LPG & K's Per 100

I love LPG, it is a really versatile fuel but in a standard petrol engine it is restricted by the speed it burns and that is why it burns so much to make the same amount of power.

Because of that, no matter what induction system you have you wont get huge changes in economy.

The Vapour injection is the better of the different set ups, Ive never had much to do with the stepper motor type systems (though my AU had )but simple and complex systems I have played with a bit on several of my cars.

If you want to get economy out of LPG and find the extra power that is available you have to build an engine to suit the way the fuel burns so up the comp, recurve the dizzy and if possible use a short stroke high reving engine rather than a lazy stroker.

Big valves and huge lift and duration on the cam Ive heard help as well but I havnt played with that side of things to know for my self.

I havnt owned a Rover with LPG but all the figures are much of a muchness from what I can see so without major changes then I dont think you will get much better.

To get the best out of your system though, keep the plugs gapped spot on and clean, keep it in tune and keep a clean air filter in it as all 3 of these will effect your LPG economy/power significantly more than on petrol.

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Originally Posted by mark2

I get about 25 liters per 100 from a twin carb 4.3 I recently fitted a vacuum gauge - I think thats going to make a fair difference as it tends to make you a lot more aware when you're getting heavy on the loud pedal.

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I had a fairly well known Landy mechanic tell me that fitting a vacuum gauge will ultimately damage the vehicle.


You'll end up running up the clacker of someone whilst watching the gauge :o:o



Martyn

I cant say what I get as yet, as I dont have a spedo that works (cable is busted). But I think here the main thing is that you like to drive with a heavy foot :)

At the end of the day, its a bid v8 motor, and you wont get big v8 power without feeding it lots of juice.

If you want to get economy out of LPG and find the extra power that is available you have to build an engine to suit the way the fuel burns so up the comp, recurve the dizzy and if possible use a short stroke high reving engine rather than a lazy stroker.....


so subarus EJ20 is a likely candidate?

I want to get my dizzy recurved, as I can only set the timing to be right for low revs or high revs (currently pinking at 4000rpm when you put the foot down). Does anyone know where in Melbourne I might be able to get this done? I'm sure there is an extra 0.2km/L to gain from that ;)

I always thought my economy was abysmal, but when looking at what the other more modern rangies and discos get on LPG it makes me feel much better considering my car is 26 years old!

God, I wish you blokes would do the calculations instead of posting "I get x km out of y litres". :mad:

I don't want to sit down and work out what you're getting in litres/100km. The figures you quote are useless as they aren't to a common standard.

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Originally Posted by procrastination inc

If you want to get economy out of LPG and find the extra power that is available you have to build an engine to suit the way the fuel burns so up the comp, recurve the dizzy and if possible use a short stroke high reving engine rather than a lazy stroker.....


so subarus EJ20 is a likely candidate?

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If you want to quote me then please actually quote me.....

Subaru engines take LPG really really well, Ive had an EA81 in a Brumby on LPG and got up to 600kms out of 80ltrs as dual fuel, made it from Mansfield to Sydney (actually Richmond) and back to Goulborn on a fill of gas and petrol.

If the engine had been built for gas im pretty sure it could have done better but I wouldnt imagine that you would get 12 to 14ltrs/100kms with an EA81 in a Rangie or Disco.

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Originally Posted by p38arover

God, I wish you blokes would do the calculations instead of posting "I get x km out of y litres". :mad:

I don't want to sit down and work out what you're getting in litres/100km. The figures you quote are useless as they aren't to a common standard.

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Ron I did I did I did:D:D:D

so this works out to 23.11L / 100K's (average taken over 9 fills)

so come on the rest of you do as Ron says lets have a common standerd

now a lot of people have talked about loss of power building the engine special for LPG to keep the power, well guys my little red rocket runs great on LPG you would not tell the difference between the two fuels...power wise, and the switching (done manually cuz thats the way I wont it ) between fuels is instantaneous I reckon if I put two fuel maps into the unichip I will improve the fuel economical

Tony

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Originally Posted by tony

Ron I did I did I did:D:D:D

so this works out to 23.11L / 100K's (average taken over 9 fills)

so come on the rest of you do as Ron says lets have a common standerd

now a lot of people have talked about loss of power building the engine special for LPG to keep the power, well guys my little red rocket runs great on LPG you would not tell the difference between the two fuels...power wise, and the switching (done manually cuz thats the way I wont it ) between fuels is instantaneous I reckon if I put two fuel maps into the unichip I will improve the fuel economical

Tony

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I may not have explained my self properly in my comment about building an engine specifically for gas.

LPG has a higher octane rating than petrol though it burns faster so to put it simply and not getting too deep into reasons why, you want to bump up the compression to get the biggest bang possible and you want as shorter stroke as possible as to use the fast burning caracteristics of the LPG.

Doing this then you should in theory be able to extract more power than the same capacity engine on petrol.

I dont think that you will get anything close to a base line to work from from getting other peoples figures as blends of propane to butane change from delivery to delivery and that can change the economy to a very noticable amount.

All you could do with these figures is get a basic average and then you would know if your close to the average then your doing well.

Sadly you cant get more HP from a LPG engine even though you might have a higher octane fuel.

If So then Ford and GM would build them for straight LPG.... Fords BA engine is built for LPG in the LPG only model and its still not that good.

if anyone can get 12L/100 in a Rangie on LPG i'll do more than shake there hand