Installing an LPG system

September 30th 2006

Preparing for the latest project: getting the car converted to run on LPG which costs a third of the price (!) of regular petrol. The most obvious change to the car will be two 55-liter LPG tanks in the trunk. This meant I had to get rid of the carpet on the opposite ends of the trunk... and found only little patches of surface rust underneath. There was a lot of sand and dust though. 

The most obvious change: two 55-liter tanks in the trunk.

The filler tube for the old gas tank has been removed to make room for the new left LPG tank. I emptied and closed off the gas tank. Behind the fuel filler door there now sits the nipple you use to pump LPG:

There were so many rules and restrictions I decided to have the installation done by a professional. Because he had already had to adjust the timing (needs to be retarded for LPG) and the carb I splashed out on a Pertronix Ignitor and Flamethrower coil. You also have to use colder spark plugs because LPG burns at a higher temperature than gasoline does. It also burns much cleaner. It will actually 'clean' carbon deposits in cylinder heads and the oil takes a lot longer to blacken. The car gets just over 11 MPG on the high way doing 60/65.

I can switch between LPG and gasoline while driving by means of a small switch mounted under the dash. It's important to have some gasoline pass through the carb every month because otherwise it dries out. If that happens and you flick the switch to gasoline it pours out over the engine: a common cause of burnt out classics.

This is the most noticeable change under the hood. It serves to evaporate the pressurized LPG using heat from the cooling system.

Most American classics here in Holland run on LPG & the IMPCO installation is probably most used for this. However, these won't fit in a slabside because the hood won't be able to close. So we opted for this ring that sits in the air filter on top of the carb (this is basic old school engineering). This way I get to keep my air filter. Some material still had to be removed from the carb and the ring had to be changed in some respects also. No easy fixes for sixties Lincolns!