ESE's works engine tuner

[lodgernz]

Try this for another rule of thumb - I have found that most full noise RACE engines built with single exhaust ports, like the exit area at the flange ( and thus the header diameter ) at 90% of the EFFECTIVE port area.


Never mind, I found it.

[TZ350]

Some of the work I am doing on my RG50

313696

The crank on the left has been machined right back to the thrust washer surface. An original RG50 one is on the right.

313697

Original RG50 crank at the top, modified crank at the bottom. The object is to un shroud the bigend eye for cooling and lubricating reliability. Remove stagnant pockets that damp the resonance effect in the crank case and reduce aerodynamic drag as the rod passes between the crank webs and also move as much as possible of the crankcase volume to be directly below the transfers.

313698

Most of the original volume below the old reeds will be filled in and shaped to direct the airflow coming in through the lower set of reeds up into the transfers.

The reed block is going to be divided into two functional halves, an upper half serving the inlet and boost port and the lower half serving only the crankcase volume. Basically there will be two separate inlet tracts.

313699

The rear boost ports have been opened up so they can function like one big Yamaha RD style boost port. The reed block and inlet tract is being divided into two separate tracts because I want a ram effect when the inlet closes. I want this ram effect to drive up through the boost port like the RD's did.

313700

The lower reed inlet tract will feed the lower transfers like Boyson ports do and also the greater crank case volume, while the upper reed inlet tract will feed the boost port and the changing volume under the piston through the original inlet ports.

After the reed experiment will be a 24/7 conversion. It should fit nicely into the old reed block housing.

I am looking for 18 rwhp at 15,000 rpm. Anyway that is the plan. I guess the dyno will tell us if it was a good plan.

[Flettner]

No not much happening, work (the real work) has been keeping us pretty busy so not much being done on the bikes at the moment.

I am looking forward to learning more about the Ryger engine and hope that combined with the other clean technology's like direct fuel injection that it will herald a new era for 2T's.



The old Beast has been stripped and the rolling chassis is destined for a new venture as Flettners F4 supercharged 100 or maybe a test bed for his 700cc twin or maybe the 1000cc triple two stroke track bike project he is thinking about.

That is right, 1000cc's of triple cylinder, highly tuned, insane two stroke power, soon you might be able to buy an engine from Auto Flight, fit it to whatever you like and go full on all out Track Day Kamikaze with more power than the legendary Yamaha TZ750.

313695


I am confident about 2T's and EFI and expect to use EFI and a Plenum on the new Beast, but as much as I am looking forward to riding it, the new Beast is probably not going to be ready for the start of the season because the team is trying to get a brace of 14+rwhp 50's ready for F5 this year.

If the Ryger engine concept is easy enough to adapt to an existing 2T engine then I will definitely be trying that too.

1050cc, 3 x 350cc:yes::yes::yes:

[ken seeber]

I know the feeling Neil. I'm very glad to be involved with the Ryger engine, but it has also made me very reluctant about everything I thought I knew about two-strokes.

Frits, haven't asked you any questions of late, so by saying "...............everything I thought I knew about two-strokes", did this mean specifically 2 strokes or engines in general?

[Frits Overmars]

So - if you had a super ceramic fit, no piston rings. Piston sides are spherical with no gudgin pin (fixed) so that the piston is forced to rock forward and aft through the cranshaft rotation (like these silly little chinese compressors). On the way down there would be more blowdown time because the piston would be rocked forward as the crank turns around BDC the piston would rock the other way giving more transfer time. Substantial asymmetric timing.
How the underside of the piston would shut the exhaust off at TDC I can't say...Could you say how the underside of the piston would shut the exhaust port off at any position, Neil?
We did some playing around with this type of piston too, but it's no good for a two-stroke.
313705


If I had a R&D dept with 100 people all looking for things to do i would be testing the relationship of the duct length,its exit area and the optimum transition length.
I'd have them all changing tyres cause I hate changing tyres and it turns out I'd be a vindictive power tripping control freak of a boss.
Ohh the things you find out about yourself in a moment of fantasy.Let alone the things you are about to find out about people in R&D departments. They don't change tyres. None of them (in the glory days when Aprilia was ruling the roost in the 125 and 250 cc classes, there were not 100 but 150 people working in R&D).
Taking care of the tyres was the responsibility of the racing teams, that were completely separate from the R&D dept. And they didn't change tyres either; they just dropped the wheels at the Dunlop, Michelin or Bridgestone service trucks, went for a glass of Lambrusco a cup of coffee, and picked them up again.


I know the feeling Neil. I'm very glad to be involved with the Ryger engine, but it has also made me very reluctant about everything I thought I knew about two-strokes.
When you first saw / heard of the numbers, what was your reaction? And how many times did you double-check that everything is just as it seems and that there is no miscalibrated dyno, rpm gauge etc?When I first heard the numbers, I was very sceptical. When I first got acquainted with the engine, this was my reaction:
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130866554#post1130866554
There was no need (but a huge desire) to double-check the feeling of that first ride.


If the Ryger engine concept is easy enough to adapt to an existing 2T engine then I will definitely be trying that too.You may have to farm out some of the work, but you will be able to keep using most of your current parts.


I am looking for 18 rwhp at 15,000 rpm. Anyway that is the plan.You should be looking for 20 rwhp at 13000 rpm. That is more realistic. And faster. PS: I love your crankshaft.


Frits, haven't asked you any questions of late, so by saying "...............everything I thought I knew about two-strokes", did this mean specifically 2 strokes or engines in general?Are you pulling my leg Ken? When I wrote 'everything I thought I knew about two-strokes', I meant two-strokes. Is there any other kind?
I think I know what you wish to hear. The laws of physics haven't changed but I am beginning to realize that I neglected some aspects of the gas dynamics in an engine as being unimportant, until Harry Ryger showed what can still be found there. I'd really love to be more specific, but that will have to wait until I get the green light.

[RAW]

Frits. I'm looking for a RSW 125 engine that is unless you have an RSA 125 lying around under the bench. Any help would be greatly appreciated

[husaberg]

Frits. I'm looking for a RSW 125 engine that is unless you have an RSA 125 lying around under the bench. Any help would be greatly appreciated

Pretty Sure Riley Will had one for sale a while back.
http://brceng.com/brc-motorsports/
Had an idea Francis Payart was making some singles to.

Someone was doing CNC dual rotary valve singles but can't remember where.
313706313707313708

[Frits Overmars]

Frits. I'm looking for a RSW 125 engine that is unless you have an RSA 125 lying around under the bench. Any help would be greatly appreciatedDon't look at me. Both Jan Thiel and I always steered away as far as possible from anything commercial. We don't buy, we don't sell, we don't mediate.

[Frits Overmars]

Someone was doing CNC dual rotary valve singles but can't remember where.
313706313707313708That was dutchman Thijs Hessels, but he stopped work on his twin disc engines when the 125 cc GP-class was killed.

