I used to have a Kenlowe type bulb type temperature sensor with a temperatruse adjuster but I am loathe to drill my new alloy radiator.

My engine is 1600 crossflow, standard 88 C thermostat.

I am looking to fit a intermotor fan switch that has 2 contacts, some possiblities:

88-83 / 92-87 (on-off temps).
92-87/97-92
93-88/97-92

So just trying to guage opinion of what temperature your fan kicks in and goes off.

I don't want the fan running all the time so I reckon that the temperaturs it turns must be greater than the thermostat? hence rules out the first one.

In case you are worndering why 2 contacts? I intent to have 2 fans, the second one kicks in when the higher temp second switch closes or alternatively at lowere temp, fans run in series = slower speed but at higher temp, run in parallel - faster. Might be an unnecessary complication so I may end up using since contact switch.

I'd go with the highest of you settings, although even then I'd set a fan slightly higher than that, maybe so that the second fan comes in at 100-103C. A lot of kit cars seems to be almost over cooled at times. Mine has a huge fan with a manual switch and it only ever gets switched on it traffic in summer.

other options: (both single and double contact)

Part No. Temp °C
50100 82-68
50101 84-79/88-83
50250 86-76
50012 86-77
50090 86-81
50120 88-79
50091 88-83 / 92-87
50296 88-79/110-102
50271 88-83
50217 88-83/92-87
50240 90-80
50113 92-82/95-80
50170 92-87
50215 92-87/97-92
50011 93-88
50102 93-88/97-92
50035 95-85/102-92
50130 95-86
50030 95-90
50092 95-90/100-95
50104 97-92
50103 97-92/101-96
50214 97-92/102-97
50190 100-95
50198 100-95/110-105
50000 103-98
50191 120-115

oh, I should point out that the alloy radiator is meant to cope with 1.8 l engine.

50103 looks about right to me if you need a double contact. Or 50092 if you want to be absolutely safe, although with a big ally rad, I don't think you'll have any issues.

Why bother with 2 fans? My modified 1600 cc Xflow engined car copes very well with a single fan although lagging the exhaust manifold made a huge difference in underbonnet temperatures as did a couple of vents in the nose cone and bonnet. A lot of production cars use a single fan with 2 speeds, might be worth looking at?

I tried to get advice on this but in the end just bought what made sense.

My engine stat opens at 85 so there no point of it runnignthe fan before that. Certainly it HAS to ut off at a temp above that or it will run always.

I then figured my cooling look was fairly small, with a smallish (thin polo) rad for the engine (1900cc cvh) so it might as wel not cut in too late either (boiling put of coolent is maybe 110deg)

Then picked something in the middle...

Not sure how well that plan will work yet, as currently the rad and switch is unfitted.


Daniel

quote:

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Originally posted by rusty nuts
Why bother with 2 fans?

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Don't you think all of this is a little overkill for what is, at a end of the day, a pretty bog standard engine.

No one else has had to go to this sort of levels to keep their engine cool, (Hicost's 450BHP Cossie is an exception! ) isn't it more likely you had an unusual fault of some sort that caused the problem in the first place? A Polo or Golf rad and a half decent fan is more than enough for most people.

I'm concerned you're now going to suffer from over-cooling issues- having an engine running below temp is can't be good for it either.

Anyway, not wanting to wee on your chips- just don't want you to go to unnecessary effort and expense.

All the best,
James

quote:

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Originally posted by James

I'm concerned you're now going to suffer from over-cooling issues- having an engine running below temp is can't be good for it either.

just don't want you to go to unnecessary effort and expense.

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quote:

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Originally posted by 02GF74

quote:

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Originally posted by James

I'm concerned you're now going to suffer from over-cooling issues- having an engine running below temp is can't be good for it either.

just don't want you to go to unnecessary effort and expense.

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... but if I keep the termostat, how can it be over cooled?

as for expense, if you knew how much I've been spending or red silicone hoses to try to fit the radiator to the engine, your eye would bleed!

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Keep it simple less to go wrong

(1) Polo rad has a lot more heat exchange area than the original Ford.
(2) One fan wired through a relay is enough
(3) Fit a single contact switch N.O. about 95c switch on For single contact switch see Intermotor 50041 (Volvo & BMW apps)
(3) If you have to drill and tap stick to M12x1.5 thread -- taps are relative cheap and easy to find and tapping is much easier.
(If you need a M12x1.5 Tap PM me)
(4) If you really want a duel contact switch to control two fans or two speeds on the same one fan see intermotor 50042 (BMW app) but needs suitable socket -- it might be better to use 2 swtiches say 5040 and 5041. For cheap 50040 (on at 103c) see ebay item 310003594820 I bought one off the same supplier a couple of months back.


Also see thread.
http://www.locostbuilders.co.uk/viewthread.php?tid=121137
If you want to do this PM me as I have spare 100c NO thermal switches.


The usual warning about making sure you have a by-pass connection on the coolong system applie.

Also if you want to get two speeds from a single fan wire a high wattage wire wound ressistor in series with earth side of the fan. Ffor the higher speed just arange for the resistor to be shorted to earth..

50Watt 1 ohm Alloy case resistor should be OK for any fan that will fit into a locost nose it should slow the fan to about half speed Suitable resistors can sometimes be found on ebay for a pound or so search on both "Wirewond" and "Wire wound"

[Edited on 12/1/10 by britishtrident]

BT - thx for info - given me some other ideas, especially re using different swtich with smaller thread i.e. much cheaper tap.

need to look tnrough the intermotor data.

if I were to do 2 speed thing, I'd try using 2 relays to connect the fans in series and then in parallel - don't like wasting power in resistors.