Running on LPG - the consequences..

[Stanleywindrush]

Hi, thought I'd start a thread on LPG.

I have just dismantled a B20 that ran on gas for the last 5 or so years. I was shocked to see what a state the engine block was in.

I have dismantled a number of engines and realise what excessive wear looks like on a petrol engine.

It seemed that the tops of the cylinders had started to crystalize and had build up a robust white growth. Also the valves were very burnt, considering the engine was worn and was blowing oil out every crevace the head had no trace of burnt oil at all - the plugs were the same colur as the valve - a very light brown.

the car had been maintained by a garage and I can see it had been running too hot - but the 'growth' on the pistons seemed a little excessive!

I wonder if any of you have seen what use of LPG does to your engines??

PS on a another note the inline fuel additives are a well known scam. Always use a trusted name like Castrol (the additive and octane booster is best) if you can't find any let me know - and never pay more than £10 a bottle- prices do fluctuate wildley depending where you go..

Happy volvo motoring

Baz

[Mike_Brace]

I have run my 240s on lpg as many people know for many thousands of miles over many years. Those that have been dismantled have been in clean and pristine condition. I would expect a head from a car running on lpg to be very clean with no carbon or oily build up and the valves and plugs to be a creamy/light brown colour. On the B18/20 as with any other engine designed to run on leaded fuel they should always be run on Flashlube which is an upper cylinder lubricant injected by vacuum into the inlet manifold and taking care of the upper end of the engine. Obviously it would be possible for it to be running to lean if it has not been set up and maintained correctly. The standard Amazon exhaust is very restrictive especially for the 2.0 engine. Back in the 90s I had problems with burning plugs out running on unleaded due to the engine running too hot. Indeed I have heard of cases of the valves welding themselves to the seats and pulling lumps off. Fitting a Jetex sports system along with a very good radiator eliminted these problems. The problems you describe sound to me more problems with the way the car was set up - exhaust causing restriction/mixture set too lean.

Mike

[classicswede]

Ok lets put things staight here the damage you have seen will NOT be a dirict result of running on lpg. I have know B18/B20 to have done 100,000 miles on lpg that I have personaly been able to inspect perfect much less wear than you would expect for a petrol engine. I know of these cars to have done about 300,000 miles on lpg in Holand with no problems.

The plugs should be a slightly off white colour when running on lpg - the exhaust sould look the same not black like a petrol engine.

The likely resons for what you have seen is lean burning made much worse by the problems with the amazons std exhaust. I have seen B20's completly melt spark plugs whilst running on petrol - not good at all! The easy answer is to fit the simons exhaust.
The growth on the pistons (without seeing pics) would sound like it is the oil seeping past the rings that has caused this (already worn engine most likely).

One great advantage of running on lpg is the engine oil like is extended and bottom end wear is greatly reduced.

I think you would have been better off asking WHY this has happened not LPG is SH1T

I hope this answers the question

[Stanleywindrush]

Hi Dai,

If you read what I wrote correctly you would have seen I had no view on LPG rather letting you know what I found and asked for comments.

I think your final comment was rude and unbecoming of a gentleman. I will in future keep out of these forums if I am to get replies like this..

Yours

Barrimore

[mike gilbert]

Come on fellers, its not worth falling out over. To be fair to both sides I also got the impression Baz was being critical of LPG (which I know nothing about so couldn't agree or disagree with) but his reply is right - if you carefully read his thread he isn't actually giving an opinion on LPG in general but the effect of its incorrect use in that particular engine, and therefore maybe others may be effected the same way if not set up correctly or a worn engine is converted to LPG?

[classicswede]

Baz I'm sorry for jumping down your throat.
I do get very annoyed when ppl slag off lpg when they have no real understanding of it. I often here things like LPG makes your valves burn out , make the oil seal fail, makes your exhaust fall apart, loss of power as well as some other daft things! I do come across this kind of thing quite often and it does get my back up. The way your post came across it does seem to diss lpg rather than be asking the question why?????
The answer to the question why I would like to explain but will need some pics and more info.
I would hate for you to leave this forum as we all need as much support as possible in this section - us amazon nuts need to stick together.
Please do post some pics and if you dont mind maybe consider editing your post.

Thanks

And all the best Dai

[amazondean]

I purchased a modern car the other day for the first time in about six years, as I only drive classics normaly. It was a 1992 bmw 316i. I purchased it because the guy that owned it had it from new and it was basicaly in mint condition with full bmw service history. You may ask, so what. Well, I needed to do a small repair to the bottom of the wing and I needed to find out what the colour code was for the bottom of the car. so I joined the bmw forum to ask if anyone new.

What a load of pompous asses they all are. I found that they are only interested in how fantastic they all are, and dreaming all day long. There are sometimes around twenty new threads a day and about the same replies to each thread. Talking all day long trying to find out who can spend the most money by the weekend.

The point is, sometimes we forget how good we are in this forum, actualy helping each other and there is usualy a few people who have an idea what the problems are or if not, have some serious imput. It has made me realise that this forum is exactly what I need. Light hearted and interesting. Lets hope it stays like it and keeps practical.

I have got a saying which is THERE ARE ONLY TWO THINGS IN LIFE THATS EASY, ONE IS LYING DOWN AND THE OTHER IS HANDING MONEY OVER, EVERYTHING ELSE HAS A DEGREE OF SKILL.

Dean

[jamie]

Yes Mike, the engine was very worn and inefficient when the lpg was planted on it. I suppose Baz was asking could there be a connection between the use of lpg and the state he found the stripped engine in?
Not, look what lpg does to an engine!!
Still it is good to have learnt that a restrictive std exhaust is a no goer for lpg run cars.
All the best and keep it coming
Jamie

[classicswede]

The std exhaust was bit of a problem on 4star give them unleaded and everything starts melting - gaskets and plugs (valves servive ok)
You will get away with running the amazon on unleaded or LPG as long as you do not drive them hard. The B20 suffers worst. I would never have a amazon with a std exhaust as it make them chew fuel.

[amazondean]

What exhaust do you recommend, is it just the twin down pipe, or a big bore as well.

Dean.