[gotgraham]

So here's yet another overheating thread...my 73 Cougar is running hotter than I would like. I live in Reno, NV (desert climate), and when driving for much longer than 20-30min I usually see my coolant temperatures hit 230*. Ambient temp is about 100*. I know - perhaps my standards are too high. The problem is I can't run air conditioning as the coolant temp goes even higher. Note that on cooler days (<80*) I hang round 195* coolant temp.

I am running the following:

351C - 0.030" overbore
180* high flow thermostat
Thermostat restrictor plate (from WCCC)
Flowkooler water pump
Factory 4 core brass/copper radiator
Flex-a-lite Black magic extreme 3000 cfm electric fan
180 amp alternator (ford 3g from pa-performance) - so power isn't an issue.
Straight water and water wetter
Properly 'burped'

I realize that others are seeing normal temps with stock cooling systems - however apparently climate my overbore are contributing to running hotter.

So I would like the impossible (hopefully not) - to be able to run my A/C in 100* weather in stop and go traffic and see my temps not rise much above 200* (hopefully less). Is this wishful thinking, or is this possible?

I think the only route left is an aluminum radiator - and maybe even more powerful fans - but not sure what I can upgrade to. Recommendations?

 

[maxgig]

Gotgraham,
I had the same problem you have. I have a base 69 Cougar with a 351W bored 0.20" over using the stock radiator. The car had no problems in California with that setup. When I got it to Alabama where the temps averaged 90+ degrees it started to overheat. I changed the thermostat from 160 to 180 and added water wetter to my 50/50 mixture which worked for a little bit. When I moved to Kansas where the temperature (this summer) averaged slightly more than in Alabama, my problem came back.

This time I got rid of my fanblade system for a dual fan electric system, I swapped my old radiator for an aluminum 4 row 4 core Champion one that I bought off eBay. Lately here for the past 3 weeks the temperature has been well over 100 degrees and my car has got no hotter than 220 degrees. Under normal conditions it stays around 210 or lower. If I were you, yes I'd go to the aluminum radiator, you seem to be covered everywhere else.

 

[xr7g428]

When does it over heat: running on the highway or sitting at a light in town?

 

[gotgraham]

It's a little bit of both. The temp creeps up a little faster in stop and go, but still creeps on the highway. We're talking a couple degrees maybe every 3-5 minutes or so. I haven't seen it get any higher than 230, however at that point I start doing what I can to get the temp down - turning on heater, etc.

The capacity of my engine / transmission to put energy into my cooling system slightly exceeds its capacity to release the energy - when the ambient temp is more than 85-90 degrees. With lower ambient temps I have no problems.

Ideally, my cooling system would exceed by some decent margin my engine's ability to put heat in the system (in all ambient temperatures I see here (up to 105* with very low humidity).

 

[Four-55]

I run one of those champion eBay radiators in my 70 with. 428 cj bored .020 over and it never goes over 190 even in traffic only problem is that it looks like an aftermarket radiator square edges vs stock...

 

[gotgraham]

Looking at their site they have a listing for 71-73 mustang 3-core radiator. I'm curious how it would compare to the 2-core aluminum radiator from summit racing:

http://www.summitracing.com/parts/SUM-380463/?rtype=10

The summit version looks a little closer to oem in appearance - although it comes with a $80 jump in price.

Anyway, it sounds like I would do some good to move to a modern aluminum design.

 

[doctordesoto]

have john @beko radiator(concord,ca)build you a dimple tube radiaror--i used a spal dual 11"fan/shroud with their pwm controller and 140 amp alt---seems to work good for me

 

[xr7g428]

Okay, there are two components to a cooling system air and water. If it runs hot going down the road they problem is not air. You get more CFM at 60 than any fan could ever deliver. That means it is water. Most likely the radiator is partially clogged and needs to be rodded out or replaced. There is essentially no cooling difference between aluminum and brass. The only real difference is weight. IF it only ran hot in town at stop and go this would point to not enough air delivery by the fan.

 

[Bad69cat]

I agree with Bill - something is amiss. Clevo's are known to be hot blooded and it sounds like you have everything in place - but you haven't said that the system was pressure tested, and assuming that's good the flow rate has to have an issue. First see if it holds pressure, then consider a good boil out. they didn't overheat from the factory, so if it performing those specs - you should be able to get it under control without breaking the bank.....not saying a new one wouldn't fix it, but if it's losing pressure in the block somewhere you may not fix it.

 

[gotgraham]

That's a good idea. It's worth checking out. I suspect it is holding pressure as I don't boil over when hitting 230-235* - which at 0 psi I definitely would. I'll double check regardless. The engine is a little warmer than stock, but not radical -

Comp 268h cam
KB177 flat top pistons - 9.5:1 CR
2v heads
xcelerator intake
C6 trans with 2400 stall torque converter (probably pumping some heat into the system in stop and go).

