73 Mini

[MiniDave]

At the owner's request I pulled the radiator and water pump off the engine, but found no issues with either....the block looked really clean too.....so I put everything back again. He complained that it ran hot when he got it, that's why we put the Chinesium radiator in - which absolutely cured my 89's hot running issues.

Before he tried to drive it home last week I had also found the distributor loose so I reset the timing, but he said the gauge still went to H only a few blocks from my shop....he also said it dropped back again as he stood idling at the light, then went up again the minute he took off again.

I checked the thermostat and it's new and opens as it should, so I'm down to the gauge again.

Anything I might have missed?

[BruceK]

Here's a question:  If there was no temp gauge to fixate on, would a driver even think the car was not running normally?  Any real symptoms of overheating?   

My car has a simple 2-core radiator, tropical fan, and that's it. And I drive it through balmy Texas without issues. Of course, I just have a hard-read temp gauge partially hidden behind the steering wheel, so I don't really look at it much.

[MiniDave]

Well, that's what I want to find out too.....just whether it is running hot or the gauge is crazy.

However, the owner is the type who want's everything to work correctly........so I'll carry on. If the mechanical gauge says it's not running hot, then it's a simple matter of ordering a new gauge. If it turns out the gauge is right, that's a whole nuther matter.....

Idling in the garage the hottest it's gotten according to my laser thermal gun is 180, but I didn't try checking it on the road.

[94touring]

 I'd buy a cheapo temp gauge from the auto store and take it for a drive.

[94touring]

Also it is possible to have a cracked head letting hot gasses in under throttle then cools off under idle.

[MiniDave]

I ran compression, it was good. tomorrow I'll go get a gauge....

[MiniDave]

I had to get a specialized adaptor to get the mechanical gauge to fit the head, good ol Victoria British came thru again - I had to do the same with Buzz, now that I think about it. I put the end of the gauge in boiling water to make sure it worked properly, which it does.

It's blazing hot out right now, so I'm going to wait till later this evening to go drive it and see what it does. If it checks I'll take it up to school tomorrow and finish the alignment and fix the exhaust. Still don't know why it doesn't want to start when hot, but one thing at a time.

More as it happens......

[MPlayle]

Could the not starting when hot be coil related?  The coil getting too hot from being a mismatch to the wiring (ballast coil & non-ballast wiring or vise-versa)?

The other possibility I can think off would be vapor lock on the fuel line?

I doubt timing is way out as you've indicated having reset that already.

[BruceK]

Not to be picky, but  shouldn't the gauge show 212 degrees or so when stuck in the boiling water?

[MiniDave]

Yes, but I took the pic before it got all the way up there.....I just wanted to know that it worked OK. Dooder's been having trouble with the ones he bought for his car and the speculation is that it's leaking in the capillary tube somewhere. This ne went full scale so I'm comfortable that it's good (enough)

Michael,yes it could be a bad coil. However, it is the right ohm coil, and it is getting 12V as it's supposed to. The car has an aftermarket ignition system of unknown origin or brand - could be the "black box" is getting hot and failing too. I doubt vapor lock, it has an electric fuel pump mounted in back below the tank. One thing that does concern me - every one of these I've seen has a phenolic block between the carb and manifold to act as a heat soak or insulator - this one doesn't - there's no room for it as it will make the carb hit the bulkhead.

First I want to get the temp thing sorted, then the alignment so it's drivable, then I can see about the ignition - starts perfectly when cold or if it hasn't been run that far.

Temp capillary tube taped down ready to be driven once it cools off a bit tonight....

[MiniDave]

Found a little more info......the car has a Lucas "black box" amplifier, same as what they used on many 80's and later English cars and this is apparently NOT well regarded. We're talking about switching over to a Pertronix or the like and eliminating the Lucas box.

[MiniDave]

We have an answer!

I put the mechanical temp gauge on it and hit the highway - 165* for as long as I drove - same as the thermostat opening temp. I then did a bunch of stop-go, no change. Then I let it idle in the driveway for about 5 min, the hottest it got was about 185, and as soon as I drove it around the neighborhood it immediately cooled back down to 165 again.

So, we need a new temp gauge is my guess   ;D

So, tomorrow to school, then once he gets the bulkhead panel I'll start on the gauges.

The first pic is running down the highway about 10 miles, the second after it was idling in the driveway for 5-10 min......and it's over 90* today.

[BruceK]

Good diagnostic work!   And great to know the problem is easy to solve.

[MPlayle]

Was the original gauge electric or mechanical?  An article about gauges I read a while back went into a lot of comparison between electrical and mechanical gauges for things like oil pressure, oil/water temperature.  The take-away I had was that most mechanical gauges tend to be more reliable than the electrical.  The electrical are also easy to get a mismatch between sender and gauge.

