Moparts

how hot is too hot of an operating temp?

Posted By: roe

how hot is too hot of an operating temp? - 01/02/11 06:15 AM

360 auto, car in my sig, would a steady 195-200 be too high? and will a car overheat without an overflow tank?
Posted By: DaytonaTurbo

Re: how hot is too hot of an operating temp? - 01/02/11 06:18 AM

I have a 195* thermostat in my car. Because of that the cooling system is incapable of attaining an operating temp below that rating. That's the whole point. Don't worry about your temp. You won't overheat without an overflow but you will puke coolant all over the ground when you get to temp and the rad cap vents. If you fill the rad and stop an inch or two from the top you'd probably be okay.
Posted By: RapidRobert

Re: how hot is too hot of an operating temp? - 01/02/11 06:33 AM

You're OK on the temp. The overflow jug in conjunction w a coolant recovery cap stops the majority of coolant loss (some still evaps as steam out out the jug as it has to be open for it to fill) and after it cycles a few times and gets most of the air out of the system w the coolant right up to the rad cap seal that can let it run a slight bit cooler and lessens rust formation as it needs air to form. To ans your Q if you are overheating (or not) it will be independant of whether you have an overflow system or not. Is that the temp around town or out on the hiway?
Posted By: roe

Re: how hot is too hot of an operating temp? - 01/02/11 06:36 AM

how hot is too hot? what temp do inot want to see?
Posted By: DaytonaTurbo

Re: how hot is too hot of an operating temp? - 01/02/11 06:41 AM

After driving your car for a while you should know what's normal for it to run based on driving conditions. At 230 I would start really keeping my eye on the temp gauge and at 250 I would be calling it. Remember, a perfect cooling system will keep your operating temp right around the rating of your thermostat. So anything higher than that is not ideal but not necessarily detrimental.
Posted By: dIc dOc Deity !

Re: how hot is too hot of an operating temp? - 01/02/11 07:23 AM



ANYone know if there is some type of "gauge" that will show you the operation of the 'stat?
Posted By: 1_WILD_RT

Re: how hot is too hot of an operating temp? - 01/02/11 07:34 AM

FWIW Ford doesn't even turn on the electric fan on cars so equipped till 221 degrees..
Posted By: hooziewhatsit

Re: how hot is too hot of an operating temp? - 01/02/11 07:58 AM

Quote:



ANYone know if there is some type of "gauge" that will show you the operation of the 'stat?




The temp sensor I'm working on for the Mercedes fan controller shows the temp rising right to the thermostat temp, then lowering a few degrees and hovering there (while idling).

Or are you thinking of a sensor that shows how open the thermostat is?
Posted By: Evil Monkey

Re: how hot is too hot of an operating temp? - 01/02/11 08:03 AM

It sounds like you have a 195 degree thermostat installed, which is what Ma Mopar recommends our engines have (and what a parts store will give you as a stock replacement thermostat), and running at 195 to 200 degrees would be normal for a 195 degree thermostat, as long as the temp is basically staying steady at 195 to 200.

The things you want to watch out for are:

A stady increase in temp when running down the highway. This would indicate that your cooling system is undersized or plugged up - you're not getting enough coolant flow.

Or

A steady increase in temp when idleing or crusing slowly. This would indicate that there's not enough air blowing through the radiator.
Posted By: dIc dOc Deity !

Re: how hot is too hot of an operating temp? - 01/02/11 08:06 AM

Quote:



Or are you thinking of a sensor that shows how open the thermostat is?




