BXProject

[mat_the_cat]

I'm thinking more performance TBH - it's got an ovctane rating of about 115 RON so you could have a fairly high compression ratio before pinking became a problem. But then you'd be left with an engine unsuitable to run on pump petrol, and a supercharger is the only way I can think that you could effectively have a switchable compression ratio.

[Stinkwheel(Matt)]

If you went for the later(but not latest) single point injection LPG system can you not run on these permanantly? (i.e. no petrol needed) so you could build a RV8 motor with higher comp, cam etc etc job done, Rover V8's arent that expensive to build to a better spec yourself. Or am i over simplifying?

[mat_the_cat]

Don't see any reason why not, AFAIK the main reason that they use petrol to start is to avoid the cost of enrichment control for the gas fuel when a system already exists in the vehicle for petrol. A lot of systems have an emergency 'start on gas' setting which would probably require a fair bit of cranking but would be acceptable on a weekend or track car.

On the other hand the latest sequential systems simply act as a slave to the vehicles ECU and modify the petrol injector timing to suit the characteristics of LPG and the atmosheric/tank pressures (so would probably start equally well on either fuel) - having said that the petrol ECU map wouldn't suit a tuned angine anyway. I wonder whether you'd need an electrically heated vapouriser until the coolant warms up?

Oh well, probably another project I won't get round to any time soon...

[stu]

I love this forum.

Mat posts talking about a sensible little runaround, and now we're talking about superchargers