air flowing through the front grille and then out the bottom of the vehicle is a major source of aerodynamic drag.
NASCAR teams of course routinely block off as much of the grille as cooling will allow, and the new GM Cruze has shutters on its radiator opening.
The topic is about an engine almost 35 years old..not new junk..new junk can run all day at 220...old iron won't run well for long at that temp...not designed for it....check out normal temp range...mid range is around 190....out of range is 210+
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Re: how hot is too hot of an operating temp?
[Re: terzmo]
#894196
01/06/11 02:14 PM
01/06/11 02:14 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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I have run my 40 year old junk 205-215 even 220 for years on end with zero problems mabey it's because I run thermoquads instead of holley afb and avs crabs.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: how hot is too hot of an operating temp?
[Re: terzmo]
#894198
01/08/11 01:08 PM
01/08/11 01:08 PM
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Joined: Jan 2003
Posts: 5,789 Hamilton, Ontario Canada
Magnum
master
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master
Joined: Jan 2003
Posts: 5,789
Hamilton, Ontario Canada
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For a bunch of fine tuners we all claim to be. I really don't understand what the harm is running an engine hotter.
If a car goes faster running the ignition timing at 35, why run it down at 20, 25 or 30. If a car likes a 14.7 fuel air mix, why run it at 16 or 18.
So your car overheats at 250. I see no need to run it down at 160 or 180. Get it up to 195 where it's documented to run the best.
What kind of problems are we experiencing running the factory recommended thermostat?
69 Super Bee, 93 Mustang LX, 04 Allure Super
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Re: how hot is too hot of an operating temp?
[Re: Magnum]
#894199
01/08/11 02:07 PM
01/08/11 02:07 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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The problem they have is they think a lower t-sta temp makes more power, it does but it is very little and not worth it for the increased wear and tear and lower gas mileage. It makes more power because it gets colder air into the engine witch is more dense so more total air (and corresponding fuel)molecules make it to the combustion chamber. I run mine hotter because I like MPGs smoother running and longer engine life. Whatever the factory chooses to run is a compromise. As for the factory gauges, they are showing over heating by 220 because they know that most people will not be stopped by the time it reaches a REAL critical temp unless you warn them long ahead of time, even the new cars are set up that way, can you really imagine that those metals in the engine are gonna somehow self destruct because they are 220 degrees? Is cast iron, aluminum, brass, bronze... gonna start melting at 220? Any decent oil will not be close to breaking down at that temp either and a 50 50 mix of ethylene glycol will not boil at 16 PSI either. Any one got one single good reason they would call it overheating at 220? witch piece is gonna get ruined at that temp?
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: how hot is too hot of an operating temp?
[Re: terzmo]
#894201
01/08/11 02:58 PM
01/08/11 02:58 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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You are gonna have to get way over 220 to warp a head or blow a head gasket unless the head gasket was marginal in the first place. Also you are completly wrong about the friction thing, friction goes down as temp goes up
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: how hot is too hot of an operating temp?
[Re: 469runner]
#894203
01/08/11 07:48 PM
01/08/11 07:48 PM
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Joined: Jan 2008
Posts: 3,886 Lost and Spaced
bboogieart
master
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master
Joined: Jan 2008
Posts: 3,886
Lost and Spaced
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some times I think folks put to much into these things. If it ain't pukin' it ain't over heated. That is the function of the radiator cap, no? When we were kids we would put a brick on the gas pedal put the car on blocks drain oil and water and see what broke. OK we had too much time on our hands but I remember a particular ply. just shut down and restarted when cool and we did it again. That car was driven to school for the next two years. Sure it didn't win any races but we thought that was a sign of a tough motor.
I have mechanical Aptitude. I can screw up anything.
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Re: how hot is too hot of an operating temp?
[Re: terzmo]
#894205
01/09/11 01:57 PM
01/09/11 01:57 PM
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Joined: Jan 2006
Posts: 8,162 USA
360view
Moparts resident spammer
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Moparts resident spammer
Joined: Jan 2006
Posts: 8,162
USA
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I posted that to show that the benefit of the higher MPG is small, but if people want to go after it, that is their choice, and many people like a challenge.
