MYT engine - is this genuine?

Well without a torque curve, emissions spec or a clue how the cooling works it's impossible to tell.

Chris gurgled happily, sounding much like they were saying:

I'm sceptical. But that's not news.

From that article you linked to, there's a link to their own site, with a lot more information -

) They don't exactly start off well, since they're immediately frigging the figures - a single cylinder of capacity x firing 16 times per rotation does not make it equivalent to a 32-cylinder engine with capacity 32x, any more than a Wankel rotary is "equivalent" to a six-pot with six times the capacity of a single rotor chamber.

The first video seems to be the most useful in showing the basics -

It really just seems to be a slight twist on the existing diesel, closer to a two-stroke than a four, despite two-smokes having noise & emissions against them. Looks like it's air-cooled, which has all but died out for drive-by noise reasons.

We'll see. But I'm sceptical.

Me too. Several reasons:

1. They claim that it's non-reciprocating. But the pistons have to start and stop (and are shown starting and stopping) many times per revolution. How's that managed? How is the consequent reaction torque handled?

1. The pistons travel round a toroidal "cylinder". How is the slot for the drive sealed when the piston isn't there? How is the drive flange sealed when the piston is there? The problems here look like those of the NSU rotary and Brunel's atmospheric railway combined.

and finally, the simplest one of all ...

1. Why. Don't. They. Ever. Show. One. Working? If it's so great, show us one using real fuel, attached to a real dynamometer and producing real power. At an independent test site, of course.

I'm filing this under "misguided stupidity" but I am keeping space for it in the "malevolent scam" section.

Ian

Yup, ala the mayflower engine. If it's as good as it's claimed to be then it'll clean up in racing & make building smart cars etc. trivial, so why not sell the rights or engines to a real car manufacturer? Or stick it in a superbike.

film of one running here:

On Fri, 16 Jan 2009 16:50:42 GMT, I waved a wand and this message magically appears in front of Mrcheerful:

It's quite clever how the piston caps rotate around (you can see this in the first few seconds of the film)

Ahem, a film of "aliens landing" noises and fuzzy views of the engine behind. I think the sound track got mangled but there's no way that you can be sure that the engine is "running".

This one is a bit better

I'd be more inclined to believe that this one is actually running. Curious about the digital display, could it be rpm? Certainly on compressed air they talked about it turning over as low as 40 rpm so it may be that it's an intrisically "low rpm/high torque engine"

Tim

No it isn't, it is being pushed by an outside power source.

Thus spake Tim Downie ( snipped-for-privacy@obvious.yahoo.co.uk) unto the assembled multitudes:

Still no visual evidence that anything is turning. Would be good to see it driving a shaft or something. Or - and I know this is a bit radical - actually see one in a vehicle or motorcycle actually powering the vehicle. If it's such a simple and light device surely it's not too complicated to fit it to a vehicle?

Maybe the figures are optimistic, but even if it is just twice as good as a conventional engine, it is still amazing.

Yes, it is a bit like a wankel, but without the problem of 1-dimensional seal surfaces. All friction surfaces are 2-dimensional, like in a conventional engine. Since it is small, water cooling can be added as on outer shell.

The geometry of the pistons are mind boggling, something which could never be made by hand e.g. on a classical lathe.

I am sure it will take off.

Or this, probably the best of the few i've looked at

A bit like gas turbines did?

Gas turbines weren't suitable for car engines; not good for variable power delivery such as necessary in city traffic. Very inefficient outside their power band. Maybe they could be used in hybrid cars for charging batteries?

Wheras this engine so far has no numbers for torque curve or effeciency. It could be a good idea but so far there's no evidence that it actually works anywhere near as well as it claims.

In message , Mrcheerful writes

Erm - it's a *very* blurry video of one being driven by a compressed air supply. This is a long way from a successful internal combustion test

Bet he hasn't worked out the loads and effects of leverage in the linkage during combustion. The life of the phasing gear may be very short under loads imparted from an internal combustion process. Demonstrates naivety of a layman in claim that's it's vibration free, the intermittent motion does cause vibration.

Air motors produce good torque even when stalled. Torque is high as cylinder pressure can be kept at line pressure though whole of power stroke and there is no compression stroke to work against. While an IC has a pressure peak at or near TDC which then reducuces rapidly as expansion takes place on power stroke, it takes some effort to compress the charge and on a 4 stroke 1/2 the cycle is lightly loaded.

He's mistaken when he says the other half of the engine is "loading" it up, compressing air and then expanding it works like a spring, much of the energy taken to compress it is returned during expansion.

Power demand on an air engine always means high air consumption.

Nissan are working on something very similar to Mayflower, articulated con rod with control link to adjust compression. First look suggests both will suffer from backlash in control, very high forces at link pivots due to lever ratios and could have fatigue (HCF) issues in the control mechanism. Possibly to the extent they will need to make parts from unobtainium or so massive they can't be fitted in the space available.

If you want real crackpot engines look up six stroke on the Wiki. All suffer from incomplete analysis, student error or layman's naivety. At least 2 rely on "instant" heat transfer from one working fluid to a

2nd. One fails to comprehend problem of heat transfer to air from a cylinder head, which is well known and documented from work on air cooled engines. Others just don't appreciate that air is compressible and has inertia and thus don't understand valve timing.

For outright scam, Scuderi Split-Cycle "Air Hybrid" Engine takes the prize. The prize fund stands at $8m USA Department of Defence + $6m from private investors + $?m. Initial premise was that air could be transferred between 2 chambers instantly and without loss either of air to dead space, or in state as it passed though valves and interchamber port. The cycle, which is physically impossible to achieve using device described in patent, was analysed by a research institute, the result was proclaimed to the world and used to raise funds. It seems they still haven't analysed the true efficiency, taking finite transfer time and losses into account but they are well aware of the issue. Every subsequent patent demonstrates a frantic and hopeless attempt to overcome their inablity to transfer matter instantly. They now seem to think (mistakenly) that some degree of supercharge (yet also claim the benefit of a Miller cycle) will negate the losses and clearly believe in the "Free Lunch" (well they have been eating one every day for years). Then they compounded this by demonstrating a complete lack of understanding of dynamics and mechanical systems with a laughable cam guided big end. The velocity diagram presented in the patent application shows a discontinuity and thus has highly destructive impact events at any feasibly useful operational speed. Everyone of their patents lacks merit as a feasible engine yielding the claimed efficiency gains.

Scuderi are followed closely by various "air" engines, all the ones that make claim to overall ZERO emission.

True, although they make some claims in the video based on the lower internal friction and the many compartments (cylinders) around the torus. One could imagine that it is difficult to make a complete prototype, at the same time keep it secret before the patent application is ready.

But if you haven't built a working one you don't know that there's lower internal friction. You can build a 2 stroke with very few parts but it won't be very effecient.

Yes, there is a lot that we don't know. But the pistons chasing one way round in the torus looked quite interesting. The problem is then the valving and the crankshaft connection. Somehow they have solved it.