[Flettner]

Could you say how the underside of the piston would shut the exhaust port off at any position, Neil?
We did some playing around with this type of piston too, but it's no good for a two-stroke.
313705

Let alone the things you are about to find out about people in R&D departments. They don't change tyres. None of them (in the glory days when Aprilia was ruling the roost in the 125 and 250 cc classes, there were not 100 but 150 people working in R&D).
Taking care of the tyres was the responsibility of the racing teams, that were completely separate from the R&D dept. And they didn't change tyres either; they just dropped the wheels at the Dunlop, Michelin or Bridgestone service trucks, went for a glass of Lambrusco a cup of coffee, and picked them up again.

When I first heard the numbers, I was very sceptical. When I first got acquainted with the engine, this was my reaction:
http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130866554#post1130866554
There was no need (but a huge desire) to double-check the feeling of that first ride.

You may have to farm out some of the work, but you will be able to keep using most of your current parts.

You should be looking for 20 rwhp at 13000 rpm. That is more realistic. And faster. PS: I love your crankshaft.

Are you pulling my leg Ken? When I wrote 'everything I thought I knew about two-strokes', I meant two-strokes. Is there any other kind?
I think I know what you wish to hear. The laws of physics haven't changed but I am beginning to realize that I neglected some aspects of the gas dynamics in an engine as being unimportant, until Harry Ryger showed what can still be found there. I'd really love to be more specific, but that will have to wait until I get the green light.

Oh, the bloody green light, when?

Would the FOS concept, if it were fitted on the Ryger engine, be better or worse? Gas flow wise.
https://youtu.be/htukflbiqSE
Might Ryger be up to something along these lines (or have we already coverd this)

[Frits Overmars]

Oh, the bloody green light, when?I'll let you know as soon as I get the green light Neil :yes: (what's the english word for this kind of approach: recursivity or recursion?)


Would the FOS concept, if it were fitted on the Ryger engine, be better or worse? Gas flow wise.We are certainly going to test the combination. But like I said the other day, I've become careful; I'd rather not announce expectations but wait until we get results.

[breezy]

I'll let you know as soon as I get the green light Neil :yes: (what's the english word for this kind of approach: recursivity or recursion?)

We are certainly going to test the combination. But like I said the other day, I've become careful; I'd rather not announce expectations but wait until we get results.
Frits, have you found a way to control your fos barrels transfer and exhaust ports then? sleeve or reeds or gas pressures?

[RAW]

Thank you Frits,
It's a bit awkward looking for stuff being on the other side of the world.

[lodgernz]

I'll let you know as soon as I get the green light Neil :yes: (what's the english word for this kind of approach: recursivity or recursion?)

Probably recursion, but "Catch 22" is better.

[kel]

You should be looking for 20 rwhp at 13000 rpm. That is more realistic. And faster. PS: I love your crankshaft.

I think the 15hp at 15k is a bit of a ruse. A rotary conversion, and 18+hp :nono:

[ken seeber]

Are you pulling my leg Ken? When I wrote 'everything I thought I knew about two-strokes', I meant two-strokes. Is there any other kind?
I think I know what you wish to hear. The laws of physics haven't changed but I am beginning to realize that I neglected some aspects of the gas dynamics in an engine as being unimportant, until Harry Ryger showed what can still be found there. I'd really love to be more specific, but that will have to wait until I get the green light.

Frits, pulling your leg, nah, don't want to see you fall over, you're a great source of info and inspiration.

If it relies on gas dynamics, then does it start easily at low speeds with no positive mechanical displacer for the incoming gas (or air) only?

[husaberg]

That was dutchman Thijs Hessels, but he stopped work on his twin disc engines when the 125 cc GP-class was killed.

He was the one doing the beautiful RSA like Cylinders but alas his site seems to no longer have them or the other Honda conversion stuff.
he has this test bench listed but I can't figure it out .
http://www.he-ja.nl/winkel/werkbank/#

[Yow Ling]

He was the one doing the beautiful RSA like Cylinders but alas his site seems to no longer have them or the other Honda conversion stuff.
he has this test bench listed but I can't figure it out .
http://www.he-ja.nl/winkel/werkbank/#

It looks like an engine dyno

[husaberg]

It looks like an engine dyno

Gee thanks Mike,:laugh: But what does it drive to measure the output.

edit I google transdutchrelatered the text
looks like its an inertia one only minus its flywheel.


This test bench is used by us to test engines oavoor karts . This bank is completely finished on a flywheel and after the necessary software. (Supplied by Rotec Yselmuiden www.roteg.nl )

All materials are provided. Motorbikes can be mounted on an adjustable carriage . The drive goes through the motor output shaft to an intermediate shaft which in turn drives the large main axis at the bottom of the bank to this should be so to place a flywheel .

Complete with cooling water pump and radiator hoses , circuitry, temperature gauge, gas and clutch cable programs. Everything is little used all bearings are of the best quality

[Yow Ling]

Gee thanks Mike,:laugh: But what does it drive to measure the output.

edit I google transdutchrelatered the text
looks like its an inertia one only minus its flywheel.

So are we all sorted out then?

[husaberg]

So are we all sorted out then?

Yes Mike thanks for all your help:innocent:

[mr bucketracer]

He was the one doing the beautiful BSA like Cylinders but alas his site seems to no longer have them or the other Honda conversion stuff.
he has this test bench listed but I can't figure it out .
http://www.he-ja.nl/winkel/werkbank/#BSA are not going to take on honda:laugh:

[Frits Overmars]

https://youtu.be/htukflbiqSE
Might Ryger be up to something along these linesI happened to notice this addition to your original post, Neil. Normally I would have missed it. And I hate missing things, so from my point of view it would have been safer to put it in a new post instead of adding it to a post that I already thought I'd seen. Come to think of it: God knows how many valuable additions I've already missed because I usually don't go back to 'old' posts.
That Husqvarna video of yours reminds me of a Stihl patent ( http://www.google.com/patents/US6415750?hl=nl&dq=two-stroke+%2B+engine+two-stroke+OR+engine ) wherein scavenging is also taken care of by air only, after which the fuel-air mixture is transferred. But I don't see any similarities with the Ryger engine.

[Frits Overmars]

Frits, have you found a way to control your fos barrels transfer and exhaust ports then? sleeve or reeds or gas pressures?I never planned to control the exhaust ports. We talked about controlling the transfer ports here (via the 'commas') but once Flettner showed an interest, I thankfully turned my mind to other (Ryger) things.

[Frits Overmars]

Frits, pulling your leg, nah, don't want to see you fall over, you're a great source of info and inspiration.It may be just my suspicious mind, but do I feel a hand on my leg again?


