What is the "normal" operating temperature?

[BrianN]

Until yesterday the car ran at about 190 indicated, regardless of load and temp (albeit the ambiant temp never got above about 80f).

Yesterday I took the car over to Gilroy, where the ambiant temp was in the high 90's. At freeway speed the temp gauge was very near the 212 level and climbing. Fortunately we reached our destination about that time.

Even on a hot day should the cooling system still be able to keep the operating temperature down around 190?

The only other difference was that I leaned out the carburetors quite a bit, which gave a performance and mileage improvement.

Any thoughts on this?

How big a problem to I have to chase after here? The car has an original style 4 blade fan. Is there a better one that does not break?

Or is a radiator overhaul a more likely solution?

 

[Skip & Lynne]

Hi Brian if you could see inside a Healey radiator you would understand why they all seem to run so hot. They are 2 pass small tube radiators. Any restriction causes overheating quickly. I just had mine rebuilt using a 4 pass core with larger tubes using the same Healey tanks, It looks the same but when you take a closer look you can see 4 tubes instead of the 2 that were origionally used. I am also using a 6 blabed fiberglass fan with the cooling shrouds. Skip

 

[Keoke]

HI Brian. it has ben reported by very well known specialists that the running temp on the big healey engine is about 190 Deg. However, as you just experienced at that temp you have no margin if the engine is under load {climbing Hills} or the ambient temperature increases above about 80 Deg F,On a hot day[Temps at 100-to-120Deg] the standard cooling system in the healey is taxed beyond its capability to cool the engine.There is a fan known as the Texas Cooler that will improve the cooling somewhat.On the otherhand,to adequately address this problem also requires adding a larger core to the radiator the cost here is about $300. There has been considerable discusion on this topic on the forum recently and you might wish to review those comments.-FWIW---Keoke

 

[Bugeye58]

Brian, look here.

https://www.britishcarforum.com/ubbthread...part=1&vc=1

Jeff

 

[ron wilson]

I have had a BJ 8 for 20 years and it always runs about 190
The only thing I have done is several years ago I put on a 6 blade fan that I think I got from Moss. (Ialso added a coolant recovery tank but that was more to keep people from telling me my radiator was running over every time I stopped after a long drive. Because of th shape of the top of the radiator it tends to seek its own level so if you fill it to the top it will spit out some fluid. the tank has eliminated this.

 

[Dave Russell]

Hi Brian,
A few observations on Healey cooling systems.
Altough the cars were built mostly for USA export, West coast even, they never seemed to realize that many places are far hotter than in England. They did acknowledge this somewhat by making six, eight & more bladed fans for special export on request. The radiator cores were too small for the hot US climes.

The factory combinations of two, four & six bladed fans just added pairs as needed. These fans have been know to lose a blade with serious consequences, as have the older four blade cast aluminum ones.

A couple of illustrations - My 100-4 had five rows of widely spaced 1/2" tubes, 150 tubes total, with plate type fins spaced at 10 fins per inch. A four blade fan was used. My replacement core has four rows of 48 more narrowly spaced 5/8" tubes, 192 tubes total, with serpentine fins spaced at 14 fins per inch. This represents about 60% more tube area & 40% more fin area.

This more dense & efficient core requires more air flow pressure to force the air through. I'm using a steel 6 blade engine driven fan. At speed, the engine runs at 180 on a very hot day, & up to 190 in stop & go traffic.

The six cylinder radiator designs usually used two rows of a similarly inefficient design. Most of the people I know who drive in hot climates have converted their radiator cores to four rows of more densely spaced tubes. Remember, it takes more fan also. The later Healeys also had front side ducting between the grille & radiator. These ducts sometimes get left out somewhere along the way.

Another item that people miss is that the six cylinder Healeys have an internal radiator bypass port in the head for inrernal flow when the thermostat is closed. As the thermostat opens, there is supposed to be a sleeve on it that blocks the internal radiator bypass. Many replacement thermostats do not have this sleeve or the sleeve is improperly located.

A fan that is powerful enough to do the job requires about two hp to drive it. Very few accessory type electric fans are powerful enough to substitute for the engine driven fan. A two HP electric fan will draw over 100 amps. Fans mounted in front of the radiator are about 40% less efficient than those mounted behind the radiator.

