General Discussion on Heat

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MPGmustang

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Hey Guys I'm looking for a General way of cooling our cars better. "yes another post of heat and how to get rid of it..." don't worry I've gone through the other posts and searches but still havn't found answers/solutions...

Here is the setup I have.

1) 2 Row alum Radiator (a 1 inch core and a 1/2 inch core) (cleaned 3 weeks ago)
2) new hoses (yes brand new)
3) 180* t-stat (new)
4) clean heater box (good flush, free flow from both directions)
5) richer Jet, more gas should mean less heat inside the head and more down the tail pipe????
6) new 50/50 mix with water wetter, no added water.

currently, I can watch my temp guage dance (maybe that just needs to be replaced?)
drive w/o a\c = at temp (half way)
drive w a\c low= (3/4)
drive w a\c mid = 100%
drive w a\c traffic = low it shows 7/8ths, high it goes up to 150% (yes past the guage) scary!!

My concern is when hotter, it rattles/pings sometimes, the second I hear it I back off and try to let it cool. this is a new engine so cool is important.

My question comes to this...
With A/C and in AZ could I run No t-stat with my mechanical fan?
Is that Dangerous?
What can it hurt?

Is there other way's of cooling the car to have it run no hotter than 190*? even in +110* degree weather with the A/C on? (without electric)

what do you guy's think?

edit: cleaned it up a bit, it hurt my head to read... and i wrote it!
 
Generally speaking its either an "air" side problem or a "water" side problem. If the car goes hot at low speed then the problem is usually not enough air is being push/pulled/sucked thru and over the radiator tubes. If the water temps increase while driving and going faster then the heat transfer surface where the water is circulating is the problem. My other project car a '68 Catalina convertible overheated while driving down the highway. I later found out that the rad was only passing at 60% (or so what I was told by the radiator shop). A new, larger core radiator has solved the highway overheating problems. The same car got hot during city driving once, so I replaced the fan clutch and the car/water kept at temp. Again, if it heats up at low speed then the "water" side is fine and you need to get more air thru the radiator. If it heats up "at speed" then either the internal surfaces (water side) are fouled or there just isn't enough internal surface area to transfer the heat out.

Right after I rebuilt the Mustang's engine it was running hot. I replaced the stock rad for a bigger rad and changed the cam timing from 4* retard to 2* advanced; that helped with most of the problem. Now it only gets hot at highway speeds. I just ordered an Aluminum 2 core radiator from evil-bay yesterday and hope that will fix the high speed heating problem.
 
I knocked 10 degrees off the 200 by having heat sinks welded on each side of the fill neck and across the bottom. Cost me about a 100 dollar bill. aluminum radiator
 
also, you will want to get a "real" temp gage that gives you real numbers. any local parts store will have cheap aftermarket gages starting around $20-30, and going up from there. buy and install one so you can be sure how things respond to your work.
 
Besides that, a pyrometer is neat to have (one of the laser pointer type). You can "shoot" temperatures in a variety of places; it helps gauge how evenly a radiator is cooling, for example.
 
My waterneck has a threaded bung for a PVS, which I am not using, so I put the sender for my temp guage there, and get coolant readings as the thermostat opens. The temperature of the coolant coming from the block sits really steady at around 180° once the system is warmed up. And that's with an AC condenser in from of the rad. Although the system is working well, I'm planning to go to an electric fan. I don't like having a mechanical fan always blowing air around, they are noisy and dangerous, and mostly unnecessary here in the winter.

I am thinking I'd like the engine to run hotter, and started a thread inquiring about optimal running temperatures.
So what is the "best" temperature for this engine to be running. How hot is too hot?
 
addo":26hrbgue said:
Besides that, a pyrometer is neat to have (one of the laser pointer type). You can "shoot" temperatures in a variety of places; it helps gauge how evenly a radiator is cooling, for example.
Click to expand...
X2
Yes check the top and bottom hose that will tell you for sure how well its working.


And:
The Plankster Prankster":26hrbgue said:
also, you will want to get a "real" temp gage that gives you real numbers. any local parts store will have cheap aftermarket gages starting around $20-30, and going up from there. buy and install one so you can be sure how things respond to your work.
Click to expand...
Just make sure its a mechanical gauge.
 
