cool new motor

[mtcookson]

The MYT is not a reciprocating engine. The pistons never reverse direction, they move in the same direction. Even though they do stop and go, it would still be considered a rotary engine.

 

I believe the patent on the MYT is mostly on the timing components. The toroidal cylinder design was developed in the 1950's or 1960's I believe. The big thing with the MYT is the timing components.

[TheNeedForZ]

Sure you can define it like that. If rotary engine is defined as having continuous piston motion, then MYT is neither reciprocating nor rotary.

[mtcookson]

Rotary simply means rotating which is a spinning motion... exactly how the MYT works, even though it starts and stops.

 

Reciprocation is moving in one direction then another.

 

Going by each definition, there's no possible way the MYT is a reciprocating engine but can definitely be defined as a rotary engine.

[TheNeedForZ]

Their website never categorize it as a rotary engine. The inventor of the MYT engine specifically said it's not a rotary engine. I suppose "rotary engine" specifically refers to Wankel/Mazda rotary engine. Let's not talk about the name of things.

[dj paul]

i think this engine has potential but i believe it needs a lot of work before it actually gets ready to run with a load on it. i doubt anything is going to come of this engine in terms of a complete revolutionary motor, but hopefully some of the ideas and can be incorporated into current motors.

[mtcookson]

Yeah, on the website he didn't want it to be considered a rotary in terms of the Wankel.

 

They've actually already changed the design of the pistons and such and are supposed to be setting it up for fuel pretty soon from what I understand. Hopefully more will come out very soon.

[TheNeedForZ]

Where did you see the new design of the pistons?

[mtcookson]

On their forum. Should be the next to last post http://www.angellabsllc.com/forum/posts/list/30/6.page

[TheNeedForZ]

Wow they actually have a forum. I was surprised that in a thread talking about the flaws of MYT, no one mentioned inertial loads. Apparently when they did a fuel run with the demo engine, a piston did broke off. I don't know how much better the new design can deal with inertial load, but it seems better. They mount the piston on an arm to allow piston to wobble and the doughtnut chamber wall will take out the inertial load, but the new design can lead to some sealing problem and chamber wall wear problem.

 

If they make the pistons and chamber "half-moon" instead of a full round, they can rid many problems.

[mtcookson]

I see what you're talking about a "D" chamber now. How would it get rid of the problems you're speaking of.

 

I don't see how they could fit all of the pistons in there that they do with the current design like that though. Plus, you would lose half of your displacement... I could see that decrease helping the load you're speaking of but then you start to lose some of the size benefits and such.

 

How much force would there be with only 26.5 ci of displacement per "cylinder"?

[TheNeedForZ]

Their problem is that they have low funds. So every modification they do are retrofitted to their old demo engnie. They have no money to build a new one from the ground up. So you see they build their solution in and around the old engine.

 

Why will D shaped pistons be better : if you make a coin stand on a table, the available contact between the table and coin is only a small spot. If you cut the coin into two halves and let half a coin stand on table with fat side down, the contact spot between the table and coin increased many times. If the piston is shaped like a "D" then there is a lot of material at the base to attach to the rotor. To make up for the displacement, make a bigger "D"(radius of "D" is 1.414 times that of "O"). Sure the engine will be longer, but the diameter will be smaller. Benefit of small size only applies if the engine can run, if the engine can't run, there is no benefit no matter how small it appears on the drawing board. There is no special reason why they make the pistons/chamber round, they are round only because of ease of making parts. I do believe with a "D" chamber the combustion will be more efficient since flame has lesser distance to travel and we are talking about pistons with equal area, no displacement loss.

[mtcookson]

I understand what you're saying now. The only problem I would see in that design would likely be sealing issues similar to the Wankel's. Having the round cylinders makes it a lot easier to seal.

 

I wonder if they could do something along the lines of having half of the pistons connected instead of 1/4. With a 3" piston you would have roughly a little over 4.5 inches of material connected to the rotor, which would probably rival the D shape setup of similar displacement, and sealing shouldn't be a problem with that setup.

