Max coolant temp

[Gary Schulz]

My car also reads toward the hot end of the temp scale and I was wondering what a max "normal" temperature reading would be when measuring the top radiator header tank or thermostat housing? All parts are 100% brand new and I am using 50% mix coolant and water. Last year when I had the car out I was seeing around 208F with the car sitting stationary for a while... Seems that the car runs surprisingly hot and makes me concerned to drive it on hot days.

[bwaminispeed]

water temps up to about 215 Deg F are okay.......I like my engines to run on the warm side, rather than too cool....Engines wear out quite a bit faster if run too cool......

As an example, the overheat light on a Chevy Chevette doesn't come on till 235 Deg F.......

[andy1071]

I recommend you try some 'temperature strips':

https://www.demon-tweeks.com/se/racetec ... rs-249593/

Place on various positions on the engine, such as the radiator top hose, radiator top-tank, cylinder head, etc.

These are a 'one-time-only' indicator that tell you the maximum temperature reached.
They are pretty accurate (about 3% variation).

I find these to be much better than trying to 'second-guess' a aged BMC temperature gauge....

Sorry, I have only listed a UK shop, I'm sure you can find them in a USA race parts shop?
(maybe you can get Deg F in USA as well...?)

[Gary Schulz]

Thanks for the replies. I am definitely not relying on the old gauge but instead was using a thermocouple attached to the header tank and thermostat housing. Also used a non-contact IR thermometer which shows a little more variability than the thermocouple setup. I know it cools a little once you are driving and have air being pushed through the engine compartment.

[Coalhod]

I have autocrossed my thin flange 1275 S for 20 years in the summer and have gone well past boiling without any problems. AEG163 head but I took Vizard's advice and installed a pressurized coolant catch tank with 13 psi cap, 50/50 antifreeze. Had new guides installed last year, no cracks found on the head under magnaflux!

[Peter Laidler]

Hardly an autocross or a slog across the alps but yesterday on the run down to Beaulieu - and back - was certainly the hottest day of the year - and certainly a hot one for a Cooper S. A34 for 6 miles before the M3, stop start for ages. M3 to M27....... need I say more? Needle creeping up and up, past N until it got to midway between N and H. And there it stayed all the time while engine running and stationary. On to the M27 and a run to settle it down and it ran like a little bird until the traffic slowed to a stop. Needle up but I didn't have a care in the world. No poundage in my rad cap, it's there just to keep the waterless coolant from escaping. No water system pressure and it ain't going to boil until it reaches 171.

Waterless coolant..... why isn't everyone using this stuff. Listen to the engine and not the naysayers I say!

[Gary Schulz]

Waterless coolant..... why isn't everyone using this stuff. Listen to the engine and not the naysayers I say!

I think waterless coolant is wonderful however it actually is slightly less efficient at heat transfer and would result in my car running ever so slightly hotter than it does with good old water. I would ideally like to see if I could get my car to run slightly cooler so that wouldn't buy me too much. Where the waterless coolant really shines is, as you point out, it doesn't wind up pressurizing the system because it is running no where near its boiling point. It is especially good when being used on cooling systems that might fail given higher operating pressure.

Everything has its place I suppose...

[floormanager]

Hardly an autocross or a slog across the alps but yesterday on the run down to Beaulieu - and back - was certainly the hottest day of the year - and certainly a hot one for a Cooper S. A34 for 6 miles before the M3, stop start for ages. M3 to M27....... need I say more? Needle creeping up and up, past N until it got to midway between N and H. And there it stayed all the time while engine running and stationary. On to the M27 and a run to settle it down and it ran like a little bird until the traffic slowed to a stop. Needle up but I didn't have a care in the world. No poundage in my rad cap, it's there just to keep the waterless coolant from escaping. No water system pressure and it ain't going to boil until it reaches 171.

Waterless coolant..... why isn't everyone using this stuff. Listen to the engine and not the naysayers I say!

