ESE's works engine tuner

[WilDun]

No not on holiday, the thread moves on faster than I can make stuff and post about it, I am just getting left behind a bit, that's all.

That's good and it explains why Flettner is so busy!

I'm now looking at Ken's stuff to see what he's been doing. I did learn a bit about mechanics (forces, loads vectors and stuff) long ago, but it all escapes me now and I'm too lazy to try to understand it all so I'll just look at the pictures and work on hunches (as you do).

[Sketchy_Racer]

Ryger confession time. Yep, the stepped piston I posted a few days ago was a mock-up.
Attachment 317198

Sort of a joke, but, more seriously, another contribution as to what might be inside the Ryger.
Some time ago, I did a range of sketches, one being as below.

Attachment 317199

Following that, after we found out it has a 90 rod and the piston skirt can be seen at all time after EO, we started thinking along these lines again. We then created a scale schematic layout of the engine based on all the knowns. To this then we added a stepped piston version that might comply, as is shown below:

Attachment 317200

From that, we just created the mock-up out of scrap and an hour of my time. One big question was, would the piece of skirt just break off? Well, referring to a spreadsheet we did on piston forces and accelerations, we can see at 30k, the peak acceleration is around 350,000 met/sec^2.

Attachment 317202

Then looked at the skirt.

Attachment 317201

From this the force acting on the shaded area (or base of the skirt) can be calculated. From F=ma, = (12.5/1000)* 350,000 = 4375 N. Given this force, acting on the area of 220 mm^2, the stress can be calculated from Stress = F/area = 4375/(220^10-6) = 19.9 Mpa = safe, given the UTS might be around 300 MPa. Hope I’m not fundamentally wrong here.
This is all based on no shock loads, no side thrust etc. In fact, given all this it could be simply made much thinner (less weight, less area = same stress), not too sure though if it could go to beer can thickness (Heineken of course?)

What it all tells is that we have no idea really, but all it does is to put some scale to a range of possibilities and raises more questions & points:

1. How the valving works?
2. Does the reduced under-piston working volume cause issues?
3. Although the volume is less, the primary compression ratio (formerly crankcase compression ratio) can be much, much higher.
4. Maybe this is adequate for starting and low speed running, but then maybe das dynamics, 24/7,HCCI, take over and do the trick
5. Maybe the exh port doesn’t go to BDC, allowing for a much shorter piston skirt and possibly another transfer port under the exhaust
6. How does the rest of the engine, particularly the rest of the piston, the rod and its bearings, survive the 30k, notwithstanding nice lubricating conditions?

52 days to go

Better do some real work.

I'd imagine that it is not so much the force trying to tear the skirtlet off which would be the biggest problem. I would have thought that it would be the bending moment that the eccentric skirt would create through the rod as it accelerates.

So as I understand it the bore is 54mm so for simplification I'll assume the moment to be centered in the bore so ((54/2)/1000)*4375=118.125Nm

That's a hell of a moment for a long slender rod to bear!!

[Frits Overmars]

Thanks a lot guys. Once again petty personal issues ruin it for everyone.

Well, I'm sure most people here don't take the posts personally

I'm equally sure Wobbly did and I can understand why.

...I miss Frits, Wobbly, TZ350, Hooser etc, etc and I want them back and back now.

I never left, Ken. It's just that I can't comment on everything, especially not on your posts .

So you guys had better sort that miniscule "tiff" you had, you don't even have to apologise or feel silly, just come back as if nothing happened and think of others in future.

I think that did not come out the way you meant it, Will. The way I see it, Wobbly has nothing to apologize for. He has shared a tremendous amount of hard-gained knowledge here and to me he is one of the pillars of this forum.

[m4r]

I'd imagine that it is not so much the force trying to tear the skirtlet off which would be the biggest problem. I would have thought that it would be the bending moment that the eccentric skirt would create through the rod as it accelerates.

So as I understand it the bore is 54mm so for simplification I'll assume the moment to be centered in the bore so ((54/2)/1000)*4375=118.125Nm

That's a hell of a moment for a long slender rod to bear!!

how much force is left on the skirt, if we have a lower cylinder that could take a lot of guidance?

[AndreasL]

The way I see it, Wobbly has nothing to apologize for. He has shared a tremendous amount of hard-gained knowledge here and to me he is one of the pillars of this forum.

Agree!

I wouldn't been i.e running sims in EngMod without Wooblys help. That's for sure.

