Mini Propane Engine?

Perhaps one of those engines they use in RC could be converted, but I doubt it. They make 4 strokes, but I believe the lubrication is still mixed with the fuel.

I've seen some really small steam engines, but not quite that small.

I think most of the RC engines that use nitromethane the fuel is between 50 to 80% oil for lubrication. Their are RC engines that run off of a CO2 cartridge (pressure) which are basically a steam engine, those get down to marshmallow size. If you combusted the propane external to the engine to produce pressure to feed to the engine it could work.

There is a gentleman who regularly shows at G.E.A.R.S. who makes miniature steam engines. He shows a tie tack running engine and an engine on a ring. Check www.oregongears.org for info on the upcoming show.

Hi JE,

Here is an internet address for you; www.gyroscope.com

This company has a web page showing among other things two different types of model propane engines that you can buy, try it now, you will be surprised!

Spencer.

A guided tour of the local model aeroplane stockists' engine selections, perhaps? Yellow Pages?

how would that answer my question?

I can find suppliers, i want experience and knowledge

Years ago I saw adverts for mini jet engines that were in the fist-sized range, but I don't recall if they were propane fuelled. I presume they could be, jet burners aren't all that picky for the most part.

As others before have mentioned, try the RC industry. There are miniature jets available. Not piston engines set in a jet plane. Real jet engines.

Almost any small 4 stroke engine, with an oil sump of some sort can be converted.....not that I am saying that its easy, but you need an engine that does not need the lubrication mixed in with the fuel (most 2 strokes), or you need somehow to add it in some other way....

A Gas turbine would be the easiest to miniaturize - one moving part - a turbine. As the engine gets smaller, the turbine could have fewer and simpler blades. I can see photo etching techniques allowing a very small turbine.

Use your friend Google. There are companies that make conversion kits for small gasoline engines to allow them to burn propane. From the description of the kits it does not seem to be too difficult a task.

I am considering buying a generator for emergency ham radio use and I will have it converted to propane because I am not comfortable with the idea of storing gasoline which is not only flamable but has a limited shelf life. I could store a couple of bottles of propane and I would also have back-up in case the barbeque runs out half way through supper.

An additional advantage of propane is refueling the generator after it has been running for a while. I think that it is probably safer to disconnect and reconnect a hose than pouring a flammable liquid into a tank that is fixed to a hot engine.

Of course a diesel engined version fixes most of these problems that you mention, some of which are NOT fixed by having gas cylinders.

The problems that I see with gas are basically the same ones with petrol:-

1) in the event of a fire, exploding gas cylinders are not funny, the fire department may refuse to get close to the fire for safety reasons.....

2) Most gases for burning are heavier than air (as petroleum vapor is too) and it seeks the lowest level which could be your cellar, where your heating system is.....

3) When refilling, you will must stop the engine (with petrol one SHOULD stop the engine!), in the middle of the night, that might be a lot of fun......

I certainly do not see a radical enough change/improvement to make the conversion worthwhile, also, I do believe that the amounts of gas used will be far larger than petrol, and its more expensive in the first place in most countries and you need specially reinforced (expensive) containers too......

Diesel is less likely to burn, gases far less (under 45°C almost nothing at all), the engine is far simpler and less likely to deteriorate as there are far less electrics/electronics and is far far more economical too......

All true, except diesel fuel is now a bit more expensive than gasoline (petrol) here. Can't see why, but there it is.

That hardly matters as generally, the usage will be half as much and the safety factor is much much better in all respects. They also last much longer provided oil and filter changes are made correctly. Most small petrol engines have no oil filter, even if if 4 stroke, which shortens the life and many are 2 stroke and not so economical and much louder too.....

Only negative with Diesel is that Diesel generators are more expensive, but that is a one time cost only.....

Another plus for the diesel generator. Generators in the under 10k size are usually run at 3600 rpm for gasoline or propane power. The same size diesel powered generators run at 1800 rpm. I believe this is because diesels make best torque at these low speeds, while gas motors have torque peaks higher in the rpm range.

Well put Bob c, I completely forgot that important point!

Hi Andy,

As I said in my first post try; www.gyroscope.com In the first post the guy was looking for a propane/butane engine that would fit into his hand, well this company produces these small engines that have been specially produced for this type of fuel!

They make three types of these engines, single cylinder, V twin and a radial type, so take a look you will be surprised.

Spencer.

The point I was trying to make was a) a home grown modified to gas engine would be an interesting project, but not one that is going to be as good as a developed engine(s) as you correctly point out, and b) the safety factors for a gas driven engine are in some areas WORSE than a petrol driven engine in the first place and safety was the reason given for the conversion idea.....

The Diesel engine wins on all fronts, not to mention the reduced RPM and the economy, but also the intrinsic better fire and explosion safety of Diesel over both Gas and petrol.

Many people may not understand why the RPM is so important, but wear and tear on a diesel revving at half the speed, will generally, all other points being equal, much less than a petrol engine....Diesels are built heavier/better and last usually far far longer too....because the electric and electronics are also far simpler...no need for high voltages for ignition for example.....and therefore far less affected by damp..

Almost any small 4-cycle IC engine that runs on gasoline can be converted to use propane, butane or other gas, because they have lubrication separate from the fuel. Durability is not dependent on size. To be durable the engine must be made of durable material, machined with precision and properly designed. For years Chevrolet made big V-8 engines that would really wind, then would suddenly leave themselves in pieces due to poor material, little precision and poor design.