Cooling problems continue

[73azbronco]

I still say, get a good fan and shroud, run a 195 t stat, and the rest matters not. Although I'm digging the baffles on top of the core support, I'm installing the stainless version myself.

 

[nickeboy]

So, I couldn't leave well enough alone. I had a mechanical auto meter gauge, so I installed it and rigged it up so I could get a real time reading. With no real load on the Bronco it ran about 190 all around town. I parked and sat for 6 minutes and watched the temp get to 200. It didn't fluctuate so I drove off. I went and did some hills and then went through a part of town with lots of stoplights. She ran consistently at 200. I got home and parked in the driveway directly after and temps creeped up to 220 in park. (1 minute) I shut it off and it spewed out some fluid (8-16oz). I think I will try the 7 blade fan recommended above. Today's temp when driving was 90 degrees.

 

[Timmy390]

I shut it off and it spewed out some fluid (8-16oz).

No overflow tank? Better known as an expansion tank.

The tank is there to catch the overflow and allow that overflow to return to the system as it cools.

Tim

 

[nickeboy]

I added an overflow tank recently. This is where it spewed from. Im pretty sure I have a correct setup for this. It's a small overflow tank.

 

[Steve83]

I added an overflow tank recently. This is where it spewed from. ... It's a small overflow tank.

Then there's probably nothing wrong with the coolant system, and changing the fan won't change anything. It sounds more like there wasn't enough space in the overflow tank when the system burped, so it came out of the tank. If you get a larger tank (or just let it burp a few times & refill itself from the tank as it cools down), it shouldn't dump any more onto the ground.

BTW
Boiling over (while the engine is running) is NOT evidence of "overheating". It's just the system's last attempt NOT to overheat. If it boils over to the point that there's only steam coming out (no liquid), and you keep the engine running; THAT'S "overheating".

 

[nickeboy]

Ya, I think its close. I'm thinking a fan might help keep it cool when stuck at an idle for long periods of time.

 

[Slowleak]

I disagree with "changing the fan won't change anything". That 6 blade fan is a wimp. I had exactly the same symptoms. I went from the 6 blade to the 7 blade flex and now it can sit and idle all day without breaking 195. Changing the fan will make a big difference. 72% more airflow and a 20+ degree temp drop for me. Going from 200 to 220 after one minute of idling is not normal......

 

[nickeboy]

I disagree with "changing the fan won't change anything". That 6 blade fan is a wimp. I had exactly the same symptoms. I went from the 6 blade to the 7 blade flex and now it can sit and idle all day without breaking 195. Changing the fan will make a big difference. 72% more airflow and a 20+ degree temp drop for me. Going from 200 to 220 after one minute of idling is not normal......

Agreed, so I'm hoping someone here chimes in with the fix. I'm getting tired of chasing this issue. I'm going to buy the fan that someone mentioned above unless someone has something better to recommend?

 

[Slowleak]

The new fan is the fix. Swap your thermostat to a 190 or 195 while you are under the hood. You will be good to go.....

 

[nickeboy]

I've completed the radiator, Tstat at 195. new hoses and next will be a fan. I currently have a 6 blade flex fan.

 

[5001craig]

I've been researching this topic as I'm not that happy with my max engine temps.

I have an OEM 7 blade fan, staggered four core single pass from WH and a Ron Davis fan shroud. Fan isn't spaced too bad in the shroud but I really can't move it any closer to the engine as it's close to a belt. Transmission cooling goes to it's own stacked-plate cooler with puller fan from Derale out back. Thermostat is a Robert Shaw 160° (that temperature t-stat is based on direction of the engine builder--I have a 198° Rober Shaw on the shelf). Water pump is OEM T3046. 16# cap. Nothing is in front of the radiator. I have not verified my fairly cheap water temp gauge--which I need to do.

I've seen 230° once in very slow stop and go traffic with fairly high ambient temps. When I saw that temp the engine ran the same as normal. 220° after hitting it hard on the sand is not that uncommon in higher ambient temps. I'm working on getting it lower.

