ESE's works engine tuner

[TZ350]

TZ your spaced crankcase obviously need some fettling. If you have spare junk cases you can cut big sections out to observe correct operation which is hard with cluster in just one side. The engagement on the broken gear would be the place to start but several others may need reshimming or maybe just observe if there is free float on shafts to start with.

With Glen from Morgan Engineering's help I have followed up on F5 Daves suggestion to use a cutaway gearbox case to help in properly setting up a new gearbox for the Beast.



Well it sure looks the business and should be very useful. The good thing is that I still have a usable set of engine cases as well. They might be useful for a CVT project.

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[Frits Overmars]

On a standard Kawasaki the valve opens after the transfers shut but with 'cut' valves I saw the port open before the transfers shut and I guess on the pipe that's a good thing but how much? I thought I read somewhere here that the transfer event was largely over by BDC , is that so? If so, on the pipe I might as well open the RV as soon as possible.

At max.torque rpm the transfer event is not even on full song by BDC; the transfer flow is still accelerating.
About 20° after BDC the crankcase pressure has dropped to atmospheric level; then it is time to connect the case to the outside world.
If you open the inlet earlier, you will lose case pressure. If you open it later, the case pressure will drop more than it would need to, slowing down the transfer flow.

There is a reason that the disk opened later on many rotary road bikes: if you let the case pressure drop lower before opening the disk, there will be a stronger suction signal to the carburetter, making carb. setting more responsive. But hey, you've got EFI.

[katinas]

Add to youtube or what ever your preference is then post in a link using the video option
Second row fifth from the right it the icon looks looks film roll.
I am picking you were trying to add it as an image or a file attachement, rather than a video.

Thank you, youtube - Rygerised or https://youtu.be/OnLMiMiXoR8

This, pipe header on video, from Ns 400 3 cylinder, is too long and last time I rode ns 400 two years ago, max power around 10000 rpm. Carburetor and ignition not tested anywhere, so this video only to hear whether it works or not.
Before the test, I was thinking that the engine will fail after 10s, but not. So now, I want only ride and feel what it is (with proper header) , before engine fail.

[katinas]

Thank you, youtube - Rygerised or https://youtu.be/OnLMiMiXoR8

This, pipe header on video, from Ns 400 3 cylinder, is too long and last time I rode ns 400 two years ago, max power around 10000 rpm. Carburetor and ignition not tested anywhere, so this video only to hear whether it works or not.
Before the test, I was thinking that the engine will fail after 10s, but not. So now, I want only ride and feel what it is (with proper header) , before engine fail.

Sorry https://youtu.be/OnLMIMiXoR8

[katinas]

I think there should not be any windows in pistons at all, Peewee. I'd rather bring the inlet port down and shorten the piston. Apart from this, Husas Comet-link is worth reading.
Radiusing all sharp edges is good. Not only for stress concentration avoidance, but also because radiused edges won't scrape as much oil off the bore as sharp edges would.

Hi,

Two years ago tested various "holed" pistons on honda ns-250, and totally agree with Frits, do not make any holes on the pistons with cylinder type like in photo. Holes just not works. Pistons from left to right going better and better. But maybe cooling with holes better. The power maybe similar, but acceleration and controls without holes is best.

[jonny quest]

Katinas, nice vid. I was going to say earlier to you it was your imagination that engine sounded good and different.

It actually does sound very fast revving when it gets on the pipe!

[shnaggs]

@katinas Whoa that thing sounds very rev happy!

[tjbw]

Sorry https://youtu.be/OnLMIMiXoR8

Ryger should put that link on their website, so that potential customers can hear what a Ryger engine sounds like

[peewee]

katinas how does the lower rod and crank bearings get lube if theres no hole under the 20mm plate? maybe im missing something

[Flettner]

yes thank you for your video katinas, now all we need is Trump to write an executive order to ban ice and snow so you can go out and ride it

Bottom end oiled by splash in it's own bath?

Re the RV gib on the 360, I'm going to have to have a gib on the open side anyway, perhaps I'll just dick with it's opening sequence on a dyno and see what it likes.

