gas conversion anyone?

[deian]

i had a quote ages ago when i had my bmw, but it was like Ԛ£1200, anyone gone ahead with such a conversion? how is it? i understand lpg is 100ron, does this help the engine?

thanks
deian

[Simon]

Stick LPG conversion into the search function and take a read of some of the previous posts, there's been quite a few now.

[Brianmoooore]

i had a quote ages ago when i had my bmw, but it was like Ԛ£1200, anyone gone ahead with such a conversion? how is it? i understand lpg is 100ron, does this help the engine?

thanks
deian

Conversion to a M40 or M20 can be done for Ԛ£300 - Ԛ£400 with a little help from ebay, if you know one end of a spanner from the other.
Job must be done properly ,though, and in accordance with the current regulations, known as COP 11.
Higher octane rating is only of use if the engine is modified to make use of it, or if the engine has knock sensors, like the M50 (the engine I've just obtained the LPG parts for).

[deian]

Can the M30 be converted? do they have knock sensors?

[Brianmoooore]

Can the M30 be converted? do they have knock sensors?

Can't think of any reason why a M30 can't be converted in exactly the same way as a M20.
I doubt if any M30 ever had a knock sensor.

[exup]

i m interested in converting ( once i ve built / fitted the 2.7 eta) i run a octivia 1.8 turbo ( audi tt lump ) chipped to 200bhp on lpg at present , so the bmw next

[6inline]

Yes mine is LPG powered, 320i L-jet. Keeps the oil cleaner and the head.
Loss of 10 to 15 BHP however and runs smoothly then petrol. Has to be done properly. Can give you details if interested

[deian]

ok here's what i know, lpg is 100RON right, hence smoother, less economical but cheaper to buy hence the savings, also the gas can will weigh the rear down, so we lose about 10bhp? damn, so before this conversion u'd need a top notch engine to have max bhp, 6 branch manifold, cold air (shielded air filter to keep cooler and a k&n kit?), etc etc? plan was to shove it on an M30 converted e30, and to turbo it too, not sure how it works with a turbo, damn so complicated here

[Brianmoooore]

There are two types of LPG conversion around these days. The earlier venturi based systems, such as 6inline has, and the newer gas injection kits, now redially available and sufficiently developed to be easily set up and reliable. There should be no power loss at all with the latter, but the parts required will be about Ԛ£400 extra over the former.
By using a torroidal tank in the spare wheel well, you can keep the weight of the tank low down, although behind the axle. LPG is less dense than petrol, and I doubt if there's much difference in the weight of a full tank of gas over a full tank of petrol, although an empty gas tank weighs much more than an empty petrol tank.
Theres no problem in fitting LPG to a turbo engine, although it presents some extra things to be considered. Basically you connect the atmospheric pressure sensing of the system so that it can see the turbo boost pressure.
LPGed E30s can't usually make use of the extra octane rating of LPG, but with a turbo it could probably be utilised.

[deian]

excellent, thanks for that brian, it answered all my concerns.

[kam-325i]

The higher octane of the LPG can only be made use of if the engine is set up to use LPG permantley, has you need a higher compresion to use the higer octane and to stop pre-ignition (pinking ?).