2 stroke thread (with occasional F1 relevance!)

[Big Tea]

&, for any members who've missed the obsessive 'mechanical marvel' posts by a certain, ahem,
Polish member.. check this 10cyl 2-row radial 2T homebuilt out, (& at least it runs, to be fair).

https://thekneeslider.com/bistella-500- ... ek-foltis/

I was disappointed in the sound that made. Very original though, nice

[coaster]

The 5 pairs of two lobed rotors look great, almost like an f1 scavenge pump system.
That tiny little front drum brake sorta tells me that this bike is gonna be a shelf queen.
An inventive personal challenge with an optimal outcome.

[J.A.W.]

The 5 pairs of two lobed rotors look great, almost like an f1 scavenge pump system.
That tiny little front drum brake sorta tells me that this bike is gonna be a shelf queen.
An inventive personal challenge with an optimal outcome.

Well, given it is a back-shed build based on an elderly Communist-era Jawa, the arcane,
almost alchemy-like morphing of horology-level multiplicity in mechanical parts from such
a basic 2T concept is a more'n a tad 'cuckoo', so keeping it in a quaint chassis seems apropos.

& it has been savagely de-rated to a fraction of its supposed potential output, which would tend
to both not exceed its road-holding dynamics, & cause the stifled aural effect noted by Big Tea.

[J.A.W.]

Linked below is a curious research paper that claims - significant effects on basic 2T engine
efficiency/emissions output - via gasoline fuel molecular values affected by passing the fuel
through a magnetic field:

http://www.supereconomiseurdecarburant. ... 2_iraq.pdf


Given the level of electrickery utilised in current F1, has this potential for 'on-car fuel development'
ever been a topic of discussion here?

Or is it perhaps somewhat like the oil-consumption matter, being not explicitly mentioned in the rules,
& only likely to become an issue - if a team/engine-maker gets a marked advantage from exploiting it?

[tok-tokkie]

The concept sounds just like the quackery devices that appear constantly. However it is a proper academic research report and clearly written.
However Fig 3 has something missing. It purports to show the fuel consumed at 3 engine speeds dropping with increased magnetic flux. Fuel consumed when? Why does the engine consume more fuel at different speeds. I suppose it is fuel consumed in some time period but they fail to say so.
A 9%-14% gain in fuel consumption by simply passing it through a magnetic field would be a huge benefit in the current F1 environment. How long does the dissociation of the clusters persist, does the pressurization for injection undo it & can the magnetic field be applied successfully between the pump & injector?

[gruntguru]

My snake-oil alarm is almost deafening right now.

[J.A.W.]

See linked below; a more recent (2020) & comprehensively considered re-test of the concept,
with a seemingly similar outcome.. Bullshit, or not?

https://journal.unnes.ac.id/nju/index.p ... 7491/10309

[johnny comelately]

See linked below; a more recent (2020) & comprehensively considered re-test of the concept,
with a seemingly similar outcome.. Bullshit, or not?

https://journal.unnes.ac.id/nju/index.p ... 7491/10309

Inconclusive about the BS, muddled may be a better question mark
working backwards from the conclusion where it's stated that the improvement is a result of not one but two factors (linked or not?)
The second factor ("accompanied by the increase
of molecular vibrational energy") alludes to temperature if I interprate it right, and of course this could account for all the improvement. This has been amply demonstrated by it's affect on fuels of many kinds, eg, Honda and the turbo fuels of the 80's
All that being said, this is a fascinating area of possible improvement, the world of quantum chemistry, of which little is really known except what can be demonstrated mathematically or otherwise

[gruntguru]

Interesting - does it only work on little 2 strokes?

[saviour stivala]

The Bistella 500cc 2-stroke 2-row supercharged 10-cylinder radial engine. Marek Foltis having designed the crankshaft, masters (2) and slave-rods (8), carful design of the link-pin location on the master-rod big-end would have lead him to consistent TDC position for all cylinders, as well as consistent compression ratio. And so would have avoided the need to use a number of cylinder head gaskets used as shims to obtain consistent compression. There exists a kinematic model that can be used for radial engine design. In my circle of scale model ICE making that really works we use that kinematic modelling for radial engine design.

[saviour stivala]

Interesting - does it only work on little 2 strokes?

Yes. An even number of cylinders radial can only work well if in 2-T configuration. A 4-stroke radial design with an even number of cylinders an equally timed firing cycle would not be feasible.

[J.A.W.]

Interesting - does it only work on little 2 strokes?

Dunno, mayhaps the effects are most evident with 'em, yet there are studies on
largish diesel-powered machines (fishing trawlers) with reportedly good results,
however, all I've seen so far are from "3rd World" sources...

[J.A.W.]

While on 'H2', here below is a link to a reasonably recent Kawasaki 2-stroke development
design patent which appears to cross-reference both Toyota's attempts to make a DOHC 4V
design run as a 2-cycle, & Kawasaki's own 'blown' (supercharged) 'H2' 4T engine.

But don't get too excited, its a hybrid-electric 'range-extender' tuned for hi-efficiency,
narrow-band running akin to the prototype Audi machines racing in the the 'Dakar Rally'...


https://www.visordown.com/news/new-bike ... lane-crank

I posted the Kawasaki patent 'range-extender' 2T-hybrid as seen above, now Toyo Kogyo/Mazda
has released a somewhat similar 2T poppet-valve OHC/externally blown-scavenged engine
(albeit claiming a 'spin off' from 'Sky Active'-to-2T tech), which also features the kind of semi-CI,
yet SI when required, which BRP's Evinrude marine 2Ts already utilized for trolling-to-WOT powers.

https://www.motortrend.com/news/mazda-p ... on-engine/

[J.A.W.]

Interesting - does it only work on little 2 strokes?

Yes. An even number of cylinders radial can only work well if in 2-T configuration. A 4-stroke radial design with an even number of cylinders an equally timed firing cycle would not be feasible.

No, g-g wasn't asking you, there were huge 2T radials built & used as stationary engines by Nordberg,
as described with his usual aplomb, by Bill Pearce:

https://oldmachinepress.com/2014/01/12/ ... al-engine/

I'd also add that while 4T radial engines must necessarily run uneven numbers of cylinders per bank
naturally enough - yet a multi-bank iteration will also of course - result in even numbers per total..

[saviour stivala]

As explained, an even number of cylinders 4-stroke radial would not be feasible to have an equally timed firing cycle. As such the Nordberg radials being of even number of cylinders configurations were of the 2T cycle mode.