Yes .. MORE in this area ....but the Benz idea is good to. That RV project I am working on now ....in the heads and water-pump ... there are all sorts of places to put sensors EVERYwhere.
Posted By: ademon

Re: how hot is too hot of an operating temp? - 01/02/11 08:46 AM

200 is good, i would worry if it creeps up over 200 and starts to get to 220/230 and does not come down at speeds better than 35/40mph. also timing and jetting can affect temp.
Posted By: roe

Re: how hot is too hot of an operating temp? - 01/02/11 03:43 PM

thanks for the info guys. I get a steady 200 on the highway, but idling in stop and go traffic it hits 230, then drops when I start moving again. I'll attribute a lot of that to not having a fan shroud at all. The 318 stayed cool without it but tue 360 seems to need it. Gotta find one.
Posted By: roe

Re: how hot is too hot of an operating temp? - 01/02/11 03:47 PM

also need to either get a new cap for my overflow tank, or pick up a universal one. One of the nipples broke off my original so coolant can go in but can't come back out to the radiator.
Posted By: RapidRobert

Re: how hot is too hot of an operating temp? - 01/02/11 03:49 PM

Quote:

The things you want to watch out for are:

A stady increase in temp when running down the highway. This would indicate that your cooling system is undersized or plugged up - you're not getting enough coolant flow. Or

A steady increase in temp when idleing or crusing slowly. This would indicate that there's not enough air blowing through the radiator.


good explanation
Posted By: ireland383

Re: how hot is too hot of an operating temp? - 01/02/11 04:05 PM

Is this a new build? If so they tend to run hotter for awhile. Also you can use a laser temp gun to find how accurate your gauge really is. Lastly make sure you have no air pockets in the cooling system.
Posted By: Pool Fixer

Re: how hot is too hot of an operating temp? - 01/02/11 04:21 PM

I know I don't know as much as many members here, but I just don't like 200 for our cars. I know that new cars run that hot but they are designed to run safely on the edge. EFI, knock sensors, computer spark control to retard timing, etc..

Personally, I don't want mine going over 180 if I can help it. I took my big block charger on a road trip this summer, sat in 3 hours of stop and go traffic to get a total of about 20 miles. It got to 210 in stop and go. No, it didn't puke and overheat, but I still didn't like it. I'm trying to come with some solution to get it to run cooler at idle. as soon as the car moves, even 20-30 mph, the temp drops right to 170 where my temp sensor is set (electric fans running off sensor)
Posted By: RapidRobert

Re: how hot is too hot of an operating temp? - 01/02/11 04:44 PM

Quote:

I'm trying to come with some solution to get it to run cooler at idle. as soon as the car moves, even 20-30 mph, the temp drops


the tried/true setup of a MP thermal clutch fan spaced ~2/3 into a shroud does work good and check the dia of your WP pulley and might be able to source a smaller dia one to speed up the fan/pump and pull the pump to tack on an anti cav plate on the vanes to make it more efficient. EDIT (re)read & missed that you're running electric fan(s)
Posted By: Pool Fixer

Re: how hot is too hot of an operating temp? - 01/02/11 05:19 PM

Quote:

Quote:

I'm trying to come with some solution to get it to run cooler at idle. as soon as the car moves, even 20-30 mph, the temp drops


the tried/true setup of a MP thermal clutch fan spaced ~2/3 into a shroud does work good and check the dia of your WP pulley and might be able to source a smaller dia one to speed up the fan/pump and pull the pump to tack on an anti cav plate on the vanes to make it more efficient. EDIT (re)read & missed that you're running electric fan(s)




yes, dual spal fans (1300cfm each) but due to total lack of room between WP pulley and the rad core(two row aluminum Fluidyne) the fans are mounted up high on the rad. bottom third of rad isn't getting air pulled through it. I think that's my problem. I don't know if I should create some sort of shroud to cover that part of the rad and leave fans where they are or maybe go with the feets mercedes fan that would cover more of the core (I am a bit short on clearance even for that though so i'd have to get creative)

I was running a flowkooler wp with the plate tacked on and I switched it out for a parts store stock replacement. There was no change in performance.. but enough of a hijack here. As much as I'd love to get my issue resolved, it's this guys thread...If you have any suggestions though, please please PM me. Thanks so much. Kevin.
Posted By: terzmo

Re: how hot is too hot of an operating temp? - 01/02/11 05:23 PM

Quote:

FWIW Ford doesn't even turn on the electric fan on cars so equipped till 221 degrees..




