NJSPDER

iTrader: (2)

hey guys,

while i am shopping for a swap project(looking for an older 5series BMW) i was thinking about doing it really different and going to propane as my fuel of choice.

i figure being the equivalent of 105 octane will help me make more power and leaving only 5% of the particulate of gasoline will make all my tree hugger neighbors happy for once.

are there any general issues with propane i should look out for?

does anyone know of any really good instructional or conversion parts sites i can refer to?

TIA for the help.

enos44

http://www.eng-tips.com/viewthread.cfm?qid=93871 this is pretty interesting, so are these http://usealtfuels.com/resources/e-m...20VS%20GAS.xls http://usealtfuels.com/propane.htm hope this helps some. We actually have a few bobtail trucks that run on propane and we have had hardly any problem with them, good luck with your build

mrhzk35404

iTrader: (7)

I use to work on some propane delivery trucks that ran off of propane. The system they had was crap in the cold and would gum up alot. not sure if they have upgraded to eliminate that issue.

JB151

iTrader: (3)

my friend had an 80 gallon propane tank to fuel his ford bronco. It was horribly slow, however he didn't ever have to change the oil because it ran so clean!

jimmyblue

iTrader: (11)

More octane does not make more power necessarily,
it just burns slower. Propane has low energy content
compared to gasoline. Mass for mass, a gaseous light
fuel "steals" more airflow volume from the air stream.
Which should cost you power.

You want a motor set up for high compression to use
propane well. Or, turbo on stock heads might be cool.
If you can manage to have the propane expansion
happen inside the manifold and not have an expansion
valve you'd get charge-cooling benefits. Do not know
if there are propane direct-injection injectors though
perhaps (or not) the nitrous "progressive" type solenoid
could be rigged. I gather that expansion valves are a
pain in gas-flow type systems.

chuntington101

you might not make as much power as you do with you would with normal fuel, but it would be nice to see how it worked if you turbocharged the engine!

thanks Chris.

Afterhours Performan

Check out this company this is where i get most of my stuff for my experiments www.fairbankequipment.com

enos44

i thought the higher the octane the more heat to ignite?

jeejee

iTrader: (3)

yes it can be done, no problem, i run several engines all converted to run on propane, some even make more power (at the same boost level) then when run on petrol
The newer sytems use vapour injection with uses the normal petrol injector timing (with a conversion factor) to inject the propane per cylinder.





Here is a review of a holden v8 converted propane car:

http://www.caradvice.com.au/997/hold...-ve-range-lpg/

although i'm curious to how the american regulations are with regards to the propane setup

there was even a bmw m5 with 550hp propane injected engine on the last motorshow in germany, so it's quite hot at the moment

jeejee

iTrader: (3)

my bad :

the holden is only a v6, but same applies to a v8 ofcourse

Beaflag VonRathburg

iTrader: (176)

That's still a pretty cool idea.

NJSPDER

iTrader: (2)

in teh US the emissions standards do not have any compensation for the type of fuel being run, only a standard of gases and particulate being dropped from the tailpipe based on the production year and type of vehicle.

i figure with the detonation resistance of propane i coudl runn aroun 12:1 compression in a streeter and have it act as normal as running race gas. my only worry is consumption.

i like working on street cars, driven to and from the track. anyone know of a formula to compare consumption of gas to propane? i have seen formulas around that can estimate fuel consumption of gas, i will have to try finding them again.

thanks for hte help guys. i am learning a lot from this discussion

NJSPDER

iTrader: (2)

looking at the posted article i cna see where consumption may be an issue.

100km = 62.1mi

16l LPG = 3.5gal = 17.7 mpg

11.7l gas = 2.6gal = 23.9mpg

that is a 26% drop in mileage between fuel sources. the price of propane is certainly low enough to justify the expense, but the range would make taking trips somewhat annoying. extra planning would have to be done as well to compensate for the lacking LPG infrastructure in the US.