Here are 10 tips to address with any overheating problem:

[DanR]

Here is an interesting post I found on the Rootes (post vintage) Parts Service web site

Here are 10 tips to address with any overheating problem:

1. Many cars overheat from more than one problem. Often we assume a bigger radiator or a similar big gun solution will fix our problem. Maybe it will, but often by so doing you are addressing the symptom and not the cause. Many cars over the years pick up little annoyances that contribute to overheating. Individually none of them would overheat your car. Collectively you have an overheating problem. Look at the whole car when addressing overheating problems.

2. Before you do anything else, tune up the car. Many overheating cars are out of tune, Be dead nuts certain you are not running lean or with retarded timing.
A lean fuel mixture will overheat your car right now. If your engine runs lean you can chase your tail looking for problems in the cooling system and never figure it out. Be sure you are not running lean. The easy way to do this is richen your jetting a couple of steps. If the overheating is better, you're on the right track.

3. There is a lot of misinformation about ignition timing and cooling. Retarded timing contributes to overheating. Advanced timing helps cooling. Bump up your initial timing a few degrees and see if it helps the car run cooler. It's an easy and practical fix. Of course, if you advance enough to enter pre-ignition or detonation you will start to overheat. Detonation contributes to overheating. If you start to detonate back off the timing. Overheating cars should always run vacuum advance. Vacuum advance helps cooling.

4. Cars can overheat from coolant circulation that is either too slow or too fast. When your car left the factory it probably had the correct speed for the water pump. Over the years things change, pulleys are swapped, rear end ratios are changed, tire sizes vary. Your car may not have the right circulation speed for the water pump. Remember cars can overheat from circulation that is either too fast or too slow.

5. Look at your airflow. Be sure your shroud fits properly and is sealed to the radiator. What'd ya mean you don't have a fan shroud??!!?? If not, obtain a shroud before you do anything else. You can adapt a shroud from the junkyard or many after market suppliers can provide you one. Seal the shroud to the radiator with weather stripping.

6. The best all around fan is the factory design with a thermal fan clutch. Flex fans aren't as versatile, Solid fans pull lots of air but are noisy and suck horsepower when you don't need the extra cooling.
If you need extra air flow there are many electric fans on the market that can help. Be sure your charging system is up to the task of handling the extras amps from an electric fan.

7. Reduce the antifreeze in your coolant. A 50/50 mixture does not help cooling. Either run 100% distilled water with water pump lubricant or distilled water with about 15-20 % antifreeze. Either mixture will cool better than 50/50 and still lubricate the water pump and provide corrosion protection for your system. Remember when the weather turns cool to switch back to 50/50.

8. Use a better grade of gas. If you are not running premium and you are overheating, step up to the top grade. If there is no improvement, try advancing your timing a few degrees. The extra octane will allow you a little extra timing without getting into detonation. Many older cars and particular muscle cars were designed for better gas (4 or 5 star, > 98 octane) than is now available. If you are detonating on today's gas you can be overheating. Remember not all detonation is audible.

9. If you are running an automatic, install a quality after market transmission cooler. Cooling the transmission is added work for an already overtaxed radiator. Do not mount the cooler in front of the radiator where it will overheat the cooling air. Rather mount it to one side.

10. Notice your driving habits. The more gas you burn the more heat the engine produces. Jackrabbit starts followed by hard braking, constant acceleration, flogging the engine uphill, all burn lots of gas. Yes, these are performance cars and that's why we love them. We're not saying don't enjoy your car, but if you are constantly into the accelerator, you are producing extra heat that the cooling system has to get rid of.

Compared to the expense of buying parts in a hit and miss fashion to solve your problem, investing in researching the origin of the issue is a downright good investment.

Arnoud Malherbe

(text based on information from various sources on the internet)

 

[DanR]

There are all sorts of solutions that may be tried to eliminate an overheating problem whether it is real or imagined. In the above POST I found there are some real ideas that have proven to be of great help even before you actually have a heating problem.

Bigger radiators, Aluminum radiators, Fan assist units etc., etc.... are considered "the answer" in most cases it seems. Lots of these actually work and are improvements.