FWIT...that ford must be a newer car...old iron was in the danger zone at 210 plus...I don't understand why anyone would run old iron motors at 230 and wait for 250......195 to 200 nis ok...I prefer to see it around 190 for My Bee and GTX...both 440 motors
Posted By: cjs69mope

Re: how hot is too hot of an operating temp? - 01/02/11 05:27 PM

I run a seven blade flex fan 17 in dia with stock shroud on a 26 inch
3 core stock brass type radiator .
with a 160 t-stat the eng would run to cool for school , never even got to 180 unless very warm out side . the eng has aprox 600 hp.
had to switch to 195 t stat to correct some air fuel distributon issiues and car still runs 195 on hyway will creep to 210 if sitting in trafic to long but still ok .
I have a friend with a all alumnum 850hp hemi that runs stock seven blade fan with the viscus thermo clutch and keeps cool and says that he has tried every fan out there and none can beat the factory seven blade pulls about 4000 cfm so he says . try to find electric fans that will fit on a 26 in radiator and pull like that ! very dificult !
Posted By: OzHemi

Re: how hot is too hot of an operating temp? - 01/02/11 05:27 PM

Quote:

yes, dual spal fans (1300cfm each) but due to total lack of room between WP pulley and the rad core(two row aluminum Fluidyne) the fans are mounted up high on the rad. bottom third of rad isn't getting air pulled through it. I think that's my problem. I don't know if I should create some sort of shroud to cover that part of the rad and leave fans where they are or maybe go with the feets mercedes fan that would cover more of the core (I am a bit short on clearance even for that though so i'd have to get creative)

I was running a flowkooler wp with the plate tacked on and I switched it out for a parts store stock replacement. There was no change in performance.. but enough of a hijack here. As much as I'd love to get my issue resolved, it's this guys thread...If you have any suggestions though, please please PM me. Thanks so much. Kevin.




Can you run an aluminum shroud and mount the fans in it, so it pulls from the entire radiator ?
I used this setup in my Torana (Not a Mopar, but you get the idea ) and works very well.
Spal fans as well by the way...

Attached picture 6392518-056(3).JPG
Posted By: chache876

Re: how hot is too hot of an operating temp? - 01/02/11 05:43 PM

Quote:

I know I don't know as much as many members here, but I just don't like 200 for our cars. I know that new cars run that hot but they are designed to run safely on the edge. EFI, knock sensors, computer spark control to retard timing, etc..

Personally, I don't want mine going over 180 if I can help it. I took my big block charger on a road trip this summer, sat in 3 hours of stop and go traffic to get a total of about 20 miles. It got to 210 in stop and go. No, it didn't puke and overheat, but I still didn't like it. I'm trying to come with some solution to get it to run cooler at idle. as soon as the car moves, even 20-30 mph, the temp drops right to 170 where my temp sensor is set (electric fans running off sensor)




True, a lot of reasons why today's engines are able to run a lot hotter comfortably has to do with new technology, materials, etc...Even if youre still running an original untouched engine from 40 years ago I think anything under 180 is not nearly warm enough. For example I know on my 72 demon's stock temp gauge, when the temp is at about 180 the needle has barely moved, at about 200 its right in the middle. I just did a quick lookup on thermostats from a few different engines back then and they all said 195 was the OE thermostat temp. Whether thats right or not I couldn't tell however.

An engine thats not fully warmed up is going to cause some problems. As inefficient as internal combustion engines are, they are even less efficient at cold operating temperatures. Youre going to see worse gas mileage since the colder than engine is, the richer the mixture has to be and youre going to see less power because of that.

