Can we call you EC?
Like you i would appreciate hearing exactly what others think of some of my more "airy fairy theories" - say what you think, I can take it - better than having people muttering in the background!
Yes I do agree that poppet valves would probably not be up to the job in a competition engine, but they might survive in an engine for more mundane jobs around the streets. Also ohv type poppets for the inlet would of course need a blower if the crankase is to be wet sump style.
Personally I don't believe that there is a future for expansion chambers in an ordinary road/street machine as basically they are used to great effect (read necessary) in a competition machine but in a relatively restricted rev range and to make them work perfectly all over the rev range is a very different thing and will require different remedies to the point that it is not worthwhile!
The market for the two stroke (in my opinion) lies with the general public acceptance - that will be governed by the sound and the cleanliness of the exhaust, also how it needs to be marketed and this is the only way I can see as a means to get back again - all despite the fact that it has been proven to have the possibility of simplicity, compactness and a power to weight ratio second to none, so as I see it, it has no hope of rejoining the world wide market until it's exhaust issues have been completely resolved - there is no longer any sense in encouraging the use of the present day Schneurle system of charging the cylinder or using the exhaust in lieu of a (necessary) supercharger in the form of an expansion chamber. The banning of superchargers was not sensible - it was introduced by those who knew better ie those at the top, who also saw fit to dispose of the two stroke in racing altogether, maybe not worded in that way, but it effectively made it impossible for the two stroke to continue racing!
Hopefully the engines they are beginning to look at for GP racing will be bring the two stroke back from the brink and have it accepted again. I believe that it can be, but it needs a complete redesign - the opposed piston layout could offer many benefits, one of which includes keeping the fresh charge away from the spent charge - this will reduce distortion and hence will help in the ability of using smaller clearances - that, along with not using an expansion chamber exhaust where a lot of charge mixing is bound to be taking place, will make the filling of the cylinder by a supercharger a more sensible approach.
I believe we have to look at the overall world wide use of the two stroke and take note of why there is such opposition to it
i also would be interested in using a constant speed piston engine (two stroke of course) running at its most efficient speed driving an electric motor through a generator where - only a simple but efficient engine would be required, that instead of trying various remedies to make it operate perfectly right throughout the rev range!
Fuel injection and HCCI has to be looked into as well and both will surely? be looked into.
As an afterthought I have decided to mention the Commer TS3 ( also Foden trucks,) - the TS3 was a 3 cylinder, 6 piston (opposed piston layout) diesel which is said to be the most efficient two stroke engine ever produced! - it was used for many years in trucks and fishing boats - was exceptionally smooth running and very economical.
However they (Rootes Group) were bought out by Chrysler who immediately scrapped it, to remove all opposition to their Cummins four stroke trucks. ....... sad saga of the two stroke - always the loser??
Strokers Galore!
Yeah EC works.
Obviously the idea I had wasn’t actually thought out using any calculations or anything just picturing what I think I know in my head (which is probably not as much as I think), it would be neat though to have it super charged and direct injected. Surely you would be able to keep the transfers open after the exhaust closes if you’re supercharging/turbocharging. Variable valve timing would be easier to achieve at least for intake valves like a VTEC set up or how Suzuki changes the cam timing with centrifugal force. You could also have a power valve on the exhaust to spread the power. Also cranks could be one piece and all the bearings could be plain bearings.
After looking at that opposed piston truck motor and watching some videos I couldn’t help but admire the simplicity and ‘terrible sound’. It’s a shame that it was scrapped.
If you got the supercharger to whine loud enough the exhaust noise wouldn’t be a problem for the general population, assuming everyone loves the sound of a whining supercharger and assuming it’s belt driven. But jokes aside couldn’t It be muffled down like any other modern car which is virtually silent. Or even having it coupled with a plug in hybrid set up would work as it wouldn’t be started for most daily driving tasks. Therefore not offending as many eardrums.
I can’t imagine they would resort to efficient stationary engines for racing, unless they give CVT the go ahead in F1. It would probably sound terrible though, cars droning around for an hour or so racing in a procession to the flag as they will all be restricted by how much fuel they can waste.
You may be right Lohring and I know that you are in favour of pure electric - I would like that too! ..... but it is highly dependent on infrastructure - people in less developed countries want individual transport and these countries are not well known for good infrastructure!
I think the hybrid is still viable, at least for the moment.
Motors (used in pure electric and hybrids) can be made cheaply, as can simple (clean) two stroke engines - I do believe that the electronic motor controllers can probably be made relatively cheaply and that seems to me to be easier than making an IC engine complicated in order to make it perform perfectly ( and probably less efficiently) over the entire rev range!