If it relies on gas dynamics, then does it start easily at low speeds with no positive mechanical displacer for the incoming gas (or air) only?It starts like any other kart engine. You get a push, you knock the shift lever into second gear and off you go. And I don't need to tell you that any conventional two-stroke is started with the help of a positive mechanical displacer for the incoming gas or air: the crankcase pump. That's all I can say right now.

[ken seeber]

It may be just my suspicious mind, but do I feel a hand on my leg again?


Frits, don't worry, you're safe

[breezy]

Wobbly/Frits , after combustion of the fuel in the two stroke cycle, the gases produced expand and force the piston back down the cylinder... this explosion causes a pressure wave . is the pressure wave a different thing to the expanding gas pressure? if the blowdown is not enough to allow the pressure in the cylinder to drop below that of the transfer ports , is it the gasses pressure or the pressure wave which causes the stalling of the transfer flow. if they are two different things, what happens to the pressure wave if some of it disappears down the transfer ports :sherlock:

[Flettner]

I happened to notice this addition to your original post, Neil. Normally I would have missed it. And I hate missing things, so from my point of view it would have been safer to put it in a new post instead of adding it to a post that I already thought I'd seen. Come to think of it: God knows how many valuable additions I've already missed because I usually don't go back to 'old' posts.
That Husqvarna video of yours reminds me of a Stihl patent ( http://www.google.com/patents/US6415750?hl=nl&dq=two-stroke+%2B+engine+two-stroke+OR+engine ) wherein scavenging is also taken care of by air only, after which the fuel-air mixture is transferred. But I don't see any similarities with the Ryger engine.

Ok, thank you.

[wobbly]

I know its only semantics but we may as well get it right.
Its not "after " combustion, its as soon as the initial kernel of ionized molecules starts to consume the trapped A/F mixture
that the pressure begins to rise due to the increase in temperature.
Remember PV=nrT, the V varies only with piston movement thus P is proportional to T ( n&r being gas constants ).
We DONT have any " explosions " at all in this process, only fuel and oxygen being converted into pressure.
There is a moving wave front within the combustion space as the burning mixture expands out from the plug gap in the center, but pressure by definition is equal in all directions
and a wave must have a vector to define its direction.
When the transfers open, and if due to the design intent, or a lack of design knowledge , we have excess pressure above the port over that
within the duct, then reverse flow into the duct occurs.
This initial reverse flow can, and if you are clever usually is ,used to affect the scavenging pattern within the rising gas column ( Frits leaning tower from Italian parts )
by delaying the bulk flow from the transfer that opens first.
This effect as a general rule works to enhance midrange power if the A port opens first, or enhances peak and overev power if the B port opens first.
So this answers the question often asked re is it possible to have too much blowdown STA - no its not in a full race setup,but its very possible in lower power scenarios
and if it occurs then we have no reverse flow having a positive affect on the scavenging.
There is 20 more pages of detail, but even this is too long.

[RAW]

Wobbly would you PM me the 20 pages. Sounds like a good read 😃

[husaberg]

It may be just my suspicious mind, but do I feel a hand on my leg again?

That's all I can say right now.

Here is some questions you can answer Frits.
313722313723313724313725313726
I had heard of a Swissauto/Roc powered mock up. is this it?

[Frits Overmars]

313722313723313724313725313726
I had heard of a Swissauto/Roc powered mock up. is this it?This is a genuine Aprilia 500-V4 Grand Prix racer. That means: it was built in the Aprilia Racing Department with the intention of replacing the RSV500 twin.
But the V-4 never appeared in an actual GP. The engine was from Swissauto (very compact, but with a horrible welded-up crankshaft and a terrible vibration).
I don't recall if the frame was Italian-made or brought in from the French ROC company that built 500 cc production racers based on Yamaha V-4 engines.
A couple more pictures of the bike:
313727 313728

[husaberg]

This is a genuine Aprilia 500-V4 Grand Prix racer. That means: it was built in the Aprilia Racing Department with the intention of replacing the RSV500 twin.
But the V-4 never appeared in an actual GP. The engine was from Swissauto (very compact, but with a horrible welded-up crankshaft and a terrible vibration).
I don't recall if the frame was Italian-made or brought in from the French ROC company that built 500 cc production racers based on Yamaha V-4 engines.
A couple more pictures of the bike:


Thanks Frits I would say to my untrained eye the chassis it looks very ROC like.
313729313730
313733313734
Wobbly does it look like the same as the Pulse 500 Frame?
313731313732

[Frits Overmars]

Thanks Frits I would say to my untrained eye the chassis it looks very ROC like.I'd say you're right Husa. Here are some more pictures of the various bikes that have been built around the Swissauto engine:
http://www.google.de/imgres?imgurl=http%3A%2F%2Ffarm6.static.flickr.com %2F5591%2F13664850363_9641339795_m.jpg&imgrefurl=http%3A%2F%2Fflickrhivemind.net%2FTags%2 F500cc%2Cswissauto%2FInteresting&h=137&w=240&tbnid=IHInMaK2zUppvM%3A&docid=g-2cTAdmF94OGM&itg=1&hl=en&ei=TtOnVZuYNcGosAGLq6-oCA&tbm=isch&iact=rc&uact=3&dur=2116&page=1&start=0&ndsp=17&ved=0CDUQrQMwB2oVChMIm_e4gIHgxgIVQRQsCh2L1QuF

[breezy]

I know its only semantics but we may as well get it right.
Its not "after " combustion, its as soon as the initial kernel of ionized molecules starts to consume the trapped A/F mixture
that the pressure begins to rise due to the increase in temperature.
Remember PV=nrT, the V varies only with piston movement thus P is proportional to T ( n&r being gas constants ).
We DONT have any " explosions " at all in this process, only fuel and oxygen being converted into pressure.
There is a moving wave front within the combustion space as the burning mixture expands out from the plug gap in the center, but pressure by definition is equal in all directions
and a wave must have a vector to define its direction.
When the transfers open, and if due to the design intent, or a lack of design knowledge , we have excess pressure above the port over that
within the duct, then reverse flow into the duct occurs.
This initial reverse flow can, and if you are clever usually is ,used to affect the scavenging pattern within the rising gas column ( Frits leaning tower from Italian parts )
by delaying the bulk flow from the transfer that opens first.
This effect as a general rule works to enhance midrange power if the A port opens first, or enhances peak and overev power if the B port opens first.
So this answers the question often asked re is it possible to have too much blowdown STA - no its not in a full race setup,but its very possible in lower power scenarios
and if it occurs then we have no reverse flow having a positive affect on the scavenging.
There is 20 more pages of detail, but even this is too long.

Wobbly thanks for reply...:niceone::niceone: .

[breezy]

wobbly, detonation is a destructive force?... is that only because the materials used in pistons and cylinder heads spark plugs cant withstand its actions. if they could, would inducing detonation produce more heat... pressure, than combustion?

[FastFred]

Here is a Thought Experiment. re combustion vis explosion.

