LPG Cobra

[Naumoff]

Originally Posted by dingocooke

interesting perspective on life across the pond Tony; Id still swap you your $4.25 gallon for our £5.50 odd ($10.50).............our wonderful government tax gas iro 85p in the pound (85%)

Well you know the colonist never like paying taxes. They had a little tea party in Boston over a penny increase.

Seriously though, I don't know how you do it.

[dingocooke]

Originally Posted by Naumoff

......Seriously though, I don't know how you do it.....

LOL yeah sometimes we dont; I guess we have just got used to being stitched up on fuel prices over here generally; everytime I go stateside it brings it home to me how expensive it is over here! Of course our politicians have realised that we dont have an alternative so ream us at every opportunity...

[zeb]

I think it is all down to mileage travelled and space wanted.

I have a 1.8 toyota on LPG, as I do quite a lot of mileage so it pays off.

If you did do a lot of mileage on a cob, you would end up filling the boot with the tank.

LPG does have place until the government decides to hit this also. Not on a cobra though.

[Clive]

With diesel now more than 15p/litre dearer than unleaded the benefit of diesel is becoming a lot less attractive!

[cobal]

From what ive read from other web sites LPG has an above 100 octane rating, so you can use higher compresion levels to get the same power, also it needs more timing advance. So if you were building a engine and car for LPG from the start the LPG system would not cost a lot different to building a car with an aftermarket petrol PI system. Also with the doubling of road tax for high CO2 levels the imissions would be a lot lower. Can someone tell me the current road tax for LPG cars.
cobal

[Purple AK]

LPG Tax concessions only apply to Type Approved M1 class vehicles. So in our case it will still be £185 per year as it is for all kit cars.

[cobal]

I didnt realise that kit cars will be exempt from the new rod tax chrges, thanks for that info

[maurice butler]

Originally Posted by cobal

From what ive read from other web sites LPG has an above 100 octane rating, so you can use higher compresion levels to get the same power, also it needs more timing advance. So if you were building a engine and car for LPG from the start the LPG system would not cost a lot different to building a car with an aftermarket petrol PI system. Also with the doubling of road tax for high CO2 levels the imissions would be a lot lower. Can someone tell me the current road tax for LPG cars.
cobal

depends on the the mix of propane vs butane to the equivilent octane rating.

The timing is very different and more advance can cause damage.
The intial advance is higher but the total advance is less - therefore dyno time calibrating advance curve

Maurice - running modified nissian bluebird u11 on lpg - experimenting for cobra project. Better to blow up a cheap jap 4cylinder, (1 cracked head, 1 burnt valves, 1 bent valve - ok that wasn't the lpg) than a good v8.

[cobal]

Maurice, isnt there some kind of industrial standard for LPG sold at the pumps, If not surely their should be, as I was led to believe it had a higer octane rating than petrol and was slower to burn, hence my comments that it is better to build an engine designed to run on LPG taking into account compression ratio, timing, etc, to get the best power from the motor, which is what you are doing. If I was building from scratch I would go the LPG route as I could take my car out more often.
PS, good luck with your cob engine

[maurice butler]

I live in the South Island of New Zealand.

All LPG is imported either from the North Island of NZ or the West Island (also known as Austraila).

The quality varies between the two sources. Also if the lpg has been stored too long, the propane and butane start to seperate in the tank. When that happens, the propane rich gas is supplied then it transitions to butane rich gas. So it pays to get it from somewhere that has a good turn over.

I am no expert in the field but have picked a bit with my experimentation and reading of impco manuals.

Maurice