Best / safest LPG system for 3.9 Classic

[superquag]

I've been trawling the LPG section ... and still cannot quite make up my mind as to The Answer... Thing is, kits etc have advanced, so the Great Debate of vapour vs Injector appears less than certain.

I've got a /95 Classic Vogue, SE. 3.9 Auto with just over 165K. If I can get a reasonable consumption I'll keep it 5+ years, otherwise it may have to go by year's end. Or sooner.
At present its doing 20 llitres per hundred, maybe 19.5 but no better. Replaced vac advance unit, Bosch leads, new plugs, advanced a bit more than standard... Co$t is $30 per 100km at $1.49 per litre. LPG is 90 cents/litre.

Which way ? Vapour with a ring mixer, or 'injected' ? - Can't afford to lose a noticeable amount of power.... NOT impressed with the 3.9.:mad:

I really do *not* want a back-fire prone system. - Had one before (vapour) which eventually destroyed the flapper, despite various 'backfire prevention devices'. Did my heart no good either !:p

Thanks !

[bee utey]

Ring mixer systems can be made very resistant to backfires, but not 100% idiot proof. Power loss is modest if you use the correct mixer. Economy is good if you use a LPG processor and O2 sensor. It's what I do most to D1/RRC's etc. Not much negative feedback from owners.

Aftermarket vapour sequential systems aren't 100% optimum as they rely on the (dreadful Lucas) petrol system remaining in tune, as they petrol use injector pulses as their input. EXCEPT:::

There is a company in Perth that have designed and built a fully standalone sequential injection kit that could be run as dual fuel if you wished, retaining the old 14CUX for petrol only. I am 1/2 way through installing a demo one on my car. The brand is Profire, ProFIRE Engine Management (http://www.profire.com.au) . This is of course the most expensive way but then it's certainly the most sophisticated.

Enjoy your cost/benefit calcs!

[superquag]

Enjoy your cost/benefit calcs!

:twisted::twisted::(:o:(:twisted::twisted:

[bee utey]

:twisted::twisted::(:o:(:twisted::twisted:

:p:p:p:p:p:p

Look, if you want my opinion, use a good ring mixer system, learn how to keep it in tune, keep grotty mechanic's mitts away from the plugs/leads/timing and you'll be fine. Fit an earlier model steel air filter assembly and it will survive an occasional backfire without damage. Once you have chosen your local gas fitter I can advise/supply bits as required. Not hard, I've done it all before.