Given that they both give off the same amount of total energy.

On a cold evening which would you rather sit in front of:- a nice warm open fire or an exploding stick of dynamite.

Pressure is the product of the combustion heating the gases in the combustion space and the amount of heat energy is dependent on the fuel. Burn more fuel in a given time and you get more power.

So my guess is that the end result between combustion and explosion for the same amount of fuel is the same amount of heat induced pressure but the speed of the pressure rise between the two is dramatically different.

Same total energy but one gives a sliding action because its applied over a longer period of time the other is an abrupt hammering action that overloads components.

Anyway that is how I understand it and it would be interesting to hear more about this.

[husaberg]

I'd say you're right Husa. Here are some more pictures of the various bikes that have been built around the Swissauto engine:
http://www.google.de/imgres?imgurl=http%3A%2F%2Ffarm6.static.flickr.com %2F5591%2F13664850363_9641339795_m.jpg&imgrefurl=http%3A%2F%2Fflickrhivemind.net%2FTags%2 F500cc%2Cswissauto%2FInteresting&h=137&w=240&tbnid=IHInMaK2zUppvM%3A&docid=g-2cTAdmF94OGM&itg=1&hl=en&ei=TtOnVZuYNcGosAGLq6-oCA&tbm=isch&iact=rc&uact=3&dur=2116&page=1&start=0&ndsp=17&ved=0CDUQrQMwB2oVChMIm_e4gIHgxgIVQRQsCh2L1QuF

Here is some other pics the Website missed.
http://www.kiwibiker.co.nz/forums/album.php?albumid=4833

When you said the crank was welded that confused me. Where was it welded
I remember Wob saying it was a bloody expensive crank.

[wobbly]

The Pulse chassis was built by the Roberts Team in England around the SA engine,I could find out easy enough if one was sent to Aprilia
either by Dave ( thieving bastard ) Stewart recouping cash or if another of the chassis was copied and sold to them by by Roberts.

Re the power potential as you approach det conditions.
As I said there is a finite energy load in each combustion event and its easy enough in a 2T to dramatically redistribute where this energy goes.
Crank up the timing or the com and more heat goes into the piston/head/water, and less remains to activate the pipe wave action.

But deto is a completely different animal.
The excessive heat in the combustion space and the resultant shock wave moving uncontrolled thru the burning mixture destroys the all important boundary layer
that protects the piston and the squish band head material.
Thus the end gases erupt,creating more heat,and this gas trapped in the squish is so violently consumed due to the spastic levels of turbulence,that free radicals begin to form.
Once this starts,huge amounts of the available energy is used to create even more free radicals - a thermonuclear reaction in reverse.
These radicals are highly chemically reactive, and it is this property that eats away the alloy piston/head giving the classic deto signs around the bore periphery.

Using up huge amounts of the combustion energy like this of course means less is used to give the pressure rise,pushing down the piston - but also less heat
escapes into the pipe.
Thus the instant deto is forming the egt drops, and NO its not lean, its about to explode - literally.
Result - power craps out big time, but as is human nature,when det counters became available the rule of thumb that gave best performance was to have 3 det
"events" per Km.
All this meant was that the tuning was being pushed right to the edge by monitoring the amount of deto happening.
Made for lazy tuners that never learned how to read a plug accurately - just read a gauge.

[swarfie]

By welded up crank he probably means that the crankpins are tig welded to the crank webs (flywheels) so that the crank doesn't go out of phase. I did that to the 90 degree crank I made for my Matchless sidecar. It stops the "push" from one cylinder from turning the web on the crankpins, as the push is phased and hence not equal or at least not at the same time or 180 degrees apart. The weld only needs to be very small (not all the way around the crankpin) to ensure the pins don't turn.

[FastFred]

<iframe width="560" height="315" src="https://www.youtube.com/embed/D1WiAMSGntQ" frameborder="0" allowfullscreen></iframe>

More real than TopGear

<iframe width="420" height="315" src="https://www.youtube.com/embed/rsBPFPomjp4" frameborder="0" allowfullscreen></iframe>

[jonny quest]

Welding a crank is useless. Poor design is what causes crank to move. Even welded cranks move in a poor design

[husaberg]

Welding a crank is useless. Poor design is what causes crank to move. Even welded cranks move in a poor design

The crank on the Pulse/ROC/SwissAuto/MUZ 500 gp bike is a little special as its a flying web design.
When Fits said welded I wondered if he was referring to where the original Hirth joint was.

313738313739313740313741313742


The unsupported disc between the cylinders is also the type of crank design as used in the SwissAuto V4 - Gp engine, that ended up as the Pulse 500 as run by some of the guys from the BSL500 team..This is called a flying web crank, but has the pins opposite to give 180* firing in adjacent cylinders.

One thing to note in the pics of the cylinder held by Thomas - the real RSA does not have any taper at all at the top of the duct divider ( septum), the end of the divider just has a small radius on each side.
This is to reduce the area ratio between the duct entry and the port exit.
Edit, here is a better pic I have just got.


That notch for timing reminds me of one of the cleverest triggering setups I have seen.
In the SwissAuto/Pulse flying web engine there were two magnets at 180* in one crank web with only 1 sensor, setup much as the pic of the RSA125.
I spent ages trying to figure out how it worked, untill one day I grabbed another magnet and discovered that each one inside the crank
was orientated N & S pole outward.
The trigger sensed the N pole as cylinders 1,3 and the S pole as 2,4, bloody clever and as simple as it could be made.


The SA500 engine was used in the Pulse and I rebuilt the one that Bill has when it first arrived in NZ..
Its cylinders did fire in pairs, and were very cleverly triggered by a N and S pole magnet embedded in a flywheel with a single trigger.
The pistons were A Kit Honda, with the domes machined off, leaving only the squish band radiused up from the timing edge.
Made them very light, but wow I thought the dome would sink for sure - never did.
Having a flying web only supported by a pin on each side of a flat plate in essence made for hideous stress levels and the only way the cranks would live
for any reasonable time was having them made in unbelievably expensive materials and processes.
They cost in the region of E20,000 each I believe, did 1500Km and then in the bin.

The reeds were very small in area and the carbs ( mag Keihins at E120,000 for 2 pairs ) were equivalent to a 35mm area, so the design was biased toward good acceleration, but it still made
close to 180 Hp at the sprocket.
The cylinders were very close in design to an A kit Honda, the big difference being the B port hook was a smooth radius, pointing to 1/3 across the piston to bore centre ( and of course SA on the side )
Again, all designed for mid power - I have some sitting on my bench if you want some pics , but nothing to see of interest really.

I have got access to one of the Team Roberts built, Mike Sinclair designed frames from the Pulse project and its an amazing piece of alloy artwork.