Timing/carb is getting dialed-in by a tuner on 8/28. If I don't see a change after that it's between switching to a stock thermostat from the high-flow to increase the block pressure. Or I am thinking about a Flowkooler or Stewart water pump. Stock thermostat would be very cheap. Not exactly sure why I want to spend more money on a high-flow water pump and keep the high-flow thermostat but I do.

My good friend that is a big-time radiator repair/builder (seriously--maybe one of the best) wants to build a "special" radiator this winter. He wants to go with a two large core aluminum for the increased airflow over the staggered four core (he says to stay away from epoxied tubes to headers as they are known to fail). I don't think I have a problem with my radiator just maybe block pressure (I purchased the radiator new 5/10/2015). Or maybe part of my problem is under hood airflow as I've read the larger motors restrict airflow (and I could see my fenderwell headers blocking some underhood airflow too). Purchased an anemometer to work on that and will do perforated inner fenderwells if needed after going with a stock thermostat or upgraded water pump. I also need to shoot some temps with my I/R gun to see if hot air is coming out the hood and back into the radiator as once it's heat-soaked it doesn't want to cool-off while idling. Wish I could fit a fan clutch. Really don't want to go with serpentine at this time. Explorer fan/clutch seems to be a pretty good way to go, though.

 

[sykanr0ng]

FlowKooler recommends and sells Robertshaw thermostats themselves, a pretty good endorsement for using both together in my opinion.

 

[nickeboy]

I disagree with "changing the fan won't change anything". That 6 blade fan is a wimp. I had exactly the same symptoms. I went from the 6 blade to the 7 blade flex and now it can sit and idle all day without breaking 195. Changing the fan will make a big difference. 72% more airflow and a 20+ degree temp drop for me. Going from 200 to 220 after one minute of idling is not normal......

Which fan did you buy?

 

[Slowleak]

Which fan did you buy?

I have the OEM 18 inch seven blade fan. I found it on eBay. There are often some for sale on the forum here. Tom's has one but it's a bit pricey....
https://www.tomsbroncoparts.com/pro...ry-v8-289302351w-66-77-early-ford-bronco-used

 

[Steve83]

I had exactly the same symptoms.

The only "symptom" I saw in his post yesterday was:

I shut it off and it spewed out some fluid...

The number of blades on the fan has no effect on what happens when the engine is off.

Going from 200 to 220 after one minute of idling is not normal.

Maybe not. But it's also not a problem. 220 won't hurt anything. And heat flows OUT of the engine faster when it's at 220 than it does when it's at 195.

...to increase the block pressure.

Increasing the coolant's pressure in the block will not affect temperature. It will only increase the boiling point. So if the coolant ISN'T boiling already, it will have no effect.

 

[blubuckaroo]

Back in the early '70s I worked in a Chevrolet garage. The mechanics hated that some cars had temperature gauges. Most drivers just don't understand how to process that information. Owners would come in complaining of overheating and want it fixed.
There were even some models that came out with gauges that had no numbers. Just a red spot to indicate too hot.
With the proper coolant and pressure cap, an engine can run fine over 250*.
Of coarse, that's not ideal, but under the right conditions it could be expected.
Short term, it's fine as long as it doesn't boil over.

The bigger issue is when using a carburetor with the modern fuel we have.
All that engine heat also finds it's way into the fuel. There's just no way of stopping it completely.
Hot engine compartments will boil the fuel in the lines and float bowl.
It gets even worse when you shut the car off and the heat is allowed to soak in.
Modern fuel boils at a lower temperature than when these cars were made. It's not much issue for fuel injected engines, but those of us with carbs have been thrown under the buss for sure!

 

[sykanr0ng]

220° is at the upper end of optimum operating temperature for an engine which is running with the coolant flowing and fan moving air through the radiator.

Stop thinking about the boiling temperature of pure water at sea level pressure, it has nothing to do with coolant mix under pressure.

This engine is not overheating.

blu has a good point about carburetors though, definitely avoid ethanol mixes that stuff boils away at 140° which a car parked in the sun can reach without even running that day.

 

[Slowleak]

The bigger issue is when using a carburetor with the modern fuel we have.

All that engine heat also finds it's way into the fuel. There's just no way of stopping it completely.

