1 / 8 Scale Galloway Build

[gbritnell]

Hi Gary,
I'm attaching a PDF drawing of the carb I made. It's not the best drawing but everything is there.
gbritnell

View attachment CARB ALTERNATE.pdf

 

[zneb]

Thanks Bob I go with this .It will be the answer I'm Sure Gary H

 

[BobsModels]

Gary

That was George that sent you the drawing, not me

Good to see you are plugging away. I am attaching a picture of one of
the first ones running, you can see the fuel system and as I recall
he told me he built the mixer to the drawing.

Bob

 

[zneb]

Thanks George.I'm a bit connfused where the needle valve go;s .are there o rings there because it seems to go through the fuel supply.Also from Bobs photo the fuel tank needs to be above mixer [Gravity Flow} right..Sorry I'm so dumb but I need to get it right.We have A big show coming up in Chilton Wi. and I would like to get it running by then..Glad there are folks like george and Bob who are willing to help us out...Thanks Gary H

 

[gbritnell]

There are no O rings used on the carb. The fit is tight enough that the fuel won't leak. The fuel supply does in fact go through the needle valve, well at least the tip. I'm attaching a video clip of the engine running with my carb. The top of the fuel level shouldn't be above the needle valve with this carb. With the Lunkenheimer carb it can be above as that carb has a built in check valve but with the small size of everything it takes some very precision machining as Bob can attest to.
[ame]http://youtu.be/mby5cKT0Cg4[/ame]
gbritnell

 

[BobsModels]

Gary

As you can see from the photo I posted and Georges explination, the venturi type mixer needs the fuel tank low enough so it does not just drain out through the mixer. Too bad you are not a little closer too me. You could stop by. I live in NW ILL about 5 miles south of the Wi border. Keep at it it will go. Do you go to the Baraboo show? They have a model building and lots of modlers bring engines.

Bob

 

[gus]

Great looking engine and very good paint work. Please post video when you get running.
I am putting finishing touches to Webster IC Engine and be trying to get engine going.

 

[Brian Rupnow]

That makes 3 of us all trying to get engines going---or keep them going. Good luck to all of us!!!---Brian

 

[gus]

Hi Brian,
Let me quote this------------"Birds of the same feather flock together". There is no Chinese eqv quote.
Translating this to Chinese will be tough. There is a Chinese quote picturing loving couple as two birds together in a forest.

Now to Biz/work.

Busted the cylinder lubricator while turning over the engine . About to machine replacement.
Make the leaf spring. Then come tomorrow start & run. Hope my neighbours won't come running in with a battle axe.

 

[zneb]

Bob ,Brian ,George ,Gus and anyone else interested, I just discoverd My intake valve is leaking.What do you guys use to set these small valves.I've tryed everything I can think of and it still leaks .Even made a new valve .I also found out when I spin with make shift starter It shoot fuel out of the carb {mixer}.Timing appears to be right on.My fuel tank is now below mixer and has a check valve in line..I've made 2 other small engines and never had such a hard time getting them to run.When is the baraboo show I'm thinking maybe I should Go .I never was to that Show but our club displays big time at Chilton Wj. show in aug. and I need to get this runing by then..Thank To All Gary H

 

[Brian Rupnow]

zneb--Valves in small engines are an absolute curse. I find that the answer is #1--make the valve seat as small as possible. I try and aim for about .015" x 45 degrees. #2- Make the angle on the valve face 92 degrees included angle.--(see my details for valve and valve cages on "Rupnow i.c. engine with governor"). I lap first with 350 grit oil base carborundum lapping compound, then with 400, then with 600. I was told that the best way to totally seat the valves was to hook the engine up to an electric motor, turn on the engine ignition, turn on the engine fuel supply, and make whatever adjustments are necessary to get the engine firing while it is being driven by the electric motor. The pressure created by combustion in the cylinder will finish "seating" the valves completely. I tried this approach on the engine I am currently building and it seems to work miracles. Of course, if it is shooting air back thru the fuel tank, I think you need to do more lapping before you try this approach. That's all the knowledge I have to give you.---Brian

 

[gbritnell]

zneb,
Sealing valves is one of the biggest problems on these small engines. I never cut the seat while I'm machining the valve pocket and guide. I make up a tool to do this. I'm attaching the PDF drawing of the tool. I hope this helps you out.
gbritnell

View attachment VALVE SEAT CUTTER and INSTRUCTIONS.pdf

 

[Brian Rupnow]

I have made and used the tool George shows, and it does indeed work miracles. I forgot to mention it.

