Optimum converter temperature

[jono]

I have noticed things in here have gone real quiet in here. Another dedicated lpg forum based in Australia seems to have disappeared into cyberspace. I hope this does not happen to this forum.

This forum has been very informative and the many questions I have asked in the past have been answered or commented on, which I greatly appreciate, so I am learning. I like to share said learning. From what I understand about converter temps having an effect on the gas mixture is that the hotter the converter becomes , the leaner the outgoing fuel mix becomes. I have found comment on altfuel.com that the ultimate temp for a converter and its vapour delivery is between 130 and 140 degrees F (54 to 60 C) A few degrees below normal engine thermostats opening temps. They have produced and patented an inline thermostat designed to fit into either the converter or inline on the outgoing coolant path to keep the converter at the temps mentioned.The cold of expansion keeping it cooler. Nice idea for those needing some precision in their fuel delivery and also apparently the way to stop other added chemicals in the LPG mix from falling out of the vapour - and forming as an oil in the converter to then have an effect on diaphragms and gasket etc. I bought a few to try in my cars. Not sure if i will notice anything at all from seat of the pants or fuel economy, maybe just less or no oil build up in the L converter sitting flat under the bonnet

Jono

[C3H8]

Under normal circumstances the lean condition is not an issue since the fuel mixtures should always be set at full engine temp. The seperation is another issue. In countries where quality is an issue the higher heat definitely causes the heavy ends to fall out of the vapour and clog up parts. Keeping the vapour cooler, especially in stop and go traffic is best. This is when most of the heavy ends are generated. At constant speeds when fuel is being vapourized at a steady rate the fuel temps actually stay reasonably low as liquid enters at a constant rate and leaves at a constant rate so the temp stays very stable and the heavy ends do not have time to fall out. As for the rec temp some manufacturers recommend full engine temp, however 130 to 140F usually works well. An example is Vialle. They rec we not use an add on thermostat. This is likely debateable depending on the climate the vehicle operates in. Our yearly average is 37 degrees F. Temperatures over 86F are only for short periods of time. In countries that are much warmer the add on thermostat would be a serious consideration.

[jono]

Thanks for the input C3.

I rushed off to show my guru, thinking it was new fangled idea. Yep, seen 'em. He has already tried his own method of temp gauge pluged into converter and use a tap to control flow. Got no power benefit so gave up.Reckons Impco gear self adjusts to lean rich thing based on the changes of temp. This little baby does it all for you no fiddling with another gauge and a tap to alter. My main concern is with the fallout at hotter temps. I had a hydrin diaphragm get some sort of oil contamination and made it all gooey, caught in time to avoid a let down and used a second hand silicone diaphragm. And our LPG quality is well, um, yes, not made to a standard set by any concerned authority . My motor is some sort of waste disposal unit in disguise from the sounds of things. LPG price went up from 49.5 to 59.9 cpl at our cheapest site this week. one ausie dollar bought about 92 cent US

[Steptoe]

To get around the oil/gunge drop out mount the impco L outlet down.

I have wondered about that thermostat thing
I run the stock 69 camaro radiator...these are way over built.
A 160 thermostat in the engine...water temp is constant regardles of ambiant temps, from frosty morning to afternoon summer temps, heavy traffic or towing one of my vintage cars.....except when go to the mountains, up in the snow line from sea level it gets upto 175/180.
I think that a good cooling system that gives constant temps is all that is needed.

[400HPONGAS]

Its a Crock . unless you live in a Temp zone that lets your engine run happily at around 60 C , been there ,done that , even ran a a semi eutetic cooling coil around the vapor line ,(easy , redirerect the low side AC hose ) made SFA diffrence . A Quality air-gap manifold that is well insulated with quality hollow wall insulated spacers , that isolates the mixer/throttlebody has much more effect . Well for a little while until engine heat soak catches up with you . I DRAG race with straight LPG emgines , its tuned to run cold , engine temp wise .
The Drop out thing is true , but thats if you live in an area that produces/sells crap fuel .(like the US and Canada) Learn to strip and clean your Convertors regularly . Mount convertors veritcally and 90 degrees to the thrust ( sounds like you have fitted a jet engine , yeah a Gas Turbine , LOL)

[jono]

Crock or not, info sounds good enough to warrant a try if only just to keep the heavy ends in the flow of things. I use an engine watchdog giving temps between 77 and 86 deg C so about 20 above optimium. Australia has no standard to adhere to for fuel quality as far as LPG is concerned. At least the US has a standard available. As for temperatures 38 deg C is measured in the shade, stick thermometer out in the sun or measure the temp of black road as it melts.....


