cliftyhanger wrote: ↑Sat Jun 21, 2025 9:11 am
yorkshire_spam wrote: ↑Sat Jun 21, 2025 5:52 am
For reliability I switched the fan on my Spitfire to the earlier fixed and deleted the vc years ago. Trouble free cooling!
A most sensible idea. Same can be done on a dolly I expect?
I have been thinking, and I reckon a manual fan saps naff all power when on the move, as the speed of the air through the fan will match what the fan would be doing, give or take. I suppose in low gears/high revs that won't be the case, but the amount of power will be diddly squat.
I do have an electric fan as it was the simplist way forward as I didn't have a fixed fan available. I used a spal fan that is very effective, and zero vibration, much better than the ebay cheapies. It produces hurricane-force airflow when it kicks in, needs over 20A initially, settles to a little over 10A once running. No point in messing about!
The whole point of a viscous is that it wastes less power than a fixed fan (quieter too) Though I can understand why a lot of people seek to dispense with their viscous with the number that have penetrated expensive alloy radiators in the last few years. And the ever increasing cost of new viscous couplings (and worries over quality)
The quoted "waste power" back in the day (Kenlowe fan ads, not the most unbiased source!) from a fixed fan was 6-8%. And it IS wasted because the fan does sweet FA once the car is moving over 10mph. And ANY power wasted offends my engineering sensibilities. So an electric fan that only cuts in when needed, ie stationary in traffic, is far more efficient and also offers much finer temperature control. You just have to get used to the idea that the guage will wander all over the shop, rather than staying in one spot permanently once warmed up. Something that often gives Sprint owners, used to panicking at a few thou shift of the guage needle, heart failure!
You can get any sort of fan you want, a complete kit for novice electricians is more expensive but less hassle. But if you WANT a Revotec, cut out the middleman and deal with Revotec themselves!
Personally I buy my fan kits from Simon BBC on ebay (who also supply my Ei kits) at circa £50, a hose mounted sender from Stoney Racing, circa £25, a relay from wherever is cheap and wire it myself. And I ALWAYS build in a manual override switch in case the sender fails! Only ever happened once, but, of course, in the most complex and embarassing situation possible! Once bitten twice shy!
Steve
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