JackFish":3et4zkvy said:
I am thinking I'd like the engine to run hotter, and started a thread inquiring about optimal running temperatures.
So what is the "best" temperature for this engine to be running. How hot is too hot?
Click to expand...

I assume you are doing the cardboard baffle thing in the winter, cutting the amount of free space on the radiator to eliminate over-cooling. I wonder if there IS a 'too hot'. Seems to me that it is a function of the outside air temp, humidity and engine speed. Too hot would be where the coolant boils over or invades another space, at which point you are hosed. And all that is a function of the radiator cap and the seals at the water jacket. If it doesn't do that stuff and the engine operates well over a wide range of exterior temps, then the question is moot. I think the 180* is sort of a target number so we can estimate a 'range'. Besides, the boiling point is raised far above 212* with the pressurized system anyway.

But I could be wrong.
 
mugsy":2lhypvnx said:
Generally speaking its either an "air" side problem or a "water" side problem. If the car goes hot at low speed then the problem is usually not enough air is being push/pulled/sucked thru and over the radiator tubes. If the water temps increase while driving and going faster then the heat transfer surface where the water is circulating is the problem.
Click to expand...
water temp goes down at speed, so not enough air.
Broncitis":2lhypvnx said:
I knocked 10 degrees off the 200 by having heat sinks welded on each side of the fill neck and across the bottom. Cost me about a 100 dollar bill. aluminum radiator
Click to expand...
this would give more surface area, do you have a picture? I'd like to see
The Plankster Prankster":2lhypvnx said:
also, you will want to get a "real" temp gage that gives you real numbers. any local parts store will have cheap aftermarket gages starting around $20-30, and going up from there. buy and install one so you can be sure how things respond to your work.
Click to expand...
know of any temp gauge that can go where the original one went?
JackFish":2lhypvnx said:
My waterneck has a threaded bung for a PVS, which I am not using, so I put the sender for my temp guage there, and get coolant readings as the thermostat opens. The temperature of the coolant coming from the block sits really steady at around 180° once the system is warmed up...
Click to expand...
I have that threaded bung too, can I swap bung and sender without complications? (threads work?) or do u have 2 temp gauges?
ludwig":2lhypvnx said:
I assume you are doing the cardboard baffle thing in the winter
Click to expand...
before A/C I had to do that for winter, just to warm up on the way to work, then take it out on the way home. But I also had a FlexFan that was 1/4~1/2 inch away from the rad. (think I should go back to that setup?)
1bad6t":2lhypvnx said:
[Do you have the reinforcement spring in the lower hose to keep it from collapsing?
Click to expand...
no stock, I don't think new hoses would collapse that fast would they?? I'll check it out with someone revving the engine and me watching (or is it a load thing?)
addo":2lhypvnx said:
Besides that, a pyrometer is neat to have (one of the laser pointer type). You can "shoot" temperatures in a variety of places; it helps gauge how evenly a radiator is cooling, for example.
Click to expand...
I wish I could justify it... but my empty wallet won't let me... :cry:
 
Wow. This is now the 'radiator cooling blog'.

You could probably use the original bung for the water temp sender at the rear of the block. Just hook it up to a more accurate sender and thermometer gauge and let the dash light or original dash gauge sit on zero. That extra bung at the T-stat is often used for the temp probe to the electric fan solenoid.
 
mugsy

Nice clear description.

There are two heat exchangers in most auto engine cooling systems. One from the engine into the "coolant" and one from the "coolant" into the air.

Anything that interferes with these two interfaces can cause overheating.

First to get good heat transfer from the engine to the coolant the engine passages need to be free flowing and the surfaces need to be fairly clean, otherwise your engine can start to ping and perform badly while your coolant temperature gage still reads in the safe zone.
Flush the block in both directions to remove all loose debris.
Use a good cooling system cleaner designed to remove rust.
Flush again
Use some 'water wetter' in the coolant to help with coolant contact to the engine cooling surfaces.