An efficient fan shroud will do wonders for the cooling situation, if the radiator is up to it. The shroud should be designed to collect air from the entire back surface of the radiator, not just a small barrel in the center. I've seen a couple of custom made or adapted shrouds that fit the requirements. Of course, any shroud is better than none.

In stop & go driving, a 160 thermostat offers some margine over a 180. If the engine can cool to 160 between stops it takes a little longer to get too hot than if it can only drop to 180 between stops. Not much gain, but a little.

As a matter of curiousity I measured the temps on my late model Toyota V6. After an extended drive & idling period, AC turned on, I measured the engine to radiator outlet temperature at 180 degrees. The dash temp gage was reading right in the center. So much for late models running hotter, at least in this case. This car has a very efficient aluminum/plastic composite radiator & two electric fans which draw about 50 amps each. This car has a pretty hefty electrical system. I use an infrared "thermo gun" for instant temp readings.

If you are not the worrying perfectionest type of person, just ignore the temp gage & don't get excited unless the car actually boils & looses it's coolant.
D

 

[Keoke]

I do not advise ignoring the temperature guage it is the only indicator you have to preempt engine overheating.Just make sure it is functioning correctly and be cognizant of its accuracy.-FWIW---Keoke

 

[Bruce Bowker]

[ QUOTE ]
The only other difference was that I leaned out the carburetors quite a bit, which gave a performance and mileage improvement.

[/ QUOTE ]

Be very careful they are not TOO lean. I would set them back to where they were (as an experiment) and see if that makes any tempertaure difference. By what specifications did you set the carbs?

 

[aeronca65t]

I was just going to recommend using a 160 F thermostat (I realize Dave mentioned this above too).
While the 160 F thermostat is not truly a "fix", it will give you a bit more "cushion" in hot weather.
Also, be sure that you are not running too much pure anti-feeze in your mix. The best ratio is about 50/50. Water rejects heat better than pure anti-freeze, so if there is too little water in the mix, the car will run hotter. A product called "Water-Wetter" can be added to improve cooling also.

 

[Klepper]

I am a little confused by the comments that adding a 160 F thermosat will help lower operating temperature. Your thermostat sets the "floor" temperature that your cooling system operates at. It sets the temperature at which the antifreeze is allowed to circulate through the rad. On a hot day when your car is running 190 to 212, both a 180 thermostat and a 160 termostat will be wide open. A 160 termosat will close when the rad cools down the antifreeze to 160. If your rad can't do the cooling, the termostat will not close.

It has been my experience that on a very hot day when my Healey is overheating in traffic (ie pushing 212), it does not cool down to 160 when I start driving. It cools to maybe 185. At all these times my 160 F thermostat is wide open, really playing no part in helping to keep my car running cooler. Am I missing something?

 

[bighly]

[ QUOTE ]
Until yesterday the car ran at about 190 indicated, regardless of load and temp (albeit the ambiant temp never got above about 80f).

[/ QUOTE ]
Normal is the gage at 6-oclock (190). Brian what did you change? We have the same car, same set-up and drive the same roads. Mine runs at 190 unless I get stuck in traffic on a hot day when both car and driver temps go up but never beyond 220 - 225. I would go back to your original set-up and try again. Also make sure you have rad shrouds. Uh, fan blades cupped side to front.

Tracy

BTW: Watsonville speedway Friday night races (7/23). Be there or be square.

 

[Keoke]

/ubbthreads/images/graemlins/savewave.gif Not mising to much Klepper, However, Initially, having a lower opening thermostat can delay over heating and allows all the coolent to participate in a cool down for a longer period of time.-FWIW---Keoke

 

[Dave Russell]

[ QUOTE ]
I am a little confused by the comments that adding a 160 F thermosat will help lower operating temperature.


[/ QUOTE ]
"In stop & go driving, a 160 thermostat offers some margin over a 180. If the engine can cool to 160 between stops it takes a little longer to get too hot than if it can only drop to 180 between stops. Not much gain, but a little."

You missed a very important IF in the above statement. "IF the engine can cool to 160 between stops".

"In stop & go driving, a 160 thermostat offers some margin over a 180. IF the engine can cool to 160 between stops it takes a little longer to get too hot than if it can only drop to 180 between stops. Not much gain, but a little."

Obviously, if the engine can't cool to below 180 there will ne no advantage.

On "Water Wetter". I have been told by a few that a couple of drops, not a lot, of dish washing detergent will do the same thing. They both lower the surface tension of the water.

