LPG optimisation

[malbeare]

Dear fellow members I would like as much info as possible on the optimising of an SI petrol engine to be specificly tuned to run on only LPG. What is the calourific value of LPG compared to Petrol and what is its octain rating?
Thankyou Malbeare

 

[franzh]

I seem to get tasked with answering LPG questions, but before we get too deep, this has been discussed many times, please do a search on this forum.

Franz

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[malbeare]

I should refine this a bit more.
specificly what is available for small engines in the way of carburettors vapourisers and gas mixers . We are talking about single cylinder 4-stroke 125cc to 250cc air cooled motorbike engines.
Does anyone have any experience in this?
malbeare

 

[franzh]

(From the US perspective)
Not much equipment is available, I'm sad to say. In the US, motorbike conversion to LPG has never had any interest, but in other parts of the world, there is some interest, primarily due to economics, but more recently, emissions. In some third world countries, the motorbike is the dominant form of transportation, most of them are two-cycle with the inherent emissions problems.

As for what equipment, I know of one vapor injection system that works well and dont particularly care for the field installed "kits" that are used in generators and pumping engines (also called "spud kits").
Franz


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[pbloore]

As Franzh has said there are a lot of small motorbike/moped conversions in the third world mainly using equipment from Italian suppliers I think, certainly BRC supply kits to India. To the best of my knowledge they do not supply any kits in the UK

 

[GregLocock]

Making a wild guess, mal beare is in oz, not the UK.

Cheers

Greg Locock