Second to get good heat transfer from the coolant to the air you need a 'radiator in good shape.
Radiator fins can come loose from the cooling tubes over time.
Radiator fins can be blocked by debris such as leaves and dead bugs.
Radiator cooling tubes can become blocked by debris carried in the coolant.
To increase your cooling capacity get an aluminum radiator.

To check your cooling system for performance you will need a thermometer sold in grocery stores that has a range of 100 to 250 degrees Fahrenheit, a large box fan and an infer red thermometer.
With the engine cold remove the radiator cap and insert the thermometer. Start the
engine and allow it to warm up till the thermometer in the radiator
stops rising. Look in the radiator and observe the flow as you rev the engine, the flow
should be strong and increase as the engine speed increases.

Next use the infer red thermometer to measure the temperature of the upper and lower
radiator tanks. The difference between them should be at least 40 degrees.

Lastly turn on the box fan and place it in front of the radiator. The coolant temperature
Should drop.

To increase air flow you can get an electric fan and control it with a thermostat or a switch in the cockpit. To increase water flow you can get an electric water pump.

I have a 69.5 Maverick with a 170-6. I can and have driven it with out a fan and with an electric fan.
I drove that car in AZ in the 80’s in Sierra Vista with no overheating issues.

Last but not least you should examine the gasketing around the hood to insure that no air can enter the engine compartment except through the radiator. Any air that bypasses the radiator is air flow lost from the cooling cycle.
 
69.5Mav":2zud3164 said:
Use some 'water wetter' in the coolant to help with coolant contact to the engine cooling surfaces.
Click to expand...
That's excellent advise, and cheap to do. Also, did you put antifreeze in the radiator? A lot of people in Arizona don't think you need it when it's 110-115*, but it will help. EDIT: I just re-read your firt post and saw that you have both. My bad...

What ever you do, don't drive it when its over-heating, even if it means pulling over to the curb for half an hour or more. You certainly don't want to start over from scratch. That rattle/pinging noise your hearing is pre-ignition/detonation, which will destroy the motor in short order.
 
That rattle/pinging noise your hearing is pre-ignition/detonation, which will destroy the motor in short order.
Click to expand...

Of course this is absolutely correct. Furthermore, a too lean A/F mix will cause the engine to overheat in very short order.
 
mugsy wrote:Generally speaking its either an "air" side problem or a "water" side problem. If the car goes hot at low speed then the problem is usually not enough air is being push/pulled/sucked thru and over the radiator tubes. If the water temps increase while driving and going faster then the heat transfer surface where the water is circulating is the problem.


water temp goes down at speed, so not enough air.
Click to expand...

The old rule of thumb was that after 35 mph the fan is useless; the speed of the car is causing more air to flow than the fan can pull. A fan is not needed after this speed. And you are correct, the engine does run cooler, because of the air flow. so if you engine is seeing more air than the fan can create but the engine runs hot that mean then the heat transfer is being reduce/impeded by something on the "water side". Either the interior surfaces are fouled, water is not flowing thru enough passages, or the heat transfer surfaces are just not large enough. Any changes to the fan will not fix the problem, the fix lies on the "water side" or getting the radiator to function correctly (assuming that the rad is sized and engineered correctly).
 
I'm sure you've already had the radiator cleaned (aka: boiled) out. After that, flush the block in BOTH directions, from above and from below. I believe you can still get a fitting that is the female end of a garden hose to insert in one of the heater sides. Then you run the engine and flush with fresh water. You can also flush from below. There are solvents that help eat away lime and corrosion on the inside of the block. These will help your 'water' side. These also require multiple flushes.

When I got my car, the original block had a lot of debris in the cooling jacket. The radiator was pretty gummed up too.
 
ludwig":hyzqo6gw said:
You could probably use the original bung for the water temp sender at the rear of the block. Just hook it up to a more accurate sender and thermometer gauge and let the dash light or original dash gauge sit on zero. That extra bung at the T-stat is often used for the temp probe to the electric fan solenoid.
Click to expand...
I guess adding an extra temp guage won't hurt then I can consantly compare them, I'll run by a shop today and pick up a cheap mechanical with numbers to give good readings instead of "1/2 way" readings...
Wouldn't temp differ from the t-housting compared to the block at cyl #6?

