Yesterday, after the drive back home through the mountains, I got out the IR temp gun and checked Bosley's head and cylinders. I was told that the temp should be below 210F, and that any higher for extended periods and I was running the risk of damaging the engine. I've noticed he runs a bit warm, especially in stop-and-go situations, but I've wondered if it was just a faulty temp sensor. Well, the temp gun is telling me that he was 218F at his hottest spot, near one of the drive-side cylinders. Ideas? I can order a new thermostat or whatever from Mini Mania, and I can also order a new water pump as apparently these cars weren't designed to drive in warm areas. I can only imagine what his temps will do when it really starts to heat up here in Arkansas. The thermostat seems like it'd be a very easy DIY project, but what about the water pump?

 

Before jumping in and taking things apart and such... You may want to simply flush the system and replace the coolant. I had similar issues with my car (prior to the engine swap) that this seemed to help. Beyond that I would move on to the usual culprits of the thermostat and then maybe the water pump.

 

There's an idea. Is flushing the system pretty straightforward? I haven't read about it in my owner's manual but I'm sure it's in there.

 

I eventually had to upgrade my radiator to a super two core radiator. I replaced the water pump and the t'stat while I was in there. It seemed to help, but a classic really doesn't like the heat.

 

I would do the flush first and you could always put a 3 core radiator in with a 170 degree thermostat and if it's not already equipped you could put a electric fan in on the other side of the inner fender (these were installed in the late 80's ealry 90's to end of production, doing all but the electric fan, has help mine keep somewhat cool during hot summers here in germany and autobahn driving

 

I was gonna say to put on an electric fan. more cooling and you save the 2 horses to drive the stock one. how about putting in 2 fans? i think it can be done and will make a big difference.

 

The t-stat is same as a Chevy V8.....

Flush system, check cap.
If you go with a new pump get the pump with the larger impeller.

 

The water pump is not a really easy thing to do... It's in a very tight space. My dad changed mine in my Mini and he said it took him about 4 hours to do...

 

i got this crazy idea.... take some dried ice and put it in the engine! lol jk

Now heres a good idea, cut some slots underneith the headlights and have them directed towards the engine. youd have a custom look, a cooler engine, and youd save some weight! =D

 

yes, do the flush, check the thermostat and pump... everything above is a good start. There's also a tropical-climate, larger volume fan option available as well - might help if everything else fails:



Beyond that, upgrading the radiator IS an option, but it's kinda pricy - I'd do that as a last resort.

 

When I changed my water pump I noticed that the one on the car had a folded metal open impeller. The new one had a cast closed impeller. Since I was putting in a new rad, the water pump was a "might as well" item.

 

Make sure the fan is on the right way. I had a mechanics reverse mine and it just kept overheating, until I fixed it.

 

Hmm, does it need to be blowing to or away from the radiator?

We bought the flush supplies today and will do that when things around here thaw out.

 

Yes, if you have the plastic fan, having it on backwards is very common...

"
The America and all other ADO-16's, as well as the Mini (ADO-15), use a radiator that is turned sideways to the airflow entering the engine compartment. Not a very good idea if you want to keep an engine cool. If that weren't enough of an issue, the radiator fan mounted on the front of the water pump, actually pushes air through the radiator from the engine side. Thus, airflow comes into the engine compartment through the front grill opening and is then blown through the radiator and out the left inner fender over the left tire. An additional problem is that since the fan is basically "sucking" air from around the engine block (the back side of which has a cast iron exhaust manifold)....the air moving throught the radiator is already hot. This is especially critical when you're stuck in stop-and-go traffic, or climbing a long grade at a slower speed. Engine temps begin to rise, and that increases the tempurature of the air that is blown through the radiator.

All this aside, the system does work, even in it's most stock configurations. However, there are plenty of improvements that are both economical and easy to perform. Thanks to the survival of the Mini, there are upgraded radiator fans available, as well as upgraded, "High-Flow" water pumps. Both are well worth the money and effort.

An 11 blade plastic fan is available which has 1-1/2" wide fan blades. Approximately $30. The original fans usually had 1-1/4" wide blades and are less efficient. Especially the early metal fans found on the 1968 and 1969 models.

A 6 blade metal "Tropical" fan is also available. These make a bit more noise, but they move a lot of air.

A note on fan blade installation:
The concave side of the fan blades face the radiator.
Like this: (<---------This side toward radiator!
" http://members.tripod.com/austin_america/id77.html

I'd also ask what are you running for coolant. Conventional wisdom on Mini's, at least pre Mpi, seems to be no more than a 25% solution augmented with water wetter.
"
-Don't use more than about 25% coolant mix with water. Unless the car will be submitted to freezing tempuratures. Any coolant to water ratio past 25% will hinder the water's ability to dissapate heat. The cooling system uses 1 gallon, so mix 1 quart of anti-freeze with 3 quarts of water. I like to use distilled water. Less minerals to corrode the radiator.
" ditto the source
{this is once source I have handy, but lots of digging lead me to believe this is the average or mean opinion and works for me}

I've got a stock rad' in mine with a 1275 (and plastic fan) and my temp in the hottest of Fl days, per the gauge, is just above 'N', except for the time my thermostat stuck closed . I know, that's not a specific temp but usually it is just below N, right where the owner's manual says it should be....

{sorry - I should mention I have an FRG clip up front, and no inner fenders }

 

Capt BJ Summed it up. great job!