Hot engine compartments will boil the fuel in the lines and float bowl.

It gets even worse when you shut the car off and the heat is allowed to soak in.

Modern fuel boils at a lower temperature than when these cars were made. It's not much issue for fuel injected engines, but those of us with carbs have been thrown under the buss for sure!

That's what I was running into. You get to 220 or so and park it and all the fuel boils out. You also start to wonder how hot the thing would eventually get if you were stuck in traffic...... I'm much more comfortable running at 190-200.

 

[DirtDonk]

Ok, sorry about throwing all this into one post. But I just stayed out of the conversation too long and wanted to my comments out quickly. Before more info comes out and I learn something new to make it all change!:-[%)

I still say, get a good fan and shroud, run a 195 t stat...

Totally agree.

... and the rest matters not.

Totally disagree.
Well, I think you were just throwing out that generically, and know full well that other things matter. But I had to call you on it!

After all, how many times have we seen a heating issue here where the installation of a shroud made no difference? And changing to different thermostats made no difference? And doing many other things made no difference until the actual underlying issue was resolved. Whatever that happened to be on that particular Bronco.

Although I'm digging the baffles on top of the core support, I'm installing the stainless version myself.

See, some stuff does matter. I like them too and have a set waiting to go on to both Broncos.

With no real load on the Bronco it ran about 190 all around town. I parked and sat for 6 minutes and watched the temp get to 200. It didn't fluctuate so I drove off. I went and did some hills and then went through a part of town with lots of stoplights. She ran consistently at 200. I got home and parked in the driveway directly after and temps creeped up to 220 in park. (1 minute) I shut it off and it spewed out some fluid (8-16oz).

It's higher than you'd like, but also sounds somewhat normal. Like the others have said, the temps creeping up a bit when parked after driving is common. Temps jumping up after the engine is shut down is totally normal (heat soak) and also as said, the reservoir puking after shut down is normal too a time or three. If it continues to do this, then yes, something is wrong.
But that "wrong" in your case could be the size of the reservoir, as Steve mentioned.

I added an overflow tank recently. This is where it spewed from. Im pretty sure I have a correct setup for this. It's a small overflow tank.

How small? There is such a thing as too small for a particular radiator size. What it's supposed to do is to catch the heat expanded coolant and return it to the radiator when cooled down.
If it's too small, or too full, you will have this problem always.
You could try running the recovery tank almost empty to see how it acts. If it starts to puke, then it's too small. We don't have huge radiators as these things go, but they're large enough in capacity that a too-small recovery tank is just going to keep puking every time the coolant in the radiator expands and exits the cap.
There should come a time when the liquid level in the radiator does not go out of the cap enough to fill the outside tank, but you have to determine if that's a normal level or not, when it gets to that point.

I have an OEM 7 blade fan, staggered four core single pass from WH and a Ron Davis fan shroud. Fan isn't spaced too bad in the shroud but I really can't move it any closer to the engine as it's close to a belt. Transmission cooling goes to it's own stacked-plate cooler with puller fan from Derale out back. Thermostat is a Robert Shaw 160° (that temperature t-stat is based on direction of the engine builder--I have a 198° Rober Shaw on the shelf). Water pump is OEM T3046. 16# cap. Nothing is in front of the radiator.

I should know by now Craig, but how is your engine set up? If the builder thought you should use a 160 thermostat (old school hi-po trick, but certainly not right for every setup) then you have a pretty high performance engine?
You've got lots of go-cool goodies in the cooling system, but as you've figured, the fan is not the best out there available.
It's certainly been good enough for most of us with moderate engines, but if your engine is building more heat than the air flow can evacuate from the radiator, more air flow can be a good thing. Whether it takes the form of improved aerodynamic flow through the body, or a better fan pulling more air, more is still good until it robs more power than you want to lose.
Luckily for most of us, we're not racing so that extra 30hp we lose to a big-ass fan isn't a factor.

I have not verified my fairly cheap water temp gauge--which I need to do.

Most definitely!!!! In fact, short of removing the hood temporarily to check air flow, I would verify the temps with an independent gauge or meter before anything else.
After all, as we've seen here before, you could be tracking down a problem that is not actually a problem.