I would tend to want to recommend replacing the old gauge with a mechanical.

[MiniDave]

Well, it will be up to the owner which he chooses - as he wants to keep it period, I'm not sure they make a Smith's mechanical - I'll have to check into that.

[BruceK]

Well, it will be up to the owner which he chooses - as he wants to keep it period, I'm not sure they make a Smith's mechanical - I'll have to check into that.

I had a Smiths mechanical temp gauge on my Mini Traveller, and it was the capillary type.   But it was a combo gauge.  This one.

https://www.bpnorthwest.com/gauge-dual-oil-pres-water-temp-in-fahrenheit-ah-bj8-mga-mgb-63-to-67-sprite-midget.html?gdffi=7c26fa82af054ed48c16509776f45115&gdfms=26C6272BB45F4638B6E6C7ADD9928D25&gclid=EAIaIQobChMIg9TOnrT81AIVFRuBCh2cxAKfEAQYASABEgLiQvD_BwE

Not sure if they make a standalone one.

[MiniDave]

MiniSport has one - spendy tho.....$152 plus shipping

https://usa.minisport.com/smitg131001-c078-smiths-classic-mechanical-water-temperature-gauge-has-a-range-of-30-110-degrees-c-and-comes-with-black-face-and-chrome-bezel.html

[BruceK]

MiniSport has one - spendy tho.....$152 plus shipping

https://usa.minisport.com/smitg131001-c078-smiths-classic-mechanical-water-temperature-gauge-has-a-range-of-30-110-degrees-c-and-comes-with-black-face-and-chrome-bezel.html

Got to be sold cheaper elsewhere.

Edit:  Yup, here's one for about US$90 plus shipping.

http://bullmotifminispares.com/4828/mini_capillary_water_temperature_gauge_tg1310-00c078_sib422

[MiniDave]

That's a lot better! Thanks for the link......I'll pass that along this afternoon when he comes to get the car.  4.gif

Mania wanted $220 plus shipping......vs about $90 plus shipping from Bull Motif.

[Willie_B]

Watch that you forder one in fahrenheit.

[MPlayle]

They don't seem to be available scaled in Fahrenheit anymore - only Celsius.

[MiniDave]

Well, I drove up to school today in 95* temps and set the ride height and aligned the car, the temp on the highway stayed right at 165, on the way back it stayed the same till I got stopped at a long light, where it got up to about 175, as soon as I started driving again it dropped right back down to 165 again.......so this engine is NOT overheating, in fact it runs exactly the way my green one did when I put the chinesium radiator in it. The car really drives nicely, the suspension is so smooth and composed and the car runs sweet thru the gears and pulls well getting onto the highway......this will be a great daily driver for him.

BTW, anyone who tells you you can't align a Mini with 10" wheels on a modern Hunter alignment machine is either full of it or just doesn't want to do the work......it is NOT a problem.

I also got the exhaust reset and installed the new hanger, so it's tucked up where it belongs and is no longer vibrating against the subframe.

He's coming to get it this evening and will drive it about 20 miles to his house, I'm going to take my gauge off and reinstall his sensor, but I'm going to leave the wire off so it reads C all the time - nothing scares you worse than to see that gauge climbing up to the H!

The hot start situation didn't happen to me today, so I'm going to see what it does when he comes to get it......later when we do the dash install we're going to swap out the Lucas box for a Pertronix and std coil, I think that will take care of it once and for all.

[MiniDave]

The owner just texted me that he made it to his plant (where he stores his cars) with no issues, car ran strong, rode smoothly, no rattles and the temp gauge never went above "C"   ;D

(I left it disconnected  ;D)

The next round will start in a couple of weeks when the bulkhead plate comes in and I install the new dash, in the meantime he's asked me to build him a towbar like mine so he can haul the car to me instead of having to arrange rides and such. This car is finally taking the shape he saw in his mind when he bought it.

[MiniDave]

I showed the owner of this 73 my towbar and he immediately said "what a great idea, let's build one!"

He's been having to work the logistics of bringing his cars over to my shop from the other side of town, arranging rides and so on and he quickly "got" how much easier it would be to simply tow the car over, so I built him one, and he ordered the parts from Harbor Freight. Due to the lightbar mounted on this car I had to do things a little differently, but I actually think this design works better. He will have to buy a different light bar for his 71 Cooper S as the current one is mounted in the holes where we attach our towbars.

Pics of the 71 lightbar, and the new towbar mounted on the 73

[94touring]

Nice job.