electromechanical cold-start thingie

[JHertzman <JHertzman@aol.com>]

In AD6-022 Tim Lentz wrote "A friend and I were talking about the Thermostatic
Actuators on SPICA equipped cars. We both thought that having an
electromechanical device seemed like a much better way to go. This friend
thought he had once saw a digest post about just such a device. Anyone know if
this "animal" exists?"

Good question. Scott Johnson raised it in AD3:273 (3 Dec '96) quoting an
earlier post which I could not locate (Anybody know who?)

>    Also, I was thinking a while back that there should be a way to
> replace the thermostatic actuator, without losing the temperature
> compensation.  I was thinking something along the lines of a small
> circuit hooked to the coolant temperature sensor driving a stepper
> motor.  The stepper motor would turn a threaded shaft, therefore
> adjusting the protrusion into the pump. 

"My thoughts exactly! I've been mulling over this for a long time, 
since, it would seem, that there would be a *substantial*, if small, 
market for a replacement. I mean, *I* would be willing to fork over 
quite a bit for a lifetime replacement for that actuator, and the 
parts don't *seem* to be that expensive, so the possiblity for profit 
exists, at least on the face of it.

"The equipment would seem to exist already... temprature sensors,
both electric and electronic, are plentiful and cheap, stepper
motors are all over the place, and, if one went electronic, the
logic should be quite straightforward (someone good at "diffy-Q" or
other advanced mathmatics shouldn't have too much trouble figuring
out the curve). Nothing you can't pick up at Radio Shack. The
housing shouldn't be horribly difficult to create, and mounting
points from the old TA could be used with seeming ease.

"The only things I can think of to hold it up are space restrictions 
at the pump, and perhaps calibration. 

"The fact that nobody's done this yet seems to indicate its a lot more 
difficult than that, but I just don't know.

"Has anyone got any info about this electromechanical device? It would 
seem to be the way to go."

The next post I found was in AD4-286, from: Paul Witek who wrote
"For some time, I've  been convinced that there had to be a better replacement
for a broken thermostatic actuator than the Shankle Sure Start. I even began
to niggle around a bit designing a hybrid electromechanical version, using the
coolant temperature sensor and a stepper motor. Recently, I've seen ads in
Alfa Owner for a company selling that very thing, an electromechanical TA
replacement.  Has anyone tried this?"

Then Bill LeClair in AD4-337 asked "On the same subject, there was a post of
an electromechanical replacement for the TA, is this true and has anyone had
any experience with it?? 

To which the estimable Rich Hirsch replied in AD4-338 " I've seen it
advertised but have no experience with it. I've seen rebuilt TAs for $160 -
$199 (exchange) and of course there's the Shankle Sure Start for $50, so I
don't see the need for an electromechanical one. 

"I gave given some thought to the construction of such a device, however. What
bothers me is that it would have to be energized all the time. Otherwise,
you'd have to wait for the thing to sense the temp and adjust the screw to set
the mixture before you could start the car."

Did I leave anyone out? Probably. Unintentional, of course.

Such a device has been advertised regularly in the newsletter of the San Diego
chapter of AROC, by Alfacat Products, 4524 Mt. Frissel Drive, San Diego CA
92117, phone 619-57601800, fax 619-278-3528. Since this is verging on being an
FAQ without a published answer (that I have seen, anyhow) it would be
interesting if anyone in the San Diego area (or elsewhere, of course) could
report on the product. 

John