"Can a conversion of EFI and Carb'ed Plus 8s from petro to alternative fuels such as LPG be done and if so, could you comment?


Bill Fink


The LPG conversion of EFI Plus 8's can certainly be done, using a propane mixer in the inlet stream between the air flow meter, which may be taken off line, and the plenum. In regards to the fuel, it contains something like 85% of the energy per gallon of petrol, so unless you are able to neutralize that disadvantage by optimizing other parts of the system, like the emission constrained EFI computer, you will lose out on top end.

There is a Dutch firm which has developed a liquid fuel injection system for LPG which would be worth looking at, although I don't know the name of the company. In any case, it is possible to tie a lambda sensor to the Impco system to maintain the proper mixture for catalysts.

I did some experimentation with LPG on an EFI car years ago, and found a dramatic improvement in throttle response and apparent power in bypassing the constraints of operation imposed by the EFI computer. Wheelspin in second was very dramatic.

As to non-EFI systems, we have run LPG with a carburettor through a twin catalyst exhaust without the benefit of Lambda sensors and had no problems with California smog checks.

Several years ago, Calor Gas did a dual fuel conversion on a dark blue Plus 8 in the UK which I saw at the works and it ran very well indeed - it may have been one of Rob Wells' cars.

Your correspondents should note that there are myriad UK regulations governing the fitment of LPG systems to motor cars.

A properly engineered system will perform superbly - a lash-up job will result in appalling fuel mileage, greatly reduced performance, and numerous safety considerations with quite dreadful consequences.



John Sheally II

Ok Lorne,

Bill Fink is your man on this one. On my part I use and love the propane. Iit is clean and gives you a 99.9% burn. The oil stays sweet as there is no wash down of the cylinder walls, and the spark plugs stay perfect.. The flash point is supposed to be 10% less than gas however with a 99.9% total burn that is offset in my applied opinion. I have discussed propane with Peter Morgan as to using it in the UK but he tells me it is not as easily available in the UK as in the USA.

You can use LPG but it is supplied in vapor form and accordingly takes a much bigger tank to store where propane is gallon for gallon in liquid form. All the parts,Carb,Offey/manifold/preheater,switches, etc.are ready available in the USA. It's a great fuel.


John H. Sheally II

Gerry Willburn

Hi Lorne,

Bill Fink is the world's expert on propane Morgans.  Other than the American affinity for gasoline, I have never heard a complaint about one of Bill's conversions.

All the best,


John Worrall

Suggest you contact Bill Fink at Isis Imports, USA,  he used to convert the Plus 8s to Propane to
get through the US regulations...he is therefore the EXPERT on this !

John Worrall