Suggestions for First I.C. Engine

[Mike1]

I have seen it run at cabin fever model expo about 10 years ago. Can you explain to me how you layout and machine the rotary valve. I even went as far as trying to machine it on a indexing head. It would try to run but still no joy.
View attachment 159132Here is a pic. of my none working engine version

Will these help

 

[wce4]

Will these help

Thanks for the info. I am going to make a go at it again after I finish the engine I am working on now. This engine has become a personal vendetta with me.

 

[Steamchick]

Pileskis. Your engine (Posts #24 & 25 ) is fairly simple, but is quite high precision, and well tuned in order to work as well as it does. Really nice to watch, but not balanced for crank/piston imbalance, I see? It "moves" a lot! I agree automatic inlet over exhaust (geared) is quite simple, but there are simpler engines that encompass fewer variables, to teach beginners.
For me, it simple starts with a 2 stroke "aero engine" style of engine. Piston, Crank, Bore Glow-plug head, ported cylinders, CARBURETTOR, etc.
But without gear for any valves, or any valves. And without a governor, and "No timed ignition". Just a glow plug.
That way you can concentrate your machining skills getting a small piston and bore to develop compression, as the first hurdle that needs your skills to be developed to a fine degree.
After that you can consider valves and valve gear and ignition for a 4 stroke.
Just an opinion though.
K2

 

[Steamchick]

WCE4: I should try double the diameter of flywheel. It looks a bit small to me for a single acting engine. Tractor's engine looks to be a bigger diameter? They only develop power for ~1/3 of a rotation, as steam/air have to get in and out during the rest of the time. So the flywheel has to keep it going for 2/3rds of the time when there is no power - but needs some rotary energy to help exhaust the cylinder!
Without any air, does it spin freely for a number of turns (5 or more?) with a flick of the wrist? If it only does 1 or 2 turns, then either compression, valve timing, friction or something is stopping it running. Friction and valve timing are the first things to focus on for me... And you need to be able to develop some compression so the piston seals in the bore, when you put a finger onto the exhaust hole. If you put a finger on the inlet hole and rotate the engine by hand, does it suck your finger, so you feel resistance to rotation?
I haven't made one of these crank timed engines, but I guess the valve has to be effectively leak-free between the drum and casing too.
K2

 

[wce4]

WCE4: I should try double the diameter of flywheel. It looks a bit small to me for a single acting engine. Tractor's engine looks to be a bigger diameter? They only develop power for ~1/3 of a rotation, as steam/air have to get in and out during the rest of the time. So the flywheel has to keep it going for 2/3rds of the time when there is no power - but needs some rotary energy to help exhaust the cylinder!
Without any air, does it spin freely for a number of turns (5 or more?) with a flick of the wrist? If it only does 1 or 2 turns, then either compression, valve timing, friction or something is stopping it running. Friction and valve timing are the first things to focus on for me... And you need to be able to develop some compression so the piston seals in the bore, when you put a finger onto the exhaust hole. If you put a finger on the inlet hole and rotate the engine by hand, does it suck your finger, so you feel resistance to rotation?
I haven't made one of these crank timed engines, but I guess the valve has to be effectively leak-free between the drum and casing too.
K2

Steamchick , I think you may have something here about the flywheel.
The engine is a single acting type and it tries to run, it just may need a little more momentum as you suggested.
Thank you, I am going to give it a go.

 

[Steamchick]

Sometimes it is easier to spot things from a distance? 50:50 chance this will help.
Good luck.
K2

 

[quattrohaje]

I have seen it run at cabin fever model expo about 10 years ago. Can you explain to me how you layout and machine the rotary valve. I even went as far as trying to machine it on a indexing head. It would try to run but still no joy.
View attachment 159132Here is a pic. of my none working engine version

Hi, I also tried building a rotary engine last year. I modified the construction and it worked. I was quite scared, but he started running almost immediately.

 

[wce4]

Hi, I also tried building a rotary engine last year. I modified the construction and it worked. I was quite scared, but he started running almost immediately.

I see that you incorporated a reversing valve, nicely done. I am going to try Steamchick suggestion after I complete the engine project I am working on now.
I personally think he hit the nail on the head about the flywheel.

 

[Steamchick]

Usually I hit my head, not the nail...
K2

 

[Aerostar55]

Just one salutary lesson, from a clockmaker who built 9 cylinder radials, etc.
He regretted not dong more to improve longevity of his engines, as after just a dozen demo runs, they would lose compression and never run again... He felt that although they were beautiful ornaments, they were "failures" in that they needed new pistons, rings, bores, valves and seats after very short lifetimes. - Just a few 5 minute runs! I have an ICE marine diesel (for a boat) that never made it into the boat because it ran once, then lost compression. New piston, new head for Glow instead of compression ignition, and that ran once before it lost compression. Tolerances were too fine for the Running-in to still have a usable engine. Despite surfaces being polished and carefully handled, etc.
I later found out from a shop that he sold aero engines that had short lives, but he sold replacement pistons and cylinders, so the users could re-build the engines and get more flights ... Typically 10 flights wore the engine out!
But "buying" cylinders and pistons - or even making replacements - is not on my agenda. I'll stick to durable designs, so I can continue to dust-off an old engine from the "shelf of boxes", to demonstrate at the next show...
K2

Might I suggest using spell check on your posts?

 

[Aerostar55]

I have built model steam engines that run on compressed air. 2 of the 3 run well; but, the 3rd one with a rotary valve won't run, even after rebuilding parts. All 3 were built from bar stock with free online plans.

I would like to try my hand at an I.C. engine that I can get to run. I would like to build from bar stock and free or minimal cost plans. On the smaller side would be the size I desire. Would like one to run with easily available and inexpensive ignition system.

I would greatly appreciate suggestions.

There are a lot of first time builds on YouTube, you might want to view some of these videos and see which one appeals the most. The "Webster" engine is very simple and can be built from bar stock. The drawings are posted online in several places. Having said that even experienced builders often run into problems getting that new model engine to run. With every engine I've built that eventually runs I've had to tweak, adjust and tune and so forth usually for several days until it starts and runs reliably. But when it first barks into life with a puff of smoke you will be delighted, it's a wonderful sense of accomplishment.

 

[Aerostar55]

https://imgur.com/gallery/H8Rqbiw

Take a look.

Sid

Looks good

 

[Steamchick]

Noted Aerostar. But it missed Dong as that is simply a correctly spelled word - just the wrong word. I frequently find spell check changes words - engineering terms mostly - that I have spelled correctly, but it doesn't have them listed. So it is a major frustration that means I usually write something, correct it to what I want, then re-visit it a 3rd time for a final read. But being human I do miss some things. Sorry if I have caused any offence with something I published in error.
E.g. It has tried to change "Aerostar"! Also "offence", "something" but not "dong", in this screed.
K2

 

[wce4]

Might I suggest using spell check on your posts?

I personally do not think spell check would work with the word Dong.
verb
(of a bell) make a deep resonant sound.
noun
the deep, resonant sound of a large bell.

 

[stanstocker]

Might I suggest using spell check on your posts?

May I suggest that many of us probably have a bit of arthritis in our fingers and while we all try to catch our typos and the forum system does pretty well in flagging the obvious ones a few will get through. Some are even quite funny.

 

[Richard Hed]

"Dong" a name in Philippino. Actually, it's not a name as such, more like calling a waiter; "boy", it's not impolite.

 

[wce4]

"Dong" a name in Philippino.

The Vietnamese dong (VND) is the current currency of Vietnam.

 

[Steamchick]

As soon as money is involved, Google thinks it is correct?
K2