I've toyed with the idea of switching to waterless coolant but yet taken the plunge. Pleased to hear a recommendation.
Paul

[jay weinstein]

water temps up to about 215 Deg F are okay.......I like my engines to run on the warm side, rather than too cool....Engines wear out quite a bit faster if run too cool......

As an example, the overheat light on a Chevy Chevette doesn't come on till 235 Deg F.......

Bull Shit !!! If you run your engine at 215 F YOU WILL KILL IT.
Find the problem and get it down to 180 or 190.

[Peter Laidler]

I'm glad you said that Paul but at the risk of upsetting others, I've been singing its praises since a few of us engineering and chemist types set about doing some lab and road run tests and giving our results to the makers. I admit that our bit-part tests were hardly scientiific but did a) corect the makers (it boils BELOW their stated temp, at 171 and not 180) and fed them some easy ideas. And more to the point, b) prove some of the pure naysayer guff wrong too.

Doesn't create a pressure system and during the course of our lab workshop tests, I used my 2001 RCSport as a test-bed and loosened the fan belt too.

Just read Jays thread and...........

[jay weinstein]

And what ?

[bwaminispeed]

Jay, you need to do some actual research before yelling BS......

https://theautowarehouse.com/need-know- ... ure-gauge/

Short summation "The ideal engine temperature should be somewhere between 195 and 220 degrees. An engine is operating normally when the needle points at the center or near the center of the gauge."

https://www.vanchevrolet.com/blog/2017/ ... r%20gauge.

From a Chevy Van site, "NORMAL TEMPERATURE ENGINE TEMPERATURE GAUGE
So what's a normal temperature for your vehicle's engine? Most experts agree that your engine should run between 195 degrees and 220 degrees. In ideal situations, your needle will maintain a posture right in the middle of your gauge. Keep in mind that this can go up or down depending on the conditions in the vehicle itself (such as running the air conditioner or heater)."

https://www.bimmerfest.com/threads/engi ... yl.987866/

Apparently, Beemers are quite happy at 250Deg F water temp....

[jay weinstein]

Older cars like cooler temps....

[bwaminispeed]

Sorry, no they don't......

From 1968 to early 70s, I worked at a major oil companies research lab.....We had 5 dyno cells, where engines were tested to destruction........We tested oils, gasolines, researched optimum temperature of both.....Engines were pulled apart at regular intervals, and, measured for wear......this carried on till the engine expired.....They rarely blew up spectacularly, just, kind of wore out and, wouldn't start/run anymore......

We did this primarily for the Big Three, but, also, industrial small engines both diesel and gas....

The evidence was overwhelming, that engine temps needed to be in the 200-230 range for best longentivity......

Engines wore out twice as fast at 160 degrees as they did at 200 plus......

I have seen test results from the 30s/40s, that show similar outcomes.....

[jay weinstein]

I give up .....still love you

[TECH396]

Personal opinion only here. If someone runs a Mini engine at 215deg regularly. It's toast. Theorize all you want. They don't like it.
170-190 is comfortable. Even though the vintage testing program may work for some, it doesn't work for me. 190-195 is a realistic max target temp, & after that, these primitive beauties get sick.

[bwaminispeed]

I run my Mini engines over 200 degrees all the time, and, have since my first one, a 61 Woody Wagon......That engine made it to 96,000 miles without a rebuild.....did the valves twice, but, block crank and pistons were never touched......I only stopped running it because the body was well gone......Same cone transmission too.....

I fail to understand why many Mini owners think Mini engines are so weak......They are tough little buggers

[Coalhod]

Agreed on how tough these engines are. Mine was rebuilt in the 80's and the builder had raced them for years. Granted, it was balanced but other than that stock and bored 40 over. I have wound it up to 7K while gritting my teeth. I took it back to the builder who now has a shop with other mechanics and kiddingly told them "I have tried to break it but can't".