The code does not care about what part of the input is used to represent the duct/pipe, except to say that the duct temp is part of
the jigsaw as much as the pipe wall temp is.
Thus in this case we have an alloy spigot extension that has the slip joint around it, and water is a fair distance away.
I would opine that this alloy extension would be closer to the pipe temp than the duct wall temp, so should be considered part of the header.

Re the relative "betterness" of any one physical layout for a boat, in the case of the 4 cylinder the differences between say a twin crank
contra rotating stack ie a square 4 Vs an inline 4 Vs a V4 would all come down to the number of seals/bearings in total used to support
the flywheels.
As it would appear that balance, firing order and rotational precession have little bearing on the final result then FMEP would become important, except
maybe the inline 4 would have a much higher C of G and this may overcome any perceived frictional advantage.
Maybe the best compromise ( but problematic to implement reliably ) is a flying web setup.
Go buy a Swiss Auto, they were cheap enough in comparison to a Japanese factory engine at the time.


What you describe is exactly what SA Design did with the flying web V4 - 500, but needed no sealing between the crank pairs.
The Swiss Auto had adjacent cylinders crankpins running at 90* opposite each other off a common web that was sitting inside a common crankcase volume.
This eliminated a seal and bearing between those cylinder pairs.
Gave a very small package, but required very expensive materials, extensive FEA and heat treatment to overcome the stress levels generated in
the unsupported "flying web".

http://www.swissauto.com/d/motor/projekt_galerie.jsp?ID_Display=20000D


The SA didnt need to seal adjacent cylinders - they fired together off a common case volume.
ie the crank pins on each side of the flying web were displaced by 90*, as were the cylinder axes - thus both pistons arrived at TDC together.
Put two of these pairs in line and you have a V4 with the minimum seals/bearings.

I found the cost hidden in there 20000 euros and 1500km for the crank back in the day.
Conversely the Yamaha 500 cranks were 3000 pounds each (they have 2) in 1994
The recommended interval then was 1800km, Pretty sure the big bank cranks would have been half of that km though.

[2T Institute]

He was the one doing the beautiful RSA like Cylinders but alas his site seems to no longer have them or the other Honda conversion stuff.
he has this test bench listed but I can't figure it out .
http://www.he-ja.nl/winkel/werkbank/#
Wasn't just Thijs, the engine was designed by Mike Austin of Exaxctweld fame and Patrick Unger was to design the data aquisition. Jonas Folger was their rider, Patrick was Jack Millers engineer last year and is still working with Aki Ajo. Got knock on the head when.........."someone" convinced Gary Taylor and John Surtees that "his" design would be better. Any guesses on the name of that genius?

[husaberg]

Wasn't just Thijs, the engine was designed by Mike Austin of Exaxctweld fame and Patrick Unger was to design the data aquisition. Jonas Folger was their rider, Patrick was Jack Millers engineer last year and is still working with Aki Ajo. Got knock on the head when.........."someone" convinced Gary Taylor and John Surtees that "his" design would be better. Any guesses on the name of that genius?

I am picking it is something along the lines of Macbeth.................
I do try not to mention Macbeths name in Hope that the other Jan might post rather than just visit occasionally.

[jonny quest]

I mentioned it husaberg because so many people love to weld the crank pins on a perfectly good crank.

[jonny quest]

Has air ever been injected into a 2t pipe? Potentially raising temps at key rpm points?

[mr bucketracer]

I mentioned it husaberg because so many people love to weld the crank pins on a perfectly good crank.only animals do that

[husaberg]

only animals do that

Mention husaberg that is...........

I have seen some stuff about using weld to secure Mallory. I assume its an overlap only securing technique to stop it falling out anyone?

The MUZ500
313786313785313784313783313782

[gravmax88]

RGV250 cranks come with the center section welded from the Suzuki factory..............

[Frits Overmars]

my guess is that the end result between combustion and explosion for the same amount of fuel is the same amount of heat induced pressure...Peak temperature during combustion is in excess of 2000°C. Aluminium melts at 660°C, so why doesn't the piston come dripping out of the exhaust? Because it is protected by the boundary layer of stationary gas that is clinging to all metal surfaces.
This boundary layer is an excellent heat insulator, but the shock waves caused by detonation can blow it away and once it is gone, there is much more heat transfer from the combustion gases to the metal, so the metal gets hotter and the heat-induced pressure will be less.


When Frits said welded I wondered if he was referring to where the original Hirth joint was.

By welded up crank he probably means that the crankpins are tig welded to the crank webs (flywheels) so that the crank doesn't go out of phase. It stops the "push" from one cylinder from turning the web on the crankpins, as the push is phased and hence not equal or at least not at the same time or 180 degrees apart. The weld only needs to be very small (not all the way around the crankpin) to ensure the pins don't turn.That is exactly right Swarfie. I've seen welds where the crank pins were pressed into the flying webs (B), and in some cases also where they were pressed into the outer webs (A). The Hirth joints that made the Swissauto crank so expensive, were not welded.
313745

[husaberg]

That is exactly right Swarfie. I've seen welds where the crank pins were pressed into the flying webs (B), and in some cases also where they were pressed into the outer webs (A). The Hirth joints that made the Swissauto crank so expensive, were not welded.
313745



So zee Swiss could have learned a bit from zee Germans.
I guess in their defence it was because the Swiss designers were used to working with Cheese and Chocolates
313746313747313748313749313750313751
The Konig crank (above) seems to be a better solution.
Anyone know how long it lasted. Yes I realise the HP was a bit lower then. It would be a bitch to make that way but it was how the Hondas twins were done so it must have been cheaper.

[Frits Overmars]

So zee Swiss could have learned a bit from zee Germans. I guess in their defence it was because the Swiss designers were used to working with Cheese and Chocolates.Don't forget the cuckoo clocks.


The Konig crank (above) seems to be a better solution. Anyone know how long it lasted. Yes I realise the HP was a bit lower then. It would be a bitch to make that way but it was how the Hondas twins were done so it must have been cheaper.What you are showing is not a König but a Konny crankshaft. Konny (http://www.konny.cz./) is a Czech company that started producing hard-to-get König parts, but their products are of higher quality than the original Berlin-made König parts.
I have little experience with the longeivity of König crankshafts in the boat engines for which they were designed, but their life expectancy in racing sidecars was not unlike that of a snowball in hell. The grip of a boat propeller seemed to be much more forgiving than the grip of a mile-wide sidecar slick on hot tarmac.

No Honda engine ever had a flying crank web; what they did have, was crank webs with one integrated crank pin each. It was not a cheap solution either, but it allowed the crank to be made narrower because per cylinder there was one less press fit that depended on length for rigidity.
313752313753

[chrisc]

Excuse my ignorance but why do many of the 2 stroke cranks I see appear to have a cover on the web? Such as the crank above.

[husaberg]

Don't forget the cuckoo clocks.

