Cng(ngv) Or Lpg?

[monty]

To run a Diesel engine entirely on CNG (NGV) or LPG:

There are a lot of Changes to be made if CNG is to used in Diesel engine.

1. The Cylinder head need to be changed as we need to install the Spark plugs instead of the Fuel Injectors( Diesel) .

We need to reduce the compression Ration from 21:1 (approx) to 9: 1( for CNG).

2. We need to install a firing / Ignition device to send spark to the spark plug.

We need to change the Manifold or modify the existing manifold to plumb the gas ( CNG ) into the inlet manifold

3. We need to install the Venturi to control the gas / air mixture

Then of course we need to change the piston / cylinder head etc and all these changes will involve a complete engine change.

Hence to convert a Gasoline ( Petrol) engine to CNG is much easier. You will also need a timing device for the ignition system

Of course, now the engine doesn't run on diesel anymore!

The above only make sense on vehicles doing lots and lots of miles, since it'll take a loooong time to recuperate costs.

There is however a system, where a diesel engine can partly operate on LPG. The engine principle remains the same, but instead of 100% diesel, it'll run on a mixture of diesel and LPG.

Here the advantage is in the fact that in a regular diesel engine, only 75-80% of the diesel actually burns., When injecting a low amount of LPG (10%) up to 95% of the fuel mixture gets burned resulting in better power, better economy. Up to 30% LPG can be used for maximum savings.

So the total cost of a liter of burned fuel is about 22% less now (with diesel at 40 Baht and LPG at 10 Baht), add to that a 10% increase in fuel economy of your engine, and your per km driving cost goes down up to 35%.

Still only good if doing a lot of km!

This system cost just a tad more then a conventional LPG installation.

[Lancashirelad]

Thanks for that Monty. Interesting. Makes sense, will not run on 100% gas on a compression ignition basis. Hence the requirement for a means of ignition (spark plugs).

The 30% mix fits exactly with what a haulage co. boss here was recently telling me.

Has any member done this? or know where to get it done?

[krystian]

Any update of installation costs as of this week,I heard prices will be lower as the taxes will be reduced for the shops that install these, and does anybody know of LPG installed in a 98 Honda civic?

[Plus]

I asked the garage I did my conversion over a month ago about current prices and was told that everything went up. There's a severe shortage of JZ engines (popular choice for diesel vans) - at least 60k, and even the cheapest "vacuum" LPG systems are over 20k, and there's a long waiting list, too, so no reason to lower the prices, business wise.

Tomorrow I'll probably have a long chat about it again, maybe it was only scaremongering.

[Gary A]

I just read an article about dual fuel diesels. An Australian company claims to have the answer. They run on about 30 percent LPG and 70 percent diesel. Supposedly the LPG causes complete combustion of the diesel so it makes the diesel more efficient as well as burning cheaper LPG.

I should have copied the link but ifyou want to find it, Google dual fuel diesel/LPG.

I saved the cost for last. $8,000 Aussie dollars.

[Plus]

I once read that retrofitting this system means you have to use only the mixture - you can't run only on diesel anymore, if you run out of LPG, you are fuc_ked.

I remember this is what they told me when I was asking for conversion for myself, and the price was 50k.

Factory fitted NGV+Diesel Colorado trucks can run on diesel even if you run out of gas.

>>>>>

Also the mixture means saving are not that high to justify the costs.

>>>>>

I also read that there are long queues for NGV tanks, again, tomorrow I'm planning on asking for first hand information on all the options and prices - we have two diesel vans we want to convert.

[0Mix1up]

Watch out for systems that start on petrol and switch to gas when you rev it.

Not a good system I think or what I've experienced.

[Gary A]

I once read that retrofitting this system means you have to use only the mixture - you can't run only on diesel anymore, if you run out of LPG, you are fuc_ked.

--------------------------------------------------------------------------------

The Aussie system will simply run on diesel if you run out of LPG. For $8,000 Australian dollars it should and it does. The package uses an ECU to monitor combustion and the normal fuel system is not altered.

