Optimum converter temperature

[DODGEN1]

Hal. your converters are run in seireis? does this cause any problems with the temps in the second converter? i would think that the second one would be delivering a cooler charge to the rear mixer. when i put mine together i split the water feed close to the out let at the block. i've got one of the thermostats put one of the techs at impco told me to use a restrictor. personally i prefer that the heavy ends fall out in the converter instead of gumming up the mixer.

[franz]

If the thermostat senses coolant temp, it should be mounted after the vaporizer. if the thermostat senses vapor temp, the control valve should be mounted before the vaporizer.

[Hal]

Hal. your converters are run in seireis? does this cause any problems with the temps in the second converter? i would think that the second one would be delivering a cooler charge to the rear mixer. .

That sounds right, but i would make it as simple as possible for the visual appearance.
It seems also that the temperature difference of the converters is not so fundamental, i could not feel any differenz by hand.

Greetings
Hal

[DODGEN1]

Hal,
where did the pict go of your set up go? i wanted to look again.

[Hal]

look at the "Twin Impco" thread, DODGEN1

Greetings
Hal

[Frank]

Similar to the Dual Curve temperature controller, Technocarb also made a similar device that controlled gas temperature in the converter. They too discontinued it due to low demand as there was minimum order quantity for the board in its microprocessor, which they could not justify. They would consider making it available again provided they could get orders for around 25 units. The Thermal Feed-Back Controller had an MSRP of US$359.00 when it was previously available.

Thermal Feed-Back Controller Brochure

[Steptoe]

With due respect..I really do have a problem with that.
"Min peak fuel temps..." yes , unless one drops the pedal and going from data above, anychange of water temp will be way after the event..note how the sensor is on the unit, not in the feed pipe?

"Switches off coolant when on petrol" Why, would it not ne far better to have coolant/antifreeze going thru all the time to prevent corrosion etc?

"Increased duration between service" Mounted and set up right theres no need for servicing for many yrs...

"Reduced maintance" what maintance, above.

"Improved reliablity" set up right...above 2 posts

"intregated temp sensor" again is it where it reads right and is it sensitive , fast enough, to sense and relay that info???

"More cost effective than an over haul" again above.

They too discontinued it due to low demand

I wonder why?..Im no engineer, but I see no real use or that the unit would be effective or work, at all.

Looking at the components....a GM like heater vac operated shut off valve, a temp gauge sensor, and another thingy bob..certainly not high value items

[storm]

Looking at the components....a GM like heater vac operated shut off valve, a temp gauge sensor, and another thingy bob..certainly not high value items

I really don't think it is rocket science, it could be done with a GM type TVS (Thermal Vacuum Switch) and the vacuum operated heater tap.

[Frank]

For more information about Technocarb's Thermal Feedback Controller, please see the following pages:

• Thermal Feed-Back Controller Operation
• Thermal Feed-Back Controller Installation

To answer the concerns above:

• This controller regulates GAS temperature supplied to the mixer and not the temperature of the water leaving the converter.
• The controller just modulates the water flow rate through the converter. It can only limit the maximum temperature of the gas flowing through it.
• Because the water control valve only works by an ON & OFF action, operation during petrol operation would simply result in unnecessary wear. Although there could potentially be corrosion issues from no water flow through the converter, most people use propane because it's cheaper and I would expect that petrol use would be minimal. Please remember that low-price LPG is not always readily available in the USA and petrol use would often be likely.
• Going back to the USA, propane motor fuel (HD-5) is not readily available everywhere. Many places get commercial LPG which does not have a specified content of constituent gases. Especially for those places, it would be helpful to keep gas temperatures low. I suppose that, for fleet managers that run commercial LPG, reduced converter temperatures would reduce their maintenance costs and downtime.
• The vacuum switch is electronically controlled unlike the TVS. The TVS would not be able to maintain a maximum gas temperature of ~50°C/~122°F.

Incidentally, this topic has been discussed earlier (Temperature Control, propane sludge, long thread). As Franz has had positive experiences with the Dual Curve controller and since the Technocarb unit is similar, I would expect that it should perform similarly.

[Steptoe]

•This controller regulates GAS temperature supplied to the mixer and not the temperature of the water leaving the converter.

This is where I cant get my head around.
One drops the throttle at around 50 mphfor a passing manuver...say a truck trailer unit...
Gas drops in temp near instantly....sensor opens the water to heat the convertor, water flows heating up the gas...before the water could transfer the heat, the passing manuvor is over, ....throttle is back to cruise or coast, by this time the converter is to hot and the valve closes.

Thu If say towing up a steep hill where the throttle is further open for a longer period, I can see the advantage.

[Frank]

Steps, I'm not quite sure what the issue would be with temperature control. In your passing maneuver situation, converter gas temperature would initially drop whether there was temperature control or not. With converter gas temperature control, the gas temperature would drop from a lower temperature but not drop as relatively far because the controller would start adding more heat. However, in the long term, the average converter temperatures would be much lower with potentially lower heavy end residual deposits.

Interestingly, 400HPONGAS found that the thermostatically controlled throttling devices he's used could not operate fast enough to prevent converter Ice-up. 400, were those control devices like the GANN MR456 or like the Technocarb Feed-Back Controller?

The other benefit from converter gas temperature control would be improved fuel mixture control from having a more constant gas density supplied to the mixer. This would probably be more useful to those people using open-loop fuel systems. Franz, do you recall if the the Dual Curve controller had a measurable effect on fuel economy or power?

For those of us living in regions that experience cold winters, I would also expect that a converter temperature controller would provide a bit more cabin heat since less water would be bypassing the heater core.

Just in case anyone is interested in this device, I've added the Thermal Feed-Back Controller to my e-store.

[jono]

YES ! In colder climate and got better heater temps after instaled the inline unit

[franz]

A thermal vacuum switch is too slow to operate plus it senses coolant temp, not vapor temp. The most effective means is a thermister mounted at the vapor outlet of the vaporizer. A circuit board reads the thermister output and activates a vacuum solenoid which then activates a water control valve. The valve can actuate almost instantly and is very effective. I have one unit here on my desk I tested for a while and it functioned wonderfully. It too was discontinued due to low sales, from DuaCurve. Pity.

Franz