As for EcoMotors - I never did like the layout of that with it's "pullrods" etc - totally unnecessary, especially when the problem most probably could have been solved in the form of a much neater package, as was used in the successful Commer TS3 (with it's "Sultzer" style engine).
- still, I would never dismiss anything offhand, everything has both good and bad parts!
I (like EC) am not going into details, calculations, etc. (because i'm not really proficient in that area!)
Strokers Galore!
Frits said something about that a while ago in this thread (from memory).
Flettner also had something to say on this thread about the supercharger and exhaust noise - (reckoned it was the lobed supercharger which was actually causing most of the noise coming from the exhaust!).
Strokers Galore!
Well, been a bit busy on an idea. 2 stroke of course. Nope, not a 54 hp @ 13,624 rpm KZ engine that is dependent on the 3rd divergent cone to be within 0.5 mm in diameter, but something really mundane, perhaps with much reduced HC emissions and fuel consumption. Maybe running at the 3000 rpm range.
More to come on this…possibly. Seeing Hewsa created Oddball, I figured that this is the right place to post it.
So, have had one running, but how do I compare it to a regular carby engine? As the thing is being based on a 100 cc Yamaha KT100J kart engine, I do have something to create a baseline. But how to measure it? Need a dyno.
Essentially out of bits from of years of hording, I made a single speed dyno or, more correctly, a comparator.
As I will be in the power range of 3 - 4 kW, I based it on 5.6kW (7.5 hp) 3 phase elec motor, connected to the engine via a V belt. This will both enable me to start the engine and also act as an absorber, returning power back to the mains. Essentially running at a fixed synchronous speed, apart from slippage, either way. In this case, the motor spins at 3000 rpm and the engine at around 3400 due to slightly different pulley sizes.
How to measure power as there is no torque measurement? What I did is to use a single phase domestic kWhr meter, this being an old “mechanical” type with a rotating disc. A nice feature being as the load reverses, the disc visually changes direction of rotation. This was connected to just one of the 3 phases. So, I could measure power by timing the disc rotation speed, but as the thing now seems to work, will just get a digital ammeter, relying on the kWhr meter to tell me the sense of the current.
Looks a bit shitty, but the focus has been on convincing myself that it might work. I can measure fuel flow by timing the fall in level with the graduated glass tube, turning off the outlet tap of the tank. So, get to the set speed, set a load (based on current) and then measure fuel flow. Take standard engine off, put on THE engine and compare fuel flow rates.
Anyways, that’s the story and here’s a couple of pics:
"Success is the ability to go from one failure to another with no loss of enthusiasm.”
Well done Ken, still life in the old dog yet!
It interests me very much and I hope it continues to develop successfully. also, old technology never dies (look at Harley) and as you more or less suggest, there is a lot more than racing out there too!
However ....... Must take issue with Husa being considersd the sole originator of the thread, (doesn't matter anyhow) - I suggested it in ESE a couple of times (to take the weight off that very busy thread and maybe give this sort of stuff a chance to be seen) and was asking around if anyone thought it would be a good idea - but Husa was keen and probably thought I was pissing around too much, so just got on and set it up before there were any answers (good on you Husa! ...... motto of the story - don't piss around).
Anyway we have got on ever since and the thread has worked ok - we both give it a good kick up the arse every time it falters -eh Husa? .......(the "Kick Arse Thread"?).
- to both you guys.
Strokers Galore!
The final kick for survival? (the thread? - no, but maybe that as well!) - a very significant last kick it is too (in both cases) I think!
https://www.cycleworld.com/story/bik...JuVLOc8QvaLgc0
Are the decision makers wise enough or brave enough to take the plunge?
These guys (Achates) are now well down the track, following on from the successful designs of Junkers, Napier, Sultzer, The Rootes Group (Commer), Foden, who all had successful opposed piston (and piston ported) two strokes over 60 years ago - Junkers really set the ball rolling both before WW2 and during WW2, - they had this engine operating in some of their bombers but were more well known on their E boats. .... then in the fifties, fashion overtook them and they got dismissed by those who should have known better!
Achates are taking it a step further! but this time, is anyone going to be wise enough to see that it could be the best way forward for two stroke suvival?
(BTW the thread is petering out). the two stroke future is still teetering on the brink as well (God forbid that it ever falls back! - that would really end its chances!).
I don't think that there is much that I can do about that (except blabber on ) - so it's goodbye from me and it's goodbye from him (he's not even here either!)
Time to go and do all the other stuff I really should be doing and pondering my future!