Worst of all, cylinder wall wear increases the colder you go, especially under 150 degrees and under 130 is when rust occurs rapidly. For every gallon of gas burned, about a gallon of moisture is created in the cylinders. That combined with unburned gas that gets by the piston rings into the crankcase and forms acids that wear parts and form rust, making it important that the engine reaches a hot enough temperature to combat that.

In my opinion I wouldn't run anything lower than a 180 tstat. If you have electric fans make sure the turn off temp is higher than what your tstat's rating is.

Sorry for the long post and not trying to attack you or anything, just figured I'd share some info with you that would maybe make you not worry about those temps youre seeing. 210 degrees is perfectly fine IMO
Posted By: RapidRobert

Re: how hot is too hot of an operating temp? - 01/02/11 05:57 PM

Quote:

I think anything under 180 is not nearly warm enough. An engine thats not fully warmed up is going to cause some problems. As inefficient as internal combustion engines are, they are even less efficient at cold operating temperatures. Youre going to see worse gas mileage since the colder than engine is, the richer the mixture has to be.
Worst of all, cylinder wall wear increases the colder you go, making it important that the engine reaches a hot enough temperature to combat that.In my opinion I wouldn't run anything lower than a 180 tstat.


I couldn't agree more. I'm getting horrible mileage in my 65 dart ('83 318 w eddy 1406/streetmaster/15 initial) & the vacuum break choke pulloff is not operating plus inop heat riser. I have work to do.
Posted By: bboogieart

Re: how hot is too hot of an operating temp? - 01/02/11 06:21 PM

Quote
[Or are you thinking of a sensor that shows how open the thermostat is.]
doc, maybe something like this would help. I know you mentioned the heads had several locations, but was thinking you couldn't get much closer to the stat than this.

Attached picture 6392665-thermostat.jpg
Posted By: RapidRobert

Re: how hot is too hot of an operating temp? - 01/02/11 06:39 PM

Quote:

you couldn't get much closer to the stat than this.


what a trick piece! Hell I'd cut a piece of glass from a dishwasher safe glass cup or bowl and epoxy it in for a sight glass & eyeball it directly
Posted By: bboogieart

Re: how hot is too hot of an operating temp? - 01/02/11 06:48 PM

could probably pick up a sight glass from a hydraulic supply house that will screw right in.
Great idea robert I was gonna see about fitting a regular gauge but now if you don't mind I'm gonna steal yer idea.
Posted By: RapidRobert

Re: how hot is too hot of an operating temp? - 01/02/11 06:54 PM

Actually I'm flattered
Posted By: terzmo

Re: how hot is too hot of an operating temp? - 01/02/11 07:54 PM

Quote:

I run a seven blade flex fan 17 in dia with stock shroud on a 26 inch
3 core stock brass type radiator .
with a 160 t-stat the eng would run to cool for school , never even got to 180 unless very warm out side . the eng has aprox 600 hp.
had to switch to 195 t stat to correct some air fuel distributon issiues and car still runs 195 on hyway will creep to 210 if sitting in trafic to long but still ok .
I have a friend with a all alumnum 850hp hemi that runs stock seven blade fan with the viscus thermo clutch and keeps cool and says that he has tried every fan out there and none can beat the factory seven blade pulls about 4000 cfm so he says . try to find electric fans that will fit on a 26 in radiator and pull like that ! very dificult !





I tried the electric fan route on My 440 (bored and stroked to 500) and couldn't keep it cool in traffic. Went back to a mechanical 7 blade clutch fan and shroud...motor runs cool in traffic...very happy...also has a cheap aluminum 26 inch rad. 160 stat....cars runs between 180 to 190

Attached picture 6392895-IM000613.JPG
Posted By: Magnum

Re: how hot is too hot of an operating temp? - 01/04/11 06:32 AM

Quote:

also need to either get a new cap for my overflow tank, or pick up a universal one. One of the nipples broke off my original so coolant can go in but can't come back out to the radiator.




If you chose a universal overflow. That's all it may be. To catch overflow and never put it back where it came from.

