All gassed up

[77CVT]

FYI....from a NGK site:

THE INFLUENCE OF L.P.G.
An engine converted from petrol to L.P.G. (liquefied petroleum gas) will cause a change in the spark plug operating conditions. Therefore, some consideration should be made on the type of spark plug being installed.

As L.P.G. has different properties to petrol it influences the spark plug operating temperature and required voltage. The extent of this influence can be seen when comparisons are made on spark plugs which were fitted in an engine using L.P.G. and petrol.

Typical results are as follows :
1. Spark Plug Temperature   2. Spark Plug Required Voltage
 


Temperatures are higher with L.P.G.
compared to petrol. This occurs due
to L.P.G.'s reduced cooling effect.    




Required voltage increases with L.P.G.
because of the difference in the bonding
of gas particles between the two fuels.

Recommendation

To eliminate the influence of L.P.G. and to obtain optimum spark plug performance, NGK recommends:

-The use of a spark plug with one heat range colder (if possible) than that listed in the catalogue: eg, BPR6EFS-13 (L.P.G.) instead of BPR5EFS-13 (petrol) for VN 6 Cylinder Commodore.

AND

-The reduction of the electrode gap by 0.1 mm (which lowers the spark plug required voltage)


Or go to: Plugs for LPG

[Adam]

Interesting, thanks for the info! Will keep in mind when I get some new plugs- prolly soon.

A small follow up- I drove 128km today, most of which was on the freeway and got 15.6L per 100km "fuel" economy. At an optimistic gas price of 33c thats $5.10 per 100km eheheh...

I recently fitted an alarm too, so now i'm slowly going through the engine bay and trimming some of the wires and hoses. About 50% don't go anywhere anymore and are redundant, (my old carburettor was an early electronic type).

Adam

[Adam]

Anyway, heres a pic of the gas system in the engine bay. I've since been able to take out a lot of obselite hoses and wires once i found out they didn go anywhere! (I think im still in a "getting to know u" phase of vette ownership.)