New Mexican T1 Thermostat and Failsafe

[MGVWfan]

Yeah, a chimney damper, that's a good idea. Ray's right, to get enough delta length and force from a bimetal coil, it takes a fair amount of strip length (which is why a choke tstat won't do it by itself), and a chimney damper has that.

[albert]

YES,,MG,, but were we can buy tooday a chimney ,,spring ,,bi-métal,, for the smooke damper,, tooday witch the modern stove ,, the factory for this application is in the end of production,,but if we look on the net,,we can bee lucky,,albert

[vwbill]

Hey Guys, what about a Outboard motor choke solenoid (ebayer # 220399946366 ) with a temp switch to break the ground or current....??? Bill,jr. P.s.WHat about a door lock solenoid.. (ebayer# 150387638094 or 180447892152 or 180402767391 !)

[albert]

BILL,,the problem witch the 412 air flap,, he work all the time for to keep the motor at 175 dg,fr, + or- ,, and the thermo switch witch the solenoid is ON OR OFF only ,,you have not the med. temp.. it is ok if we d,t can find something like original,, i have see one long by-métal blade in the hvac duck,, for to close a damper for fire protection,,it is appx. 5'' long 1'' lardge ,and he can moove for 3 '' long ,adjustable,,he look like alf moon,, it is fix on the frame by the 2 extémitys and the arm for to close or open the damper is fix in the midle,,( adjustable ) BY A SLUT SCREW,, and we can buy that for différent dg,fr,,, we have the same systhem for to mix the outside air and inside air,, excepted the dg,fr, are différent,,if we want something like the original i thing we can doo something witch that,, or if we want a betther précisition we can buy the same systhem but witch the électric motor and small cpu,,for to open or close the damper and controle the dg,fr, albert

[raygreenwood]

The performance of the stock thermostat may vary some in extremely cold climates...like Canada ....but in general a properly functioning stock thermostat does no modulation of engeine temp. I have never found the case in in weather in the "teens"...that my thermostat allowed the flaps to be partially open once the engine is warmed up. It may be slow to open...but once expansion begins.....it has always been complete with flaps wide open. Ray

[MGVWfan]

By "modulation" I meant that the flaps don't bang open in millisenconds at the setpoint...they open gradually over a few minutes at ambient temps in the 40's (like we've had for the past week or two at night). I'm betting that banging open at a certain temp, with an almost instantly increased cooling air flow, isn't terribly good for the engine, compared to a more gradual increase in cooling air.

[albert]

that is exact MG,, if we have a by-métal thermostat it is there for to modulate the temp,, for one good reason the métal expention,,if the fresh air arrive to fast on the head that can bee dangerous for the head gasket witch the allu. expention,,if we want to use the selenoid,, we have need a minimum of 2 électric thermostat witch 2 différent calibration ,, and 2 selenoid,, but that is not like the by-métal,,albert

[albert]

MG, have you receeve my pict. last week,,albert

[albert]

plus,,one good thing for to put the good thermostat,, not only for canada,,lol, if we want the heat inside,, witch the good thermostat ,, the heat start to arrive on the right side in first,, and afther 4-5 minutes the hot air arrive on the lefgth side,,and afther 3-4 more minutes the 2 side are egual,,plus if the motor stay too cold he use more gas and more gas= more pollution ,, if the motor stay at 180 dg,fr, averadge ,,he burn the maximum her gas,, ok if you have the bosch,,L,, jet injection witch the oxigen sensor the combustion is more perfect,,but witch the bosh ,,D,, injection the thermostat is extremly important,,albert

[MGVWfan]

EMAIL's hosed up right now, Albert

[raygreenwood]

Yes...I know it does not just bang open...that much I totally agree on. However, the time factor here is about 4 minutes in hot weather and 8 minutes in cold. The longest I have ever seen in light to light traffic in weathr in the teens...is about 12 minutes to full open. And....I have NEVER seen a flap thermostat re-close while the engine is operating once it is warmed up...even in weather in the teens....that is what I am getting at.

The thermostat is NOT for modulating temperature up and down during operation. It is for modulating it UP only....during warm-up. Precisely...it is for speeding up the warm up process. The bellows unit itself banks enough heat that once warm...and being worked upon by decent spring pressure, it does not generally begin to close the flaps again until the engine is off for a considerable amount of time in hot ....and close to an hour in cold weather.

There are days whe I have just thought about installing a nice pull knob on the dash with a warning buzzer on start-up. The buzzer would tell you to pull the lever to close the flaps. That action ...activates an adjustable timer....maybe 8 minutes...wherin it sets off red light and buzzer again telling you to push the lever back in opening the flaps. Kinda lik a manual choke. If the cable breaks...the failsafe spring just opens the flaps. Ray

[MGVWfan]

I got to that point too, Ray After failing the third bellows-type thermostat in 3 years to pinhole corrosion, I was thinking choke cable and pull knob. Good thing the MG's choke cable was too short

If we can decide on a decent "push the knob in dummy" warning temp at the thermostat location, and a "fail-safe" temp, Klixon-type thermostats are cheap and have actuation temps in the range we're interested in...one to light the light at the "push it in dummy" point, and a mechanical fusible link at the "fail safe" point (every thermostat design needs a fusible link I'm now thinking...). If we can get to the point where we've found a damper motor device, then use the FI CHT signal as an input to the motor controller, with the fail-safe covered by the fusible link (and maybe a Klixon-style thermostat switch to cut power to the motor at the fail-safe point?).

So back to the (sort of) original question...what's a good fail-safe air temp?

[Piledriver]

I suppose one could run coil power through the NC contacts of an overtemp switch a "reminder:... Anything short of that would be ignored.

The only thing wrong with manual control is then you are relying on the "dummy" behind the wheel to remember something best left as an automatic function.

The Corvair dumped fan plenum air pressure in it's setup... the thermostats are physically adaptable.

If you can find the pinhole in the bellows, you can sometimes repair it, saw a "how-to" somewhere.

[MGVWfan]

Yep, tried that repair...and failed . Seems the flexing of the bellows is enough to eventually crack the solder, even silver solder (tried that too), and the leak comes back. I've got one on the bench right now with a slow leak, just enough to make it not work right, the leak is around the last repair site (verified with my refrigerant sniffer, isopropanol will trigger it, too).

So the Vairs dumped plenum pressure rather than restricting flow in the plenum...never knew that. More than one way to skin a cat, eh?

[albert]

MG,, if you want something with 4 set of conctact,, use the private home oven thermostat,, it is not expensive and you can plug-in indicator light and the selenoid for the damper,, it is good for 220 volts but not important if you put 12 volts,, and you can adjust that at 175-180 dg,fr, the différacial is adjustable 0-8 dg,fr, by the center of the shaft,,the sensor bulb is at the end of 6 foots of capilary tube,, and can bee good for many years,, leak safe ,, albert