How reliable are LPG conversions?

The reason I ask is I had one on a previous fuel injected car and it lunched the engine. What I was told by various LPG fitters was that higher mileage engines couldn't take the extra heat generated by the LPG systems. I understand the LPG systems for engines like mine 3.5 V8 on twin carbs are simpler?

Anyone have any experience good or bad of running LPG on these engines?

on carbs is simpler, to be honest my experience with them has only been on old installations and old cars, mainly RRC's and there ****e in my opinion. if you do buy new and have it installed properly i cant see there being a problem and should be reliable enough for you.

RAZ8550TDI said:

on carbs is simpler, to be honest my experience with them has only been on old installations and old cars, mainly RRC's and there ****e in my opinion. if you do buy new and have it installed properly i cant see there being a problem and should be reliable enough for you.

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worked in a dealership years ago and they ate the valves and seats at that time on new engines because of the heat as you say. I don't really see you getting your money back on a conversion, short term at least, or even long term unless you are doing a lot of miles. Coupled with that where do you fill up, not any that I know in my area, must be some but where.

As said they are reliable but cost must be taken into consideration, do your maths since it's a long term investment.

Zonda_ said:

The reason I ask is I had one on a previous fuel injected car and it lunched the engine. What I was told by various LPG fitters was that higher mileage engines couldn't take the extra heat generated by the LPG systems. I understand the LPG systems for engines like mine 3.5 V8 on twin carbs are simpler?

Anyone have any experience good or bad of running LPG on these engines?

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I converted a 45,000 mile 3.5V8i Discovery in March 2000, and went on to add a further 45,000 with no problems whatsoever.

I reckon it saved me £30 everytime I filled up, which over the time I ran it on LPG, amounted to around £5000. Not bad for a £1200 gas conversion!

OK, the payback will depend a lot on the number of miles you drive, but as I was driving approximately 1000 miles a month it paid for itself IN A YEAR, and this was at 2000-2004 fuel prices...

Maintenance wise I noticed no difference at all - no overheating, no additional service costs, no problems at all.

I appreciate this may be the exception rather than the rule, and others might have a different experience, but in my opinion it's a no brainer, especially as it arguably makes the vehicle more sellable too.

I have run lpg V8 and 6cyl (ford) in UK and Oz (V HOt) with good results, for usability best on fuel inj vehicles due to easier switch from pet to gas and back . Best economy on gas inj system (most expensive) . Lpg makes V8 as cheap to fuel as tdi . Most probs are down to people who buy lpg vehicles for cheap motoring and make the ''cheap'' stretch to maintenance as well . Most probs are with the cooling side as there are more hoses and therefore chance of leaks .
Modern unleaded compatible engines have no valve seat probs dealing with lpg. Oil change intervals can be extended as lpg is a lot less damaging to the oil (combustion by products) . Due to the lesser energy density of lpg you use about 25 to33% more per mile .
If the vehicle is set up properly(tuning) backfire chances are a lot less , these can damage the flapper type air meter on 3.5 engines. You can buy dedicated lpg vehicles from Holden(Vauxhall) GM HTSH

The system on my 4.6 rr (now at 113000 miles) works fine, I just keep an eye on the oil and water levels. Usally needs a bit of water every 2 weeks or so, apart from that it makes it almost as cheap to run as my old 1.8 mondeo.

can someone explain how the water level is effected by an lpg conversion?

dunno but my old works van an lpg ford connect used to burn oil and ford said that was normal and to just keep an eye on it!
Not sure if that's just ford being retards and not bothering to repair it properly.

being retards seems the appropriate term.

Maybe they upped the CR to get the most from the lpg and decided to use water injection, and to save money they used the cooling system as the supply ?

RAZ8550TDI said:

can someone explain how the water level is effected by an lpg conversion?

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Because the engine runs hotter with lpg, and because if like mine your engine has a slight water leak, you'll loose more water because it's hotter.

I should really fix the leak but it's one of thos annoying ones where it's so slight it's bloody hard to find, plus I've got several other jobs to do on the car as well, ie, retrim all the seats, fix rear window washer and respray bumpers and sills( got a bit over enthusiastic off road).

RAZ8550TDI said:

being retards seems the appropriate term.

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It certainly is, my now works van (a transit diesel) is crunching into 3rd, took it to ford, they said they'd adjusted the gear linkage and gave it back to me, just had to take it back cos it's still doing it, they now have admitted it needs some gearbox parts. As i said before, RETARDS!
Sorry for thread hi jack, rant over now.