lpg injection on turbo diesel

Extra power used in anger will eventually cost, extra power doled out with a little common sense should cause you no heartache...

Was talking to a roadtrain driver a couple of months back who said his company had installed it for economy, he complained that they had also derated the engines back under 500hp for reliability.

I did some research about twelve months ago on the merits of fitting LPG to a 1HZ engine similar to yours. All the mechanically qualified people I spoke to said, "No, don't go there."

The figures quoted by the company installing them are wildly distorted, a 22% increase in torque with a similar decrease in fuel consumption just doesn't wash.

Since then I have read several tales of woe concerning LPG fitted to diesels in "The Wanderer", the monthly mag of the Campervan and Motorhome Club of Aust.
Sorry to be the bearer of news you didn't want to read.

Rob.

I wouldnt worry about what he said too much.....i would be fitting an exhaust gas temperature gauge (egt) straight after the turbo so u can see whats going on in the motor temperature wise, and drive by it...ie when it reaches 600 deg celcuis, back off or down shift...that will ensure you dont do any damage.
Id like to see someone bend a hdfte crank.
Andrew

My old mate Chook had lpg injection fitted to his '01 mitsy Triton TD last year with less than 150,000ks on it.
We could never prove it was the gas injection, and I'm not saying it definetly was, but that motor was stuffed within 20,000ks of having it fitted.
Rings burnt out and started badly bypassing, turbo sh-t itself aswell.
Chook did have a habit (still does!) of using whatever power is available and tows alot ( camper-not that heavy) so it may have nothing to do with the lpg, but it just seemed a bit suss on a low km motor.
Sorry if that doesn't help your concerns, but after that I decided not to go with lpg injection just to be on the safe side.
I'm sure there is plenty of people out there who have had no problems at all - hope a few of them can give you a better peace of mind than I have done.

Cheers, Keith

Which motor do you have - the 1Hz or the 1HD-FTE? Responses above are for both.

Don't engines have to be rated for LPG? A mechanic told me once that one problem with LPG is it doesn't have any lube qualities. I was thinking that diesel displaced in the engine by LPG will result in less lubrication in the cylinders, valves etc.

So the next question is, will diesel fuel additives counteract this? We all know the off the shelf ones, as well as those who run things like 2-stroke or vegie oil. Will this give the engine what it needs to keep the wear and tear at a point where you get an 'expected' lifespan from the engine?

when gas first came out for petrol engines didt they have have a lot of dramas??, although they seem to have it fixed now.

used to do work for a hospital that had natural gas engines.....lot of troubles they had....i was there one day when one of the engines began making a horrible noise and let go.....scared the be geezes out of me...

wonder if its cos diesel type engines just still are'nt built for gas???

I am researching this issue at the moment so this post is very valuable and timely for me. One issue that has not been raised is the type of system - there are 3 types of gas injection. The earlier ones can "over inject" under some driving conditions and probably in the long term do harm to the engine. the one that propmpted my interest was the one that won the Inventors (ABC TV) episode earlier this year. their technology appears to better than the earlier ones. My point is that the type of system used can play a big role in how successful or not the process is. As someone else has already said the earlier gas petrol conversions had problems but they appear to have been sorted out. If the injection of gas provides better combustion of the diesel fuel - all other things being equal - it suggests to me that the principle of gas injection should give more power and better economy.

What system did you install The Bull?
I would like to hear from anyone that has installed gastek system.

Here is an extract from their web page regarding the 3 types of systems:

"Oils aint Oils
On the market there are three main types of diesel/LPG systems.
Solenoids and Jets
Stepper and Venturi
True Gas Injection
The solenoid/jet method is the oldest and most crude system available on the market. Basically the system consists of a solenoid to turn the system on and off and a jet to control the flow of gas.

The problem with this method is that while the system is on, the flow of gas is constant when the engine is not. This mean that while the vehicle is idling, there is too much gas going in, damaging the engine. While pulling a caravan or horse float, the engine is working hard, there is not enough gas, giving poor performance and fuel savings.