What you are showing is not a König but a Konny crankshaft. Konny (http://www.konny.cz./) is a Czech company that started producing hard-to-get König parts, but their products are of higher quality than the original Berlin-made König parts.
I have little experience with the longeivity of König crankshafts in the boat engines for which they were designed, but their life expectancy in racing sidecars was not unlike that of a snowball in hell. The grip of a boat propeller seemed to be much more forgiving than the grip of a mile-wide sidecar slick on hot tarmac.

No Honda engine ever had a flying crank web; what they did have, was crank webs with one integrated crank pin each. It was not a cheap solution either, but it allowed the crank to be made narrower because per cylinder there was one less press fit that depended on length for rigidity.
313752313753

I was meaning the integral crankpin but you missed the Honda that I would say was one of the bigger sellers i can't help but think Good ol Honda would have done it to save a few yen.
I can't see it being narrower because of it, they are problematic once the hardening starts to peel.Pretty sure most if not all early Honda twins were made the same way the cr93 were.
313754313756
Yes I was cheating with the reproduction Konig I just assumed the design never changed.
I do have a pic of the original Konig Crank but not in bits though.
313757

[Frits Overmars]

Excuse my ignorance but why do many of the 2 stroke cranks I see appear to have a cover on the web? Such as the crank above.Because it's the cheapo solution. The crankshaft shown in my previous post is from the Honda RS250 production racer. The crank webs are forgings with the material distributed correctly for balancing. But that would leave a clobbered external shape, so a tin cover is pressed around the lot.
The crankshaft below is from the NSR500. That was a works racer; no tins there...
313758

[mr bucketracer]

RGV250 cranks come with the center section welded from the Suzuki factory..............not case harden there then

[swarfie]

That is exactly right Swarfie. I've seen welds where the crank pins were pressed into the flying webs (B), and in some cases also where they were pressed into the outer webs (A). The Hirth joints that made the Swissauto crank so expensive, were not welded.
313745

Thanks Frits....I only welded my crank at A in your diagram (only a twin cylinder engine), as I had had a crank years ago turn/move (and subsequently go out of true on the output shaft) that I had made out of two TT500 Yamaha cranks for a mates Matchless twin. I use a "Hurth" coupling of my own design which will never rotate, which is basically square holes in the centre two crank webs with a centre mainshaft with corresponding squares each side of the round centre bearing shaft. This is pressed up with only 0.02mm interference but by it's very nature can never rotate (and has never separated/moved). I'm reminded of the old saying "keep it simple stupid:lol: Interesting that I use the original Yamaha TT crankpins (on a 34 mm diameter pin) which even at an interference of the original Yamaha spec at 0.1 mm can still move/slip and is the reason I welded as a precaution more than anything else. So actually IMHO even good design can sometimes (and in the case of a sidecar where the loads are so much more than a solo) come back and bite you in the arse.
As a side note, my "Matchless" replica engine has won the Classic sidecar trophy in NZ 17 times to date and at first attempt in Australia in 2000 took out the Ausy Championship (knocking more than 2 seconds off the classic lap record at Syney's Eastern Creak circuit in the process)....so we'll have no more of this "bad design" BS please from Mr J Quest....sour grapes...not much:rolleyes:

[husaberg]

Because it's the cheapo solution. The crankshaft shown in my previous post is from the Honda RS250 production racer. The crank webs are forgings with the material distributed correctly for balancing. But that would leave a clobbered external shape, so a tin cover is pressed around the lot.
The crankshaft below is from the NSR500. That was a works racer; no tins there...
313758

I also note the hand finishing on the rods.



Thanks Frits....I only welded my crank at A in your diagram (only a twin cylinder engine), as I had had a crank years ago turn/move (and subsequently go out of true on the output shaft) that I had made out of two TT500 Yamaha cranks for a mates Matchless twin. I use a "Hurth" coupling of my own design which will never rotate, which is basically square holes in the centre two crank webs with a centre mainshaft with corresponding squares each side of the round centre bearing shaft. This is pressed up with only 0.02mm interference but by it's very nature can never rotate (and has never separated/moved). I'm reminded of the old saying "keep it simple stupid:lol: Interesting that I use the original Yamaha TT crankpins (on a 34 mm diameter pin) which even at an interference of the original Yamaha spec at 0.1 mm can still move/slip and is the reason I welded as a precaution more than anything else. So actually IMHO even good design can sometimes (and in the case of a sidecar where the loads are so much more than a solo) come back and bite you in the arse.
As a side note, my "Matchless" replica engine has won the Classic sidecar trophy in NZ 17 times to date and at first attempt in Australia in 2000 took out the Ausy Championship (knocking more than 2 seconds off the classic lap record at Syney's Eastern Creak circuit in the process)....so we'll have no more of this "bad design" BS please from Mr J Quest....sour grapes...not much:rolleyes:

So the Matchless is it still three bearing plain center or roller?

[swarfie]

Three roller bearing crank. Parallel roller in the centre and shouldered roller bearings each side for axial alignment. In fact the only bushes left in the engine are in the OHV rockers, even the cams and timing gears run on needle roller bearings. Done it all proper like....unlike the poms:bleh:

Also made my own rods after a Yamaha one broke in 2010 and wrecked things a bit. The engine makes really good torque and doesn't need to rev past 6500 but the TT rods couldn't hack the pace so made the new ones out of Assab 718. Doubt I'll have to see them for a while.

[Tim Ey]

Talking cranks a question occured to me:
with which size of press fit are Aluminium and tungsten inserts pressed in the crank?

[swarfie]

I don't know as I haven't had to use them to get a balance factor but as there's no load on them they probably only need to be 0.01/0.02 mm press to hold them in place. I work with fits and tolerances on a daily basis for my job (toolmaker) and for like materials a size for size fit is a press fit so only having to allow for a differential in expansion would keep inserts in place.

[Flettner]

I don't know as I haven't had to use them to get a balance factor but as there's no load on them they probably only need to be 0.01/0.02 mm press to hold them in place. I work with fits and tolerances on a daily basis for my job (toolmaker) and for like materials a size for size fit is a press fit so only having to allow for a differential in expansion would keep inserts in place.

Neville M , I assume?

[swarfie]

Neville M , I assume?

:2thumbsup

You might be able to answer Tim Ey on the subject of crank stuffing plugs better than me Neil.

[Flettner]

:2thumbsup

You might be able to answer Tim Ey on the subject of crank stuffing plugs better than me Neil.

Yes, I've stuffed a few cranks in my time:laugh:

[41juergen]

Thank's a lot Wob for the answer about the reeds, will follow that and will do some testing.

Just an other question, does somebody can tell me if the Yamaha stated 87 HP of the mid 90th TZ250 V twins was rear wheel HP or "at the crank"?

Juergen

[husaberg]

Thank's a lot Wob for the answer about the reeds, will follow that and will do some testing.

