Pivotal engine

[cowpoos]

Wadddya guys think of this http://www.pivotalengine.com/flashversion.html


It really looks just like a new way to get power with two cycles,without alot of benifit??

[Taz]

Just looks more complicated than using a piston. What are the percieved advantages?

[p.dath]

It looks to me like only a small portion is under power on the down stroke, and then the exhaust port is reached, throwing away any power that may be left. And there looks like a lot of overlap between the inlet and exhaust port.

My guess is this engine would be really inefficient.

[Skunk]

Clean burning two stroke-ish power is the advantage. The engine is injected so (in theory) there is no unburned fuel going down the exhaust.

[Ocean1]

Timing looks not dissimillar to a typical 2X. On this one, though the intake volume is greater than the swept combustion volume, it’s effectively supercharged.

Seen a couple with similar design intent. What they don't show here, and what's the achilles heel of most arrangements like this is the seal details, especially the (non-radial) side seals.

[bogan]

machining that bore would be a bit of a challenge, and i agree, what are the advantages over a standard two stroke, direct injection of course, but the pivot design doesnt seem help with that. The more common two stroke supercharged deisle engine seems far better.

Also, i find this one interesting The Rotoblock

[Ocean1]

Also, i find this one interesting The Rotoblock

Not new, but I haven't seen quite that linkage setup before. Very cute, slow though, double the piston surface speed.

What do we think of this, then: http://kugelmotor.peraves.ch/index_en.htm

[bogan]

What do we think of this, then: http://kugelmotor.peraves.ch/index_en.htm

hmmm, thats pretty cool actually, sealing the compression bits cud be difficult though.

[erik]

I don't get excited about "new" engine designs. I reckon the standard piston engine configuration must be the optimal configuration, all the new engine designs I've seen have been more complicated and look like they'd be difficult to produce. Improvements come from refining the existing designs, not from thinking up some weird new design.
That's my opinion, maybe I'm too cynical.

[tychver]

I don't get excited about "new" engine designs. I reckon the standard piston engine configuration must be the optimal configuration, all the new engine designs I've seen have been more complicated and look like they'd be difficult to produce. Improvements come from refining the existing designs, not from thinking up some weird new design.
That's my opinion, maybe I'm too cynical.

Some, like the wankel, are simpler in construction. We're just too far down the path with the conventional 4 stroke piston engine now.

[sAsLEX]

I don't get excited about "new" engine designs. I reckon the standard piston engine configuration must be the optimal configuration, all the new engine designs I've seen have been more complicated and look like they'd be difficult to produce. Improvements come from refining the existing designs, not from thinking up some weird new design.
That's my opinion, maybe I'm too cynical.

Where would we be if engineers thought like that before the steam engine?? Or then the diesel? etc

another idea http://auto.howstuffworks.com/quasiturbine1.htm

[Dare]

I don't get excited about "new" engine designs. I reckon the standard piston engine configuration must be the optimal configuration, all the new engine designs I've seen have been more complicated and look like they'd be difficult to produce. Improvements come from refining the existing designs, not from thinking up some weird new design.
That's my opinion, maybe I'm too cynical.

That's old person talk, many great inventions go through an 'early adopter' phase. This phase is where the technology is expensive and unreliable, then if the idea is good things start to improve. Early motorvehicles had nothing over horses and carts.

That superballmotor has three moving parts, not exactly insane considering the huge list of things added to petrol engines over the years. DOHC, superchargers, turbos, EFI, 4 valves per cylinder, etc, etc.

Having played with CAD and rapid prototyping machines, and getting all excited about 5-axis milling machines, concept to prototype is now worth the effort. Bikes however have all the power to weight they need IMO, its just efficiency and simplicity (hence reliability) that needs improving.

Also, if battery tech improves sooner rather than later then its possible that electric bikes could kick carbon fuels ass. After all the only parts to wear in an electric motor are (broadly speaking) the bearings. I'd prefer it if they made a sweet noise though!

[mouldy]

No better than a 2 stroke and more bits to wear out , noones built a better motor then piston engines for cars and bikes yet , many have tried .

[Madness]

Hallelujah.

[Pixie]

It looks to me like only a small portion is under power on the down stroke, and then the exhaust port is reached, throwing away any power that may be left. And there looks like a lot of overlap between the inlet and exhaust port.

My guess is this engine would be really inefficient.

You're looking at an animation,KnobHead,I doubt you can accurately derive the port timing from it.

The advantage of the Pivotal Engine is that the piston is precisely constrained by the pivot bearings,instead of flapping around like a conventional piston does.
The piston is also watercooled,which makes it ideal for hydrogen fuel.