2 stroke thread (with occasional F1 relevance!)

[J.A.W.]

Here's what Renault have been developing.. "powerful" 2-stroke-wise.. ..note efficiency claims..

http://www.greencarcongress.com/2014/12 ... erful.html

[J.A.W.]

Yet another new 2-stroke approach.. http://www.citsengine.com.au/?page_id=64

[FW17]

[FW17]

Can somebody translate the french

[J.A.W.]

Thanks for posting those Honda articles W-F1, 'tis a pity that Honda - for ideological reasons-
"Honda is a 4-stroke company!" abandoned such promising developments..

Just look at Honda's large range of gardening machinery,
- yet they still cannot market a competitive chainsaw,
since a 4-stroke would be far too complex/heavy/expensive..
& due to their ideological stance - can't accept that 2-strokes simply do such things - so much better..

Honda was forced to build 2-stroke motorcycles to race competitively, but got
around that embarrassment - by having 2-strokes excluded by the rules..

[langwadt]

Thanks for posting those Honda articles W-F1, 'tis a pity that Honda - for ideological reasons-
"Honda is a 4-stroke company!" abandoned such promising developments..

Just look at Honda's large range of gardening machinery,
- yet they still cannot market a competitive chainsaw,
since a 4-stroke would be far too complex/heavy/expensive..
& due to their ideological stance - can't accept that 2-strokes simply do such things - so much better..

Honda was forced to build 2-stroke motorcycles to race competitively, but got
around that embarrassment - by having 2-strokes excluded by the rules..

I'm sure winning helped soothe the pain

the beauty of two-strokes is the simplicity, once you add all kinds of weird valves, sleeves, cranks, etc. to make it "work"
I'm not sure what is left, bragging about less cc per hp ?

[uniflow]

No, more HP per cc!

[J.A.W.]

the beauty of two-strokes is the simplicity, once you add all kinds of weird valves, sleeves, cranks, etc. to make it "work"
I'm not sure what is left, bragging about less cc per hp ?

The actual simple advantage of 2-strokes - is fundamentally due to the way they do their "work"..

Every downstroke of the piston is doing "work"..
Unlike the huffing & puffing, down-time dancing, 4-stroke..

As Sir Stanley Hooker put it.. "One stroke to make power, & three to wear the engine out"..

Sophistications & technical improvements notwithstanding, by their very nature 4-strokes always need more of the..

"...all kinds of weird valves..." & etc,

.. plus extra boost &/or - revving their tits off - to do useful "work", & this is bulky-complex-costly-weighty..

[langwadt]

the beauty of two-strokes is the simplicity, once you add all kinds of weird valves, sleeves, cranks, etc. to make it "work"
I'm not sure what is left, bragging about less cc per hp ?

The actual simple advantage of 2-strokes - is fundamentally due to the way they do their "work"..

Every downstroke of the piston is doing "work"..
Unlike the huffing & puffing, down-time dancing, 4-stroke..

As Sir Stanley Hooker put it.. "One stroke to make power, & three to wear the engine out"..

Sophistications & technical improvements notwithstanding, by their very nature 4-strokes always need more of the..

"...all kinds of weird valves..." & etc,

.. plus extra boost &/or - revving their tits off - to do useful "work", & this is bulky-complex-costly-weighty..

I know how a two-stroke works

my point is that at some point adding sleeves, weird valves, crazy mechanisms to actuate them and figuring lubrication etc. a cam shaft and poppet valves starts to look simple and functional

[J.A.W.]

I know how a two-stroke works

my point is that at some point adding sleeves, weird valves, crazy mechanisms to actuate them and figuring lubrication etc. a cam shaft and poppet valves starts to look simple and functional

Yeah well, L, how the 2-stroke works.. ..is actually - the point..

Any other additional technical items ( regardless of how "weird" or "crazy" you think them to be,
& which 4-strokes - have of course - always needed) do not alter the fundamental X 2 BMEP working advantage..

[FW17]

The current 2 strokes in the market such as rotex have electronically controlled for variable intake and exhaust. Elextonics is actually simpler than trying to do the same mechanicaly which is the case with 4 stokes


The Honda hcci was amazingly simple as per its designer and was done using existing knowledge and machinery. It is a pity that it was not taken up by some other manufacturer. I would have loved a hatch back or a caterham 7 with a 2 stoke hcci

[J.A.W.]

Yes, W-F1, & Lotus too, almost got there, with their version of the "trapping valve" 2-stroke..

The attributes of even the basic 2-stroke - are so natural for machines like personal flyers & bikes,
..it surely has to happen, & esp' if good keen men like Manolis & Uniflow can get a fair go..

[J.A.W.]

This site offers a basic inexpensive EFI for 2-strokes..

http://www.ecotrons.com/products/2_stro ... ction_kit/

[manolis]

Yet another new 2-stroke approach.. http://www.citsengine.com.au/?page_id=64

Hello J.A.W. and thanks for the CITS link.

Here is 2-stroke ( we call it PatTwo ) running on Miller cycle:



With a separator the space between the two ends of the piston is divided into two sections; the separator comprises a passage between the two sections and a valve that controls the passage from fully closed to wide open.



The valve controls the load precisely "all the way", from idling to full load.




Here is an unconventional PatTwo Harmonic engine:



With its single-piece double-acting piston, this two-cylinder engine has two combustions per crank rotation (i.e. as many as a 4-cylinder 4-stroke) and, in total, only three moving parts:
a rotating, at constant angular velocity, power shaft,
a rotating, also at constant angular velocity, intermediate shaft,
and a reciprocating piston.

Among others, the Harmonic PatTwo engine is:
compact,
lightweight,
simple,
fuel efficient (Miller cycle at partial loads).
it has "four stroke like" lubrication,
it is as vibration free as the Wankel Rotary engine.


For more: http://www.pattakon.com/pattakonPatTwo.htm

Thanks
Manolis Pattakos

[riff_raff]

With its single-piece double-acting piston, this two-cylinder engine has two combustions per crank rotation (i.e. as many as a 4-cylinder 4-stroke) and, in total, only three moving parts:

Seriously, only three moving parts? Have you actually considered just how you will assemble the counter-rotating, geared crank system? Or what will you do if more than one pair of pistons is required? The overhung crankpin will also present some problems.