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Just a thought from the peanut gallery. Anyone ever tried a propane conversion on a stovebolt? I remember the old 6 cyl. tractors with LP tanks. Boy would they run! I would think a bolt would do just as good. The only thing that has me worried is the valve seats. Would you need to have the head cut for hardened seats? The heated intake on a bolt would work great for vaporizing the LP. Anyway, just a thought.

Yes, there were LP conversions for Chevrolets, mostly 235s, but V-8s later. Yes, the original valve seats don't hold up very well under heavy load; light load/passenger car service seems better, but still not without risk. Hard seats are advisable. Also, the heat riser in your engine is not meant for vaporizing LP- there is a 'vaporizer' for that purpose. I don't think it is worth the trouble to make that conversion, given the potential for trouble, even though users in the past claimed longer oil life (probable), longer spark plug life (generally true), better fuel mileage (doubtful), and more power (imaginary unless you want to recurve the timing advance mechanisms, and you know what you are doing). The better fuel 'economy' was mostly referring to the lower fuel price, compared with gasoline.

LP conversions became popular during the 1970's, but they didn't last long with the public, after the public got some experience with the inconveniences and troubles that often came with that conversion.

I would advise staying away from an LP conversion for your 216 engine. Others may differ with that view.

Harvester

I have heard that the LP is not a good choice for the simple fact that it runs drier then gas vapors causing premature cylinder wear. I don't know if this is totally true but I did hear it from someone who has been in the business of car repair for close to 50 years and I trust very much when it comes to his advice

the vaporizers have fittings for hooking lines to the rad water for preheat, only need for other heat is first startup in really freezing weather, for which I have a magnetic 500W block heater that only needs to be plugged in for an hour or so beforehand

Rusty - yer mech is going by the standard myth, not repair experience .... I've got a 4 cyl forklift that was converted to propane ages ago - in the 20 years I've had it it's never needed oil added, and I've never changed the oil granted it doesn't get high miles racked up, but it regularly gets started, used hard for 5-10 minutes with no warm up, and shut off again, oil still looks new - works fine summer or winter

Bill

We have a propane distributer here who started in business in the late 40's and tried to convert everyone in the county to propane. He still goes to work every day, but his son runs the business. The last 20 years his delivery trucks have been Diesel instead of propane. Maybe there is a reason. Also, we had a trucking company here who converted their fleet of RD450 International engines to propane. About a year later, they were back on gasoline. There had to be a reason.

I am not trying to start a fight or anything but he worked for a deliver company as a mechanic and the trucks there used Propane. Don't get me wrong you may be right. I was just going by what he said

OH I don't know..... depends on where that nut is??

To get any noticeable power gain, the compression must be raised to outrageous levels, like 11:1 or higher. LP gas has an octane rating of approximately 110, but the vapor that's introduced through the air horn above the venturi displaces enough air to limit the power to approximately 85% of what's available on gasoline. If the compression is raised, the "dual fuel" capability goes away, as gasoline can't be used in an emergency. (Massive detonation/dieseling).

I worked for a California sand & gravel company that ran almost all their gas engines on LP, and only ran diesels in their big rigs like concrete mixer trucks. The technology is so primitive that even gasoline carburetion, let alone fuel injection, would be a major improvement. Now, figure out how to fuel-inject liquid LP and work all the bugs out, and you'll have something!
Jerry

I used to service a fleet of step vans that went to propane. It was a nightmare. The valve seats pounded out. The were constantly haveing problems & break downs. The drivers haited them as it was difficult to fuel up & if you ran out you had to be towed back to the waerehouse. They soon went to deisels.

Here in this province (Alberta), all the cabs run on propane and when you see an old cab at the junkyard, it has more than 500,000km on it; a lot of commercial vans and pick-ups also use propane. Propane is reliable and does not pollute; it is also cheaper than regular gas here.
There is a cost of course to convert the engine and you need to drive a lot to recover that cost. You also need a place for the tank (in the box, usually) and you need to check locally if a propane-powered vehicle is allowed in closed areas such as underground parking lots or road tunnels.
With propane, your engine will also loose some power (up to 20%, depends on the engines). As for the valve seats, it is the same "fantasy" as when leaded gas disappeared: a regular daily driver will not have any problem with the valve seats; go racing, rev to high rpms, or tow a heavy load and your valve seats will suffer indeed (same as an old engine on unleaded, really).
As a conclusion, I cannot really see the point on a hobby vehicle, unless you really care about clean exhaust!

Thanks guys, it was just a thought. I don't have any plans to do a propane conversion. It was just an idea. I've seen some rock crawlers and 4x4's with propane power, but that was so they can run at crazy angles. Like I said some of the old tractors such as Oliver's and Allis Chalmers did LP, but most of them are in the graveyard now. There must of been a reason for there demise. I may tinker around with LP one of these days, but I would definately make sure my stovebolt can still run on dinosaur juice.