I have no idea why this system is so expensive. Unless you drive a LOT, the system would never pay for itself.

[monty]

I have seen the 70% diesel / 30% LPG (or CNG) systems in Thailand at a fair, advertised at around 25,000 Baht.

I would guess the Colorado NGV/diesel runs the above system. It is simply technically impossible to create an engine running both 100% on diesel and 100% on LPG/CNG.

Watch out for systems that start on petrol and switch to gas when you rev it.

Not a good system I think or what I've experienced.

I have such a system, never any problems. Why would it not be good!

With the systems which do not do that, you have to do it yourself manually (on injection engines). If you do not do it, you can render your petrol system inoperable within 1000 km.

[tigerbeer]

I drive a honda civic 06 fitted with NGV. Let me share my opinions:

- there is some power loss using NGV. approx 15%.

- frustrating queues for fill ups at the moment. PTT has promised to increase NGV delivery trucks by 3 fold before the end of this year. refueling stations by 2 fold before the end of year.

- PTT extremely strict on who installs the NGV system in your car. A full report is given to you on the testing of your tank etc. No approval card from PTT, no NGV for you. simple as that.

- at least 60k installation for a 4 cylinder car.

- no one i know does NGV conversions for Audi. (confirmed cause my we asked around for our Audi). their reason: too difficult to do and the engine just does not run well on NGV. i am not a technical person, so don't ask me why.

- car runs very smoothly with NGV. no major problems. just little teething problems that perhaps takes a month of two to sort out to perfect it. as in initial tuning etc.

- the range for my car is exactly 220km on a 70 litre tank. of course the fill up is by Kgs. approximately THB120 for a fill up. its 10.35 per kg for CNG here in chiang mai. 8 baht something in bangkok. a 100 litre tank can be installed for a camry or an accord. (mid sized cars) which would technically give you the same range of 220 or more.

- the tank is heavy! you might be required to do some modifications to the back suspension system. i added more coil and the car is a bit higher on the back. but perfect now. honda's have very soft suspensions.

- NGV is the fuel for the future.

- green car - 90% less pollutants for the environment. feel proud being part of this.

my thoughts for LPG:

- the most "make sense" conversion for the moment. its widely available and cheaper to install and gives you a longer range.

- my only concern is at least 1 baht increase for every few months for the rest of the year. It would still be cheaper than petrol no doubt but still volatile. I do not like being unsure!.. hence my choice for NGV.

- safety issues, too many LPG installers, too many different manufacturers of LPG parts. how is the quality control of installation and parts? just paranoid about it.

its actually very clear on what would be your preferred choice. but i would recommend converting to NGV if you intend to drive that car of yours for a while.

TB..

Edited June 13, 2008 by tigerbeer

[Plus]

Went to a couple of shops to inquire about converting diesel vans. No good, no leads either. One installs NGV only on Isuzu/Chevy engines, probably the same system they fit in Colorado. Price - 159,000 for 70l tank.

Then went to a shop that did engine swap + LPG. Total price for a van - 103,000 baht, cheapest, oldest engine, cheapest system, and after selling the old engine. For comparison - I paid 83k for five year old 2JZ-VVTi and injection system for six cylinders, and it was only two months ago.

1JZ engines were 25k two months ago, now it's 45k.

Good news is that waiting lists for NGV are only about a month, price for a Camry 60-80k depending on brand and size of a tank. Smaller engines about 5k cheaper.

Maybe it was Friday 13th, I don't know, but LPG increase is unbelievable.

[tigerbeer]

Went to a couple of shops to inquire about converting diesel vans. No good, no leads either. One installs NGV only on Isuzu/Chevy engines, probably the same system they fit in Colorado. Price - 159,000 for 70l tank.

Then went to a shop that did engine swap + LPG. Total price for a van - 103,000 baht, cheapest, oldest engine, cheapest system, and after selling the old engine. For comparison - I paid 83k for five year old 2JZ-VVTi and injection system for six cylinders, and it was only two months ago.