A factory tank is actually a resorvoir and will expell any air from your cooling system. Catch any overflow and put it back when the engine cools. Less air is better.
Posted By: DennisH

Re: how hot is too hot of an operating temp? - 01/04/11 02:09 PM

180 Superstat. Clutch fan. Copper. 26"
Posted By: MY340

Re: how hot is too hot of an operating temp? - 01/04/11 03:20 PM

Quote:

Quote:

FWIW Ford doesn't even turn on the electric fan on cars so equipped till 221 degrees..




FWIT...that ford must be a newer car...old iron was in the danger zone at 210 plus...I don't understand why anyone would run old iron motors at 230 and wait for 250......195 to 200 nis ok...I prefer to see it around 190 for My Bee and GTX...both 440 motors




Ya ever wonder why some Ford vehicles had head gasket problems?
Posted By: Big Bad Bee

Re: how hot is too hot of an operating temp? - 01/04/11 05:58 PM

Rick Ehrenberg did an excellent article a couple issues back on cooling systems, fans, shrouds. He talks specifically to the high temperature issue. 200 degree running temps don't freak him out, and he's flogged more than a couple of cars.

I hate to sound like I worship the guy but he is THE MAN.
Posted By: DaytonaTurbo

Re: how hot is too hot of an operating temp? - 01/04/11 07:04 PM

Quote:

200 degree running temps don't freak him out




Well considering 195 is a factory t-stat I don't see why anyone would be freaked out with a 200* temp.
Posted By: buildanother

Re: how hot is too hot of an operating temp? - 01/04/11 08:00 PM

200 is not hot, and GM has had some switches on front drive elec fan cars, not coming on until almost 240. So sit in traffic with your non a/c car on a hot day and enjoy.
Posted By: roe

Re: how hot is too hot of an operating temp? - 01/06/11 12:40 AM

well guys I replaced my factory sensor so now i have both gauges. When my aftermarket gauge reads 200 degrees my factory gauge is right in the middle of the operating temp. Actually its just a little less than halfway. it hasn't.spiked up to 220-230 again yet, must have worked the air pockets out. If it does I will report back what my factory gauge reads when it does.

roe
Posted By: bboogieart

Re: how hot is too hot of an operating temp? - 01/06/11 12:44 AM

Right On
So you are good to go.
Posted By: terzmo

Re: how hot is too hot of an operating temp? - 01/06/11 03:06 AM

Quote:

200 is not hot, and GM has had some switches on front drive elec fan cars, not coming on until almost 240. So sit in traffic with your non a/c car on a hot day and enjoy.




another apple and orange comparison
Posted By: 360view

Re: how hot is too hot of an operating temp? - 01/06/11 02:14 PM


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.
Posted By: Pale_Roader

Re: how hot is too hot of an operating temp? - 01/06/11 02:55 PM


One thing i can safely, authoritatively tell you from experience is that a 67 440 does not like to run well at 400 degrees. Trust me on this...
Posted By: Von

Re: how hot is too hot of an operating temp? - 01/06/11 03:51 PM

Quote:

try to find electric fans that will fit on a 26 in radiator and pull like that ! very dificult !






Mercedes fan!!
Posted By: terzmo

Re: how hot is too hot of an operating temp? - 01/06/11 05:22 PM

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+
Posted By: HotRodDave

Re: how hot is too hot of an operating temp? - 01/06/11 06:14 PM

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.
Posted By: terzmo

Re: how hot is too hot of an operating temp? - 01/06/11 07:10 PM

and on the stock dash gauge it would be in the overheat zone at 220...not a manufacturers recommended temp
Posted By: Magnum

Re: how hot is too hot of an operating temp? - 01/08/11 05:08 PM

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?
Posted By: HotRodDave

Re: how hot is too hot of an operating temp? - 01/08/11 06:07 PM

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?
Posted By: terzmo

Re: how hot is too hot of an operating temp? - 01/08/11 06:52 PM

guess you never warped a head, blew a headgasket or just plain blew a motor.....You youngsters can run em as hot as You want.....probably not for long though.....heat wears down oil...more friction...more bad things....
Posted By: HotRodDave

