I'm not going to get rid of perfectly good mechanical parts to put a system running on voodoo in any time remotely soon, but I have been enjoying the discussion so as I can add something here I will do.

I had a fan failure a while back where the fan stopped rotating on a normal system, the car flew along at 80mph, and overheated after about four miles. This would suggest to me that the current fan is not restrictive in its spinning state at top speed and does do useful cooling work above the air flow. That said in its non spinning state it may produce more restriction than no fan at all would. Maybe at 80mph no fan at all produces a safe state not that I'm keen to try this.

Is the most logical solution not to have a larger number of oil coolers mounted like the one on your wing, and one simply just add more to the circuit as required for the given set of conditions perhaps with some form of valve system. These look good http://www.jagg.com/by-pass.html and would perhaps facilitate no fans at all for oil cooling. Wether you could get enough air flow over the heads is perhaps another question, and the oil pump might struggle to shift the oil round the system fast enough.

Some Graphs.

Electric Fan 12" (Pacet) vs 2cv Fan over a route with hills - Duration 25mins.

The electric fan works but the heads and oil run hotter.

So in other words.....why change to something that might appear more "high tech", is very fiddly to fit and control, over something that clearly was well designed and works exceptionally well except maybe when very cold - like that's a problem 10/12 of the year!

Because for many of us our 2cvs are things we keeping no small part as fun tinkering material I'd guess. If you want something that just works and can be ignored why not lease a new computer controlled box. The only involvement I want for electricity in my tinkering is to strike an arc, the need for it to make the lights work and the spark plugs go bang (sometimes) is at best a significant source of frustration and inconvenience, but some people like the stuff.

If there wasn't a significant appetite to tinker for debatable improvement there would be no following for the 1-2 Spark. Its certainly not for me but I'd not begrudge other people wanting to play with it.

Exept the need to remove the fan when making deep river crossings to avoid the blades making a bid for freedom when they come into contact with a mass of water, sending plastic shards into the oil cooler.
Not an issue for everyone but substantial enough to tinker.

Harley

Found some pics and some thoughts...

Set up in pictures 12" fan @ 7 amps (flow 1490 CFM) with standard oil cooler,

An Idea....
Fit 14" fan @ 17 amps (flow 1844 CFM), fit remote oil cooler/filter , blank off the gap, so that all air flow go to heads, remove heat exchangers and enlarge exits.

Pacet 12"

These are my thoughts too.... except taking a fan from a C5..

Not sure C5 fan is big enough, the Pacet (et al) fans are for serious Race/Rally cars etc...

Something about these fans...

17A*14V=238W

Xm 2.1td fans, two 200W

If original 2cv fan takes 3HP, it is about 2,5kW (3HP, I'm pretty sure the power is close that)

Think about that...

Do not even think about it!

been there and done it, with proper fans from kenlow and

2cv fan is far more efficient than an electric fan
efficient by at least 3 to 4 times, everyone who did it over heated their engine and lost a
good set of barrrels and pistons.
more over the electric controls often fail !

better tune your engine properly and fit good tyres!

pony