Loved it, haven't heard anything like that for years.Originally Posted by WristTwister
Hardcore Biker
Loved it, haven't heard anything like that for years.
Muddler/Dabbler.
Yes Ken, I'm sorry for having bought one, but that was at a time when I wasn't thinking straight!Sadly Will, the thing operates on a 4 stroke cycle (and how dare you for ever buying one....),that is one of the arguments for crank case scavenged 2 strokes, that the oil is disposed in the best possible way, combustion.
Still, some one had better get a move on to get the clean 2 stroke thing going before electricity takes over. ........ if there is no place to run it, then it's all over.
What you say though is very true - I firmly believe that electricity will eventually eliminate both types of internal combustion piston engine plus the need for gearboxes ( to a large extent anyway),- but let us close our ears and minds to any suggestions of that ever happening with racing two strokes!
And as for the "Turbo Encabulator" - there is probably a niche somewhere for it, but when (if) I finally figure that out, time will have run out for me!
As for those who have got it sussed then time for them has already run out!
Strokers Galore!
Hardcore Biker
Hi Wildun, sorry for the delayed reply, I've been away for a week.Daryl, Don't get the top post! - Is there something missing? or have I become completely befuddled?
-
UPDATE : yes, definitely confused I think!- I actually do remember an Italian kart engine ( from memory, AMI or something like that)) which used that principle but don't think it could be switched to four stroke mode (guess half speed camshaft required for four stroke)
The Top Post: the Ricardo one, needs a bit of thought and a very open mind.
Its a 4 stroke (poppet valve) engine that can operate as a two stroke.
(Or a two stroke engine, with poppet valves, that can operate on a 4 stroke cycle)
Looking at the diagram, the entire cycle is completed in 2 strokes/One revolution.
It uses a loop type scavenge, but from the O/H valves at the top, not ports at the bottom.
Maybe it could be crankcase scavenged, but I expect would be way, way better, with a forced induction system.
Remember also, as so often explained, it's the exhaust doing the scavenging anyway.
Variable exhaust system geometry would be a plus.
Note the orientation of the inlet tract to assist the scavenging.
I could see this being ideal for a Heron set up, with the combustion chamber in the piston.
(Not withstanding the inherent problems with the Heron approach, it was Very Successfully applied in some cases).
As indicated in the post, computerised control of the valves could optimise the transfer processes at any given rpm,
and allow shifting from 2 to 4 stroke operation when desirable. (Not exactly KISS, but not too bad).
Easy to underestimate the potential, but this is a true innovation, rather than just optimisation of existing processes.
The diagram has been around for a number of years, I don't know what the state of development is,
(the Ricardo Coy. has been around engines for "a Number of Years" too!).
Cheers, Daryl.
Muddler/Dabbler.
Yes Daryl, I just wasn't looking at it closely enough, (also wasn't wearing my proper glasses) - I have seen something similar to that many years ago (about 50 or so). and I had it sussed out then.
Here in the South Island Richard Pearce (who flew his own homebuilt aircraft said to be in 1903 ) actually invented a similar arrangement for a later contraption he built, this could be changed between 2 and 4 stroke operation and would have been pre first world war too.
Not really a fan of the Heron arrangement although I once had a Hillman Avenger car and the Heron head arrangement was used (very successfully) in that, a very good engine. The Avenger was the very best of the cheaper cars of that period.
Guess you could say that.
Yes, a lot of years, more than most.
Strokers Galore!
Hardcore Biker
Discussing the Ricardo 2/4sight engine with a friend, the question was Why? Why switch from 2 to 4 Stroke?
Best Idea we came up with was this:
Quickly accelerate your vehicle up to speed as a powerful 2 stroke.
Once you get to cruise speed, change over to 4 Stroke operation.
Result: Same engine speed with around Half the Power output.
Perhaps better BSFC than a severely throttled 2 Stroke.
Cheers, Daryl.
Muddler/Dabbler.
Or, don't piss around, just buy a Prius or a Camry instead! less hassle!
Strokers Galore!
Hardcore Biker
If we weren't the type of loonies who tend to take the road less travelled (& Do it the Hard Way), we wouldn't be here on this forum.Or, don't piss around, just buy a Prius or a Camry instead! less hassle! ........
cheers, Daryl.
Muddler/Dabbler.
Dead right, there's no harm in living outside the square, in fact I find it very comfortable out there - (I mean here)!If we weren't the type of loonies who tend to take the road less travelled (& Do it the Hard Way), we wouldn't be here on this forum.cheers, Daryl.
"Loonies" are those who refuse to follow the crowd!
That's according to "sensible" people. like my wife - she actually expects me to keep my workshop tidy - can you believe that! - then of course my garage has a laundry in it as well - I guess not many people would be allowed to have a workshop and a laundry sharing space!
