Coolant temp 220+

[OldZeuski]

I just rebuilt my 302 (block hot tanked), but even before this it used to run over 200 basically always. I never thought anything of it. New pump (stock flow from summit), stat, radiator, sensors, hoses, clamps. The works. Stock fan tho.

Car is on a Holley terminator X with an MFKustoms adapter so it’s using the stock sensors. Gage on the cluster also rises as expected.

It has a 195 stat. Now after a few light pulls on a hot day it’s sitting at 222 just cruising.

I’ve burped the system, can’t seem to get any more air out of it. Hi and low fans work, I can test them with the Holley and they are set low fan : on 208 off 202. Hi fan : on 216 off 210. They work as expected. All of the cooling shroud is still in place.

Is there a secret to burping these that I’m missing. I don’t know of a bleeder or anything. I have friends with the same setup on a Holley and they barely break into the 200. Should I get a lower stat?

 

[shovel]

The water temp sender is above the water pump so it's not real likely that there's more air in it.

If you turn your own wrenches you owe it to yourself to get a coolant funnel anyway, after I finally bought one I couldn't believe I had worked all those years without it - but I also don't think that's what your challenge is.

Clogged cats can make a car run hot, lean AFR can make it run hot, the 94-95 air conditioner condenser is much more densely packed fins than later so that can have an effect, missing air dam especially on a lowered car can have an effect, if your radiator upper cover is missing that can let air up around the radiator instead of cooling.

I'm not saying any of these things specifically are what's up with yours it's just things to check off the list. Good luck!

 

[OldZeuski]

The water temp sender is above the water pump so it's not real likely that there's more air in it.

If you turn your own wrenches you owe it to yourself to get a coolant funnel anyway, after I finally bought one I couldn't believe I had worked all those years without it - but I also don't think that's what your challenge is.

Clogged cats can make a car run hot, lean AFR can make it run hot, the 94-95 air conditioner condenser is much more densely packed fins than later so that can have an effect, missing air dam especially on a lowered car can have an effect, if your radiator upper cover is missing that can let air up around the radiator instead of cooling.

I'm not saying any of these things specifically are what's up with yours it's just things to check off the list. Good luck!

I have a coolant funnel so I’m fairly positive the air is out. No cats. New radiator and AC condenser. Stock Air dams in place. Stock height. And the tune is conservative so it isn’t leaning out.

 

[Terrorist 5.0]

A lower thermostat will not lower your coolant temps, it will just take longer for the temps to rise because the thermostat is allowing coolant to flow earlier (at a lower temp).

These motors have a reputation for being hard to bleed from what I’ve read but I never had any issues. Maybe I was just lucky. Regardless, there may be a little bleeder screw on your thermostat housing that you can crack open and let any possible air bubbles out of if your thermostat housing is aftermarket.

 

[ttocs]

for getting the air out look into a zero spill funnel. You fill it up and it lets the air bubble out while it idles and I was amazed how long I had to let mine go before it stopped.

Is it getting hot while rolling but not at idle? If so get down and make sure the wind deflector under the core support is in place as it is designed to suck the hot air out from under the car when moving. It looks like a useless little piece of plastic and that is why a lot that are not torn off from low clearance are pulled off just because...

 

[dsrtjeeper]

I second the no spill funnel. It plain works and it's the only way I can get all of the air out of the system.
The 94-95 cars have an a/c condenser with a very high fin count. This restricts airflow to the radiator. The fix for this is installing a '97 GT condenser with less fin count.
A high volume water pump and t-stat helps as well.
The factory fans do not move enough air if you're in a hot climate. You'd be better served with a Contour fan setup or dual 11" SPAL fans from Summit. The dual fans cover more of the radiator core than the stock fan.
Are the side deflectors in place on both sides of the radiator?
Just so you know; 222 degrees won't hurt a thing. The factory ECU turned on the low speed fan at 220 degrees.
Try lowering your fan of/on temps.
If you can in your area; use 100% distilled water and Royal Purple Purple Ice coolant additive.
What radiator did you install?

 

[OldZeuski]

I second the no spill funnel. It plain works and it's the only way I can get all of the air out of the system.
The 94-95 cars have an a/c condenser with a very high fin count. This restricts airflow to the radiator. The fix for this is installing a '97 GT condenser with less fin count.
A high volume water pump and t-stat helps as well.
The factory fans do not move enough air if you're in a hot climate. You'd be better served with a Contour fan setup or dual 11" SPAL fans from Summit. The dual fans cover more of the radiator core than the stock fan.
Are the side deflectors in place on both sides of the radiator?
Just so you know; 222 degrees won't hurt a thing. The factory ECU turned on the low speed fan at 220 degrees.
Try lowering your fan of/on temps.
If you can in your area; use 100% distilled water and Royal Purple Purple Ice coolant additive.
What radiator did you install?

I used the no spill funnel. Distilled water and “water wetter” additive, but 50% coolant.

I’m using the stock fan and radiator and all of the air ducts and dams are still there. I’m not convinced the stock system is unable to cool a mostly stock car but maybe I’m wrong.

When it comes to after market fans, which ones are reliable? I’d prefer not to change the radiator first just because it’s new and i just got the car back on the road. But
A fan swap might be sensible.

 

[dsrtjeeper]

I'm in Phoenix so I tend to go to the extreme. You'll most likely benefit from the Contour fans. There's plenty of writeups online to help you. You'll need to use 2 relays mounted near or on the fan shroud. Relay power signal will come from the CCRM fan output wires. Use 10awg power wires direct to the battery. I choose to use a 100amp circuit breaker on the power wires.

