Cooling fan

[trackerjack]

Can anyone help me please?

I wish to have my cooling fan run on after switching the engine off as the MK1 1.6 engine has an HSK turbo and I want it to continue blowing until the thermo cuts it off, I would rather use the cars inbuilt thermo than add another but how can I energise the switch with out the ign circuit?
Obviously I am not a leccy man!

[trackerjack]

You know I never thought of that, so simple its so obvious and I love simple cos its all I understand!

Yes just a fuse and live wire.
The car is a special so I have the battery in the front so not far away.

[trackerjack]

Its in a seven type kit car and as this type of car is narrow I have an alloy rad which is non standard.
It has a fibreglass bonnet which is close to the turbo (which is lagged) but still gets mighty hot and the fan is to keep air running over the engine to avoid a hot spot.

The car does not run hot but I have not put it on track yet.

Thanks for the replies and all I have to do is replace the ign live with a battery live with a fuse protecting and it will continue as it does on most modern cars.

[trackerjack]

Yes thanks it has really been helpful picking you guys brains, the car is a hoot to drive and quite the quickest car I have had as it weighs just 650kg with an output of approx 170bhp so 60 comes up in 4 sec or so and took me 3 years to build.
The boss has an immaculate Mk1 so technically we are a 2 MX family but hers is a standard 1.6 and though very nice to drive and be in its not fast but fast enough.

[trackerjack]

Picture request is a yes and the old fart in the car is me.
The original donor was PPC magazine owners brother and the quest was to get as much power as they could. The car was a 1990 Mk1 and reputed to kick out about 170bhp and I reckon it certainly feels like it does.
First picture is the other toys with my wifes superb 1991 MK1 import my 944 (big brother to the MX5)and on the right is my track Quantum 2+2 RS turbo.
I have learnt that the fan operates without ECU intervention by means of the thermo earthing out to create the relay trigger. I can merely supply the relay seperately with a live wire and hey presto it will run all the time the thermo earths the relay.

[trackerjack]

cwinterb said:

Relay with a built in switch off delay and a push button on the dash to start it off, or if you're cleverer trigger it on the ignition switch off?

Something like this:

http://www.autoelectricsupplies.co.uk/product/836/...

Edit: This sounds like what you need, if you can find one in the UK:

http://www.wolstentech.com/products/timedelayrelay...

Edited by cwinterb on Friday 5th September 16:52

Special thanks to you sir for finding these products as the rear heated screen in my Porsche 944 has emptied my battery twice now!
Both can be used for the fan and I may still do that.

Someone had to buy the 1980's MG Montego and I was that man as it suited the family then and was one of the first cars to keep its lights and interior lights on as you left the car, I remember several people saying "Oh you left your lights on", however the quickest thing on an MG Montego was the trip to the scrapyard in the sky.

[trackerjack]

VladD said:

Great car collection Jon. Thanks for the pictures.

The wifes MX is a peach and lives in the garage, when I bought it for her it was owned by a guy in Portsmouth who lived close to the footy ground and we surmised with red car and a number plate with LFC (Liverpool FC) it would be vandalised sooner rather than later hence up for sale. I have done the usual springs replace(they break on their own in cold weather).
The one car not shown is the wifes office as she is a fully qualified driving instructor for AA. (she has given up on me)

Cooling the turbo ect is not a concern as I live and work in residential areas so slow before stopping.

[trackerjack]

Matter of personal choice.
I like it and think it matches the car.
I am biased of course but I love the Mk1 shape.

[trackerjack]

She will keep her car exactly as it is as she loves it and will never sell it for personal reasons (not just because its the only thing I have bought her!)

Back to the special now, I would pick your brains as I will not track the car until I have installed a 13 row oil cooler and fitted an accurate temp gauge as opposed to standard.

The heater is not connected but that could also run through a small rad to aid cooling (I always have the heater on full when tracking).

Any other suggestions please?

[trackerjack]

Thanks for the advice all and though the bonnet is not on show in my picture I have an air inlet just in front of the turbo and an alloy grille above it so plenty of air cooling when moving.

The HSK turbo instalation has a piggy back ECU that plugs in to control the fuel etc and using the MOT emissions meter you can actually see the effect unplugging it has!

A lot of people do not know how important oil is in the cooling of an engine which is why I wont track it till its fully sorted.

Daughter has a BMW that does 0-60 in 5 sec at the moment and my little special is faster to at least 100 in my opinion so about 4 or so sec would be about right.
Boy its fun I cannot wait to see how it fares against the bike engine cars!

[trackerjack]

Right back to the threadline, I took the cooling fan relay out and wired it seperately as standard apart from the small connecter nearest the wing which is the ign power in and wired this to a permanent live because the thermo switch works by earthing the relay and energising the fan so it now works until the top of the engine is below thermo switch operating temp.
This makes me happy to leave the car after stopping it and dont worry about the bonnet and car going up in smoke!

Next to fit is a 13 row oil cooler and then track bound!

Thanks again lads and I look forward to seeing some of you at a track sometime.