 

[gus]

Hi Gurus,

Thanks for the advance notice. Did have a gut feeling that valves wee bitty leaky which spun over.Gus should be starting engine anytime this/next week. Now admiring my work and cleaning/polishing base and frame.Will reassemble and wire up ignition etc. Meanwhile taking it easy before 'D' day. Got stuck reading/clearing mail today. Watching the market & $$$$$$.

 

[BobsModels]

Gary

The Baraboo Show is aug 16-18. There is a model building where you can come and show your engines. I am planning on coming on Friday for the day and being some models for display. If you bring models for display, there is a vendor exhibitor entrance you should use. Bring the Galloway!

http://www.badgersteamandgas.com/index.html

Hope you can make it

Bob

 

[zneb]

Hi Bob< Well I got Time to work on My !/8 Galloway again and found the problem, I think .I took the Fuel line off and spun it with My Make shift starter and after a bunch of spinning it started to run..{Firing and Trying to Run}.The needle valve was open a very little bit.I closed it tight and put fuel line on ,Primed it 1 or 2 turns by hand and turned with starter.Nothing happened .So I toke fuel line off again and spun a few times and it started to run again.Now I'm thinking the hole in bottem of carb is to small {not Enough Air} So I drilled it a little larger .Not touching anything else I spun with starter nothing happened, Even when I chocked it a little,.So I took off fuel line and after spinning awhile it started to run again...Does anyone have a Idea as where to go next..I checked the size of the needle valve hole and I'm right on there.It has something to do with fuel I'm quite sure.. I;m leaning to making the carb hole bigger for more air and less fuel what do you think ? Our Chilton Show Is this WK end ,So I;m getting antzzy. ..AS far as Baraboo I;m still not sure I can get There. Thanks for your help to everyone Gary H

 

[Jasonb]

Do you have a vent hole in the fuel tank?

 

[gbritnell]

If you take the fuel line off and it starts to run then that means it was drawing too much fuel and was flooding. If it starts with the fuel line off then quite naturally it's getting enough air so I wouldn't enlarge the air hole. With these tiny carbs the needles are very sensitive, sometimes just a minute turn is enough to go from rich to lean. I would turn your needle in until it bottoms, then open it no more than 1/4 turn. Try starting the engine. If it does nothing then open it 1/8 more and try again. At some point you will hit the sweet spot and it should start running. The size of the venturi only controls how fast the engine will run. The fuel is always adjusted to whatever size venturi you have.
gbritnell

 

[BobsModels]

Gary

I agree with George. Let me make sure I understand what you are doing. You apply fuel with needle open and it will not start. You remove fuel line which is equivalent of closing the needle and it starts off. Let me tell how my engine normally starts when cold.

I open the needle about one turn (my needle is 112TPI) and flip it a few times - 90% of the time it does nothing. I then close the needle valve and flip it a few times - 90+% of the time it starts. I let it hit a few times to clear it out and open the needle - on my engine I open it 1 1/2 turns until it gets warm and then close it a little let it run for awhile close a bit again until it wants to stop, then open a bit and it usually runs until it is out of fuel. If I keep filling the tank on the run, I get it to run all day no stops.

Sounds like you need to do as George says find your sweet spot, and I think it will run. If you used Georges' carb I would try my sequence, but just open it slowly as George says.

This engine, at least mine floods real easy so by closing the needle letting it clear out the fuel is the trick.

Good luck

Bob

 

[zneb]

Hi.Again ,Well I couldn't get no where with the fuel tank Low so I put It Back Where The Drawing Shows.After Trying all of your Ideas I find The Needle vale seems to be off some where.If I open 1/16 turn it still floods out.close the valve and it will start and run for about 3 seconds and stop.If I open just A touch it floods out .could the hole in needle be to large.