LPG conversation

[Dimitri_Raptis]

Hi. I have been overlanding Europe and Greece the last 3 months. It costed me 4500 USD. I have decided to convert my car to LPG (propane). The propane tank will take up storage space but I will save about 50% in fuel cost. The conversion will cost me 1200 USD in Greece (friendly price). What are your thoughts?

 

[smritte]

Propane conversions were very popular out here in the 80's. The benefits are, cleaner running, oil doesn't get contaminated as fast. On a carbureted vehicle steep hills caused fuel sloshing, propane didn't care, cold starts were never an issue any more and elevation changes don't effect fuel mixture.
The down side is, the engine was designed to run on gasoline. The cam and compression are wrong. This typically caused a major power loss.
When I was younger I worked for a trucking company, we had three propane converted trucks in the fleet. They were good for local deliveries but driving both propane and gas, you could really feel the difference.

Back then what made propane appealing to me was, it made a vehicle smog exempt. This made me embark on a new project, a 1974 Chevy Vega. The vehicle was going to have a small block 383 with a super charger. During my research I spent some time with one of the best turbo charge/super charge guys out here. He had written books on forced induction using natural gas and propane (Natural gas was for irrigation pumps). He helped me figure out the correct cam and compression to match propane.

What I learned after all this was propane works great as a swap but you will loose power. How much is mostly based on compression. If its going on your Cayenne, you run a bit higher compression then most. Hopefully the power loss is slight.
The mod is simple, the propane is just fogged down the intake. What would interest me is if they tie your computer into the system or just have the throttle plate do all the controlling. On the conversions I was around, the propane adapter replaced the carburetor with its own plate and the ones that were "dual fuel" it mounted on the carb, using the carb throttle plate.

The environmentalists were able to get propane outlawed for the street, I stopped seeing them late 80's-early 90's. Done properly they put out almost no emissions. The are popular in some Rock Crawl classes because you can drive the car upside down and it will still run.

If you do this, I would be very interested in the outcome.

 

[Dimitri_Raptis]

Propane conversions were very popular out here in the 80's. The benefits are, cleaner running, oil doesn't get contaminated as fast. On a carbureted vehicle steep hills caused fuel sloshing, propane didn't care, cold starts were never an issue any more and elevation changes don't effect fuel mixture.
The down side is, the engine was designed to run on gasoline. The cam and compression are wrong. This typically caused a major power loss.
When I was younger I worked for a trucking company, we had three propane converted trucks in the fleet. They were good for local deliveries but driving both propane and gas, you could really feel the difference.

Back then what made propane appealing to me was, it made a vehicle smog exempt. This made me embark on a new project, a 1974 Chevy Vega. The vehicle was going to have a small block 383 with a super charger. During my research I spent some time with one of the best turbo charge/super charge guys out here. He had written books on forced induction using natural gas and propane (Natural gas was for irrigation pumps). He helped me figure out the correct cam and compression to match propane.

What I learned after all this was propane works great as a swap but you will loose power. How much is mostly based on compression. If its going on your Cayenne, you run a bit higher compression then most. Hopefully the power loss is slight.
The mod is simple, the propane is just fogged down the intake. What would interest me is if they tie your computer into the system or just have the throttle plate do all the controlling. On the conversions I was around, the propane adapter replaced the carburetor with its own plate and the ones that were "dual fuel" it mounted on the carb, using the carb throttle plate.

The environmentalists were able to get propane outlawed for the street, I stopped seeing them late 80's-early 90's. Done properly they put out almost no emissions. The are popular in some Rock Crawl classes because you can drive the car upside down and it will still run.

If you do this, I would be very interested in the outcome.

Thank you very for your detailed reply, I learned a lot with information not available in the internet.

We have chose for dual fuel, a small amount of petrol will be used to ensure adequate lubrication etc.

I will ask my mechanic, regarding the computer vs. Throttle controlling and will get back to you with all the details and equipment used.

Thanks again and will keep you updated.

Best Regards,

Dimitri

 

[smritte]

Propane still appeals to me with a dual fuel system but I wont pass visual emissions. I will be very interested to see how they tie in for a dual fuel on a modern vehicle.

Looking forward to seeing how your system performs.

 

[Dimitri_Raptis]

Thank you all for your suggestions and information provided. Currently the LPG system is under construction. It is quite sophisticated with its own computer, fluid propane reducer and injection becks. All Italian. Please see photos. Will let you know about performance once I test it.