Unfortunately the majority of diesel/LPG systems on the market use this method because it's cheap to make and fast to install, allowing the manufacturer and installer to make a quick buck before it all turns pear shaped. Tuning is done by unscrewing the jet and replacing with a bigger or smaller jet. These systems damage engines and give poor fuel savings.
Being the cheapest to make also means these are the cheapest to buy and give truth to the phrase “Buyer Beware”. "

I have no association with gastek.

Cheers


The stepper and venturi method is an improvement over the solenoid/jet method but still falls way short of a true injection system. This system uses a stepper to open and close a valve gradually to meter the gas flow and a venturi to allow the gas to be sucked into the engine.

The killer with the stepper/ventrui system is the response time. These systems make take up to 20 seconds to catch up with the engine. Just think how long it takes you to turn your garden hose on from fully open to fully closed and back again. These systems work just as fast.

With a response time like that, you have already overtaken the car ahead before the gas has caught up with the engine. If you hit the brakes hard, the system is putting gas into the engine long after the diesel has stopped, damaging the engine.

A true injection system uses a needle injector, which is the same injector used in all modern petrol/LPG systems. The flow of gas is metered by pulsing the injectors rapidly. This rapid pulsing allows the gas to be exactly measured while giving an almost instantaneous response time.

The faster, more accurate delivery means that better performance and fuel savings can be achieved using less gas and without damaging the engine.

All of these systems claim to “Inject” in their marketing but only a true injection systems use a needle injector. When selecting a system ask your installer if they use a jet, ventrui or a needle injector cause "Oils ain't Oils".

Firstly does the 15-16 per 100 include LPG usage.

Secondly your rig, unless vehicle has been certified for more than standard is seriously overweight.

The weights are for a 1 HZ motor

payload 824kg

GVM 3180kg

GCVM 6680KG

Roofrack 200kg


Dont have a prang.

My GXL tows 2800kg and driving at 90k averages 17l per 100km so dont know how you do better with the thirstier motor and an extra tonne

Hi

I have LPG injection to my ZD30 TD Patrol. Travelled about 45,000 kms in the 3 years since installation.

Total average fuel consumption over 10,000 kms (all types of driving conditions) remained the same at 12.2 lts/100kms.

However, diesel consumption dropped to 10.9 ltrs/100 and LPG 1.3 ltrs/100.

Engine performance enhanced significantly, especially 0 to 40 kph and in low range hard work situations.

Vehicle now travelled 182,000 kms since new with no engine problems. Runs like new, starts easy, heaps of power, quiet and smooth and no oil consumption.

My service mechanic (not LPG installer) says LPG injection cleans up the combustion chamber resulting in more efficient fuel burning and less engine oil contamination which should result in longer engine life. I hope his information is correct.

I have not met any one with diesel LPG injection who has experienced engine problems.

I have met a few who know of people who have next door neighbours 2nd cousin twice removed etc who have had terrible trouble with diesel gas. The problems get worse after they have had their 6th stubbie.

Hope this helps
Cheers
Phil

hi
with that weight in tow and cvm hope you've got a keen eye great reflexes and above all extremely good brakes and a slow crumple rate

To me fitting gas injection is against the KISS principle. Regardless of its merits or otherwise on fuel economy power and engine life it adds complexity and the need for two fuels instead of one.

The benefits would need to be sizable to offset this disadvantage. Doubt very much that any significant advantage has been demonstrated by going down gas injection path for a motorist. A few percent theoretical advantage is not enough IMHO.

the 4.2 will be lucky to make it to 400,000 especially towing a van around. I would have said 350,000 tops. The gearbox will go first as these are the weak link in the chain. Expect it to jump out of 5th by 300,000 and have all the wining noises by about 275,000. It will need a rebuild at 350,000 tops as thats about all they are good for.

Hi Bull have had diesel/gas on my Did Pajero for3+ years and have done over70000ks car starts easy uses no oil i have never heard of anyone personally who has had a problem,the expert told you it would bend the crankshaft where as some one else claims it will burn out valves i had mine fitted by Diesel/Gas technologies i also went back a few times to get the flow cut back it runs about 2.60l per 100k. I get around 200ks extra per tank of diesel at the cost of gas. I would be very interested to hear of any 1st hand problems

In victoria fitting lpg to diesel's make them unroadworthy, as they no longer meet emission standards, this is in the latest tech bulletin from vicroads.