In my experience Webber performs better at high revs but other than that a decent size SU would be better, easier to tune and more economical
 
Rebuild the petrol with a higher compression and a warmer cam, give around 100bhp there, should do around 20mpg if set up right, a decent LPG kit will do about 90% of economy but half the price.

As above Megasquirt does sound fun
 
One reason for suggesting megasquirt is the ability to use a Lambda probe to set mixture, injectors, loads of injection cars in the scrap yards.

Also SGI LPG systems are so much better than mixer systems, I DIYed a GM V6 (RIP) and that was great.

Saved around £15,000 over the time I had that car
 
TDi engines are all getting on a bit now (at least 25 years old) and no one's quite sure what the prospects are for diesel going forward.

I think you're right about the future of diesels, I know that there has been a big push to purge the older ones from cities and it's all too easy to say to yourself "well it's only my hobby vehicle, we don't go into cities" but if you look at progressive (regressive and damn right extortionate) Holland, 1/2 of my £2400/yr road tax was what they classed as a "diesel surcharge", basically they pulled your pants down and raped you for running the devils juice :(
 
LPG does burn much hotter than petrol so valve issues are a possibility, don't know how hard the seats are on the 2 1/4 so can't say but that is a drawback.

It'll eat sparkplugs and the ignition system has to be 100% all the time!

TBH from what i've heard the 2 1/4 should do 20mpg, a friend of mine has a 109 and it is an old worn out rattly unit and its still pretty frugal for an old landy!! ;)
 
Lots of good advise for you. Dieseldog69 certainly knows his stuff from personal experience, but I run a 200tdi and happy enough with it. I got around 32 mpg before the roof rack went on......
 
LPG does burn much hotter than petrol so valve issues are a possibility, don't know how hard the seats are on the 2 1/4 so can't say but that is a drawback.

It'll eat sparkplugs and the ignition system has to be 100% all the time!

TBH from what i've heard the 2 1/4 should do 20mpg, a friend of mine has a 109 and it is an old worn out rattly unit and its still pretty frugal for an old landy!! ;)
The problem isn't so much the heat generation but the ignition timing, being of a higher octane value the LPG has a longer burn cycle than petrol and therefore needs advanced timing, unless it is advanced it then affects the valve seats as the gasses are still burning as they are being evacuated through the exhaust valves thus burning the seats away. IWEMA technologies make ignition advance modules that enable you to switch between the two fuels and run seamlessly, there are other manufacturers that do similar but I've used these ones and can recommend them. The 100% solution is to run an EFI system for both fuels through MS with the added benefit of being able to select between two purpose designed ignition maps that would be selected automatically when switching fuels.

Sorry, getting myself a bit of a semi with all this erotica, might have to do an engine swap in my Disco now to satisfy my craving........ :confused:
 
The problem isn't so much the heat generation but the ignition timing, being of a higher octane value the LPG has a longer burn cycle than petrol and therefore needs advanced timing, unless it is advanced it then affects the valve seats as the gasses are still burning as they are being evacuated through the exhaust valves thus burning the seats away. IWEMA technologies make ignition advance modules that enable you to switch between the two fuels and run seamlessly, there are other manufacturers that do similar but I've used these ones and can recommend them. The 100% solution is to run an EFI system for both fuels through MS with the added benefit of being able to select between two purpose designed ignition maps that would be selected automatically when switching fuels.

Sorry, getting myself a bit of a semi with all this erotica, might have to do an engine swap in my Disco now to satisfy my craving........ :confused:

Thanks for the detailed explanation!

Aye a V8 3.9 slightly built with an LPG system would go well! or maybe even a stage 2-3 4.6 or!! a nice 5.2!! ;)
 
Thanks for the detailed explanation!

Aye a V8 3.9 slightly built with an LPG system would go well! or maybe even a stage 2-3 4.6 or!! a nice 5.2!! ;)
My old 3.9 Disco with a fast road cam running LPG with an MJ install was the bomb, still single figures on the economy though, I put it down to my drive it like you stole it motto :)

I've previously done a decent amount of porting and polishing of heads and have found that even simple gas flowing and gasket matching can yield great results for as little as a few hours sitting at the bench with a die grinder and a carbide bur.
 
My old 2.6 GM V6 was knocking out nearly 200bhp and I got it down to 11mpg towing a caravan against a head wind.

I ported it, LPGed it, fitted lumpier cams, sports springs, had it over 8 years from only 4 years old.

GM screwed up when they dropped their big saloons, they are all boring now
 

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