Otto Langen engine 1867

[PhilL]

I'm not quite sure what you are asking, but I'll try.

I think you're asking what causes the eccentric to catch?
The flat bar on the right side gets pushed down by the tab sticking out of the rack as it come down.
That allows the pawl to rise and catch a tooth on the rotating gear and be pulled around the eccentric.

 

[PhilL]

I looked at your pictures and maybe I have your question backwards.
Looking at your post #11, the 5th picture...
It's hard to tell, but I think the bar I spoke of is in the raised position and catching the pawl. However, it looks like the pawl tooth is in the path of the gear so it will catch and rotate.

If that is the case, while the bottom of the pawl is held by the latch sear on the bar, the pawl should NOT catch a tooth of the gear. Check your dimentions on everything if they do. They need to be spot on. I made that bar a couple times. Then I learned the hard way to do all the bends in the bar THEN cut that latch sear.

 

[gg89220]

sorry this is not my question, I would like to know what position should have the drawer in the carburetor with the eccentrics not trained
in other words, what are the adjustments to make to the admission system.

 

[PhilL]

OK, Now I understand. The link you posted looks to me like someone put together a few different sets of drawings. The ones in color are the set I used to build mine. On page 4 of that set, is the instructions to setup the valve. I copied it here:

The setting of the Slide Valve is similar to timing the valves in a modern day engine. The valve must be set to allow fuel into the engine at the right time, trigger the ignition to fire the engine, and then allow for release of the exhaust gases. The engine should be fully assembled except for the Slide Valve and the valve cover. Lift the rack high enough to clear the levers so the pawl will unlatch from the Ratchet Wheel. This will allow the FlyWheel and the shafts to spin freely. The high point of the Slide Valve Eccentric should be in the horizontal position with the high point toward the rack. Hold the FlyWheel to prevent the rack from going down and the shafts from turning. Screw the Yoke with Slide Valve attached up or down on the Valve Rod so the exhaust hole in the Slide Valve and the Port Face are aligned. This may take a little fiddling and screwing the Valve Rod up or down in the Eccentric Valve Strap to have proper adjustment at the Yoke end of the Valve Rod. Now you can install the Valve Cover, Springs, and nuts. Tighten the nuts only enough to apply light pressure on the Slide Valve. Apply only enough pressure to prevent the Slide Valve from leaving the the Port Face when the engine is running.

 

[gg89220]

hello
that's the answer I wanted ok. thank you
_for ignition what is the dimension of the end of the contact with the drawer.
_you have the same candle

 

[gg89220]

the ignition must produce a single spark or several at each contact ?

 

[gg89220]

hello
I see the spring placed under the head of the ignition pin, it is a mistake, it must be above ??

 

[Mechanicboy]

Try first with propane, then acetylene. Butane is not good enough.. See fact and compare between propane and acetylene..
http://www.cousesteel.com/AndysPlace/PropaneAcetylene.html

 

[Mechanicboy]

To check spark point: After the piston is raised by eccentric to suck the gas into cylinder and the valve is closed -> give a spark on gas to shoot piston up.

 

[gg89220]

I added oxygen to the air intake, there are explosions at each turn and stronger, he turned a few turns alone. it would be a lack of air in the cylinder, I will try with propane

 

[Mechanicboy]

Pure gas without air works bad. Maybe timing is not correct or passage is not correct. Remeasure all passage and hole etc to be sure all is ok before adjusting timing to get air and gas mixed into the cylinder when piston is raised up before closing and ignite the gas/air mix. Too much gas mixed in air will not works or too lean gas too..

 

[Mechanicboy]

To Set the Slide Valve.
The setting of the Slide Valve is similar to timing the valves in a modern day engine. The valve must be set to allow fuel into the engine at the right time, trigger the ignition to fire the engine, and then allow for release of the exhaust gases. The engine should be fully assembled except for the Slide Valve and the valve cover. Lift the rack high enough to clear the levers so the pawl will unlatch from the Ratchet Wheel. This will allow the flywheel and the shafts to spin freely. The high point of the Slide Valve Eccentric should be in the horizontal position with the high point toward the rack. Hold the flywheel to prevent the rack from going down and the shafts from turning. Screw the Yoke with Slide Valve attached up or down on the Valve Rod so the exhaust hole in the Slide Valve and the Port Face are aligned. This may take a little fiddling and screwing the Valve Rod up or down in the Eccentric Valve Strap to have proper adjustment at the Yoke end of the Valve Rod. Now you can install the Valve Cover, Springs, and nuts. Tighten the nuts only enough to apply light pressure on the Slide Valve. Apply only enough pressure to prevent the Slide Valve from leaving the the Port Face when the engine is running.

 

[Mechanicboy]

Exhaust valve (reed blade) works without big pressure to push valve open? Try to test valve works when you are suck the vavle via exhaust pipe and it must not be force to open the valve. With exhaust inside cylinder under suction period to get gas/air mix will not works well if the reed blade for exhaust is stiff.

 

[gg89220]

hello
it turns but still adding a little oxygen ?? I do not know what to do..Try with acethylene?

 

[Cogsy]

Maybe it is freeing up a bit and won't need the oxygen once it's fully 'run in'? Or possibly your gas mixture is off a bit? It might be just me but I wouldn't like to run a model on acetylene. It's so dangerous/powerful a gas that I don't muck with it except in commercially produced cutting torches. Just in case you do, and think about building your own tank, acetylene raised to anything over 12 PSI will spontaneously explode - acetylene tanks are specially constructed with internal structures and compounds to prevent this from occurring. It will also react with many common metals and make even more explosive materials.
There is more energy in MAPP gas than propane, maybe give that a go instead?

Edit to add: It's a remarkable engine, very unique and you're done an excellent job on it!

 

[Jasonb]

It's just those characteristics that make acetylene the easiest gas to use as it will ignite over a wide range of mixtures and pressures. Propane and even more so Butane have a very small band when they will ignite so pressure and mix proportions are very critical. This particular version is based on a copy of a copy of the Lenaz drawings, I know someone who has build an engine to these drawings and his runs on acetylene. Full size ones that still exist are run on a hydrogen based cocktail.

You are probably having to add oxygen as you have more gas than needed and the air/gas ratio does not have enough oxygen when just drawing air, cut the gas to almost no flow and run it through the smallest gas jet you can find to further restrict it. I've recently finished a hot tube ignition engine and that is critical on the gas setting only needing the valve opening a couple of degrees and that is going through a 0.15mm jet too.

When my 1/4scale Otto is finished I will get a small acetylene generator which are available from camping suppliers and at least one supplier of model engine castings.

 

[Chiptosser]

I believe Wayne Grenning, uses a mix of gasses. Like hydrogen and another gas.
You can look up Grenning engines, to contact him or go to Smokstack forums.

 

[gg89220]

hello
i managet to run it without oxygen!!!

 

[Cogsy]

That is a remarkable engine. Well done!

 

[ShopShoe]

It is nice to see it finally running. You have done a good job. I admire your persistence.

Thank You for posting,

--ShopShoe