69.5Mav , Thanks!
the Flow increases nicely when I rev it. I have a cantact thermometer that can go up to 2k* (from dad) i'll give some top tank and bottom tank readings when I get home.
would increased water flow (electric pump) give better cooling temps or just the obvious (faster water) I guess if the radiator couldn't handle it there would be no benefit, except HP. :roll:
I will have to find some foam and plug up the gaps around the radiator and radiator support, I think I saw a post on it a while back...
AzCoupe":hyzqo6gw said:
That's excellent advise, and cheap to do. Also, did you put antifreeze in the radiator? A lot of people in Arizona don't think you need it when it's 110-115*, but it will help. EDIT: I just re-read your firt post and saw that you have both. My bad...
What ever you do, don't drive it when its over-heating, even if it means pulling over to the curb for half an hour or more. You certainly don't want to start over from scratch. That rattle/pinging noise your hearing is pre-ignition/detonation, which will destroy the motor in short order.
Click to expand...
only when I was fine tuning it on some hill here in AZ (freeway) after my initial break in. now if I try It won't... I'm running at almost 15* advanced then plug in the vacum and it looks like it could be 30* total at idle. but don't ping... I think i'll be getting that DUI sooner :eek: that I wanted to as it's kinda scary...

ludwig":hyzqo6gw said:
I'm sure you've already had the radiator cleaned (aka: boiled) out. After that, flush the block in BOTH directions, from above and from below.
Click to expand...
I bought the radiator New back in April, and that's when I cleaned the old block and the heater core, then the new engine (I saw the Cleanness!!!) came and did the same (just in case), the radiator is still "new" and last time I had it off the car I ran the hose through it both directions, I'm going to say that there is NOTHING but fluid in the water system, i'm pretty confident there is nothing restricting flow... the engine shop has a dip tank, and they flow thier fluid through slow and fast a few times, I asked becuase I was worried about that too.
mugsy":hyzqo6gw said:
mugsy wrote:Generally speaking its either an "air" side problem or a "water" side problem. If the car goes hot at low speed then the problem is usually not enough air is being push/pulled/sucked thru and over the radiator tubes. If the water temps increase while driving and going faster then the heat transfer surface where the water is circulating is the problem.
water temp goes down at speed, so not enough air.
Click to expand...
The old rule of thumb was that after 35 mph the fan is useless; the speed of the car is causing more air to flow than the fan can pull. A fan is not needed after this speed. And you are correct, the engine does run cooler, because of the air flow. so if you engine is seeing more air than the fan can create but the engine runs hot that mean then the heat transfer is being reduce/impeded by something on the "water side". Either the interior surfaces are fouled, water is not flowing thru enough passages, or the heat transfer surfaces are just not large enough. Any changes to the fan will not fix the problem, the fix lies on the "water side" or getting the radiator to function correctly (assuming that the rad is sized and engineered correctly).
Click to expand...
So!! i'm trying to wrap my head around right... the Air is not enough... the water gets hot from the engine, meaning proper transfer, but the water is not transfering it to the air...
now when I sat at a stop light on the way home temp went from 7/8th's down to 3/4th's AND when I'm at speed (+35 mph to 50mph) temp went down to 5/8th's... the times that it gets up in temp is traffic stop and crawl... high rev's in traffic don't move it from 7/8th's
without the A/C, temp stay relative to 1/2~3/5 and doesn't really change to the eye.

The goal I'm trying to achieve is to have the temp guage stop moving (without unplugging it) so far and often during the hottest of days with the A/C on all the time. (wish a bigger rad would fit)

Everyone thanks for Posting... there a hell alot of things I didn't think about that I'm going to comprehend, sooner than later...
 
"Wetter water" is stuff that speed companies sell to improve their bottom line. They claim that the product absorbs heat faster. If that is true, it also loses heat slower. So, you pick up heat and carry it though the radiator, back to the engine.

No OEM manufacturer ever used "wetter water". More junk to waste money on, in my opinion.
 
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