I would guess that rubbery parts .... hoses, seals, vacuum lines would have their service life shortened by increased temperatures.
I would guess that aluminum to cast iron junctions, like cylinder heads, manifolds would be most likely to warp at higher tempertures.
I would not think that cast iron against cast iron parts would be affected much.
Since bore wall wear goes down with increased coolant temperature (Continental Motors research) I would guess that maybe piston ring wear would go down too. Much of this bore, ring and piston wear is from acids that are best kept as vapor, never as a liquid (electrolyte allows corrosion) so higher temperatures that are above the mixture's boiling temperature reduce corrosion. Similar to 50/50 anti-freeze and sea water, these mixtures of acids in water boil at temperatures above 212 F.
Continental Motors now mainly makes aircraft gasoline engines, and I for one was sad to see the press release last month where they were sold to a Chinese company.
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Re: how hot is too hot of an operating temp?
[Re: 360view]
#894206
01/09/11 03:47 PM
01/09/11 03:47 PM
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Joined: Feb 2005
Posts: 4,313 Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,313
Prospect, PA
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Quote:
I posted that to show that the benefit of the higher MPG is small, but if people want to go after it, that is their choice, and many people like a challenge.
I would guess that rubbery parts .... hoses, seals, vacuum lines would have their service life shortened by increased temperatures.
I would guess that aluminum to cast iron junctions, like cylinder heads, manifolds would be most likely to warp at higher tempertures.
I would not think that cast iron against cast iron parts would be affected much.
Since bore wall wear goes down with increased coolant temperature (Continental Motors research) I would guess that maybe piston ring wear would go down too. Much of this bore, ring and piston wear is from acids that are best kept as vapor, never as a liquid (electrolyte allows corrosion) so higher temperatures that are above the mixture's boiling temperature reduce corrosion. Similar to 50/50 anti-freeze and sea water, these mixtures of acids in water boil at temperatures above 212 F.
Continental Motors now mainly makes aircraft gasoline engines, and I for one was sad to see the press release last month where they were sold to a Chinese company.
Not really sure how acids in the coolant effects the bore and rings. If you have coolant and coolant vapor in those locations your problems are a lot bigger. Generally, you're not "boiling off" anything as the system is normally maintained below boiling conditions. Finally, mineral acids have a higher boiling temperature than water, so if you boil an acid solution, the acid concentration in the remaining liquid likely remains the same or goes up. It would be type of acid specific.
Remember that coolant temp is only part of the story. It is a reflection of the efficiency of heat transfered from the engine to the coolant to the air for a given coolant and system. 220 or 230 degrees may or may not be okay. If everything else in the system is functioning properly and you have a high temp t-stat in the system, its probably okay.
Finally, the lower t-stat will allow a good system to operate at a lower coolant temperture, and the associated analysis is that the cylinder wall wear will increases. This is true, however,I can tell you in practice that it is small and likely unnoticeable in our good weather, limited usage cars. Note that nearly all marine automotive engines use a 142 degree t-stat and their opreating conditions are an order of magnitude more grueling than in a car.
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Re: how hot is too hot of an operating temp?
[Re: BSB67]
#894207
01/09/11 04:06 PM
01/09/11 04:06 PM
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Joined: Oct 2003
Posts: 1,371 Costa Mesa, CA
chache876
pro stock
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pro stock
Joined: Oct 2003
Posts: 1,371
Costa Mesa, CA
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Quote:
Quote:
I posted that to show that the benefit of the higher MPG is small, but if people want to go after it, that is their choice, and many people like a challenge.
I would guess that rubbery parts .... hoses, seals, vacuum lines would have their service life shortened by increased temperatures.
I would guess that aluminum to cast iron junctions, like cylinder heads, manifolds would be most likely to warp at higher tempertures.
I would not think that cast iron against cast iron parts would be affected much.
Since bore wall wear goes down with increased coolant temperature (Continental Motors research) I would guess that maybe piston ring wear would go down too. Much of this bore, ring and piston wear is from acids that are best kept as vapor, never as a liquid (electrolyte allows corrosion) so higher temperatures that are above the mixture's boiling temperature reduce corrosion. Similar to 50/50 anti-freeze and sea water, these mixtures of acids in water boil at temperatures above 212 F.
