Tuning for Mileage

[van]

Kia ora.

Doesn't time fly when you are having fun?? Hard to credit that 5yrs have flown by.Well the old van is history, I parked it up about 2yrs ago and it has been sitting there deteriorating in the weather in the interim. It was replaced by an '86 Holden Commodore VK Berlina, retro-fitted with an LD 28 Nissan diesel an engine I am rather fond of. Initially little was done to it, tho recently I added an LPG fumigation array to it which saw the lpk rise from 12-15ks per l to over 20ks per litre close to around 60mpg. Much more can be done I am sure, but lacking access to a workshop and frustrated trying to source certain goodies, will probably mean it won't get much further than that.

Bill

[Chris]

OK I'm reading you correctly, you're getting over 60 miles per gallon in this car with the tuning that you spoke of years ago in the beginning of this article? I wasn't following the thread before but 60mpg has my attention!?

[van]

Kia ora Chris.

While I did hear about LPG fumigation many yrs ago, it is only in the past yr that I have installed it. Basic install, 9kg lpg cylinder in the boot, gas is solenoid controlled via a micro switch on the throttle linkage ie I can adjust when it becomes operational, and then there is an over-ride switch which can turn it all off.
It is wired up from the oil pressure switch so that if the motor is not running the gas cannot flow. Currently it is set up to come on at about 60kph. gas pressure is regulated via barbecue lpg pressure regulator (.3 lbs sq in?) and fed directly into the inlet manifold. Memory serving me right the largest jet I have is 1mm in dia which gives an enrichment supposedly of 10% tho I think it may in fact be higher.
Lpg tank , using largest jet, is good for about 3000 km.
Incidentally not only better economy, but also power increase, quite noticeable traversing hilly terrain.

Another option to add would be a fuel heater, my guess being, based on earlier experiments, to be good for perhaps 7-10%. Cold air intake may also add another few percent.