I/C Running on gas

[Tom GullanParticipant @tomgullan59234]

Hello,

I recently built the Upshur Vertical Farm 4 Stroke Petrol I/C Engine (1” bore). My next project is the horizontal version of that engine but to have it running on propane gas. I purchased the diaphragm, needle jet and plans for the demand regulator from the USA. I have built the demand valve less the inlet and outlet ports.

I intend using the standard propane camping gas cylinders. I am unsure as to how to go about regulating these cylinders. Can anyone point me in the right direction? I have read a bit about how this is done in the USA… they have totally different standards, measurements and fittings.

Regards
Tom

[Tom GullanParticipant @tomgullan59234]

[Tim StevensParticipant @timstevens64731]

The way things are measured may be quite different, but you can be assured that the basic materials are the same. US propane is exactly the same as anywhere else, and so is the air. And the propane stored in a camping cylinder is going to be at about the same pressure, etc. So, you need the same proportions in your mixture, but in your units, not theirs. This should mean that once you are confident about converting US units to yours, what you do with the results should have the same outcomes.

It is rather like adding fertiliser to a field. The US recipe might say 6 pecks per square yard, so all you need is the conversion (1 peck = 8.8 litres, one square yard = 0.836 square metres).

If I understand your problem …

Regards, Tim

[not done it yetParticipant @notdoneityet]

Tim’s reply reminded me of my little ‘Pocket Ref’ by Thomas J Glover, from Lee Valley. It has nearly every conversion factor in it that you might ever need. I rarely use it but it is a useful reference. (probably yours is the only conversion factors it doesn’t have) and smaller than a Machinery Handbook. All conversion factors are available on the net, of course, but I rather like reference books…

[Brian Sweeting 2Participant @briansweeting2]

A simple needle valve can be used to regulate the gas flow, that is all that is used for plumbers blowtorches etc.

[EmgeeParticipant @emgee]

Tom, screw on pressure regulators are available for Camping Gaz canisters and cylinders, this would reduce the pressure but would allow enough volume to run your engine via the needle valve adjustment you have.

Emgee

[MuzzerParticipant @muzzer]

Yes, you need something a bit more sophisticated than a needle valve. The regulators for camping equipment are almost certainly very similar in terms of output pressure on both sides of the pond. I have some camping gas (propane) canisters from Canada that fit my Rothenberger blowtorch, so they clearly share the same fittings on some products.

The regulators Emgee mentions will most likely be fine. Then the demand regulator you have bought will surely work as intended. Presumably it ensures a reasonably consistent, near-stochiometric fuel/air ratio like a carburettor.

Murray

[Gordon WParticipant @gordonw]

Back in the 60's/ 70's there was a man selling details on converting a standard gas bottle reg. to run engines on bottled gas, this for full size motors. Basically the comp. spring in the reg. was replaced by a tension spring. Set up by altering this spring until gas just stopped flowing, engine vacuuam then set the gas flow as needed. Sorry can't remember details, but somewhere I have the drawings, or could easily be found on web. I built one, so must be easy, and it ran a small stationary engine. I was going to put on my car but a mate got caught and was threatened with fines etc. If interested I will try and find the drawings.

[Tom GullanParticipant @tomgullan59234]

Gentlemen,

Thank you very much for your comments… food for thought.

Gordon, I would be interested in looking at those drawings if you can find them.

Regards
Tom

[PeroParticipant @pero]

Tom

It is possible you may find what you are looking for on the J. E. Howell Model Engine Plans website (model-engine-plans.com). Propane valve plans and some key components are listed under Plans and Parts – Attachments and Tools.

Plans are available for download (there is a cost for this) and key parts can be purchased online.

No connection other than I have purchased from them on several occasions and have been very happy with the online plans service and purchase of parts.

Cheers

Pero

[JasonBModerator @jasonb]

As mentioned above the small screw top camping gas canisters can be controlled quite well with this type of valve which can be screwed (M7 x 0.5) into the inlet side of the Demand regulator that you already have plans and parts for. This will allow you to adjust flow when the vacuum from the engine causes the demand regulator to open, keep pipe runs as short as possible and bleed out the air before trying to start engine.

Edited By JasonB on 15/05/2018 07:12:20

[Tom GullanParticipant @tomgullan59234]

Hello,

I would just like to say a big thank you for all the information that you guys gave me regarding my gas problem on the Upshur Engine. Before I start building my next engine, I thought I would make up a prototype to see if it would run on my last Petrol build. Here is the result:

https://www.youtube.com/watch?v=ZvXg1weFeK0

The carburettor looks a bit clumsy and is only secured to a small pipe by Locktite. I intend shortening the braided pipe from the demand valve to the carburettor but as yet I have not been able to source that particular type of pipe. Does anyone know where I would be able to purchase a made to measure piece. The thread is M7 x 0.5

Tom

Edited By JasonB on 30/05/2018 06:57:38

[Gordon WParticipant @gordonw]

Looks interesting, keep us informed. I did a search for the drawings of gas regulator but can't find them. I did find a large cardboard box full of mouse nest and fear this may be them. But I am still hopeful.

[Tom GullanParticipant @tomgullan59234]

 

Hello,

I’ve made some modifications to the carburettor but I’m not happy. I’ve fabricated a barrel at the end of the intake with a through hole so that I can have some control over the air mixture. There is a 0.100” hole running the length of the carburettor, this hole is 10% of the diameter of the bore. I’ve also set the timing is to spark just before TDC.

The engine is running “lumpy” and on the verge of stalling. Can anyone suggest how I can resolve this issue?

I thought that the length of the pipe from the demand valve to the carburettor may be an issue and would like to shorten it but as it appears to be crimped on this is not possible. Does anyone know where I would be able to buy this type of braided hose? The thread is M7 x 0.5.

Any help would be gratefully appreciated.

Regards
Tom

Edited By Tom Gullan on 31/05/2018 21:53:07

[JasonBModerator @jasonb]

As the hose it not under pressure after the demand valve you could just use model fuel line, probably the yellow Tygon and make your own fittings.

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