Continental Motors now mainly makes aircraft gasoline engines, and I for one was sad to see the press release last month where they were sold to a Chinese company.
Not really sure how acids in the coolant effects the bore and rings. If you have coolant and coolant vapor in those locations your problems are a lot bigger. Generally, you're not "boiling off" anything as the system is normally maintained below boiling conditions. Finally, mineral acids have a higher boiling temperature than water, so if you boil an acid solution, the acid concentration in the remaining liquid likely remains the same or goes up. It would be type of acid specific.
I'm assuming what he was talking about are the leftovers of combustion in the cylinders (water, unburned gas, etc...) that can form acids etc... that can cause wear on components and the need for the engine to reach a hot enough operating temperature so that those byproducts evaporate and cant cause any harm. I touched on that earlier in the thread.
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Re: how hot is too hot of an operating temp?
[Re: chache876]
#894208
01/10/11 12:50 AM
01/10/11 12:50 AM
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Joined: Feb 2005
Posts: 4,313 Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,313
Prospect, PA
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Quote:
Quote:
Quote:
I posted that to show that the benefit of the higher MPG is small, but if people want to go after it, that is their choice, and many people like a challenge.
I would guess that rubbery parts .... hoses, seals, vacuum lines would have their service life shortened by increased temperatures.
I would guess that aluminum to cast iron junctions, like cylinder heads, manifolds would be most likely to warp at higher tempertures.
I would not think that cast iron against cast iron parts would be affected much.
Since bore wall wear goes down with increased coolant temperature (Continental Motors research) I would guess that maybe piston ring wear would go down too. Much of this bore, ring and piston wear is from acids that are best kept as vapor, never as a liquid (electrolyte allows corrosion) so higher temperatures that are above the mixture's boiling temperature reduce corrosion. Similar to 50/50 anti-freeze and sea water, these mixtures of acids in water boil at temperatures above 212 F.
Continental Motors now mainly makes aircraft gasoline engines, and I for one was sad to see the press release last month where they were sold to a Chinese company.
Not really sure how acids in the coolant effects the bore and rings. If you have coolant and coolant vapor in those locations your problems are a lot bigger. Generally, you're not "boiling off" anything as the system is normally maintained below boiling conditions. Finally, mineral acids have a higher boiling temperature than water, so if you boil an acid solution, the acid concentration in the remaining liquid likely remains the same or goes up. It would be type of acid specific.
I'm assuming what he was talking about are the leftovers of combustion in the cylinders (water, unburned gas, etc...) that can form acids etc... that can cause wear on components and the need for the engine to reach a hot enough operating temperature so that those byproducts evaporate and cant cause any harm. I touched on that earlier in the thread.
Combustion temp is like 1500 to 1800 degrees. Again, 20 degree difference in the t-stat won't make a measurable difference in these cars especially at the typical hot rodder oil change frequency. Typical hot rodder also runs their carbs to fat, and that will cause greater wear than their t-stat choice.
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Re: how hot is too hot of an operating temp?
[Re: BSB67]
#894209
01/10/11 09:23 AM
01/10/11 09:23 AM
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Joined: Jan 2006
Posts: 8,162 USA
360view
Moparts resident spammer
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Moparts resident spammer
Joined: Jan 2006
Posts: 8,162
USA
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Quote:
Combustion temp is like 1500 to 1800 degrees. Again, 20 degree difference in the t-stat won't make a measurable difference in these cars especially at the typical hot rodder oil change frequency.
The point of the Continental Motors research long ago in the early 1960s, and confirmed by later investigations, is that at the end of the exhaust stroke the "pore spaces" of the ring land, bore walls, pistons, head gasket gaps, cylinder head combustion chamber, are only a bit higher in temperature than the coolant temperature.
These little 'caves' in the metal now technically called 'quench clearances' are cool enough that mixtures of acids and water can exist there as liquids and cause corrosion.
It was a surprise to most that the rust and corrosion in these little pockets were the source of most bore wall wear. It was a kinda breakthrough.
