Re: Yikes!!!! and More yikes!!!!

[Mike Wattam <101714.1343@domain.elided>]

Good to hear from you Brian, I hope all is well with you and you can now
get your trousers on.

As you say, we disagree on fans, electric fans are not reliable at all as
far as I can see in ANY car  - see correspondence in other e-nmails.

The Stag viscous coupling is held on by the crank centre bolt and a large
hardened washer so it's not going anywhere, but it makes a certain amount
of noise while it is still working - so is sort of fail-safe, which an
electric fan never is!

I agree with you about the effect of road-speed on cooling.  The viscous
fan (if the engine is not overheating) reaches no more than about 2,000 rpm
at any higher engine speeds and so is effectively idling its way through
the air passing over the blades.  It's operation is simple and there are no
connections, wiring problems etc to contend with.

The cooling airflow configuration on the Stag is not so good.  The main
problem is that the air flow is not naturally through the grille, but
mainly through the under-bumper ducting.  Thus, an electric fan needs to be
very carefully sited to enable it to pull air in and deposit it in the
right place.  The standard viscous coupling driven fan is large diameter
and so does not suffer from this problem too much.  The Tony Hart spoiler
does definitely scoop up air and use it better, but I can't stand the look
of it!

The phenomenon of blades pulling forward by any marked degree I have never
seen on a Stag, but on other cars when the radiator core is blocked.

I often (every 6 months) check the electric fans on our 3 modern cars, and
have had to replace all 3 in the last couple of years as they were open
circuit.  Opening one up, it was full of rust and filfth.  All this is
subsequent to having a fan pack up in central London causing the car to
seriously overheat in a traffic jam outside Harrods, I just managed to
retrieve the situation by turning round and heading out of town to enable
things to cool down.  I had a full car at the time, there I was with Dinner
suit on trying to look cool, and antifreeze blowing up the bonnet!

Mike Wattam
Triumph Stag Register