Just an other question, does somebody can tell me if the Yamaha stated 87 HP of the mid 90th TZ250 V twins was rear wheel HP or "at the crank"?

Juergen
Hello Juergen
Like all Japanese factory hp claims it was measured at the piston ring..............:laugh:
Unfortunately due to there small size and poor sense of direction, Maybe only 73 or so of those horses where able to find there way back to the rear wheel.

[41juergen]

Thank's Husa, just hoped that they did same like for the road bikes. I'm looking to push my TZR250R (the last 2 stroke for road use what Yamaha produced) to higher limits. Unfortunately it has the same worse bore / stroke ratio like the TZ's at that time (as a lot of the engine parts are exactly the same). But with all the advise from Wob and Frits my sim show up more than 80 HP on the wheel :shit: so lets see, next topic is the weld up the ex port and the spigot to finally match the correct dimensions, will report back.
Juergen

[Bert]

Hello Juergen
Like all Japanese factory hp claims it was measured at the piston ring..............:laugh:
Unfortunately due to there small size and poor sense of direction, Maybe only 73 or so of those horses where able to find there way back to the rear wheel.


Thank's Husa, just hoped that they did same like for the road bikes. I'm looking to push my TZR250R (the last 2 stroke for road use what Yamaha produced) to higher limits. Unfortunately it has the same worse bore / stroke ratio like the TZ's at that time (as a lot of the engine parts are exactly the same). But with all the advise from Wob and Frits my sim show up more than 80 HP on the wheel :shit: so lets see, next topic is the weld up the ex port and the spigot to finally match the correct dimensions, will report back.
Juergen

It will be interesting to see where you get too Juergen.
I'd love to see 80+ from my TZ250 (not TZR); while I have a few spare TZ barrels, much rather tinker (likely destroy) some of the 3xv sp barrels (given they are not rocking horse shit).
While you say the parts are exactly the same - there is a number of differences in the port layout and time areas.

[cotswold]

http://www.morebikes.co.uk/scoop-hondas-secret-plans-two-strokes-are-back/


Must have seen your work TZee

[RAW]

SHRINK FITS.
here is a link for you all, you just have to determine the fit you would like to try,
NOTE, assembly techniques are not discussed, softness and or hardness of materials being used,
If you are using a material that is not strong enough to wit stand the assembly forces required to assemble by force it WILL just be mashed up, assembly techniques such as dry ice, heating or both may be required. It's not as simple as you may think.

http://www.engineersedge.com/calculators/mechanical-tolerances/force-fit-tolerances.htm

[F5 Dave]

http://www.morebikes.co.uk/scoop-hondas-secret-plans-two-strokes-are-back/


Must have seen your work TZee
I'm too stoopid to visualise how that crank is supposed to work but why would the reed be aimed there? I call bogus.
Edit, now I look for 30 seconds more, is that a valve, in the head and low low single transfer?
I think I'll hold out for the NSR500 road bike as the more likely option. Make mine the V Twin, no point over egging the pudding.

[Yow Ling]

http://www.morebikes.co.uk/scoop-hondas-secret-plans-two-strokes-are-back/


Must have seen your work TZee

Could it be Hondas take on the Ryger bottom end with a detroit diesel top end, looks like a pretty ordinary uniflow 2t with the crank drive stolen from an old shaper, giving the piston different speeds up and down , longer duration power stroke , shorter duration compression. Where are you husa ??

[wobbly]

The alloy plugs cant be weld retained ( but several pressed in dimples on the circumference helps ) so i press them in with around 0.03 to 0.05mm
interference.
The Mallory inserts can be retained by simply melting the crank material into the plug in a couple of opposite arcs on each side, so the press fit can be reduced
to 0.01 - 0.02 .
You have to be careful with this as I have had a crank web split out from the Mallory hole, to the wheel circumference ,as the press fit was too tight due to the
plug being slightly oversize.

Welding of the center axle on twins is often needed - " advised " when there are two press fits on top of each other as we see in rebuildable RD/RZ/Banshee cranks.
The inner press fit simply expands outward into the hole for the big end pin.
This prevents the two inner wheels from turning in relation to each other and wreaking the phase, but usually this only occurs with a seize on one side.
Cranks like RGV and Aprilia etc have integral pins on the inner wheels so should not need welding of the axle if the press is sufficient.
If the big end press fits are not correct then welding is sometimes the only way to keep them true - but is really butchery of the first order.

[husaberg]

Could it be Hondas take on the Ryger bottom end with a detroit diesel top end, looks like a pretty ordinary uniflow 2t with the crank drive stolen from an old shaper, giving the piston different speeds up and down , longer duration power stroke , shorter duration compression. Where are you husa ??

Been freezing my wet ass off at league.
thinking the same as you I seen something similar earlier, Aye Ken will confirm
I don't like those valves as they lose the sharp pulse energy.
I do like uniflow.

[speedpro]

http://www.morebikes.co.uk/scoop-hondas-secret-plans-two-strokes-are-back/


Must have seen your work TZee

Funny as. The journos mention the fuel injection and how it sprays a cone into the cylinder, but . . . . . if you check Fig 5 there is no injection while the transfer ports are open. It does seem like there is 3 injectors, maybe. The exhaust opens at approx. 115ATDC and the transfers about 10 degrees later. That isn't much blowdown for a crankcase scavenged 2-stroke. They also talk about a 2-stroke screamer, but(again). . . . . .the exhaust valve is pushrod operated which is astounding given the lift required to allow the exhaust to escape the cylinder and the very short duration available to achieve it, about half what a 4-stroke could allow.

I'm with Dave and call bullshit, unless they use forced induction, REALLY forced!

[F5 Dave]

Oh well if we are talking `Really forced` it's time for another musical interlude ( yeah its been a few pages but I've been busy).
http://m.youtube.com/watch?v=F5sIXUbMgF0

[breezy]

Oh well if we are talking `Really forced` it's time for another musical interlude ( yeah its been a few pages but I've been busy).
http://m.youtube.com/watch?v=F5sIXUbMgF0

unbelievable video.....strange what goes on in peoples minds:blink::blink:

[breezy]

http://www.morebikes.co.uk/scoop-hondas-secret-plans-two-strokes-are-back/


Must have seen your work TZee

Flettners, sleeve valve engine , with up-to-date sleeve and piston materials... got to be a winner:yes::yes:

[F5 Dave]

unbelievable video.....strange what goes on in peoples minds:blink::blink:
And that such people could be your caregivers in later life.

Just to help you sleep tonight.