I gave some thought to installing an electric fan when I first started doing the V6 Conversion because it seemed as if everyone was having trouble with cooling their Modified Alpine. Decided to wait until I could actually test drive in various weather conditions. Sure glad I did because with what I did has paid off with a cool ride.

Number one reason I did not want an electric fan was a lack of space in front of the radiator due to the A/C condenser. With me running a stock 4 blade Ford Fan as a puller does not allow for an electric fan to be installed back of the radiator nor is an additional fan needed with my setup.

As I have stated before my radiator is copper, has 3 tubes and best of all 17 fins per inch. A stock Alpine radiator has 9 fins per inch (atleast in the Alpines I own) and in my opinion does not allow allow adequate heat dissipation, especially for the Modified.

In my 2.8 V6 Conversion, I elected to run 185 thermostat mainly thinking the flow of water earlier would also aid in cooling. I believe that is one small part in cooling.

Additionally, with a suggestion from several of my Hot Rod friends I designed and build a 2 piece Fan Shroud. Again, an improvement in air flow for better cooling.

Having read of other Alpine owners recommending closing off the openings where the horns are located seemed like a grand idea. I made some panels from 1/8 inch plastic to block any unwanted air there too!.

Then as an afterthought I cut some flat rubber about 7 or 8 inches wide and long enough to run from each side of the crossmember, fastened under the bottom of the radiator for additional blockage of air is probably another added benefit to keeping it cool.

On the hottest of days in Sunny SC, whether in or out of traffic or sitting at idle for various times, it has never overheated even running the A/C.

Maybe I am just lucky

 

[phyrman]

My first V6 mod, i used distilled water with water wetter in it for pump lube and corrosion protection
Anti-freeze is not needed in Los Angeles!!!!!

 

[Warren]

Lots of talk on this topic Cooling the Tiger, and a how I survived a 118 degree day on CAT.

It's been interesting to read all the Tiger email list CAT shop notes and urban legend postings.
Most all agree that the reduced diameter water pump pulley and curing the problem at idle is a big part. Me my car cools too well and survived the 118 degree trip through the San Fernando Valley.
I say it cools too well as I stick by the shore for much of my driving and the top never goes up. I want the car at 180 and the heater is nearly always on. I had a 122S Volvo with a pull down curtain to block the radiator, loved it.
PS Hoghead here and on CAT has a reduced diameter Ford Fairmont style pulley he has had made.

 

[65beam]

The name "antifreeze" came about when the use of alcohol in the cooling system no longer worked. It tended to evaporate off leaving the engine with water only and in a cold climate you ended up with a freeze up. It was found that ethylene glycol blended with water was a year round remedy. The rest is history. The proper name now is "coolant". Conventional coolants not only prevent freeze up but also have additives that prevent boil over and corrosion. I can remember a time that I sold a couple types of coolant/antifreeze. My guide for Chevron coolant products now is roughly 60 pages . That's only one brand that we carry. We carry several others including propylene glycol products. Regardless of where you live it's a good idea to use a 50/50 blended green conventional coolant just to protect the engine block.

 

[Cali_59]

I have a bad overheating problem. I am , ( but not for long ) running 75% coolant, an old sports car mechanic once told me.. " If you run straight coolant you won"t over heat/boil over."
I have to say, the boil over stopped but the thermostat was cranked to the far right withing 15 min.
Lots of great stuff here I am going to employ.'

 

[RootesRacer]

I have a bad overheating problem. I am , ( but not for long ) running 75% coolant, an old sports car mechanic once told me.. " If you run straight coolant you won"t over heat/boil over."
I have to say, the boil over stopped but the thermostat was cranked to the far right withing 15 min.
Lots of great stuff here I am going to employ.'

well.....
You may not boil over but you may very well still overheat the engine.

Ethylene glycol has a high boiling point but also has a poor thermal conductivity compared to straight up water.
You may not have enough pump capacity to move enough coolant to make up for the lower thermal conductivity and the engine temp
will climb till it finds a thermal equilibrium. This will certainly be at a much higher temp than it would have been with 50/50 mix or straight water.
At a stationary idle is where things will be worst.

