[Healeys] Fan Clutch for Big Healeys

[Bob Spidell]

There may be a third: I inherited my parent's 2000 Lincoln LS; it has a 
hydraulically-driven fan powered by a pump that is nearly identical to 
its power steering pump. Near as I can tell it has a bimetal valve that 
gates pressurized oil to the fan, which has a kind of turbine (it looks 
a bit like a clutch fan; well, I guess it is). The car would overheat at 
random and had to be towed a couple times; eventually, there was an SB 
and we replaced the 'clutch,' and it's worked OK ever since. I only 
recently learned why it had such a goofball setup: The early versions of 
the car had a wimpy alternator which couldn't supply enough power for an 
electric fan. Why didn't Lincoln just use a better alternator? Well, 
under the skin the car is essentially a Jag S-Type from when Ford owned 
Jaguar; this somehow seems like a very 'British' solution.

Aircraft engines, most of which have oil coolers, often have a 
'vernatherm' in the oil cooler circuit. It's bimetal, I think, and 
closes when the engine is cold so the oil can warm up quicker. I think 
some oil cooler systems in cars use something similar.

I asked about a fan clutch because the best solution I've found for a 
Healey overheating at idle was a SS flex fan, whose blades flatten at 
higher engine speed but would still offer some resistance at high speeds 
(but it was annoyingly noisy). A fan clutch /might /offer less 
resistance to airflow through the engine bay, but I haven't had much 
issue with cooling at highway speeds. Moss offers clutches for various 
Brit cars, so they do have a place apparently.



On 2/20/2024 1:26 PM, Michael Salter wrote:
> There are actually at least 2 types of fan clutches.  Thermostatic and 
> viscous.
> The thermostatic type engages as the temperature of the air passing 
> over it increases thus making the fan turn constantly when the 
> radiator is hot.
> The viscous type only drive the fan when running at relatively low 
> engine speeds thus reducing the horsepower required to drive the fan.
> I  don't think either would be of much help with a standard fan but 
> may be an advantage if a large aftermarket fan was being used.
>
> M
>
> On Tue., Feb. 20, 2024, 8:58 p.m. healeybruce--- via Healeys, 
> <healeys at autox.team.net> wrote:
>
>     Harold, what would be the purpose of installing a fan clutch,
>     assuming you can find one that will fit?  Do you really need to
>     disconnect the fan so the engine warms up faster?  Once at
>     operating temperature, the fan clutch is engaged; it won’t help a
>     Healey run any cooler, which is generally our bigger concern.
>
>     Bruce Steele
>
>     1960 BN7
>
>     *From:* Healeys <healeys-bounces at autox.team.net> *On Behalf Of
>     *Harold Manifold
>     *Sent:* Monday, February 19, 2024 9:31 AM
>     *To:* Bob Spidell <bspidell at comcast.net>
>     *Cc:* Healeys <healeys at autox.team.net>
>     *Subject:* Re: [Healeys] Fan Clutch for Big Healeys
>
>     Bob,
>
>     Is there a fan clutch available that will fit an Austin Healey?
>     There is very little space between the water pump and the radiator.
>
>     Harold
>
>     On Sun, Feb 18, 2024 at 6:11 PM Bob Spidell <bspidell at comcast.net>
>     wrote:
>
>         Anyone fitted one to a Healey? I see they're available for
>         various Brit
>         cars, including Jags, Triumphs, etc.
>
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