Overhauling an engine that's been running on Propane

[algee1]

Hello Everyone

I want to convert an engine, a 4.0 liter straight 6, running on propane back to gasoline. In the process I also want to overhaul the engine. Are there any special considerations? What, if anything, does propane do to the inside of an engine?

Thanks

Al

 

[IceStationZebra]

In my past experience with LPG fueled forklifts the engine valves were especially troublesome. ISZ

 

[RossABQ]

I've always heard that propane reduced the wear on engines, compared specifically to carbureted engines. Less cylinder wear due to there not being gas washing the walls on cold start-up, etc.

 

[marcdeluca]

Valve seat wear is about the only thing you will probably find. The cylinders, rings, and bottom end should look great. It will probably be clean enough to eat off of inside, they are usually totally sludge free.

 

[turbocohen]

generally an LP ready engine is more durable than a gasoline only engine. There might possibly be different upper valve guide seals depending on the application so check dat out.

 

[IceStationZebra]

turbocohen - What applications? In the forklift indurstry, which is heavily LPG, the engines are VERY close to the gasoline versions. Due to many factors including commonality, cost, original engine manufacturer flexibility, etc. the engines are kept as close as possible. This is starting to change with the latest emissions regulations though.

ISZ

 

[turbocohen]

A few older over the road conversions had upper guide seals that would weep a little oil to help reduce guide and seat wear. Newer engines use better valve, stem and guide materials and manufacturing processes have improved quite a bit. Weeping seals no longer needed..