A cleaned radiator is not as efficient as a new radiator of the same size. There is scale buildup on the inside of the tubes & water jackets that can only be removed by serious acid treatment. This treatment can eat completely through the thinner spots in the system. The core plugs are especially susceptable to this problem. Back flushing the block can loosen the rust chunks enough to cause them to dump into the top radiator tank & quickly block the tops of the tubes. Sometimes repeated periodic back flushing of the radiator will remove most of the tube blockages.

Tracy & Brian may have vastly different scale conditions on the insides of their cooling systems. It depends on car mileage, coolant used & how maintenance was handled by PO's. The whole cooling system degrades from the time that the car is new. If the radiator is designed with enough capacity, there can be some degredation without problems. The Healeys never had this margin.

You can spend hundreds of dollars on band-aids such as elextric fans, shrouds, water wetter, new thermostats, new water pumps, new pressure caps, & never come close to the benefits of a new, more efficient radiator core & "good" engine driven fan.
D

 

[BrianN]

Thanks for all the great advice. I think I will field test the currrent system before tinkering with it. On the next hot spell in the valley I'll pack a few jugs of water, a folding chair, a good book, and race off through some twisting canyon roads when its 95 ambient or more. Then maybe some sustained freeway driving, just to see what the gauge acutally indicates when (and if) it actually boils over. I think Dave is right, unless it does, why worry?

And from what you are all saying, opening the radiator tanks and "rodding" out the tubes is not a solution, but a four row core is. Sounds like better spent money.

 

[Mac]

Brian, I suspect leaning out the carb's are partly at fault and especially if this is a new problem that occured following a change in carb adjustments. mac

 

[Dave Russell]

Brian,
From your first question, What is the "normal" operating temperature?

A lot of speculation about timing & mixture changes & everything else.

Actually you stated that at 80 degrees ambient, the engine runs at 190 degrees. This simply means that your present cooling system is able to keep the engine temp at 110 degrees above ambient.

On another trip where ambient was around 98 degrees, the engine ran at 210 degrees, or 112 degrees above ambient. Almost the same as the earlier 110 degrees above ambient. Cooling system doing the same job, just hotter climate.

With a conservative estimate of a 230 degree boiling point, you would have to be driving in 120 degree temperatures or more for it to actually boil & lose coolant. A pressure cap raises the boiling point about three degrees for every one pound of presure.
D

 

[BrianN]

The "lift the needle" method seemed to leave everything way too rich. Smell of unburned gas. Immediate start from cold without the cold start system energized. Fouled plugs. Poor gas mileage. Low power.

So I turned each jet screw ccw 3/4 turn, these are HD6's, the easy ones to adjust. All conditions improved. I added another quarter turn, but that was way too lean. Performance and idle fell way off. So I reversed the last adjustment.

Now it all seems happy. Runs great, idles great, doesn't stink, sounds right, has clean plugs, gets 20mpg, needs the cold start system to cold start.

Just thought of another item. I mistakenly put in low octane gas, about 8 gallons to fill it. So I backed the timing off about a full turn of the adjuster on the distributor. Dave's comment reminded me that this may also contribute to the higher heat issue. Not only did I see it higher, but also the temperature changes seems more sensitive to load and ambient than before.

Maybe I'll just go out and drive through that tank of gas and correct the timing. What a shame. Another excuse to go driving the Healey.

 

[Henri]

Brian...my Healey runs at 190 normally...when I get in the heat...which we have almost continually in Southern Cal..and I'm doing Frwy driving...I get up to 212 pretty easy...and that's the high side...I think your Healey is running pretty normal...as far as the "normal" temps of a big Healey...not to worry... /ubbthreads/images/graemlins/thumbsup.gif

 

[satzman]

Try a "Water Wetter". It helps coolant bond to metal surfaces, thereby increasing heat transfer. I use it and it has reduced temp about 10 degrees. I run at about 160 to 180. It's sold by Moss -- product number 220-115. /ubbthreads/images/graemlins/driving.gif

 

[Mac]

Brian, The Healey six tends to run a little rich anyway so I wouldn't be too concerned if you smell a little gas now and then. The combination of leaning and backing off the timing, probably had a lot to do with the change in running temperature. I suspect we are all guilty of tinkering way too much, trying to make it perfect when it really isn't needed. mac