The L converter was mounted where it fits, disgruntly not as desired, sits flat like many Falcon sixes over past twenty years had been - some even factory conversion. If fitting the themostat mentioned fixes the fall out i will have achieved desired effect.


Merry Christmas and Happy New Year **

[Steptoe]

Do what ever u need to mout vertical facing forward if u have dirty gas....u can run 50,000 miles and iot will still be clean
TRY to mount it below the top of the radiator level, otherwise air locks and freezeing CAN occour after a raditor flush.
Mine is slightly above, it hasnt been a problem if I re fill the radtor with the car facing up a hill, sometimes (about 4 in 20 yrs) it has frozen up
Regarless after a flush i feel the back of the L made sure it is hot, if not I crack the top water hose, bleed it and is all ok from there on.

[400HPONGAS]

Trying to control convertor gas temps by throttling the supply water is an old trick that Vialle,OMVL and hal the other Italian LPG system manufacturers tried 10 years ago . It simply doesnt work , (Remember you can get electrically heated convertors that dont use the engine coolant at all , alas for low flow requirements on 4 cylinder forklift type arrangements . ) They , the manuacturers found , that as soon as a reasonable demand was asked for , the thermostatically controlled throttling device could not operate fast enough to prevent Convertor Ice up. This I discovered for myself by fitting a 3/4 stainless ball valve to the convertor Hot side ( yes OMVL's Vialle's Airod's , infact most positive convertors have directional flow of the coolant, unlike the run of the mill negative types like Impco E or L , or OHG/Woodward X1's and B2's). Now , all this to prevent excessive Drop out , why would you bother !, just learn to clean out your Convertor regularly . Dropout ? I use around 100l itres of LPG (50/50 blend ) in the average week , thats 5200 litres a year , When I open up the convertors , there is rarely more than a teaspoon of contaminate/dropout , probably mainly because where I live the quality seems quite good . Considering the temp control offers neither anything in the way of performance or economy , again why would you bother !!
It seems that someone is confusing the gas vapor temp delivered to where it matters . the cylinder , with the primary /secondary gas temps at the convertor , perhaps

[jono]

400HPONGAS ?? You were on the lpgperformance forum based in Australia weren't you? Not sure where it went, not been able to find it lately, there was a lot of good info shared on there as well as in here.

I understand the need for preventative maintenance can include dissemble and clean out of oils and gunk,, also understand the correct positioning of these converters if possible, but in order to have minimum vapour path from converter to mixer (for it is TURBO) and to clear distributor and also to be serviceable in place and below air bubble in the coolant line I have mounted my L converter flat - aware that I will have to keep an eye on any developments due to not being inverted. This little device has a good theory behind it - enough to be pat pending, affordable i figure it worth a try, when i can motorvate self to fit it inline in a slightly tricky position.

One thing I am mindful of is the diaphragm sealing gasket tearing beyond reuse on some dismantling of most LPG gear. One costly exercise I'd like to avoid. And many a LPG component can be left alone for decades at times without needing to be touched - LOVE THAT!

[jono]

Forgot to add that an L converter should be very comfortable in delivering fuel for my 1.8 litre turbo at no more than 8psi boost for short periods with freezing up.

The idea of this device is just to maintain the converter at these temps not the whole cooling system. It fits inline on the water outlet of the converter, retains some trickle flow all the time and then there is the thermostat control with the gas expansion providing the cooling of the water in the converter.I'm sure in vapour draw through turbo applications , such as mine, a small temp reduction of the vapour is gonna do squat. Worth a tinker in my small mind

[KILLERB468]

400hpongas you mention mounting the convertors vertically and 90* to thrust...do you have any pictures of this setup?

[jono]

picture not really needed, just imagine the secondary chamber is full of water and you want to drain it out the vapour outlet - you'd hold it the way it is recommended you mount it so as to drain the crud through the induction of your engine, then also mount the converter with its back to the left or right inside guard so the diaphragm is not forced to change position against its normal operation by the forward motion or slowing down suddenly of the car - inertia affecting its output.

[400HPONGAS]

Thanks Jono , couldnt have said it better myself !!!
In Drag racing you sure can tell the difference !!! even hard braking has just as much effect .

[jono]

As usual , I took up (wasted) more time in thinking about fitting this unit than it took to fit in the outlet of my L converter. I am happy, got one less thing sitting around, one less thing on the to do list, now I will observe at a later date as to whether any oil build up occurs within the secondary chamber of my flat mounted converter.

[dutchlincoln79]

does anybody know where to buy the neat inline thermostat?