Stuart:-
Here is an easy way to eliminate your angst--
Call Blair Engle in Tallahassee. Send him your thermostat housing and he
will adapt it for a "modern" style thermostat and send it back. The
service is inexpensive (I think he charges $25) and you can buy
thermostats at your local auto parts store.
Blair Engle
The Classic MG Shop (904) 385-2821 EVENINGS.Northern Florida
(engle@phy.fsu.edu)
David Littlefield
Houston, TX
'62 MGA MkII
'51 MGTD
'88 Jaguar XJ-S
On Thu, 06 Jul 2000 15:53:59 -0400 Stuart Keen <simbafish@home.com>
writes:
> The original thermostat in my 1951 MGTD MKII is defective and a
> similar
> type is no longer available. What should I do? Please bare with me
> as I
> explain in somewhat detail; history and what has been done to date.
>
> When I purchased the TD, the thermostat was the removable type, it
> had a
> center brass bolt which bolted to a cross arm in the upper parts of
> the
> housing. The bolt was affixed to 1) a 1 7/8 inch diameter, 5/8 inch
> high
> brass band (which affected the flow in the bypass tube) and 2) to
> the
> thermostat diaphragm. The bottom of the diaphragm was bolted to a 2
> inch
> diameter flat ring via three supporting arms. This lower ring fitted
> into a grove in the housing. To install, the thermostat was inserted
> through the bottom of the housing until seated and the top bolt was
> inserted in the crossarm and the nut tightened.
>
> The thermostat was inoperative when I purchased the car. The
> previous
> owner had soldered the diaphragm in the compressed (open) condition,
> saying that driving in Florida, the thermostat would be open all the
> time anyway. He emphasised the need for some restriction in the
> water
> flow path.
>
> When the engine was rebuilt in January, the machine shop saw the
> soldered thermostat and junked it; ie. returned the TD with no
> thermostat installed. I have the old thermostat but it is in pieces;
> i.e butchered.
>
> Being advised I should not drive the TD without a restriction in the
> water flow, I ordered a thermostat from Moss (also tried Abingdon,
> but
> they had none available). The Moss thermostat was completely
> different,
> just a flat circular plate with a small thermostat system protruding
> from the center. The replacement fit loosely in the grove in the
> bottom
> of the thermostat housing, so I flattened the raised edge to make it
> more snug.
>
> I am concerned about the thermostat since I am about to make a 5,000
> mile trip in the TD. I was about to order a housing with
> non-removable
> thermostat from Moss, but would like advice first to know if this
> expense is really necessary.
>
> Last night I read over 200 archived messages about thermostats. The
> common thread is that you should have some restriction in the bypass
> outlet. The original unit provided this with the brass band, but the
> Moss replacement does not provide any restriction. Is control of the
> bypass really necessary if I am driving in a hot climate all year?
>
> I ask if it is really necessary because I have now driven approx
> 4,000
> miles with the Moss replacement thermostat installed and with no
> restriction in the bypass outlet. Much of the driving has been in
> Florida, but even here my water temperature gauge (rebuilt several
> months ago by MoMa) never registers higher than 83 deg C, usually in
> the
> mid to high 70s. The water temperature seems to be okay, so should I
> even be worrying about the quasi thermostat installation in my TD.
> Am I
> just being a perfectionist and a worry wart?
>
> I am not even sure I installed the replacement thermostat correctly,
> but
> it seems to work. The unit is marked with the words "TOP" on the
> ring,
> with the spring and housing protruding below. This is how I have it
> installed. However, there is an annotation on the side saying "Flow"
> and
> an upward arrow. What is the direction of water in the system? Is
> water
> coming from the top of the engine, UP into the thermostat housing
> and
> then into the top of the radiator to cycle downward and be cooled.
> For
> some reason I thought it was the reverse. Shows how little I know
> about cars.
>
> I am listening to all advice, such as
>
> 1) leave well enough alone, the water temperature seems to be okay
> now
>
> 2) order a housing with non removable thermostat from Moss
>
> 3) put some kind of restriction across the bypass opening as
> suggested
> by some of the archives.
>
> Thanks for your patience in reading all this detail, for putting my
> mind
> at ease and for any suggestions.
>
> Stu Keen
> Venice, Fl
> simbafish@home.com
________________________________________________________________
http://dl.www.juno.com/get/tagj.
|