17 replies to this topic

[Purple Tom]

Hey

The 1293 has now done 450-odd miles of trouble free running. Thing is, I'm a bit paranoid about the temperature.

It is quite a high spec engine (stage 4 head, 1.5rollers, phase 3 morspeed cam, lots of other bits). I'm currently running:

- 2 core rad
- thermostat blanking sleeve
- brand new silicon or kevlar hoses (some silicon some kevlar)
- standard water pump
- big water pump pulley

At the moment I'm running with the heater on, in normal driving conditions this will see the temperature slightly below halfway on a day like today (hot but not muggy). Once stationary the temperature at idle will climb quite quickly, up to about 3/4 on the guage.

We have a multimeter with a temp sensor, and with the engine idling on the drive with the bonnet up, with the gauge at just below 3/4, we recorded a water temp (on the top of the rad) of 80deg.

Now I'm thinking it might be worthwhile getting a new temp sender unit, as I think the one I have may be reading slightly high, could this be possible?

I'd just rather have an accurate idea of the temperature, as the gauge at the moment I don't think is reliable.

Also, regards fitting a smaller pulley, I've heard varying views. Some say its better to do it and pump the water faster, others say not as the pump is pumping its maximum capacity at about 3.5k rpm anyway, so turning it faster would just induce cavitation and possible hot spots. Again, re the water pump, is it worthwhile fitting an 'upgraded' one? Or will the standard one be ok?

I'm also aware that the sender unit in the head measures the water temp at that point only, and not elsewhere, so again might not be giving a true reading.

Am I just being over-paranoid?

Thanks in advance, any advice gratefully received!

Tom

[Jammy]

Keep an eye on it, my 1425 has gone up2 about 80 on hot days, although I can't say it gets hotter when stationary really. It usually oes upto about 60 and then sits there, until I really start pushing it. Have you flushed the rad out yet? Whats the heater matrix like?

[Madmax]

fit a temp guage that runs of a capillary line, then you might get a better idea of what temp your engines running at, i had the same problem but it was down to the usual thermostat issue, havent had a problem at all with the new engine...touch wood

[ed4ran]

STOP FEEDING IT CARLING!!
Alcohol will dehydrate it!!!! :grin:

[Madmax]

get some whisky down her, that'll soon sort it out

thats quite a neat engine bay minis84, whats the deal with the top rad bracket?

[Mini Man Sam]

Mine was running hot all the time, accordiong to the guage, I mean upo to close to max normal running. I got the same readings as you of around 80 deg C at the rad with the gauge nearly off the dial. Got a new sender unit and now she runs just inbetween 1/4 and 1/2 and never goes above 1/2, even in standing traffic in hot weather.

Start amall, get a new sender unit (about 6 quid)

[Wil_h]

Is that engine bay your car Tom?

If it is, then mounting the radiator properly will help cooling when at idle.

If after doing theis and all the other things advised in theis thread you are still having problems, then try using some 'Water Wetter' or similar in the cooling system. I've had good results with this and always use it in the hillclimber.

Wil

[Purple Tom]

the rad is 6 months old, and a brand new heater - both were reverse flushed before fitting just in case.

I'll move the rad closer to the fan, I did think of that, but it was ages ago and I forgot :nugget:

I'll also get a new sender unit, may well help with the gauge.

Thanks Madmax, it'll get better with a decent rocker cover too, I need to get hold of one to spray up and get looking nice.

Thanks Wil_h, i'll get hold of some water wetter too. And thanks for the advice on the bracket, I needed reminding about that!

(thanks for getting the pic ed4ran, was good to meet you and your brother at the weekend - looking forward to seeing Olive!)

[Guess-Works.com]

The thing about the water pump pulley is that not only does it control the speed of the pump, but also the speed of the fan... I use a small one, and switch to a larger one in winter if things are not heating up sufficiently.

The other thing which cools the engine is the oil, if this is running hot or even if you have a sump guard the cooling effect of the oil is lost and then no matter what you do to the water, the oil will be keeping the temp up, maybe a small oil cooler aswell ?

[Purple Tom]

I have a smaller pulley, I'll fit it and see what its like.

Oil cooler is a good idea, where is it best to mount one? Do they plumb in between the filter and the oil return pipe?

Thanks!

Tom

[Jammy]

You might find it useful to have a proper temp guage (I have one that reads from 50 to 120 degrees). If you want I can provide pictures of where my oil cooler is mounted and where it is plumbed in (I think you are right about it being between the filter and return pipe though).

[Purple Tom]

yes please Jammy that would be good.

Also, can you get capillary temperature gauges that mount into the head, but still make use of the original temperature sender too, ala oil pressure gauges/oil pressure switch?

[Sprocket]

Here is the pump you should be running. Read what it says at the bottom, some very interesting information

http://www.minispare....aspx?pid=32778

[dklawson]

I run the pump listed in Mini Sprocket's post... except I still have the bypass active. It's a good item.

Hot isn't "hot" until you approach the boiling point of water (100oC, 212oF). When you run an anti-freeze or Water-Wetter coolant stream you raise the boiling point. When you increase the operating pressure of the system... you also increase the boiling point.

Are you guys really concerned about 80oC? That's only 176oF. Over here, where summer heat is a problem, Midgets and Minis running 1275s routinely run over 195oF (90oC). (I'd be tickled pink if my car ran 176oF after a nice summer drive). Since there are limits to what our little cars can handle we take the following steps:
6-blade tropical fan,
high-flow water pump,
Super 2-core radiator (maybe),
13 pound radiator cap,
and a fresh clean cooling system filled with a water/Water-Wetter mix.

I have acquaintances in Australia who run auxiliary radiators plumbed in parallel with the heater core. Oil coolers also help... but most year-round drivers want them thermostatically controlled so the oil isn't too cold in the winter.

[Jammy]

Haven't been able to get pictures of my oil cooler yet, it was raining all night, just stopped and its too dark. Should be nice tomorrow though.