This struck me more than most people because I am a mining engineer and 'quench clearances' between metal parts .... are the key thing that prevents explosions in mines.
You don't make things safe in mines by making the electrical equipment cabinets 'airtight' you make it safe by making the walls massively strong and thick, and by leaving ... on purpose a special gap of limited size that 'snuffs out' internal explosions you accept will always occur and keep this combustion from 'propagating' outside to open air in the mine where they sadly would become man-killing explosions and fires.
This is pretty old technology where Sir Humphrey Davie in England in the early 1800's won a national prize of 20,000 Pounds Sterling for inventing the 'Flame Safety Lantern'
MPG improvement enthusiasts note: these same 'quench clearances' also kill off anywhere from 6% to 10% of the fuel economy of an engine too!
Liquid gasoline droplets 'hide' in the tiny 'caves' of the quench clearances and either never burn during combustion or burn so late that the dropping piston has a bad angle to push against the crankshaft, or even worse, burn as the piston is trying to rise on the exhaust stroke.
This is why modern engines are going to smaller 'ring lands' more compact combustion chambers in the cylinder head, and also one of several reasons that polishing surfaces, or special coating, of combustion chambers yield small improvements.
If you think to yourself:
"Hey, those little spaces are such a small percentage of the total space that there is no way they could make much of a difference" ..... then instead think: a SCUBA tank of air at 3000 psi holds much more than the SCUBA tank would at atmospheric pressure.
The key thing is that when combustion starts in the center of the cylinder head combustion chamber, it generates very high pressures, and these high pressures in turn:
"compress unburned fuel and air into the quench clearances along the outside edges of the chamber, especially the circular gap of the ring land"
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Re: how hot is too hot of an operating temp?
[Re: BSB67]
#894210
01/10/11 10:08 AM
01/10/11 10:08 AM
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Joined: Jul 2008
Posts: 30,424 Florida STAYcation
dOrk !
The village idiot's idiot
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The village idiot's idiot
Joined: Jul 2008
Posts: 30,424
Florida STAYcation
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Quote:
Typical hot rodder also runs their carbs to fat, and that will cause greater wear than their t-stat choice.
True DAT .... and with a pig-fat crab .. it washes the oil off the cyl walls and wears the rings excessively.
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Re: how hot is too hot of an operating temp?
[Re: dOrk !]
#894211
01/10/11 11:18 AM
01/10/11 11:18 AM
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Joined: Jan 2003
Posts: 9,996 Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
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I didn't go through the whole post so this might be old info- I run a shroud that is only 3/4 inch from the fins ,using a pusher fan. Works great. Gets cooling air to all the fins, really helps over a setup that doesn't. I would bet that down to 1/2 inch would really improve things. Just be sure the shroud is as air tight to the fan as you can make it.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: how hot is too hot of an operating temp?
[Re: terzmo]
#894212
01/10/11 11:10 PM
01/10/11 11:10 PM
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Joined: Jan 2003
Posts: 5,270 Missouri
MY340
master
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master
Joined: Jan 2003
Posts: 5,270
Missouri
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For an old iron headed muscle car motor 200-210 degrees is max in my opinion.
I prefer 180-190 degrees in my Duster.
1970 FE5 Duster 360/904/3.91's SOLD
1973 TB3 SpaceDuster 340/4spd/4.10's SOLD
Moparless for now but when the opportunity is right I'll have another one.
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Re: how hot is too hot of an operating temp?
[Re: 62maxwgn]
#894214
01/11/11 12:19 PM
01/11/11 12:19 PM
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Joined: May 2003
Posts: 15,487 Florida
scratchnfotraction
I Live Here
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I Live Here
Joined: May 2003
Posts: 15,487
Florida
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stock cooling has always been good for me i do upgrade to some of the max cooling packages they had like a 3 row rad,and a HD max cooling thermo clutch with a 7 blade fan along with a stock shroud never had any troble with stock cooling packages unles it was some mech failur i add the large stock tranz coolers and have added stock oil coolers to the HD work trucks also that increases the cooling of the whole engine as a whole,IMHO
Last edited by scratchnfotraction; 01/11/11 12:20 PM.
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