The original Austin Healey thermostat had the sleeve at the bottom when
cold and it rose to the flange when hot (as seen in figure B.76.A from
BMC pubs).
The "bypass" should only be open when cold to circulate the water only
in the engine. When hot the thermostat allows the coolant to go to the
radiator.
Wilko
San Diego
On Oct 17, 2005, at 10:17 PM, Dave & M wrote:
> Hi Alan,
>
> Now you're getting me confused. The text & pic at mgaguru says "For
> this thermostat the sleeve is in the full raised position when cold,
> nearly touching the top mounting flange. The closure to block fluid
> flow is between the inner cylindrical body and the top flange. When
> this unit approaches the preset operating temperature and begins to
> open, the sleeve moves downward (along with the cylindrical body) to
> block the bypass port."
>
> From the description & the pics, it appears that the sleeve blocks the
> bypass port when the thermostat is hot. Just like it is supposed to
> do.
>
> What am I missing?
>
> Regards,
> Dave Russell
> BN2
>
>
>
> Blue One Hundred wrote:
>> Bob -
>> About 4 years ago, The Nocks were selling these with a special brass
>> ring
>> added to the thermostat, which blocked off the bypass port when cold.
>> You
>> can see it here:
>> http://mgaguru.com/mgtech/cooling/cool_103d.htm
>> Of course, they don't sell these anymore and apparently the sleeve
>> worked
>> opposite of how it is supposed to anyway... but heck it does help my
>> car
>> keep much cooler, maybe because of the wide mouth opening.
>> Cheers,
>> Alan
>> '53 BN1 '64 BJ8
>> On 10/18/05, Bob Spidell <bspidell@comcast.net> wrote:
>>> Alan,
>>>
>>>
>>> If, by "balanced sleeve," you mean this:
>>>
>>>
>>>
>> http://www.stewartcomponents.net/Merchant2/merchant.mvc?
>> Screen=CTGY&Category_
>> Code=Therm
>>> ... then this thermo doesn't block the bypass port at all. This is a
>>> standard Robertshaw
>>> thermostat with some holes drilled in it (I know, I have one). The
>>> sleeve
>>> moves, but its
>>> diameter is too small to block the bypass port. The modified thermo
>>> I'm
>>> using is one of these
>>> with an extra, outer sleeve soldered to the inner sleeve. The outer
>>> sleeve
>>> partially blocks the
>>> bypass port when the thermo opens, but it probably doesn't work as
>>> well as
>>> the
>>> original.
>>>
>>>
>>> bs
>>> ***************************************************************
>>> Bob Spidell San Jose, CA bspidell@comcast.net
>>> '67 Austin-Healey 3000 '56 Austin-Healey 100M
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