1JZ engines were 25k two months ago, now it's 45k.

Good news is that waiting lists for NGV are only about a month, price for a Camry 60-80k depending on brand and size of a tank. Smaller engines about 5k cheaper.

Maybe it was Friday 13th, I don't know, but LPG increase is unbelievable.

lots of thais are leaning towards LPG. cause of convenience and price. heard there is a lot of shortage on certain provinces in thailand with regard to LPG tank and equipment. Long long waiting periods to get it installed. prices for anything to do with LPG is going up up up.

NGV better option IMHO. like Monty mentioned, only if you can do well with short range of 200-300km per fill up.

[JAS21]

Watch out for systems that start on petrol and switch to gas when you rev it.

Not a good system I think or what I've experienced.

All LPG systems have to start on petrol. You should have a switch that will hold it on petrol. To change to LPG you must operate that switch and have achieved a certain speed of the engine. If you don’t have this switch fitted then you only have engine speed control of the changeover and that is not good. It is bad for the engine to go straight to LPG…LPG runs hotter so more initial stress as the engine heats up quicker. Best to warm up for say one kms or so on petrol and then switch over to LPG.

If you have that system then get a switch fitted, easy to get done.. The rev. change over is to ensure the engine does not try to start on LPG as it won't.

For those of you who want to calculate savings LPG/petrol, go to this web site http://www.prinslpgnetwork.com , but remember it is a UK web site so fuel input figures are in pence, so you need to convert fromThai baht to pence before inputting.

[sysmaster]

Hi all, new here but not new in the country...

LPG conversions.. I had my Chevy Zafira done last week.

Paid 31,000 THB for a 4 cylinder BSM "Bardolino" installation (multipoint injection).

Originally it should have been an "EasyJet" from Autogas Italia, but apparently that system does not work well with the fuel injectors of the 2.2 Zafira's.

Installation was done at P.S. Pornsak on On Nut Road website http://www.ps-pornsak.com.

These guy's are already in the LPG business for 25 years and it's a big place (small facade though).

Pricing goes from around 20K for a fixed mixer to about 40K for multipoint injections.

Business is brisk, average waiting list is 50 cars before you, if you are lucky you get your car back in 48H., mine took 4 day's also due to having a Sunday in between...

None of the technicians there speaks English but at least two of the secretaries do and act as interpreters.

While installing the conversion on my car the lost about 4 hours on the last day because they managed to trip the anti theft device and could no longer start the engine... took them several phone calls to Chevrolet to get that going again.

Installation is done professionally, I'm an industrial Engineer and can evaluate crappy work, this wasn't.

There was a minor problem after the installation, the day after, I drove of (cold) and it took until the car hat reached full temperature before the system switched to LPG, went back and they found that the temperature censor on the regulator was bad, replaced it and everything is fine now.

Engine runs fine, but still doesn't like my "kick-downs" to much, this is not going to be forever, the next tune up will be "life", technician with computer calibrating the ECU while I'm driving.

The package from them comes with free service, one year warranty, a 250,000 THB insurance policy to cover any damage caused by the LPG conversion to your car (engine).

One thing that pleased me very much on this installation is that the "greaser-kit" is automatically installed as well. this is a small tank containing "Flashlube", this lube is mixed into your gas as a lubricant for your cylinder valves, to compensate for lack of "natural" greasing that occurs when driving on gasoline. My advice is that where ever you have your LPG conversion done, make sure this kit is included.

And now the technicals, since I've seen some questions here.

ECU: Multipoint injector systems come with their own additional ECU, this installed as a "slave" to the car's ECU, your car ECU is not modified at all, the "slave" is doing the work.

The "slave" will gather information from the gas tank, regulator, engine temperature to determine when it can switch over to LPG, this can be set to any condition, except the initial start, this is on gasoline. Conditions like switching to LPG after you have rev'ed up you engine to 3000 rev's or so are optional.