I had the radiator pressure tested - but didn't think about a flow test. I do agree that something must be amiss - I didn't have these issues on the stock bore motor with 2 core radiator and mechanical fan.

I think I recall a potential overheating issue with the cleveland if the head gasket isn't oriented properly. Does this ring a bell with anyone? I'm pretty sure I triple checked that, but who knows.

 

[Royce Peterson]

Don't use straight water - it does not make any appreciable difference in cooling (wives tales and such ) but your block and radiator will be ruined in a year or two by rust and scale. You need to run at least a gallon of anti freeze + fill the rest of the way with water. You can forget the Water Wetter, it also doesn't do anything noteworthy at least from my experience.

You checked your timing lately? Incorrect timing can make an engine overheat. Also, do you have a working clutch fan? The 3000 CFM electric is probably adequate for a 1500 CC Honda, but way less air flow than the stock fan for your application.

 

[RayH]

Agree with Royce, need antifreeze and check you timing. If timing is correct I would hook up a vacuum gauge, disconnect the vacuum advance and set the timing where it pulls the highest vacuum and see what happens. If you want to run an electric fan find one from a late model Town car or Mark 3 with the mod motor but those things draw a lot of amps. Also it is not uncommon for a rebuilt motor to run a little warm until it is broke in. As for the water wetter I run it in my AC Cobra kit car and it does seem to help.

 

[gotgraham]

Thanks guys. I'll double check the timing and the radiator.

As far as 50/50 ethylene glycol / water vs straight water - it's just science that straight water has higher heat transfer properties over the glycol mix.

50% glycol / water has a specific heat property of 0.865 Btu/lb *F at 200 *F while straight water has a specific heat of 1.0 Btu/lb *F - so a 13.5 % improvement.

Water wetter acts a surfactant which is to reduce the surface tension of the water - improving thermal transfer properties.

Where glycol/water is beneficial is to raise the boiling point of the fluid and reduce the freezing point. Thermal properties suffer slightly, however you get a little more boil over / freeze protection.

 

[Royce Peterson]

Right - but in the real world if you have insufficient air flow and a rusty radiator and block you will have overheating. You have proved it. Time to live in the real world. Don't be an idiot, put some anti freeze in there before you ruin everything. Get a mechanical fan back on there so you have enough air moving through the radiator. The water wetter might make a 2 degree difference but you have a 30 degree problem. It won't help you, and you have proven that too.

Thanks guys. I'll double check the timing and the radiator.

As far as 50/50 ethylene glycol / water vs straight water - it's just science that straight water has higher heat transfer properties over the glycol mix.

50% glycol / water has a specific heat property of 0.865 Btu/lb *F at 200 *F while straight water has a specific heat of 1.0 Btu/lb *F - so a 13.5 % improvement.

Water wetter acts a surfactant which is to reduce the surface tension of the water - improving thermal transfer properties.

Where glycol/water is beneficial is to raise the boiling point of the fluid and reduce the freezing point. Thermal properties suffer slightly, however you get a little more boil over / freeze protection.

 

[gotgraham]

Thanks for the suggestions. I'll give them a try in the real world.

 

[doctordesoto]

does your coolant recovery sys work as designed----the rad must be full when cold a pushed out to the tank when hot , only to be sucked back in as it cools----air flow is your friend but keeping air out of the radiator is important---dont forget that boiling point increases 3 degs for every lb of pres @ sea level--ie 260 deg with a 16lb cap @sealevel---your new cars have a pres cap on the recovery sys to keep the air out of there also

 

[gotgraham]

I actually don't have a coolant recovery system I was under the impression that it didn't have a recovery bottle from the factory - at least I haven't seen one before. Did these cars come with one?

 

[ClawIt]

Why all the overheating these days? Guys in my Ford/Mercury club and sometimes my GTA have the climbing temp gauge issue. Some of us have never
touched the engine and what ran cool in the 60s & 70s is now hotter. I had my car in the south during the 70s and ran the air always, gauge stayed in
the middle. After refreshing with new 3 core radiator, 180 stat, Flowcooler pump, rebuilt clutch fan, and 50/50 Prestone I'll have to shut the air off in
traffic even in the low 80s outside.
Some guys in the club say its the lack of lead in the gas!

 

[Bad69cat]

Some of it could be realted to the fuel mixtures running ehtynol nowadays - true enough. It does burn hotter and less efficient, but the basics of the cooling system still apply. A system under pressure has an increase in boiling point, and as long as you can keep removing heat via airflow at a rate that exceeds it's ability to continue to heat up, you should be able to keep her at an even keel, even if it's a bit higher than it was in the old days.....

 

[jcbingcougar]

I actually don't have a coolant recovery system I was under the impression that it didn't have a recovery bottle from the factory - at least I haven't seen one before. Did these cars come with one?

No, Cougars didn't come with a recovery system. The hose coming from the radiator neck just overflowed to the ground.