Propane engine question

Here is a picture of the engine

Sounds like a good engine for making a genset. How may HP? chuck

Where does that black hose, coming out of the right side of the carb end up? Greg

In the top photo, that big hose that comes off the right side of the carb and heads up is the Propane inlet - but it has to be after the primary vaporizer/regulator at about 2 PSI max. You can NOT just connect it straight to a barbecue cylinder without a primary regulator.

(You might be able to get enough gaseous propane flow out of a barbecue cylinder to run the engine without the cylinder icing up and the pressure dropping off to nothing... But I wouldn't count on it. To run this flat-out, you need a forklift style tank with a liquid output fitting.)

The vaporizer is a large cylinder about the size of a quart paint can, and it will have a separate set of 3/8" or 1/2" NPT water hose fittings - in a car, you plumb it into the heater hoses and use waste heat to vaporize the liquid propane feed from a "liquid" port on the fuel tank.

If you want to test the engine for signs of life without spending for an LPG vaporizer, do you have utility-fed natural gas at your house? That's roughly 8" WC pressure, should feed right into the big hose... ;-)

I saw a Corvair conversion where they ran the motor oil cooler lines to heat the vaporizer, worked just dandy. Any waste heat source will work, Automatic Transmission cooler lines or hydraulic system.

As to what you can do with the engine, it all depends on what kind of governor system it has on it. If it doesn't have the fine-control type flyball governor built in (which it looks like it might) forget using it as a generator plant. You can get external governor systems that will hold 1800/3600 RPM on the dot, but not for cheap unless you scrounge it.

I can't tell, it looks like it has either the 6:1 reduction gearbox or the end bell from a generator (that was removed) on the back end. Though the engine looks suspiciously like Onan Green... Best use is to find a good generator with a blown engine and bolt 'em together.

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You will need the vapourizor/regulator assembly - other than that looks good.

It does have the built in governor, and it still has the bell from the genset. There is no gear reduction on this, I contacted a dealer in Canada, he said it was 16 to18.4 HP and they are still made. These are not cheap new, or even rebuilt. They do come in gas versions, some have "dual fuel" carbs. I found a price on a new carb but its not cheap, twice what the engine cost.

SNIP

Hey Wayne,

I'd look just a bit more into this, or at least the statement about "dual fuels". It is my understanding, from having owned two "alternative fuel" Dodge mini-vans a few years back, that the term dual fuel has to do with an operating mode for gasoline and propane, or else gasoline and CNG (Compressed Natural Gas), and not propane and/or CNG. Propane has none of the fuel additives that automobiles (especially newer high tech economy vehicles) require for both environmental and engine life. Instructions were explicit that the vehicle should be started on gasoline and run for at least five minutes before switching to propane, and for a short period at shut down too. And then I had one that ran on natural gas (actually fuel was CNG) didn't say that, but the operating range (distance) was so low that you ended up using gasoline a lot of the time anyway. Here in Ontario, "alternative fueled vehicles" ,new or used, are sold with no Provincial Sales Tax, an 8% saving. But the resale value does kinda suck as I recall.

I have no comments about the ability to operate on "plain" Natural Gas (not CNG), except that there was a pump you could get for home use to create the CNG. Took 10 hours for it to refill the vehicle tank, and was expensive, so I never did buy into that. I certainly have seen auxiliary power plants that ran on natural gas, but whether they ran from a standard regulator "low pressure" line, or a high pressure source I wouldn't know.

Take care.

Brian Lawson, Bothwell, Ontario.

High volume low pressure gas service is used to run irrigation pump engines all over the southwestern part of oilberta and in the oil springs/petrolia area of Ontario. Lots of small non-commercial wells have been harnessed for irrigation as well as co-generation systems.

As for propane, there is nothing required by a modern engine that is not contained in straight propane - and dual fuel engines just start easier cold on gasoline. Running them on gas until warmed up eliminates the embarassing stumble/bumble and die you get when accellerating hard with a cold evaporator when it ices up. Switching to gasoline before shutdown makes sure you have fresh gasoline available in the carb (talking older tech carbed engines here) to star next time out.

The old dual fuel system had a crude way of switching from gasoline to propane - when warmed up you just shut off the gasoline to the carb, and when the engine started to stumble you turned on the propane. Rushing the process, and getting the propane flowing while there was still gasoline in the carb made for a real nasty rich stumble if it didn't "flood" the engine right out.

I did a LOT of work on dual fuel (AS WELL AS STRAIGHT PROPANE) Toyotas back in the late seventies to mid eighties.

Clare Snyder - just up the road in Waterloo, Ontario.

Toyotas

I was working on a dual fuel, gas/propane, 4 cylinder ford engine, that ran fine on gas, but wouldn't idle on propane.

Do you have any ideas of what to check first?

Thanks.

I don't really know anything about the propane side of the thing.

If it's an IMCO system it's likely not sized right - but possibly as simple as adjusting the mixture.