Timing/carb is getting dialed-in by a tuner on 8/28.

Make sure they use a vacuum advance. Unless you're building a race engine, vacuum advance is only a good thing.
I'm assuming a pro already knows to advance it as much as the engine can handle.

If I don't see a change after that it's between switching to a stock thermostat from the high-flow to increase the block pressure. Or I am thinking about a Flowkooler or Stewart water pump. Stock thermostat would be very cheap. Not exactly sure why I want to spend more money on a high-flow water pump and keep the high-flow thermostat but I do.

It's not just about "high flow' with the thermostats. Their own literature used to call it "balanced flow" so I would just leave that in until the last.
I like the high-flow pumps, but would leave that until you've verified that air flow is not the issue. After all, here too stock water pumps have served us well and don't normally allow overheating unless something else is just too much for them.
The main thing about high-flow pumps is that, yes, they can build more pressure, and keep more coolant in the nether regions of your block, but they also flow more while taking less power and not cavitate at higher rpm levels.
That last is their main claim to racing fame. That it can flow better than most while taking less power to do so. Power is winning, but it's not a requirement for cooling.
But it doesn't hurt that less power needed probably means less heat generated.
Side effects are cool...;D

So even though I'm a big fan of both brands and would happily recommend them, chase down the other stuff before you take more time (forget the money, the time is a bitch!) to replace existing stuff that might be fine.
Take the hood off and drive in the same circumstances to see what happens.

My good friend that is a big-time radiator repair/builder (seriously--maybe one of the best) wants to build a "special" radiator this winter. He wants to go with a two large core aluminum for the increased airflow over the staggered four core (he says to stay away from epoxied tubes to headers as they are known to fail).

Maybe not a problem. Even a stock radiator could cool a V8 with some added performance and still had head-room for more. But hey, cooler is cool. And he's right about the air flow. A thinner core can flow more air with a given fan.
But your staggered 4-row is not much thicker than stock. The offset cores do slow down the air flow, but also add more surface area without quite as much of the traditional drop that a big massive 4 or 5 row core would have.
If he's willing to give the new one to you, no loss! But assuming it's costing a pretty penny even at your buddy-cost, you might hold off until you're really sure you can't cool with your existing one.
I'm about to install one just to see if there is any difference. Although in my case, it's not really a test as I did not have any cooling issues with the stock 3-row version either.
Have a 2-core aluminum to play with next, but it's so damn thick that I need custom mounts. I hate that aspect of some of the fancy big aluminum radiators, where the tank seams are inline with the mounts. The welded seams are just too darn thick. Doubt I can grind the rad down though, so modified mounts it is.
But that's later...

Or maybe part of my problem is under hood airflow as I've read the larger motors restrict airflow (and I could see my fenderwell headers blocking some underhood airflow too).

Definitely have to at least check this aspect. Whether it is or not in your case, it's often the main problem. If not the only problem.
Been that way since we've been wheeling these things in the heat. Back in the sixties and seventies, many an EB was spotted on the trails with their "custom bikini tops" strapped to their roll bars to let the heat out of the engine compartment.
The custom bikinis being the completely removed hood of course.
The bigger flowing fans are really just to overcome the deficiencies in air flow that already exist and are taxed to their max with higher performance, or poorly tuned (higher heat producing) engines.

Purchased an anemometer to work on that and will do perforated inner fenderwells if needed after going with a stock thermostat or upgraded water pump. I also need to shoot some temps with my I/R gun to see if hot air is coming out the hood and back into the radiator as once it's heat-soaked it doesn't want to cool-off while idling. Wish I could fit a fan clutch. Really don't want to go with serpentine at this time. Explorer fan/clutch seems to be a pretty good way to go, though.

Definitely let us know how the testing goes. Lots of things left before more parts get added I'm thinking.

The only "symptom" I saw in his post yesterday was:The number of blades on the fan has no effect on what happens when the engine is off.

He was very likely referring to the entire list of symptoms discussed in this thread. Not just one single thing mentioned yesterday is my take on it.