Thanks you guys for all the laughs and good company over the years!
Will.
Strokers Galore!
Will,
I looked at their Youtube vid,interesting as its design is very similar to the Junkers aircraft engine,,then noticed the vid was from 2016..Hope they are still going strong,guess they are trying to keep their old redesign quiet??
https://www.youtube.com/watch?v=JoQk...ature=youtu.be
I have just seen this video - sensible guy!
https://www.youtube.com/watch?v=zf6OH4iVUkY
Strokers Galore!
Yes,That was a good vid and looked at other company vids..Looks like they 'have their ducks in a row'..As you have said many times,the big companies have polished the 4stroke turd to a high sheen and dont want to change!A few basic questions from a country boy that has not been answered,Weight?we have 2 crankshafts and gear train to join them.would a triple twin piston weigh less than an equally powered 4poke?Can a single(twin piston) be made to run on a carb,ie chain saw,etc?Are high end electronics required to keep them running?Overhaul costs?Time between overhauls?Will they spin to the high RPMs that the formula 1 folks are looking for?The Junkers was a massive engine,it would be wonderful to see a 'flat' opposed design to give the 4stroke aircraft engines a run for their money..
OK OK I was going to move on and forget , but think I do feel the need need to answer all that!
I was once a country boy too (perhaps not as you Southern Boys perceive the term "country boy" but a country boy nevertheless!) but I have a son who lived and worked in Charlotte NC for a few years!
Yes two crankshafts with a gear train but a useful gear train the "idler gear/s" used for a power take off, (only one crankshaft in the case of the Commer/ Sultzer layout - probably no balance shafts required ( I had a ride in a Commer Truck and can vouch for its extreme smoothness.)
Wasn't suggesting it for either racing or crappy little chainsaw type applications (they can do whatever they want). My suggestion (as I also have said many times) is for a constant speed simple clean two stroke driving a generator with no complicated and sometimes not very well all over the whole rev range but something running at reasonably constant revs (at its "sweet spot"), increasing it's efficiency and the electrical stuff controlling the variations in road speed etc.(no tthe engine).so no need to have fancy electronics controlling the motor.
Anyway, wife's calling me, (my turn to do some cooking this evening it seems- gotta go! ------ yes dear!
Strokers Galore!
Will, I had a look at the Achates vid and have to agree, as I think you do, with 190mech that it is a complex affair. But it did look to be a complete package, even with cat converters (I think). However, when you look at any current 4 cyl engine, they are surrounded with bits and pieces, and although fundamentally simple (crank, rod and piston), the valve train offsets that.
How the numbers stack up can only be measured in terms of its commercial success in its most practical application.
Enjoy your dinner?
"Success is the ability to go from one failure to another with no loss of enthusiasm.”
Thought I might need to stay on another day or so to keep you guys straight!
Yes, best dinner of the week!
As I see it anyway (and I'm right),
I prefer the Sultzer/Commer layout this is the most compact, one crankshaft with beams/rockers to operate the pistons. rotating at a relatively constant speed as a hybrid powerplant/transmission.
Beams do oscillate of course and normally might need to be heavy, however, the size and weight of these beams could be greatly reduced if the engine runs at constant revs (as it would be when driving a generator) thus removing the stresses involved when an engine constantly accelerates and decelerates, as it normally does today.
Greatly reduced side thrust on the pistons as well.
Reduced manufacturing costs when the cylinder head is eliminated - no leakage problems as there often are with cylinder heads, so lower maintenance costs - Also reduced heat losses, as combustion is contained between the opposed pistons.
As I said, smooth ride, so no balance shafts necessary - smaller lighter flywheel?- I dunno.
Three cylinders working in unison it seems is the ideal scenario both in exhaust interaction and compactness of the package.
Then there is the possibility of two stroke HCCI (petrol) and that could be a winner here and really clinch the deal, as combustion chamber shape might not be nearly as important (or problematic) as they can be in a "normal" two stroke today.
Yes I agree that it might be good in light aitcraft and give the normal four stroke boxer engines a good kick up the arse! ie smoother, good power to weight ratio, good economy also - sump or pump lubrication helping to finally resolve any smoke and pollution (which to my mind is what may have sunk the two stroke forever?? ) pistons not requiring the same heavy lubrication as the rest of the engine might help!
All I can say with certainty is that I won't be the one making all these changes! - but will be watching constantly!
Some possible big changes coming up for me ( family redistribution around the world) - getting my mind to accept that I could possibly be leaving this nice little country is a problem - still not convinced I should! .... We'll see.
Strokers Galore!
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