This is what I have in my BJ8; however, I bought a 180deg Robertshaw
thermo and de/re-soldered the outer ring to it. It works well (one thing
I noticed about the Robertshaw thermos is that they open right at the
set point; some thermos let the coolant get as much as 15deg hotter
before opening and bringing the coolant temp down).
What's not been mentioned yet is that the coolant not only has to flow
by the sleeve(s), but, when open, the coolant passes through 3 (I think)
small oval holes in the top of the thermo. It appears, at least, that the
total area of these holes is smaller than the annular ring, either with or
without the extra, outer sleeve. So, overall coolant flow shouldn't be
affected too much by the outer ring (what does "balanced sleeve"
mean, anyway?).
I haven't seen Robertshaw thermos available in a while (I used to get
them at AutoZone). Maybe this is why no one is selling the modified
ones anymore. I did find them under the "Mr. Gasket" brand at a local
parts house, but they were labeled "not for street use." This is curious,
since what difference would a thermo make (must be some kind of
regulatory thing)?
If someone is making the older, "bellows-type" thermo in 180deg, I
would like to try one.
bs
***************************************************************
Bob Spidell San Jose, CA bspidell@comcast.net
'67 Austin-Healey 3000 '56 Austin-Healey 100M
***************************************************************
Subject: Re: Thermostat Question
> Dave -
> It's confusing because the original thermostat works by raising the sleeve
> up to close the port when it's hot, where the balanced sleeve version goes
> down when it opens... so it works the opposite direction it should. I don't
> know if the balanced sleeve really works correctly or not. Probably why they
> don't sell it anymore.
> Regards,
> Alan
> '53 BN1 '64 BJ8
>
> On 10/18/05, Dave & M <rusd@velocitus.net> 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
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