Increasing the coolant's pressure in the block will not affect temperature. It will only increase the boiling point.
So if the coolant ISN'T boiling already, it will have no effect.

Disagree and agree. More pressure is better from two aspects. And yes, it's a boiling issue, but at a level that most of us will never know about because it's localized inside the block and doesn't need to show itself at the radiator to have an effect on cooling.
The pressure does raise the boiling point of course. But that's more to do with the internal "ambient" pressure. It's the water flow pressure that really helps internally.
As we know, the higher pressure and flow inside the block keeps the coolant against every little tiny corner and angle of the water jacket. Reducing, or hopefully eliminating any hot spots that might create either a micro steam pocket, or just keep sufficient coolant flowing over that point of contact that it doesn't even get near the temperature to boil off the coolant.
So while I agree it increases the boiling point, I disagree that pressure does not effect temperature. It's just not always at the gauge or the radiator cap.

The mechanics hated that some cars had temperature gauges. Most drivers just don't understand how to process that information. Owners would come in complaining of overheating and want it fixed.
There were even some models that came out with gauges that had no numbers. Just a red spot to indicate too hot.
With the proper coolant and pressure cap, an engine can run fine over 250*.

Funny that. I'm sure it was a pain. Even modern cars have funny issues. On the Saturn forums there's a lot of chatter about how the electric fan is not coming on, or the gauge is reading over the center, or when tested they found the temps to be in the "overheating" range.

From the factory, the electric fan isn't even supposed to fire up until the temps reach 210° and the engine tune and aerodynamics keep the coolant temps down below that under 90% of normal operating conditions.
I forget what the gauges read, but I think there are some numbers. Just not a full scale of them. People just don't like to see that needle go over the middle!

Paul

 

[bronconut73]

Ok, sorry about throwing all this into one post. But I just stayed out of the conversation too long and wanted to my comments out quickly. Before more info comes out and I learn something new to make it all change!:-[%)



Totally agree.



Totally disagree.
Well, I think you were just throwing out that generically, and know full well that other things matter. But I had to call you on it!

After all, how many times have we seen a heating issue here where the installation of a shroud made no difference? And changing to different thermostats made no difference? And doing many other things made no difference until the actual underlying issue was resolved. Whatever that happened to be on that particular Bronco.



See, some stuff does matter. I like them too and have a set waiting to go on to both Broncos.



It's higher than you'd like, but also sounds somewhat normal. Like the others have said, the temps creeping up a bit when parked after driving is common. Temps jumping up after the engine is shut down is totally normal (heat soak) and also as said, the reservoir puking after shut down is normal too a time or three. If it continues to do this, then yes, something is wrong.
But that "wrong" in your case could be the size of the reservoir, as Steve mentioned.



How small? There is such a thing as too small for a particular radiator size. What it's supposed to do is to catch the heat expanded coolant and return it to the radiator when cooled down.
If it's too small, or too full, you will have this problem always.
You could try running the recovery tank almost empty to see how it acts. If it starts to puke, then it's too small. We don't have huge radiators as these things go, but they're large enough in capacity that a too-small recovery tank is just going to keep puking every time the coolant in the radiator expands and exits the cap.
There should come a time when the liquid level in the radiator does not go out of the cap enough to fill the outside tank, but you have to determine if that's a normal level or not, when it gets to that point.



I should know by now Craig, but how is your engine set up? If the builder thought you should use a 160 thermostat (old school hi-po trick, but certainly not right for every setup) then you have a pretty high performance engine?
You've got lots of go-cool goodies in the cooling system, but as you've figured, the fan is not the best out there available.
It's certainly been good enough for most of us with moderate engines, but if your engine is building more heat than the air flow can evacuate from the radiator, more air flow can be a good thing. Whether it takes the form of improved aerodynamic flow through the body, or a better fan pulling more air, more is still good until it robs more power than you want to lose.
Luckily for most of us, we're not racing so that extra 30hp we lose to a big-ass fan isn't a factor.



Most definitely!!!! In fact, short of removing the hood temporarily to check air flow, I would verify the temps with an independent gauge or meter before anything else.
After all, as we've seen here before, you could be tracking down a problem that is not actually a problem.