Strokers Galore!
Hardcore Biker
Found another version with some other pictures . Enjoy and Mery X-mas
https://web.archive.org/web/20080501...c2/junkers.htm
Muddler/Dabbler.
Niels, I am intrigued by the fact that the indexing of the crankshafts can be achieved by permanent magnet machines!
I believe that the very successful British locomotive engine (the Napier Deltic, now superseded by newer designs} was actually developed from the original Junkers.
Just might be a little wary of the "intermeshing props" bet they'd be very noisy! - I remember (in the area where I grew up) the Fairey Gannet anti submarine aircraft (using the Double Mamba turboprop engine) and driving co axial contra rotating props - was the noisest aircraft I have ever heard!
BTW, how did the modifications your Boxford lathe work? - (I was on the Boxford forum and talked to you sometimes) - I have just sold mine, because I just could not put up with the constantly slipping belt, also didn't have enough room in my garage. (mine was the AUD Model).
Have a happy Christmas.
Will.
Strokers Galore!
Hardcore Biker
Hello Will.
My Boxford is well and cutting.It only slips when I forget to disengage back gear after changing of chuks.
http://imgur.com/WvKsXOd
https://www.youtube.com/watch?v=DeFLeNPhqDY
I measured the noise from two props on a stationary rig and it was 3 dB more than sum of the two going alone.So long the blades do not crossover each other noise is not so bad.But it will load the synchronizing and that is not solved yet.
I have heard Deltics live on some norwegian torpedo boats and noise from gears was not pleasant.
But the scheme with AC generators on each crank will be worse(short time) as cranks are displaced 20 degree timewise.A loose connection and really expensive sound.
My AC synchronizing scheme needs almost or totally same crankangle.Maybe one can turn the stator of one generator sligthly and have variale compression within limits.
I do not know.
Regards
Niels
Muddler/Dabbler.
Happy Christmas everybody.
From Will.
Strokers Galore!
Hardcore Biker
.....and from me too!
cheers, Daryl.
Anorak
Very few, however, know that Vincent, after the demise of his motorcycle manufacturing business, addressed what he considered to be the outstanding problems of conventional piston engines in a compact three-cylinder rotary with peripheral valves much like those used in high-performance Wankels. Because he was able to raise only very limited backing for his project, Vincent forced it into being by sheer strength of character. Thanks to the generosity of former racer and Cycle World staffer Jody Nicholas, I was lent some of Vincent’s papers and drawings regarding this project.
The cylinder block, containing three 54mm-bore radial cylinders and pistons moving through 18mm strokes, revolved within and sealed against the inside surface of a cylindrical outer ring. Passing through the ring were large intake and exhaust ports. Two sparkplugs were also threaded into it. Both two-stroke and four-stroke versions were contemplated. Valving was accomplished in both cases by the sliding of the open outer ends of the 120-degree-spaced cylinders past intake and exhaust ports in the outer ring.
Vincent well knew that attempts to make high power from conventional engines ran up against limited valve area, valve float and mechanical stress. His rotary sought to provide very large ports unobstructed by rpm-limited mechanical valves. He could see no reason, thanks to his complex hydraulic sealing system, why it should not operate at extreme rpm.
This seemed achievable, I suspect, because Wankel prototypes had, not long before, overcome similar sliding-seal problems to run and make useful power. The leakage and smoking of the Vincent rotary probably resulted from heat distortion of the outer ring around its hot exhaust ports.
Sealing surface distortion around the exhaust ports of two-stroke Grand Prix-bike cylinders in the 1990s was overcome only after development of complex cylinder-shaping technologies. Vincent lacked the resources of a major R&D department to sort out his engine’s problems, so, it came to nothing. The prototype and many of his engineering drawings have been preserved.
Kinky is using a feather. Perverted is using the whole chicken
Hardcore Biker
OK Hooser, seeing you have been recently posting so many articles that I can hardly keep up with, I thought that I’d have a go.
The Vincent thing is really interesting. This must have been around 1970, which was ONLY 46 years ago. So, with that little piece of history trivia, here’s a little bit more of the Vincent concept.
Yep, he would have had sealing and sealing friction issues
Probably the thing that inspired me was the realization of the power of the exhaust pressure depression. I reckon that direct air inlet is the go. Either at the transfer port level or via the head.
Frits’s 24/7 is clearly works and is neat, but for the ones I have seen (any more Frits?) are probably compromised by rule constraints, eg KZ where all the mixture must pass via the crankcase. However, unless exh valves etc are used, we are totally constrained by the limited “tuned” rpm window of the exhaust. Still maybe relevant for constant speed applications like generators for those “clean” electric cars with inbuilt "battery anxiety".
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