Thanks Daryl. Now, if you've regained your breath, here's some more reading. It's only 302 more pages, a piece of cake for someone with your perseverance.
http://www.kiwibiker.co.nz/forums/sh...totypes/page70
http://www.kiwibiker.co.nz/forums/sh...oundry/page177
http://www.kiwibiker.co.nz/forums/sh...chassis/page55
Don't go there. I would not want you to hurt your brain after all those nice words that you just wrote.
From your nickname, may I take it that this logo is not completely alien to you?
Thanks Nick. We'll drink to that.
and 30,000 rpm potential.
Ring-less piston solves a number of problems and satisfies Harry Ryger's own statement.
Piston cooling & heat transfer by a fresh air/fuel charge in the gap each revolution.
Even cooling and lack of mechanical contact keep bore & piston round so the gap can be very narrow.
Protected from the combustion by the squish band and the narrowness of the gap itself.
The trapped squish gas (cooler) is first to go back down the gap.
Combustion pressure front chases the descending piston so leakage down the gap is relatively small.
Any Pressure loss is returned to the transfer chamber, for use next cycle.
2 sealing rings are fitted, at the top & bottom of the cross head linear bearing.
Cheers, Daryl.
"First they tell you you're wrong, and they can prove it.
Then they tell you you're right, but it's not important.
Then they tell you it is important, but they knew it all along."
Charles Kettering.
Last edited by Pursang; 17th November 2016 at 12:15. Reason: font
Thanks Frits, but it's too late too protect this poor brain.
Yes, love my Bully's. They defy just about every element of modern, acceptable 2T practice, (except, perhaps, some bits of expansion chamber design) but despite all that produced great results in their time.
I'll get stuck into the other threads soon.
Cheers, Daryl.
Your maths is a bit rusty I fear.
My formula can be simplified to:
(d^2)/8h + h/2
Not the same as yours at all.
Run some numbers through both formulae and compare the results.
For my bike's head, the dome radius is 77mm with my formula, 2063mm with yours. Bit of a difference.
+1
New series!
Clickbait? What? Who, me?
https://www.youtube.com/watch?v=cXyGJ8f8F78
You are absolutely right lodgernz. I can only claim bracket dyslexia for mangling your formula and crap memory for getting my original post wrong.
On checking carefully (like I should have before) I see the formula should read (h^2 + r^2) / 2h
where r is the radius of the tube not the diameter.
This one does give exactly the same result as your formula and has been used successfully to make several heads.
Hey P-W, Check out what Dick does with them..
http://www.dicksracing.com/motorcycl...rmance#2stroke
'Singh grooves' maybe?
Or, like here: http://www.datafan.com/twostroketuni...ngbimotion.php
Bet you know what this one is, eh Flettner...
See: http://www.klemmvintage.com
Have to comment, Klemm seem a bit too self-satisfied about getting 180 Km/h from a Kawasaki H1 triple..
..when the original `69 models did 200 Km/h showroom stock, & won their class at the Bol d' Or 24 Hour...
Had a good discussion on those years ago in the 'Banger' thread on the HAMB. (Bangers are 4cyl Flatheads).
Flatheads have shocking shaped chambers and some directional control of gas from the squish might be helpful.
(in high performance ones the squish can be 90% of the piston area).
My thought is that the grooves allow the flame front(s) to access the squished gasses and allow them to be burnt as part of the combustion process.
i.e. The combustion pressure forces the flame deep into the squish via the groove channels. The descending piston allows room for the combustion.
If it actually works, it's a good thing.
Don't want them in a Ringless engine.
"First they tell you you're wrong, and they can prove it.
Then they tell you you're right, but it's not important.
Then they tell you it is important, but they knew it all along."
Charles Kettering.
Yeah, some of these 'groove' ideas have been around for a while...
Decades ago, when I was into original Triumphs, amongst the 'porting lore' was a high comp piston 'trick'..
The deep hemispherical dome of the Triumph head made room for big valves, but then needed a real lumpy piston
to fill it up for a decently high comp ratio.. which tended to block flame travel from the spark plug.. ( the big valves
didn't leave room for a centrally mounted plug).. & twin plug head conversions were costly..
The Triumph 'tuner' approach was to cut a 'flame groove' across the edge of the piston crown from the ( indexed)
plug to the top of the combustion chamber, & yeah, it too was reputed to be worth the ( minimal) effort of doing...
I can see the possible sense in using a flame grove in a 4T but the talk is not positive about them for a 2T. But if anyone wants to front with a bike fitted with one of these heads and an identical head without the groves I would be happy to run a back to back dyno test on them for free so long as the results and pictures can be posted on here.
There are currently 18 users browsing this thread. (0 members and 18 guests)
Bookmarks