[Tim Ey]

He has shared a tremendous amount of hard-gained knowledge here and to me he is one of the pillars of this forum.

Totaly agreed!
This thread brought my thoughts in different directions and I made some very good experiences with advices from wobbly! (For example the divider in a reedvalve worked really good)
Besides I would not use EngMod2T without wobblys shared experiences and knowledge about that program.
@wobbly:
If you will not come back it would be a great loss for all of us - one way or the other I have to say: Thank you very much.

[MotleyCrue]

This forum is pretty mild for backstabbing compared to some. If all you guys (and myself) posted the crazy ideas that have been posted on here in the last few months you would be hacked to death on some forums. Looking forward to more great technical posts by Wobbly and all others.

[jasonu]

I have been working with Chambers on his RG50's for F5, trying some new ideas but we are having trouble cracking 14hp, still we will get on top of that. I hope to get the final parts needed from Flettner soon to complete the NSR110 engine. I am also putting the old fuel injected 125 air cooled back together. I have unfinished business with the EFI thing. And have to finish the NSR rolling chassis to test the new motor. Sort of busy but nothing new to post about.

What are you going to do after lunch???

[nine-thirtysix]

The way I see it, Wobbly has nothing to apologize for. He has shared a tremendous amount of hard-gained knowledge here and to me he is one of the pillars of this forum.

Totally true. This thread is followed by an enormous amount of people. And there are less than a handful who have so many proven results to share.
So to loose just you Wobbly would be a real shame! So please give yourself a jerk and tutor us oncemore.

[sidecar bob]

Good for you, but don't take credit for others ability to win because of their talents.

Dennis also rode a bike at Greymouth last year with an engine that we helped to build, and won all three races. We don't claim those as our own.

If I was too, I could bleat on about world titles and national titles as well, but most of us on these forums could say the same also.

I come in here to try and glean some knowledge, but most the time I see write ups that just sound like team talk up, so end up having to try and solve it ourselves.

My advice to this thread is to start talking in common language, preferably English, and speak laymens terms. Most of us are doers, not talkers.

Iv only just discovered this wee chucklefest.
I also fielded a bike at the Shorai with a top rider on it & an engine that Grumph had quite a hand in.
Sure, it stayed together & made the numbers, but I take no credit for where it finished apart from putting it together, the results belong to the rider.
Heres a pic im not sure what to think of, https://www.facebook.com/carlcoxmoto...type=3&theater Ken McIntosh (McIntosh Suzuki fame, google it) copying down my spring numbers.
I hope it helps make his bike faster, as it owes them 100k more than mine owes me & the two bikes were on very similar lap times. Does that make me the awesome one?

Great riders, the cheapest way to make dodgy old shit go fast.



You're behind me because I hired the best rider.
I bought 50 boxes of Heineken & drank one every time I enjoyed my race bike.
Sorry, all gone.

[WilDun]

I'm equally sure Wobbly did and I can understand why.
I think that did not come out the way you meant it, Will. The way I see it, Wobbly has nothing to apologize for.

Yes Frits , I can understand why too - but it wasn't aimed solely at Wobbly, it was just a general statement to everyone really, (ie. have a debate, but don't dive overboard if the boat starts to rock!). - serves no purpose at all and severely affects others, - I do see your point though!

PS I did actually reword this one too, so as not to be misunderstood!

[WilDun]

how much force is left on the skirt, if we have a lower cylinder that could take a lot of guidance?

That makes sense and the piston can not tilt as in a normal arrangement. Anyway, by the same token, you would get a similar effect with a normal piston arrangement where there were large windows in the skirt and that doesn't seem to cause any problems.

Oh,and Wobbly, at least a lot people know and appreciate your work, - just think of me, not even one person in my family takes any interest at all in my workshop, my foundry efforts, or my bike stuff! - best encouragement I ever had from them was "uh, yeah"

[nodrog:Me]

.... Ken McIntosh copying down my spring numbers......

that's Lols, is he planning on getting jay to ride it?

[trevor amos]

The world wide web of two-stroke enthusiasts needs you Wob, and really appreciate all that you contribute in helping others. Don`t let a few brain-deads mess with you.

Cheers, Mate

[WilDun]

The world wide web of two-stroke enthusiasts needs you Wob, and really appreciate all that you contribute in helping others. Don`t let a few brain-deads mess with you.

Cheers, Mate

Trevor, no 'brain deads' there by any means, simply just different points of view, could be easily resolved.