[wobbly]

If your engine works "better " with no piston holes, this is because your particular setup isnt making enough power to need the extra inlet flow.
Your engine has huge Boyesen ports, so probably doesnt need any extra intake flow area.
The other effect that will be coming into play is that removing the piston holes will be affecting the cavity resonance of the reed box, and this will be affecting
the reed resonance behavior.
If the engine "accelerates " better,then this is probably down to the reed resonance changing, and this then is also affecting the carb jetting as well.

In EngMod, the intake configuration page calculates the reed box volume, and this changes quite dramatically the petal lift behavior, as does adding or removing Boyesen ports
or piston holes.
I did years ago, dyno tests showing that an old RM125 made more power with no inlet holes at all ie it was piston ported with a reed as well ( it had a boost port that wouldnt work
with just the piston port setup ).
But that old engine made only something like 28 Hp.

As usual in a 2T just changing one thing, affects many others,and these can have far more influence on power than just the one change you made.
Has the piston on the right got big cutaways around the pin like the stock type - if not then this will also be affecting the port linking effects as well.

[wobbly]

I have not looked at the mass flow rates into an RV engine before,but here is the plot of inlet flow and transfer flow of the RSA at 12,000.
Out of interest the timing of the RV is 140 btdc and closing at 90 atdc, with the B port open at 114 btdc.
From the old work i did on the Rotax I know that going back to 135 opening makes little difference, going to 145 makes it impossible to jet.
Pulling back the closing to 85 would kill all the power past 12000,and going past 90 would kill all the mid power, with nothing gained in the overev.
So the closing is super sensitive, the opening not so.
Out of interest I looked at several very fast reed engines ( where inflow is totally dependent upon reed lift ) and the mass flow profiles are all but identical.

[Flettner]

I guess that's why my Kawasaki variable valve housing is so useful then, for the shut side. Wobbly, if you ignore carburetor tuneability, dose the slight more open time help with top end power. As I'm useing EFI I think I can fuel around that issue?

[katinas]

If your engine works "better " with no piston holes, this is because your particular setup isnt making enough power to need the extra inlet flow.
Your engine has huge Boyesen ports, so probably doesnt need any extra intake flow area.
The other effect that will be coming into play is that removing the piston holes will be affecting the cavity resonance of the reed box, and this will be affecting
the reed resonance behavior.
If the engine "accelerates " better,then this is probably down to the reed resonance changing, and this then is also affecting the carb jetting as well.

In EngMod, the intake configuration page calculates the reed box volume, and this changes quite dramatically the petal lift behavior, as does adding or removing Boyesen ports
or piston holes.
I did years ago, dyno tests showing that an old RM125 made more power with no inlet holes at all ie it was piston ported with a reed as well ( it had a boost port that wouldnt work
with just the piston port setup ).
But that old engine made only something like 28 Hp.

As usual in a 2T just changing one thing, affects many others,and these can have far more influence on power than just the one change you made.
Has the piston on the right got big cutaways around the pin like the stock type - if not then this will also be affecting the port linking effects as well.

Thank you, very interesting.

Two last pistons on the right without cutaways.

Yes, maybe this works only with Boyesen ports and without them would be different story. Two years ago, tested many things on Ns 250 ( compression, squash, pipe, reed, ignition, airbox, fuel, carburetor, ....... around 3000km). All tests were with "holed" piston and engine reactions, sometimes better sometimes not. But when I buy new pistons ( without holes ), simply was too lazy to do them again. Effect felt immediately, specific hole around 6700 rpm disappeared and gas felt very linear, but power remained the same. Maybe at lower revs when pipe not do so much, without holes in piston, flow through main transfers ports increase, and when piston is at BDC intake inertial flow impacted to piston and lift up to boos ports and to Boyesen ports. But its only considerations.

Photo I made in 2001 Brno GP Carlos Checa YZR 500 engine. Last, factory bike, two stroke 500 season. Piston and crankcase

[F5 Dave]

Wow, would you u look at that very detailed crank web covering.