Strange but simple engine.

[Buksie]

Hi Guys

I found a series of very interesting you tube videos showing internal combustion engines of very simple design and build (see link below), I am convinced that one would be able to build some of them without even using a lathe.
It appears to be some type of non compression engine, obviously the intake will be a atmospheric valve but what about the exhaust, sleeve port perhaps? any ideas from you guys?
I believe this design will be ideal for a first time model engine builder, it is simple and if it runs it is sure to inspire some more builds.

Regards
B.

[BronxFigs]

B.

Interesting engines....but unfortunately, I can't read German...so I have no clue just how these self-built engines work.

Thanks for the links.

Frank

[vtsteam]

Hey RussellT,

check out the valve/carburetor on the third video!

[RussellT]

That's a very similar action to my mod up engine but I think only one set of ports .  It doesn't use the screw thread retainer though.

It's quite an interesting design because it does simplify some things.  For example it seems to use the same port for inlet and exhaust and the carburation is more akin to direct injection, but I don't understand the whole engine - it doesn't have a compression chamber so my initial thought was 4 stroke, but the ports don't seem to allow a 4 stroke cycle.

I can't read German - can anyone out there translate for us?

Russell

[vtsteam]

I love the fact that a single piece of pipe is air intake, carb, valve, and pivot.

[vtsteam]

Not much help after using Babelfish on the comment:

"After two years of construction and some internal combustion engines, I have updated my first engine with my experience and new knowledge.

Now the good piece running also with Al"

Later:

I've been slowly typing the scene texts into the translator. Too much talk about how everything is not critical, and was done by eye! Finally something interesting. The sparkplug was made from half of a power resistor, and has a notch at the bottom.

Not up to the valve yet......

[shipto]

I think I have it:
bdc to approx 15 degrees is intake the fuel is fed down the side on the "spark plug" shown at about 3.10 I am guessing it is a porous material or a slightly loose fit, the spark happens a fraction before the ports are completely closed and the fuel kicks it forward until the ports reopen at around 165 degrees. inertia then takes over to exhaust the burnt gasses out until bdc is reached again.

[RussellT]

That's helpful, Dwayne.

So we have a combined induction and power stroke, with no compression, and an exhaust stroke.

I think the fuel is fed in through a small pipe with a couple of holes in running alongside the ports (3.19 - 3.21).  I suppose this must also mean that it sucks fuel through the jets on the exhaust stroke - although I suppose that might be avoided if they were at the correct angle to the airflow.

That's a clever idea for the spark plug.

Russell

[shipto]

Not saying I am 100 percent right that was just the way I think its working.
That spark plug looks very similar material to those air stones you use for fish tanks, so I am sure its running more on the fumes than actual raw fuel/air mix as I cant see any way of atomising the fuel. Having said that the intake seems very far back so if the fuel is dripping down then when the port is almost closed there may be a babbington type effect happening.
Either way I doubt that the engine is capable of producing much power.
Still neat though.

[vtsteam]

From what I see, there are only wires going to the spark plug. No fuel line.

It is made from a power resistor body cut in half, and it is inserted at right angles to the cylinder.

There is a  jet tube inside the "carb" immediately in front of the oscillating valve ports that works similar to Russel's intake port..

If you look closely you can see the tiny orifice in the tube (and the plugged end of the tube), and the point at which methanol sprays into the port.

I believe the port serves for both intake and exhaust. Actually there are two ports in line. But probably because he doesn't have the means to mill a slot. Or the realization he can file it from the two holes. It's all pretty crude from a construction skill standpoint. But it is cool from an idea standpoint.

The timing is such that the port is open both ahead and after TDC to do the exhaust and intake within that period.

It's very primitive, but very interesting in terms of simplicity......if I'm right about all this.


ps. There's also the curious matter of the other two holes opposite the cylinder ports. I'm wondering if they tend to direct exhaust away from intake air because of their location and the timing. If exhaust puff goes out those ports but then creates low pressure behind in the carb, air could be drawn in axial to the pivot/carb reducing the mixing of exhaust and intake, and giving the cylinder a reasonably fresh charge.

[vtsteam]

John was once interested in a flame licker engine that had internal combustion -- this is pretty close to that, I think. The main difference is that there is spark ignition instead of a pilot flame. I think ignition on this one may occur as the methanol is being taken in, before the intake valve is fully shut. Depending on the timing, there could be a vacuum going on while the valve is closed after BDC. And maybe time for expansion before BDC. The long thin brass tube cylinder does have a lot of cooling area.....not sure......

[RussellT]

The extra ports might well help with avoiding mixing of the intake and exhaust, I had assumed that the large cylinder volume compared to the "carburettor" would take care of that but  the induction stroke is short compared to the length of the cylinder.

It sparks as the ports close (15 deg ATDC?) and then the burning mixture expands for the power stroke, the valve opens again around BDC (165 deg ATDC or 15 deg BBDC?) to allow the exhaust gases to vent before BDC to prevent the engine having to compress them - if they continue to expand they'll be exhausted and then the piston pushes out the rest until TDC and then sucks in mixture until the ports close and the cycle repeats.  If that's right then there is a very short time for induction but it fits as the valve timing has to be symmetrical between BDC and TDC.

