Running a model engine on LP gas

[lugnut]

Yesterday I attended the 08 Great Oregon Steam-up in Brooks, Oregon. What a great show! I had no idea it would be that big of a show.
My question is about one of the model engines that was on display, it appears to be operating on LP gas. I did not get the chance to talk to the owner. Does anyone here know about using LP gas to run the little engines?

Thanks
Mel

 

[PolskiFran]

I have talked with a few people who run their engines on lp gas. One said he will never go back to gasoline again, because it was so much easier to start and cleaner to work with. Another wanted to run his on lp but was having trouble locating a regulator that would regulate in ounces due to the small size of the engine. The only drawback I have heard of is the moisture associated with lp causing corrosion (rust) in the cylinder.

Frank

 

[rake60]

I saw a big engine running on LP gas at a show one time.
Even took a terrible video of it running.



I don't know the logistics, but I do know it worked!

Rick

 

[chuck foster]

that little engine is called a red devil, the kit is produced by a company called pet shelf models.
the guy that produces it has the original full size engine and scaled it down in great detail.
the propane is a great way to go (i have never tried it) all you need is an on demand regulator and way you go.

i have some plans for the regulator and i will post them once i find them

chuck

 

[GailInNM]

There are demand valve drawings at:
http://groups.yahoo.com/group/Min_Int_Comb_Eng/

They are in the files section. You have to join the group to get to them.

A small tank regulator that some have used is the one from the Bernz-O-Matic JTH-7 torch. It is just used as a pre-regulator before the demand valve. You still need a demand valve. I have not used it myself, but the comments seem to be that while it is not the best, it works. I have a JTH-7 and they are handy around the shop any way. I have an adapter so I can use it on a 20 pound BBQ tank and it serves a second duty by firing my coffee can furnace for small metal casting.
Gail in NM,USA

 

[Tin Falcon]

Plans can be found here along with other tips and tricks
http://www.floridaame.org/HowTo2.htm
Tin

 

[lugnut]

Thanks for all the help guys. Does any one sell such a demand regulator that would do the job? Seems it would be a lot safer and not have to take any chances with a store bought one.
Mel

 

[Bogstandard]

Mel,

I think you wouldn't have much luck trying to purchase a gas demand valve. Unless you contact Richard Williams to see if he makes them to order. He can only say one of two words, or if he is unsociable two other words strung together, the second one being 'off'.

I think you will find, it is assumed that if you can build an engine to run on gas, you would have the necessary skills to make the regulator valve.

If you do build one, the most difficult part on the FAME site one looks to be the valve bit. You could easily substitute a car tyre valve, with slight mods to the plans.

John

 

[Tin Falcon]

Thanks for all the help guys. Does any one sell such a demand regulator that would do the job? Seems it would be a lot safer and not have to take any chances with a store bought one.
Mel

Mel :
By the above statement sounds like you have bought into the age of consumerism where all things are purchased in stores and made in a magical place called a factory and all things are labeled no user serviceable parts. The same world where people are incapable for making or doing anything for themselves except make money to buy stuff they want and need.

The no serviceable parts label is there for a couple of reasons 1) to keep out the folks with no clue how to fix things 2) to keep those folks from suing the manufacturer if they hurt themselves.3) we do not want the consumer to lean anything about the product so he can build his own or improve on it!!

An air/ gas regulator is actually a very simple device to design / make build
there are a few principles to follow proper spring force to match the diaphragm size and gas pressure needed. a good seal on the diaphragm and a good valve to seat fit and last but not least is clean filtered air/ gas .In high pressure application the littlest piece of dirt is a bit problem and w O2 no oil.

Mel: if you are smart enough to hang out here, operate machine tools and build engines a demand regulator should not be a difficult task to build.
I do agree that many items are made so cheaply and the design , making and QC at the factory are built in for such a low price. that may not be worth making your own . But in the case of this mini regulator it is not an off the shelf item
Tin

 

[lugnut]

I sorry I ask ???
Mel

 

[Tin Falcon]

Mel:
Sorry if you felt jumped on. If I knew where you could buy such a regulator I would tell you or give you the link.
In this hobby certain things need to be shop made and that is part of the fun .
TIN

 

[nemt]

My Wyvern engine runs on propane gas or camping gas. I do not use an extra pressure reducer since the one used for cooking gifs me the right pressure.
The carb I use is the original from the drawings. It has a lay out for two fuels. Either petrol or a gas.
I have build Topsy Turvy, a Duclos engine, and I made the same type carb for it.
Works perfect.
Nemt

 

[Lyn S.]

I have built & used the demand valve that was designed by R. Williams on the floridaame site,the one posted by Tin Falcon. My Olds and Hired Man engines start quick & run fine. Useing the original gas carb. The valve and diaphram are Tecumseh engine parts and can be found at a lawn mower and small engine service dealers

Lyn S.

 

[lugnut]

Lyn, Thanks for the information, that's kinda what I was looking for when I ask for the information. Knowing that I would have to buy a valve and diaphragm , I thought I might as well buy the whole thing. I didn't know it would be unholy to do something like that.
Mel

 

[Paula]

Okay, this is an old thread... but I have some experience to offer, for what it's worth.

I have successfully run two hit & miss engines on propane (Stickney & John Deere), and it worked really well. It may take some futzing with orifice sizes, needle settings, etc. but it does make for a very clean running engine. It also seems to give a less "severe" firing -- more like pushing on the piston, rather than hitting it with a hammer -- if that makes any sense. Less stress on the engine.

I purchased my propane setup from Leo Fellman around twelve years ago (I don't think he sells them anymore), which included the propane regulator, gauge, and demand valve. Here is the general layout for running an engine ("flow control valve" is another name for "demand valve"):

The 15 PSI regulator which screws on the propane cylinder is apparently still available from a few sources (though at least one other source listed it as "discontinued"):

http://www.amazon.com/dp/B000Q9AJZG/?tag=skimlinks_replacement-20

http://www.summitcampinggear.com/co15psire.html

http://www.ssotradingpost.com/product.sc?categoryId=9&productId=60

If you're interested in putting together a propane setup, you should probably get one of the Coleman regulators while they are still available. One source for the 15 PSI gauge is McMaster-Carr #3847K11.

As far as the demand valve, the one supplied by Mr. Fellman did not look exactly like the one in the F.A.M.E. plans. It was round, and had both inlet and outlet on the same side. It seemed like a simpler design. But I see no reason why the one detailed in the F.A.M.E. link wouldn't work just fine.

For some more detailed drawings, images of the Tecumseh parts needed, and view of the whole setup, visit Carl Carlsen's page at pbase.com:

http://www.pbase.com/captain_carl/_interesting_models&page=all

I would add that I was a bit reluctant to try propane at first (irrational fear?), but it really does work well, and my fears were unfounded.

Paula

 

[lugnut]

Thanks a bunch, Paula! That is the information I was hoping for. I think I'll get to work on it and Maybe I'll get the little bugger running now!
Thanks again
Mel

 

[dwentz]

Here is some info on a regulator I found a while back if you want to build one.


Gas Pressure Regulator http://home.claranet.nl/users/summer/16mmngm/Articles_htms/GasPressReg.htm

This is for a gas fired boiler, some other info is at http://home.claranet.nl/users/summer/16mmngm/LinkPages/Links_ConsTech.htm
Dale

 

[lugnut]

Thanks Dale, there is some great information on those sites.
Mel

 

[Paula]

Same here, Dale... Thanks for the info!

Paula

 

[dwentz]

You are welcome, Found this one today!

http://www.smokstak.com/articles/propane.html