 

[OldZeuski]

I'm in Phoenix so I tend to go to the extreme. You'll most likely benefit from the Contour fans. There's plenty of writeups online to help you. You'll need to use 2 relays mounted near or on the fan shroud. Relay power signal will come from the CCRM fan output wires. Use 10awg power wires direct to the battery. I choose to use a 100amp circuit breaker on the power wires.

Like Ford Contour? Im not familiar with them. That’s what comes up when I search it.

 

[dsrtjeeper]

Like Ford Contour? Im not familiar with them. That’s what comes up when I search it.

Yessir. LMR stocks them. Amazon and Rockauto also sell them.

 

[Terrorist 5.0]

You shouldn’t be using water wetter with antifreeze. It clogs up the cooling system. Flush everything out real good and just run a water biased mix.

Stock cooling system should be fine for a mild build. I never had any overheating issues with mine and I had underdrive pullies.

 

[dsrtjeeper]

You shouldn’t be using water wetter with antifreeze. It clogs up the cooling system. Flush everything out real good and just run a water biased mix.

Stock cooling system should be fine for a mild build. I never had any overheating issues with mine and I had underdrive pullies.

This is why I won't use WW period. It sludges up the cooling system and leaves brown slime everywhere. If you Google it, it's really a problem. RP Purple Ice is the hot ticket.

 

[Terrorist 5.0]

This is why I won't use WW period. It sludges up the cooling system and leaves brown slime everywhere. If you Google it, it's really a problem. RP Purple Ice is the hot ticket.

I personally don’t believe Purple Ice and Water Wetter are all that different. I’m sure they work to some extent, but if you want to use it, stick to straight water. Don’t let it mix with antifreeze.

This stuff is for people who go to the track where the slippery antifreeze is not allowed because if it spills onto the track it can create a serious hazard to other cars. That being said, I ran straight water for a year. Granted, I did flush it out about every month, but it’s super easy. The moment I saw the water get brown, flushing time. I kept it clear, and my temps stayed significantly lower in traffic.

 

[dsrtjeeper]

I noticed a slight temperature drop with Purple Ice and straight water vs just straight water. I mainly use the additive for cooling system protection. Straight distilled with no additive turns to corrosion quick.

 

[shovel]

It's probably worth reminding ourselves that conservation of energy isn't just a good idea - it's the law. An idling 500 horsepower SBF and an idling 200 horsepower SBF should produce almost the same amount of heat because they both have roughly the same amount of friction to overcome in order to spin 750 rpm and turn the accessories. For the same reason a 500 horsepower Mustang and a stock Mustang should produce the same amount of heat cruising at any given speed because the rolling and air resistance of the car itself is about the same.

Some parts add up, like bigger valves are probably heavier (slightly more work to slam them open), high rpm springs require more work to push open, wider tires push more air out of the way and have higher rolling resistance - on the other hand a free flowing exhaust should permit some improvement in evacuation of heat energy from under the hood.. but lowering a car means there's less room for the hot air to get out under the car.

Having said all that, hundreds of thousands of people have done all sorts of things to modify their Mustangs and most of them don't have heat problems and don't need to run special coolant or undertake other bizarre measures to deal with it.

Since you said you're using the stock sensor, is it possible the stock sensor is calibrated differently from the Holley one and maybe your temps are fine just being displayed wrong?

 

[dsrtjeeper]

You're incorrect. More HP produces more heat. We're asking a stock cooling system to displace the added heat.

• More fuel burned: Higher HP requires burning more air and fuel per second.
• More friction: Faster moving parts and higher pressures generate intense mechanical friction.
• Higher cylinder pressure: Increased pressure creates extreme combustion chamber temperatures.
• Exhaust volume: A larger volume of hot exhaust gas passes through the system.

 

[dsrtjeeper]

Google Search

 

[shovel]

You're incorrect. More HP produces more heat. We're asking a stock cooling system to displace the added heat.

• More fuel burned: Higher HP requires burning more air and fuel per second.
• More friction: Faster moving parts and higher pressures generate intense mechanical friction.
• Higher cylinder pressure: Increased pressure creates extreme combustion chamber temperatures.
• Exhaust volume: A larger volume of hot exhaust gas passes through the system.

Explain to us all without using a brainrot chat bot exactly why a 500 horsepower 302 makes more horsepower and heat at idle than a 215 horsepower 302 makes at idle. Then explain to us why a 500 horsepower SN95 is burning more air and fuel going 70mph than a 215 horsepower SN95 also going 70mph when both cars weigh the same amount and have the same coefficient of drag.

I'mma go water my lawn with some Brawndo.

 

[dsrtjeeper]

In the posters original post he states and I quote "Now after a few light pulls on a hot day it’s sitting at 222 just cruising."

He didn't state at idle nor did he designate a speed. "A few light pulls" with a 500hp engine will, more than not, produce more heat than a 200hp engine. These engines are not 100% efficient. Energy is always wasted.
Maybe you can explain why a factory stock cooling system cooled my '94 when bone stock but couldn't do so when I built a stroker.

You're forgetting at least one component that causes a 500hp 331 or 347 to run hotter than a 200hp 302. Bore size. What happens when you increase bore size in the same 302 block? I'm assuming a stroker as a 500hp 302 is a whole different animal.

 

[shovel]

I interpret "just cruising" as "just cruising". If you did some pulls and got the engine up to 250F and then you proceed to "just cruise" then the temp should drop to whatever the cooling system is made to dissipate. If it's not dropping then there remains a problem to fix.

OP said he's got a 302 not a stroker.