I wondered about whether there was any vacuum effect because it is described as an atmospheric engine (see, I can read German  ) but I can't see how there could be.

Russell

[shipto]

bdc to approx 15 degrees

just realised I got this upside down its should be tdc not bdc.

[vtsteam]

The extra ports might well help with avoiding mixing of the intake and exhaust, I had assumed that the large cylinder volume compared to the "carburettor" would take care of that but  the induction stroke is short compared to the length of the cylinder.

It sparks as the ports close (15 deg ATDC?) and then the burning mixture expands for the power stroke, the valve opens again around BDC (165 deg ATDC or 15 deg BBDC?)..............snip.........but it fits as the valve timing has to be symmetrical between BDC and TDC.

I wondered about whether there was any vacuum effect because it is described as an atmospheric engine (see, I can read German  ) but I can't see how there could be.

I'm thinking the valve timing is symetrical but that would mean just a short interval either side of TDC for both exhaust and intake. And that would support the atmospheric concept as there would be plenty of time to develop power from the vacuum.

There may be some energy from the power side, too, but methanol burn is pretty instantaneous compared to the RPM of this particular engne, and the port is open at ignition  -- or so it looks. I think it's sort of an inefficient combination of IC and atmospheric engine -- as named. A quick way to find out what was happening and how much contribution each part of the stroke provides would be to insulate the cylinder and check the RPM compared to normal.

[RussellT]

I'm thinking the valve timing is symetrical but that would mean just a short interval either side of TDC for both exhaust and intake.

I don't think I explained the symmetry very well.  I think the valve closes 15 deg after TDC and opens again 165 deg after TDC remaining open after BDC until TDC (open for 210 deg total).

The valve opening is symmetrical around the halfway point between TDC and BDC - the halfway point is the extreme end of the cylinder oscillation.  That's exactly the same as my mod up engine but I used two ports.

Russell

[vtsteam]

Ahh, yes it would be symetrical around the pivot extremes, not the piston extremes. 

But, Russell, I think it's the other way round. It opens after TDC, and closes before BDC and the vacuum pulls the motor around while the port is closed.

Check out the location of the holes on the inner stationary valve piece below, and notice that the flash marks (and moving port marks) is located below the stationary part. I noticed this lower valve location also in the video, though not as easy to see.

With clockwise rotation of the crank valve is open after TDC and closed during the return stroke. Yes? So the vacuum does the work, I believe, thus the "atmospheric engine".

[shipto]

From what I see, there are only wires going to the spark plug. No fuel line.

Quite right, I must have been filling in bits in my head that where not there. so the fuel is carried in that tiny pipe inside the pipe with the ports.
so fuel is atomised between tdc and 15 degrees or there about and ignited right before the ports close.

[RussellT]

Check out the location of the holes on the inner stationary valve piece below, and notice that the flash marks (and moving port marks) is located below the stationary part. I noticed this lower valve location also in the video, though not as easy to see.

I spent ages yesterday looking at this and even trying to read some of the text without much enlightenment.  The still you posted seems to give the best guide but I'm afraid I still don't see it as you do.

I agree that the black marks on the stationary part of the valve are caused by combustion.  So that gives two valve positions, one where the ports are (open) and one where the black marks are (closed).  The black marks are below the ports so the valve must be closed when the cylinder is below it's centre position.  Clockwise rotation makes that after TDC.

Russell

[vtsteam]

Okay Russell I see it your way, now. The 90 degree part keeps throwing me. 

I guess the long open time must be necessary to both get rid of exhaust and pull in a new charge. I'm surprised it runs at all, especially with the ports drilled out of line, as it looks in the photo. Methanol is a very forgiving fuel.

It also looks like the holes on the other side of the pivot aren't opposite the valve ports. They never close completely, and at this point I don't get what they're doing.

Quite the mystery engine.....

It would be interesting to try a pivot valve vaccuum engine similar, though. If the timing could work.

[John Hill]

John was once interested in a flame licker engine that had internal combustion -- .....

You mean me?  I did indeed ponder an internal combustion flame licker, I even got well along on the project but it is presently sitting on the shelf with a couple of other uncompleted jobs,  perhaps I will get enthused again soon?

[RussellT]

Well now we're more or less agreed on how it works, the problem is how to describe it.  It's sort of a one and two half stroke cycle.  Half for induction half for power and one for exhaust.  However that's not really accurate because the induction is less than half and exhaust is more than 1 and power is probably more than half.  Perhaps the original description is best ("strange").

After working out how it works I'm quite impressed with it.  If I were planning to build an IC engine my first thought would be two stroke or 4 stroke - and if someone had a competition whose rules banned two or 4 strokes - I'd be thinking Atkinson or 6 stroke cycle.  The builder of this one has gone his own way.

I think the Anson Engine Museum has an internal combustion atmospheric engine dating from the 1850s.

So I just googled it.

I was wrong it was made in 1877.  Here's a link.

     

Russell

[vtsteam]

John was once interested in a flame licker engine that had internal combustion -- .....

You mean me?  I did indeed ponder an internal combustion flame licker, I even got well along on the project but it is presently sitting on the shelf with a couple of other uncompleted jobs,  perhaps I will get enthused again soon?

Yes, John I did, sorry I wasn't more specific!