Friday, Jan 20, 2012 at 23:07
Fab
I used gas powered cars for 18 years but mainly for commuting to and from work. There were two long trips from
Sydney to far north Qld and two to Tasmania during that period plus a five year period living in rural NSW. I now own a diesel. I would use gas again but only in major city areas. The much higher prices in the bush reduce savings so much it would be hard to do enough ks to justify the cost of the conversion.
The first car was a 12 year old 504 Peugeot. The exhaust valve seats lasted 20,000 ks. After fitting harder ones, it went another 400,000 ks over the next 10 years without any problems. It was dual fuel but I rarely if ever switched it over to petrol.
I did not like having something in the car that I did not know anything about so I completed a 2 week full time course at Ultimo TAFE in
Sydney and got my own installation licence.
After scrapping the Pug I converted a Gemini that had been in the family for a few years to straight gas and did 180,000 ks over three years. It immediately started getting too hot. A new triple core radiator and a different thermostat did not fix it but making a fibreglass fan shroud did. There were no problems with valves or anything else. The conversion cost with a new tank and a few of the Peugeot parts was $700.
Next came a Holden powered Mitsubishi ute. The engine was rebuilt to suit straight gas from day one. It only did 80,000 ks over 5 years because I was not commuting to work any more. It cost me $600 to convert it but if I had to pay the usual conversion costs it would not have been worth it.
The conversion cost is a major factor. Even with Govt. rebates, the latest computer controlled systems are expensive. You must be certain you are going to do enough ks to make it worthwhile.
Gas can make your engine and exhaust system last longer but saving money is the main reason people use it.
When we started the TAFE course, the teacher wrote the then current price of gas and petrol on the top of the blackboard. Gas was 23 cents per litre and petrol about 50 cents from memory. Every time we discussed a disadvantage with gas, and there are plenty of them, he would point to the 23 cents and that justified it.
When calculating the expected range of gas in your car, don't forget the tank only holds 80% of its water capacity. That means a 100 litre tank will hold a maximum of 80 litres of liquid gas. This is to allow for expansion which is 2.5 times that of petrol. The tank is also 3 mm thick and fairly heavy. The older systems will use about 12 to 15% more gas than petrol to go the same distance but I think the current systems have reduced that difference considerably. It will all depend on the age of your car and the type of ignition and fuel system it has.
If you decide to do it, make a few inquires first with gas conversion companies, Pajero forums on the net and gas equipment manufacturing companies like Impco for example. Make sure your engine is suited to it. Find out how it will perform on gas with the engine still tuned for petrol. See if anything has to be modified like the cooling system, ignition etc.
These were all issues years ago but may be different now. Many cars had valve problems but now anything designed for unleaded is usually ok. A blue 202 Holden for example was as dead as can be on gas but replacing its camshaft with a stock one from an earlier 186 model made the world of difference.
Gas burns slower than petrol so advancing the ignition timing at idle was the way to go. What you added at idle had to be taken off at maximum revs though or it would over-advance at cruising speed. This made a big difference for gas but when you switched back to petrol, the engine would ping its head off. This meant dual systems were a compromise with gas performance the one that had to suffer.
The latest factory systems may allow for this in their computer designs but your petrol computer, if you have one, may not be reprogrammable. If it is then the conversion cost may be higher.
Have fun and I hope it all works out ok.
AnswerID:
475553