The gas injectors get their commands from the original injectors of your car, the firing signal from the car's ECU is passed on to the "slave", on gasoline this is then simply passed on (or ignored since your gas system is shut off). In LPG mode the "slave" will then block the signal to the gasoline injector and fire the gas injector, this with whatever timing adjustment required to achieve the same performance (or close to that).

The tuning of the Gas ECU is fairly simple (initially), the software on the PC will interact with the ECU and gather all engine (running) data and timings in petrol mode, then adjust the gas system to match it as close as possible. After programming these adjustments into to gas ECU, you can basically drive of.

This initial setup will do for the first few 100 KM, this until all components have settled in...

The second tuning is to remove the little quirks, maybe after that a third tune-up is required, but that should do it.

The modern Gas ECU's (depending on brand) are designed to fix even the most crazy conditions, gas valve timings can be adjusted withing the whole rev range of your engine, creating a so-called MAP, this is then stored in the ECU.

As to the performance of LPG cars, a well tuned system will give you about 95% of your gasoline condition, consumption will be higher, but as long as you are still paying less per mile/KM than on gasoline, that should not be the biggest concern.

By the way, not that I have seen them in TH yet, but there are quite some "Turbo's" in EU that run on LPG...

And last, if you want a LPG installation that will give you 100% equal performance/consumption match to your gasoline "mode", go for a LPI system, this is a liquid gas injection system, meaning that the gas is no longer vaporized but injected as liquid. I don't know if any company in TH is selling them yet and I fear that they will cost a lot more.

SM...

[Lancashirelad]

thanks sysmaster for that, as a clear and easily understood explanation of the workings of the modern ECU controlled LPG system.

I knew modern systems were auto switch over.....other posters thinking of older systems with manual switching take note.

I also knew the switch point was generally temperature controlled....... though interesting it can obviously be set so that it always idles (smoother?) on petrol.

Is there still a manual switch fitted aswell or not?

Is there any warning device so you know what fuel its running on?

My last LPG powered vehicle was a 1960 Land Rover in the early/mid 80's. Its still down the bottom of the workshop somewhere.

Was an old fashioned single point manually switched system never right for 2 minutes at a time. Forever cutting out at the traffic lights & refusing to go again!

Next question: Fork LIft trucks. Gas engines, START & run on gas (propane?) How?

[Lancashirelad]

double post removed

Edited June 15, 2008 by Lancashirelad

[sysmaster]

The idle running of my engine is the same for petrol and gas, no noticable difference.

The installation of a modern LPG/CNG system comes with a little control panel that is mounted on you dashboard, little: about 5/5 centimeters...

This panel has a few LED's and a button, two LED's that indicate if you are running on petrol or gas and four that give you an estimate of the remaining gas in your tank.

The button is used to manually switch between petrol and gas (if desired), its also used to confirm the "empty gas tank" warning buzzer.

As for forklifts, no idea.. two options: electric heater on the vaporizer or maybe even an LPI system that does not require a vaporizer anymore.

SM...

thanks sysmaster for that, as a clear and easily understood explanation of the workings of the modern ECU controlled LPG system.

I knew modern systems were auto switch over.....other posters thinking of older systems with manual switching take note.

I also knew the switch point was generally temperature controlled....... though interesting it can obviously be set so that it always idles (smoother?) on petrol.

Is there still a manual switch fitted aswell or not?

Is there any warning device so you know what fuel its running on?

My last LPG powered vehicle was a 1960 Land Rover in the early/mid 80's. Its still down the bottom of the workshop somewhere.

Was an old fashioned single point manually switched system never right for 2 minutes at a time. Forever cutting out at the traffic lights & refusing to go again!

Next question: Fork LIft trucks. Gas engines, START & run on gas (propane?) How?

[PeterE]

I am about to install the cheaper system of LPG on my 1.8 Toyota Altis 2002. It comes to 21.900 now since they say a 3.500 Baht piece of stainless steel (don't know what it is called) needs to be put in.

I feel my car is too old to put in the expensive NGV system and that the car is a bit small for those big tanks.

Am I making the right choice?

[Who, me ?]