Most people feel that a 50/50 water coolant mix yields the best compromise between boiling point and cooling efficiency.

 

[65beam]

well.....
You may not boil over but you may very well still overheat the engine.

Ethylene glycol has a high boiling point but also has a poor thermal conductivity compared to straight up water.
You may not have enough pump capacity to move enough coolant to make up for the lower thermal conductivity and the engine temp
will climb till it finds a thermal equilibrium. This will certainly be at a much higher temp than it would have been with 50/50 mix or straight water.
At a stationary idle is where things will be worst.

Most people feel that a 50/50 water coolant mix yields the best compromise between boiling point and cooling efficiency.

A 50/50 blend with a 15 lb cap will raise the boil point to 265 F. Even in very low temp areas a concentration of more than 67% ethylene glycol is not recommended. A 60% concentration will take the freeze point to a temp of roughly -60 F. I know of many in warm climates that use straight water but the problem with that is there are no additives to prevent foaming or rust and corrosion. Brown coolant is not a good thing.

 

[Cali_59]

I will be pulling the engine soon-ish to add my newly acquired OD, ( after it is gone through), I'll be flushing the block and installing a new water pump, ( when I find one for S1 ), and running 50/50.
I was entertaining the idea of adding an electric fan. Any thoughts on this?/ brands that work well?

 

[Gordon Holsinger]

I will be pulling the engine soon-ish to add my newly acquired OD, ( after it is gone through), I'll be flushing the block and installing a new water pump, ( when I find one for S1 ), and running 50/50.
I was entertaining the idea of adding an electric fan. Any thoughts on this?/ brands that work well?

Be careful with any kind of radiator flush. Some contain harsh chemicals that can cause problems with the alloy head. Early cars had a water outlet in the back of the head. Later cars did not. The later cars can accumulate a lot of scale and crud in the back of the block and cool number4 cylinder. My series V had a lot of scale and whatever in the block. My engine is apart and at the machine shop for rebuilding and the block will be boiled out and bored.

 

[alpine_64]

I would not recomend anyone running a stock heater core or especially series V style heater valve to go to a 15lb radiator cap unless you want to have to cut your expanded heater core out of the front scuttle or cause your valve to fail.

Even with a 10lbs cap you would want to add some cable ties or strapping to brace the heater core from ballooning at its ends... But you are still risking it causing leaks.

 

[DanR]

Michael, I have recommended the same thing as you mentioned. Run a stock cap recommended by Rootes or risk a burst heater core. I have several heater cores removed from Alpines that surely had the higher pressure caps or they may have frozen (?).

 

[65beam]

FYI, Sunbeam Specialties now sells a heater core that has reinforced ends that will not bulge under higher pressures. I have them in a couple of our cars.

 

[alpine_64]

@dan there is a lot of issues with the repro SV and MKIA/II Tiger heater valves failing. I would guess tbat while there seems a fundamental manufacturing tolerance issue there is likely additonal pressure being placed on them beyond the original design spec with people running higher psi caps.

 

[DanR]

Bob, Thanks for the tip on SS better built cores.... Didn't know that bit'o info. I may get one for my '65 SIV ST OD 70 Alpine now that I am taking it apart.

But, as you know I run a Heat &Air unit in Blue Boy. Removed the stock heater core and fan assembly so presently I run a 16 lb cap.

All of my V6 Projects will most likely have an A/C with the heat option built in like the Vintage Air in Blue Boy or the Old Air Units going in my '67 SV I call theGreen1 and '65 SIV GT BW35 V6 A4LD.

Anyone needing a good stock heater core can have one for shipping cost. I think I have about 3 or 4 left!

 

[tony perrett]

Gordon Holsinger raised an interesting point. When I replaced the core plugs a couple of years ago I was surprised to find quite a lot of compacted casting sand in the block. I loosened as much as I could with a stiff wire and hosed out the waterways but there could be some left to hinder the flow of coolant.

 

[DanR]

When I built the 1725 that was originally in Blue Boy, I took about any kind of brush or stiff piece of metal I could find and routed them in every hole available inside the casting (block). Took quite a bit of time, but it seemed well worth the effort. Even wish I had tried a sand blaster with a flexible nozzle!!