 

 

Here's another one a lot like the MYT. Its in Spanish though. http://www.terra.es/personal/sanchezv/mrcpc1.html

[TheNeedForZ]

The shape of D piston won't make the chamber hard to seal. If the engine has sealing problem, it's the inherent problem of MYT, not because the piston is round or not. In fact a D piston with half circle piston rings seals better than a round piston with near-full-circle rings.

 

A round cylinder is easier to seal in a reciprocal engine, but not in MYT. In MYT the piston rings are subjected to centrifugal forces. Imagine the ring like a "C". When the ring rotates with the piston, the opening of "C" which is on the right side, is pushed toward the left side due to centrifugal force and that causes the opening side of the ring to curl slightly inwards toward its own center. The chamber thus fails to seal when this happens since both two piston rings are subjected to the same problem.

 

If the chamber is a "D" then the half circle rings(still look like a "C" but only 180 degrees) will not curl due to centrifugal force since it is only half a circle.

[mtcookson]

The sealing problem wouldn't be the round part, it would be the flat part.

 

If I'm understanding your design idea correctly, the round part of the chamber would be cut in half to look like a D. The piston would also look like a D. The "flat" part of the piston would be connected to the rotor.

 

If that's the case, half of the flat part of one piston would be connected to one rotor and the same for the other. Right?

[TheNeedForZ]

Yes, the D piston is attached to the rotor IN THE SAME WAY AS THE ROUND PISTON.

 

There are seams between two rotors, seams between rotors and the chamber, seams between piston and rotor and seams between piston and chamber NO MATTER WHAT THE PISTON SHAPE IS. But with the D piston, there is no problem with rings lifting off the chamber wall due to centrifugal force. You understood the ring problem I was talking about?

 

The "flat part" of the D piston is not exactly flat either, the "flat"(rotor side of piston) is a curved surface that matches the rotors. Machining and honing a single curve like that is much much easier than making a compound curve like on the rotor side of a round piston. The problem with the round piston is ring lift due to centrifugal force.

[mtcookson]

I understand the design. I still see the "flat" part being a very problematic area. The "flat" part still has to be sealed where there is a seam above the adjacent rotor. It will be slightly curved to go over the rotor naturally but wouldn't have any easy way to seal and would probably see the same centrifugal issues the round piston would. With the D shape it would probably be like the Wankel, but worse due to the centrifugal force. The Wankel essentially has the "flat" part on the outside and we all know how those have sealing issues.

 

I should probably word it better... I think the major sealing issue would be the corners. That actual curved section would be relatively easy to seal but the corners wouldn't be fun at all. But like mentioned above, the seals on the D would also have the centrifugal forces on them causing the same sealing issue you're speaking of.

 

The centrifugal forces on the rings are definitely an interesting thought though. I definitely can see that being an issue depending on the ring design. I don't believe anyone has mentioned that on the forums. I'll search around and if not, I'll bring that up to them and see what they say.

[phantaz]

did anyone else get a headache trying to follow these two???

 

let me guess your both shadetree mechanics... with MIT engineering degrees?? =)

[mtcookson]

 

Me, moreso, a webgeek with nothing better to do than to read about cars all day long.

 

I think I have a pretty good understanding of how it all works, however, I love these types of debates because I can always learn even more from other people's ideas and such like above.

[TheNeedForZ]

Small seams are ok, the chamber does not need a 100% air-tight seal. The conventional engine has 3 rings, each has its own gap and we never complained. Out of round ring situation like on the round MYT piston is a no-no however. I came up with a clip than can seal the "flat" of D piston. With such design, the more centrifugal force there is, the tighter the seal becomes. It's hard to describe and I am not good at drawing pictures. I don't think it's worthwhile to draw it either.

 

True, there will be sealing issues with MYT because there are too many seams between components that form the chambers, regardless of what piston shape. The more one digs into this engine design, the more problem one can find.

[TheNeedForZ]

did anyone else get a headache trying to follow these two???

 

Yeah, I know three people that have headaches watching this thread : You, Mtcookson, and me