Re: how hot is too hot of an operating temp? - 01/08/11 06:58 PM

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
Posted By: 469runner

Re: how hot is too hot of an operating temp? - 01/08/11 10:50 PM

Piston rings will lose tension if an engine gets too hot. That does not take long either. This will usually happen before oil breaks down or head gaskets blow. So engine is ruined long before any obvious damage shows.
Posted By: bboogieart

Re: how hot is too hot of an operating temp? - 01/08/11 11:48 PM

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 butI 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.
Posted By: Junky

Re: how hot is too hot of an operating temp? - 01/09/11 01:26 AM

Above 210° to 215°, the only thing I worry about are the hoses and radiator blowing. But...if they are in good condition that shouldn't happen. The next thing I'm worried about above 215° is the engine. I hate to see the temp get above 210°.
Posted By: 360view

Re: how hot is too hot of an operating temp? - 01/09/11 05:57 PM

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.
Posted By: BSB67

Re: how hot is too hot of an operating temp? - 01/09/11 07:47 PM

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.
Posted By: chache876

Re: how hot is too hot of an operating temp? - 01/09/11 08:06 PM

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.
Posted By: BSB67

Re: how hot is too hot of an operating temp? - 01/10/11 04:50 AM

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.
Posted By: 360view

Re: how hot is too hot of an operating temp? - 01/10/11 01:23 PM

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"
Posted By: dIc dOc Deity !

Re: how hot is too hot of an operating temp? - 01/10/11 02:08 PM

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.
Posted By: gregsdart

Re: how hot is too hot of an operating temp? - 01/10/11 03:18 PM

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.
Posted By: MY340

Re: how hot is too hot of an operating temp? - 01/11/11 03:10 AM

For an old iron headed muscle car motor 200-210 degrees is max in my opinion.

I prefer 180-190 degrees in my Duster.
Posted By: 62maxwgn

Re: how hot is too hot of an operating temp? - 01/11/11 03:13 PM

If "some" of you guys would quit trying to fix things that aren't broke,you wouldn't have so many problems.When they rolled off the assembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarket water pumps and housings.WHY?
Posted By: scratchnfotraction

Re: how hot is too hot of an operating temp? - 01/11/11 04:19 PM



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

Posted By: DennisH

Re: how hot is too hot of an operating temp? - 01/11/11 04:44 PM

Quote:

If "some" of you guys would quit trying ti fix things that aren't broke,you wouldn't have so many problems.When they rolled off the asembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarker water pumps and housings.WHY?




Good question.
Posted By: SomeCarGuy

Re: how hot is too hot of an operating temp? - 01/11/11 09:04 PM

Quote:

If "some" of you guys would quit trying to fix things that aren't broke,you wouldn't have so many problems.When they rolled off the assembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarket water pumps and housings.WHY?





Uh, they didn't come with bored out blocks, higher CR, etc either. Gas was better and so on. No EFI or electric fuel pump, only a few had return lines and those that did didn't run all the way to the carb. Running one on the hot side causes issues. Do what you want.
Posted By: 62maxwgn

Re: how hot is too hot of an operating temp? - 01/11/11 09:21 PM

Quote:

Quote:

If "some" of you guys would quit trying to fix things that aren't broke,you wouldn't have so many problems.When they rolled off the assembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarket water pumps and housings.WHY?





Uh, they didn't come with bored out blocks, higher CR, etc either. Gas was better and so on. No EFI or electric fuel pump, only a few had return lines and those that did didn't run all the way to the carb. Running one on the hot side causes issues. Do what you want.





Well, this one is .030 over,10.6cr,factory 3 core 22" radiator,fixed fan,factory shroud,factory 6 blade A/C water pump,added factory A/C and it doesn't run above 195*.