I am about to install the cheaper system of LPG on my 1.8 Toyota Altis 2002. It comes to 21.900 now since they say a 3.500 Baht piece of stainless steel (don't know what it is called) needs to be put in.

I feel my car is too old to put in the expensive NGV system and that the car is a bit small for those big tanks.

Am I making the right choice?

I would recommend the Direct Injection LPG system. Around 40,000 B , but it seems to be much more efficient

My 2 cents

[sysmaster]

I had the opportunity to see a forklift engine compartment on the inside yesterday.

Not that I would call this model "representative" but the LPG system on that one

was a fixed mixer with normal evaporator.

At least here in TH, I think that an LPG driven vehicle could start on LPG only,

seen the average daily temperatures, conditions should be good enough to

run LPG on a "cold" engine.

SM...

Next question: Fork LIft trucks. Gas engines, START & run on gas (propane?) How?

[Plus]

Well, my injection system CAN't start on LPG, it needs a warm engine and fluids before it switches from petrol. On cold mornings it sometimes takes 1km driving.

Cheap vacuum systems are less demanding, I've seen taxis with a cold start.

[maverick7]

Hi

I own a avanza. Would like to switch to CNG. Any recommendation for good installer around Hadyai?

Installation cost for sequential and mixer.

Those have converted their avanzas. Could you share your experience on CNG

Thanks in advance.

Regards;

Maverick

[Plus]

I know only of Avanza on LPG, installed the mixer system for 18k, works ok.

[madjbs]

I can start my car on LPG (old system), it takes 2 to 3 times as much cranking to start compared to petrol though.

[monkeytunes]

slightly off topic, does anyone know if s there a way of finding out where PTT have NGV pumps throughout thailand, internet???

[stingray]

2 Questions: What about the registration book (blue book)? usally you should register the Gas convert in the blue book, right? What happen with the insurance.? Some insurance not cover your car anymore if it's run on LPG or NGV.

[sysmaster]

The LPG ECU prohibits a engine start on LPG, however some brands have an undocumented bypass:

---contact off --- press and hold the button on the LPG control panel --- start the engine

Like I said "some", it does not work on mine, therefor my ECU is set to switch to LPG as soon as

both temperature sensors measure above 25 deg. Celsius. Thus averagely within a minute.

I know that's a bit early, but I can't detect any problems with it.

in continuation to my first posting, yesterday we went for a "life" tuning because the "static" tuning did not

solve all quirks, now there is almost no measurable difference in performance between gasoline and LPG.

The guy was slightly impressed about the performance of a 2.2 Zafira, he said that this was the first time that he did a life tuning on a Zafi, other Zafi customers seemed to be more gentle to their engine and did not require a life tuning.

I don't know how this last tuning is going to reflect on consumption, usage will show, specially the weight of my right foot.

Well, my injection system CAN't start on LPG, it needs a warm engine and fluids before it switches from petrol. On cold mornings it sometimes takes 1km driving.

Cheap vacuum systems are less demanding, I've seen taxis with a cold start.

[bubba]

Another tidbit: I have a friend with a Chevy Optra who contacted Chevrolet regarding an NGV conversion, since Chevrolet are now producing new Optras out of the factory with NGV. Chevrolet said that yes, they will do an NGV conversion at their service centres. They have certified NGV for their 1.6L engine and the warranty would not be voided for an NGV conversion with that engine. They can also do the conversion on the 1.8L engine, but the warranty would be voided (even done at the Chevy shop), because they have not "certified" the NGV conversion for that engine.

And the cost? Chevrolet told him about $60K.

[jaideeguy]

Hopefully not a stupid question, but can a car/truck be fitted with the 'cooking gas' tanks??

It would take up a little more space, but would be much easier to replace when empty. Gas shops everywhere!!!

3 questions....

Would the cooking gas tanks be as safe as a fitted tank??

Would the cost/per ltr be the same as an LPG fill up??

Is the gas and pressure the same same?

[Plus]

Forget it, it's impossible. It's like "can I use a canister instead of my fuel tank?"

Gas is the same, though.