11 replies to this topic

[diogoteix]

My Mini has been through a lot of modifications lately.
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But there is one thing that is annoying my "I want to optimize everything" compulsion:
The mecanical fan and water pump.

I know they are "vintage", but no modern car would even think of going back to these setups for at least 2 reasons:
- noise
- power efficiency
As for the noise, I recently changed my stock Spi plastic fan to a "6 blade export" (I leave in Portugal), and the result is... a lot of noise!
The cooling improvement compare to the stock one seems small: I would expect better with a supposedly "enhanced 2 core aluminum rad", my secondary fan still cuts in frequently when I'm driving in town, just like before.

But let's go back to our topic:
I've read some post claiming "why bother? Your mini came with a mechanical fan / water pump leave it that way".
Following the same logic, my Mini would still run 63bhp, instead of 94 (and counting), be black, have a nice full plastic interior...
We want the best for our car (even if with some financial constraints) !!!

So let's recap:
A powerful water pump, available at Merlin Motorsport Here drows a maximum of 7.5A from your electric system.
A 10'' electric fan, available everywhere, including at Merlin Motorsport Here drows also a maximum of 7.5A from your electric system.
You may want to leave the secondary electric fan (my car is originally an Spi), adding another 7.5A.

That's a total of 22.5A, resulting in 270W (22.5Ax12V) of power, which is about 0,36 BHP. That's a maximum value, only achievable when the car is really running hot in traffic with all 3 electric appliances pumping together.
The alternator from the Spi is rated at 70A so there should be no problem (that's about the same draw as a set of 4 spot lamps anyway).
I suspect the removal of the mechanical fan and water pump will add more than 0,36BHP to the car, especially at high RPM.

The additional benefit will be the improved colling at engine cut, when the fan and pump are able to keep cooling the engine for a few minutes.

Now I need some help on a few points:
1- will 2 electric fans (push/pull) be enough on a side mounted radiator, or do I need to set a front mounted rad (I can even imagine setting a kind of "front mounted secondary water radiator").
2- if a front mounted radiator is necessary, is there some model that you would recommend (small, with entry/exit on the side...)
3- will I need to relocate my alternator and if so is it possible to do it while keeping the stock Spi one?

Thanks for your answer and comments

Diogo

Edited by diogoteix, 23 May 2011 - 04:37 PM.

[Big_Adam]

If you're really wanting to optimism, why not move the rad to the front?

Then you don't need fans running all the time,

[diogoteix]

That's right.
The only issue here is space.
The MPi setup has moved things around in order to accommodate for a front rad: the alternator (for sure), distributor (not an issue since I have change for a distributor-less system), and I'm probably forgetting something. I think I remember that some of the panels are different. I think that if I could avoid I'd rather stay with a side mounted rad.
Is there some topic on the forum covering this kind of conversion?

[Tupers]

Personally I would only do this if I was running a front mounted radiator with a couple fans on the back to make sure I had enough air flow.

A Vauxhall nova radiator would do quite nicely for this as it has both outlets on one side making plumbing it in a little easier. I'm not sure if you'd have to move you alternator or not although I'm sure it would be possible leave it stock with a little work.

Edited by Tupers, 23 May 2011 - 04:51 PM.

[diogoteix]

Personally I would only do this if I was running a front mounted radiator with a couple fans on the back to make sure I had enough air flow.

A Vauxhall nova radiator would do quite nicely for this as it has both outlets on one side making plumbing it in a little easier. I'm not sure if you'd have to move you alternator or not although I'm sure it would be possible leave it stock with a little work.

Thanks,

It seems indeed quite a good fit. Dimensions are 530x230x32 for some models (1.4i), 530x270x22 for the others. I'll see if it can be fitted without too much trouble with 1 or 2 small fans behind.

[Sprocket]

Fit the Davies Craig pump, and expect to replace it often. People do use them, but talking to the Miglia racers, they recon they fail often. No surprise wen they have a limited life cycle in the best of operating conditions.

[Bungle]

unless your moving the rad to the front a electric fan won't have the duty cycle to last very long

[diogoteix]

Fit the Davies Craig pump, and expect to replace it often. People do use them, but talking to the Miglia racers, they recon they fail often. No surprise wen they have a limited life cycle in the best of operating conditions.

If the pump is able to reach its estimated life cycle of 3000h without controller and 7000h with controller it should not be a problem, since I use the car on average less than 1 hour per day.
I'm afraid these figures may be a bit overrated because they do not seem to be compatible with "failing often" even of in racing applications the pump is setup to run continuously and in very harsh conditions, whereas when I drive through Lisbon, I tend to stay "on the safe side" .
Some modern cars use electric water pumps and I never heard of them failing. I may have a look to see if I can source a more reliable pump.

Edited by diogoteix, 23 May 2011 - 05:43 PM.

[Carlos W]

but electric fans as i understand it arent designed to run all the time, and a front mounted radiator has far more air pushed through it when a fan isn't running!

[diogoteix]

I just found another electric water pump supplier:
EMP Stewart Components Electric Water Pump
This one comes already fitted with its controller, whereas Davies Craig sells the 2 parts separately .

They claim 10.000h life span, and 55 GPM (200 l./mn) !

[crazycoleman118]

fit a smaller alternator if you haven't already and move the rad to the front, unless you have some sort of feed system to the rad on the side then it wont get sufficient air flow to be able to remove the mechanical fan completely.

your trying to free up power and quieten things up? however running an electric fan permanently is very noisy, and also uses quite a bit of electricity (which means its using up power too)

[Sprocket]

http://www.meziere.c...860-wp136s.aspx