I was just thinking this evening about my last employer, how they had a forklift that had a Propane driven I-4 engine from Nissan in it.

I was just wondering what kind of effects, say, propane would have if you added it to the air/fuel mixture of a gasoline engine? Any idea what the biproducts of it would be? Any potential power gain?

Just tossing ideas around...

I don't have a BTU Fuel Rating Chart handy, but it prolly wouldn't do much of anything for power. Fuel is not the problem, Oxygen is. That's why you get a big bang from Nitrous Oxide. More O, better burn.

I remember watching an episode of trucks tv when they added a propane injection system to a diesel pickup truck. It had about the same effect that nitrous has on a gas burner. Can't remember what it did exactly except make gobs of torque and h.p.

You can search Google for more information on propane injection for diesel powered vehicles.

As far as adding it to gasoline, aside from the fun of driving around with a bomb in the car, most likely (assuming you don't blow up) you'll just foul your spark plugs really really quickly

I've driven propane conversions. There are dual systems (ones where you can switch from gas to propane if you run out of one of them) and just propane systems, but I have never seen a injector system for propane (there might be one out there now). This was over 25 yrs ago and there might be new stuff out in the market.

Propane burns cleaner than gas. I have been told that engines that require work, when taken apart have very few deposits in them. You get less MPG with propane than with gas. I believe that the BTU's in propane are less than in gas, so adding it to a system won't give you a boost.

The down side to a possible propane conversion on a t4 is that the regulators/ vaporiser requires liquid to work. The propane is in liquid form and has to be turned into a gaseous state before being used by the engine. This is done by mounting the regulator to the heater core line and the liquid propane is converted to gas by using a heat exchanger inside. When the liquid propane comes into contact with the liquid from the rad. Propane boils (vaporises) at about -40C

The other problem is where to mount the tank. I'm not sure if a conversion tank will fit anywhere in a 914. They are big and heavy.

I doesn't sound like you have thought this out at all. If you are thinking that you could just turn on the propane as you would using NO2, then you are in for a big surprise. Lets say you have the engine running on gasoline, then add propane to the intake runners. Now you have lots of fuel and a reduced amount of air proportional to the amount of propane being added. What is your air/fuel ratio now? How do you think the engine will run?