Make sure they use a vacuum advance. Unless you're building a race engine, vacuum advance is only a good thing.
I'm assuming a pro already knows to advance it as much as the engine can handle.



It's not just about "high flow' with the thermostats. Their own literature used to call it "balanced flow" so I would just leave that in until the last.
I like the high-flow pumps, but would leave that until you've verified that air flow is not the issue. After all, here too stock water pumps have served us well and don't normally allow overheating unless something else is just too much for them.
The main thing about high-flow pumps is that, yes, they can build more pressure, and keep more coolant in the nether regions of your block, but they also flow more while taking less power and not cavitate at higher rpm levels.
That last is their main claim to racing fame. That it can flow better than most while taking less power to do so. Power is winning, but it's not a requirement for cooling.
But it doesn't hurt that less power needed probably means less heat generated.
Side effects are cool...;D

So even though I'm a big fan of both brands and would happily recommend them, chase down the other stuff before you take more time (forget the money, the time is a bitch!) to replace existing stuff that might be fine.
Take the hood off and drive in the same circumstances to see what happens.



Maybe not a problem. Even a stock radiator could cool a V8 with some added performance and still had head-room for more. But hey, cooler is cool. And he's right about the air flow. A thinner core can flow more air with a given fan.
But your staggered 4-row is not much thicker than stock. The offset cores do slow down the air flow, but also add more surface area without quite as much of the traditional drop that a big massive 4 or 5 row core would have.
If he's willing to give the new one to you, no loss! But assuming it's costing a pretty penny even at your buddy-cost, you might hold off until you're really sure you can't cool with your existing one.
I'm about to install one just to see if there is any difference. Although in my case, it's not really a test as I did not have any cooling issues with the stock 3-row version either.
Have a 2-core aluminum to play with next, but it's so damn thick that I need custom mounts. I hate that aspect of some of the fancy big aluminum radiators, where the tank seams are inline with the mounts. The welded seams are just too darn thick. Doubt I can grind the rad down though, so modified mounts it is.
But that's later...



Definitely have to at least check this aspect. Whether it is or not in your case, it's often the main problem. If not the only problem.
Been that way since we've been wheeling these things in the heat. Back in the sixties and seventies, many an EB was spotted on the trails with their "custom bikini tops" strapped to their roll bars to let the heat out of the engine compartment.
The custom bikinis being the completely removed hood of course.
The bigger flowing fans are really just to overcome the deficiencies in air flow that already exist and are taxed to their max with higher performance, or poorly tuned (higher heat producing) engines.



Definitely let us know how the testing goes. Lots of things left before more parts get added I'm thinking.



He was very likely referring to the entire list of symptoms discussed in this thread. Not just one single thing mentioned yesterday is my take on it.



Disagree and agree. More pressure is better from two aspects. And yes, it's a boiling issue, but at a level that most of us will never know about because it's localized inside the block and doesn't need to show itself at the radiator to have an effect on cooling.
The pressure does raise the boiling point of course. But that's more to do with the internal "ambient" pressure. It's the water flow pressure that really helps internally.
As we know, the higher pressure and flow inside the block keeps the coolant against every little tiny corner and angle of the water jacket. Reducing, or hopefully eliminating any hot spots that might create either a micro steam pocket, or just keep sufficient coolant flowing over that point of contact that it doesn't even get near the temperature to boil off the coolant.
So while I agree it increases the boiling point, I disagree that pressure does not effect temperature. It's just not always at the gauge or the radiator cap.



Funny that. I'm sure it was a pain. Even modern cars have funny issues. On the Saturn forums there's a lot of chatter about how the electric fan is not coming on, or the gauge is reading over the center, or when tested they found the temps to be in the "overheating" range.

From the factory, the electric fan isn't even supposed to fire up until the temps reach 210° and the engine tune and aerodynamics keep the coolant temps down below that under 90% of normal operating conditions.
I forget what the gauges read, but I think there are some numbers. Just not a full scale of them. People just don't like to see that needle go over the middle!

Paul

Paul,

You are amazing. We are all very lucky to have you!

Thank you Sir