Attached picture 6411327-P7070006.JPG
Posted By: dIc dOc Deity !

Re: how hot is too hot of an operating temp? - 01/11/11 09:28 PM

Quote:

If "some" of you guys would quit trying to fix things that aren't broke,you wouldn't have so many problems.When they rolled off the assembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarket water pumps and housings.WHY?






....BECAUSE alum rads are NOT AS GOOD as a brass/copper one ... from what I Have been told.
Posted By: SomeCarGuy

Re: how hot is too hot of an operating temp? - 01/11/11 09:46 PM

Quote:

Quote:

Quote:

If "some" of you guys would quit trying to fix things that aren't broke,you wouldn't have so many problems.When they rolled off the assembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarket water pumps and housings.WHY?





Uh, they didn't come with bored out blocks, higher CR, etc either. Gas was better and so on. No EFI or electric fuel pump, only a few had return lines and those that did didn't run all the way to the carb. Running one on the hot side causes issues. Do what you want.





Well, this one is .030 over,10.6cr,factory 3 core 22" radiator,fixed fan,factory shroud,factory 6 blade A/C water pump,added factory A/C and it doesn't run above 195*.




Good for you. Not every combo works the same. Not everybody wants a cast iron WP or housing. Not everybody wants an engine driven fan.

My car runs 190-200, even when idling for a long time, has no shroud either. I have aftermarket aluminum pump and housing. Works for me.

The biggest difference I have seen is switching to a bigger radiator, even leaving the opening untouched. Capacity always helps from my experience.
Posted By: roe

Re: how hot is too hot of an operating temp? - 01/11/11 11:32 PM

wow, I had no idea there was such a dispute on operating temp. I only asked because myfactory guage was inoperative and all i had was an aftermarket guage and wanted to know where the temp reading was putting me in relation to tue stock guage.
Posted By: DusterKrazy

Re: how hot is too hot of an operating temp? - 01/18/11 10:15 PM

Quote:

If "some" of you guys would quit trying to fix things that aren't broke,you wouldn't have so many problems.When they rolled off the assembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarket water pumps and housings.WHY?





I bet you still like points ignition to???
Posted By: scratchnfotraction

Re: how hot is too hot of an operating temp? - 01/18/11 10:47 PM

Quote:

Quote:

If "some" of you guys would quit trying to fix things that aren't broke,you wouldn't have so many problems.When they rolled off the assembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarket water pumps and housings.WHY?





I bet you still like points ignition to???




why yes i do...whats wrong with points?

ok I am a pertronix kinda guy also so i dont run points very long in them,just till i get a conversion put in

and if its not puking the rad shop guru said it not over heating,may be running warm due to poor circulation but its not over heating...

you woulld be surprized at what a new rad will do for a 30+ yr old car some times

roe,i think your gauge would be about 1/2+ way at that temp on the mech gauge

Posted By: DusterKrazy

Re: how hot is too hot of an operating temp? - 01/19/11 04:00 AM

Quote:

Quote:

Quote:

If "some" of you guys would quit trying to fix things that aren't broke,you wouldn't have so many problems.When they rolled off the assembly line they worked well with the original components.Now everyone has to have aluminun radiators,electric fans,high flow thermostats, aftermarket water pumps and housings.WHY?





I bet you still like points ignition to???




why yes i do...whats wrong with points?

ok I am a pertronix kinda guy also so i dont run points very long in them,just till i get a conversion put in

and if its not puking the rad shop guru said it not over heating,may be running warm due to poor circulation but its not over heating...

you woulld be surprized at what a new rad will do for a 30+ yr old car some times

roe,i think your gauge would be about 1/2+ way at that temp on the mech gauge






I use points distrubutors to but only the housing

Better fuel economy, quicker starting and longer plug life. I changed my '71 Duster over and I could not believe how much more enjoyable it was.
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