Temperature Management
Turbo Mini Forums

I'm having trouble managing the engine (and hence interior) temperature on the Sprint. Basically the engine runs cold (65 deg), this is when running on A/B roads. So to get it warmer I blocked part of the grill with cardboard wrapped in gaffer tape (nice!). BTW it has a front mounted rad with temp switched fan.

This worked a treat, engine now runs at 75 to 80 deg when running around. However, in the city traffic it gets hot. It never overheats, but the cooling fan is on and off like a brides nighty.

Any clever thoughs on resolving this? or is it just to be expected. A side mount rad in my mini seems to keep a more constant higher temperature.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

How big is the rad? Is it too big? What thermostat have you got? If it's just hitting 65, coolant shouldn't even see the radiator.

Put a bigger pulley on the water pump?
Higher temp stat?

If something is worth doing, it's worth doing half of.

88 start (new), large pulley and mk1 metro or allegro rad.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Assuming you have a good known working thermostat there must be some bypass flow to allow water through the radiator before the thermostat opens.

Does the top hose start to get warm/hot before 80 (edit 88) degrees is reached ?

Two things I have found in the past:

1 - the little ball float valve in the thermostat had disappeared leaving just the hole. It's not much of a hole but it had an effect on warmup rate. (not all thermostats have these float valves but you'll know what I mean if you've seen one).

2 - Thermostat wasn't clamped between the housings - this occured initially when I used the Metro housing and sandwich plate, for some reason there is a massive recess in the sandwich plate and it requires a special rubber ring around the outside of the thermostat to seal, otherwise the water just flows around the outside.

Edited by Rod S on 23rd Nov, 2011.

Schrödinger's cat - so which one am I ???

I would take the stat out and test it in a pan of boiling water. sounds like it's stuck open if you are seeing 65 degrees once it's been ran for a while.

Where are you reading coolant temp?

EDIT: Mike Race thought he was cooking his engine. His gauge was over reading by 20 degrees...

Edited by apbellamy on 23rd Nov, 2011.

Rod. I think you may have it there.

It uses all the metro header tank etc, but NOT the double height two-piece 'stat housing. I wonder if this results in some run-around path?

You can see the setup here:

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

There is definately a runaround.

The bottom and top hose are linked together via the header tank. Both connections are made on the rad side of the 'stat.

Just trying to work out what the hose from the 'stat housing to the header tank does?

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Is this not an issue with air flow. Looks like your engine bay has very little area for any air to escape after passing through the rad. Hence the problem in slow moving traffic.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

If I remove the cover on the grill, it's fine in traffic, even in the middle of the summer.

But now I'm thinking about it, it takes a long time to warm up, which makes me think water must be circulating all the time.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Schrödinger's cat - so which one am I ???

ok. Back to looking at the stat then.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

I've had a stat stuck at 60 ish hence stat would indeed be first thing i would look at.

As Rod said: "Does the top hose start to get warm/hot before 80 (edit 88) degrees is reached ?"

Dazed and Confused....

Right back to this.

I took the stat out, was in good condition and firmly shut. It was seated nicely in the head and there was no recess in the housing that might not have held it in place.

I thought, however, that there was a possibilty that the stat was not firmly held in place, so I fitted it with sealant around the rim to see what differance it made. Basically none.

The top hose gets warm very soon after the engine starts getting heat into it. so I'll whip the stat out and see when it opens. It is a new stat by the way.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Not that any of you probably care that I'm still freezing my tits off on the way to work. But I just checked the stat. It opened at 40 deg and was well open at 60 deg. so much for a new stat!

The old one only opened at 70 deg, so I've popped that in.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Time for a bigger coat.

If something is worth doing, it's worth doing half of.

Schrödinger's cat - so which one am I ???

That's one of the reasons I'm having my auxiliary coolant gauge sender in the sandwich plate under the stat...