[ken seeber]

thinking the same as you I seen something similar earlier, Aye Ken will confirm

Hoosa is right, there has been quite a bit of banter on the Ryger behind the scenes.
The Honda engine. No details on the exhaust system, but if you look at the exh and transfer timings, there is around a 7 degree blowdown, compared to around a 30 degree blowdown of a high performance engine (say 192 exh and 132 transfer durations) which might develop max power at 12k. Given this is approx 1/4 of the angle duration, I suggest that the engine is an industrial engine running at 3 to 3.6k to suit a synchronous alternator running at 50 or 60 hertz. That's if it does rely on a matched resonant exh system. It is not a race engine, pushrods, clunky build etc. One feature is the very longs stroke and beam mechanism, possibly to reduce friction due to piston side thrust. Not sure about oil control though. If it does rely on a strong blowdown effect (the Kadenacy effect), then the poppet valves might be a liability. Maybe that's why it looks more like a low speed engine.

[Flettner]

Might release some details of my latest engine soon, but you will all have to sign a non disclosure ageement:bleh:
This new version will have vairable everything! compression, ports (throttled transfers), exhaust, crank case, 24/7 reeds and burn no oil. With suitable injection no hydrocarbons out the exhaust, bastardised version of FOS . NOT using direct injection. Who would ever want a fourstroka again?
AND it's 100cc water cooled:msn-wink:
It does have a road bike " leagal " gearbox.
BUT I can't say any more

[F5 Dave]

Sorry your works rider is broken. You'll have to use someone talented.

[Lightbulb]

Frits, do you know Rob Met of MB engines ?
If so , you can mention me , Neil from NZ.
Been interesting reading different things on this thread.
My experience is in model racing engines, mainly 2.5cc and 6.5cc engines.
I have spent many years making mistakes and making the odd discovery as well.
Most I have discovered have been aired here in the many pages of posts by various people.
Little things can sometimes make a big difference on model engines, but I am not not sure how that pans out to
full size engines. One that comes to mind is an engine that I was involved in making,that had a bore of 21.5mm and
a stroke of 18 mm with a rod length of 34mm, transfers were 132 deg exhaust to suite the class type, ie full pipe or
tuned muffler pipe. Then we made a new version of the engine with a bore 20.37,stroke 20.06mm rod length 35.43mm
transfer of 132 deg and again exhaust to suite. When we made the new engine it performed about the same as the shorter
stroke engine. But then the tweaking came. Slightly bigger induction hole and a geometry change gave a substantial increase in
torque. Tried the same mod to the older engine and there was no gain to be seen. Then there was some small changes to the tuned
muffler that gave a measurable gain. On the short stroke engine, would not run properly on the new muffler version.The piped version of the
short stroke and the square engine both benefited from the exhaust port insert that restricted the area to 75% of the ex area, then blended
to the pipe header diameter. On the square engine there was a gain by having a small 0.4mm step on the bottom side of the insert at the
75% restriction intersection. I guess you could call it an anti reversion step. The only other change was a subtle change on the width of the
bottom of the exhaust port relative to the side transfer ports.
The power increase on the piped engine was from about 3 hp at 29,900 to over 4.2 hp at 31500 rpm
Interesting all the same.

[Haufen]

Frits, can you tell us what Harry Ryger is planning to be doing with his engine concept, in the future?

Does he intend to sell it to an OEM, like a Motorcycle or Kart manufacturer? Does he plan to start his own company as an engine supplier?
Just holding the patent(s) for as long as possible (20 years is the maximum I believe) and waiting is not going to help much, but cost quite a bit.

[Frits Overmars]

Frits, do you know Rob Met of MB engines ? If so, you can mention me , Neil from NZ.I know Rob Metkemeijer very well, Neil. We've done a couple of projects together, like introducing the first sleeveless cylinder in F3D pylon racing, on the 6,5 cc MB40 engine that has been just about unbeatable for the past 13 years or so (I stopped counting).
Below you'll see the 2002 version of the engine, the cylinder and the dyno with left to right the eddy current brake, the flywheel, the safety coupling, the engine and the quick-change exhaust pipe fixture.

313774 313775 313776

PS: don't build an inertia dyno for these kind of revs unless you know what you're doing.

[Frits Overmars]

Frits, can you tell us what Harry Ryger is planning to be doing with his engine concept, in the future? Does he intend to sell it to an OEM, like a Motorcycle or Kart manufacturer? Does he plan to start his own company as an engine supplier?I don't think the non-disclosure agreement applies here, but a normal chat between friends also deserves some privacy, so I won't give any details, but Harry intends to supply his own engines. He's not in it for the money, he's just a guy with a passion for two-strokes, just like yours truly.

[breezy]

And that such people could be your caregivers in later life.

Just to help you sleep tonight.

cheers mate:eek5::eek5:

[TZ350]

page 1240 .....



Here are some other very interesting threads:-
Foundry:- http://www.kiwibiker.co.nz/forums/showthread.php/162399-The-Bucket-Foundry/page29
Team GPR:- http://www.kiwibiker.co.nz/forums/showthread.php/150352-Team-GPR?p=1130775246#post1130775246
Frame and Chassis:- http://www.kiwibiker.co.nz/forums/showthread.php/145224-Race-chassis/page38
Chris C's photos:- http://www.kiwibiker.co.nz/forums/showthread.php/153656-Chris-Bucket-photo-thread-Bandwidth-warning/page5
Old #6:- http://www.kiwibiker.co.nz/forums/showthread.php/68694-6/page49
Bucket Lap Records:- http://www.kiwibiker.co.nz/forums/showthread.php/117354-Bucket-lap-records/page8
Photographic History of Bucket Racing:- http://www.kiwibiker.co.nz/forums/showthread.php/167592-A-photographic-history-of-Bucket-racing/page3
Ecotrons engine management:- http://www.kiwibiker.co.nz/forums/showthread.php/159112-Ecotrons-Engine-Management/page5

2T Engine development software:-

Porting Program http://www.porting-programs.com/

EngMod2T http://www.vannik.co.za/EngMod2T.htm

There are also over 7000 images on this thread, use "Thread Tools" to view them and then click through to the original post about them.

302136302135


Page 600 is worth a look at:- http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page600

And there are also over 7,000 images on this thread. Follow the link below and you will find screen shots of the process.

Blowdown STA (Specific Time Area) is everything and determines the RPM ceiling and power output of your motor.

Optimum Exhaust Port Duration is 190 deg but blowdown STA requirements may force you to use a longer exhaust duration.

Wob often refers to the vital dimensions and Frits posted a diagram of them. Stick to these %%% to get good results.

301223
Frits suggested design criteria for a good pipe.

301224

Click on Husabergs link to read about transfer port angles.


Transfer Port theory <center><center><center><center><center><center><center><center><center><center><center><center><center><center><center><center><center><center><center><center><center><center><center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center></center>
Transfer Ports. Low and Wide is the go….

The 135mm inlet tract length from tip of reed to carb bellmouth rule of thumb.

302659 Frits's version of a short carb setup.

pit-lane.biz is another really good thread:-

http://www.pit-lane.biz/f34-gp125-et-250-snif (http://www.pit-lane.biz/f34-gp125-et-250-snif)

http://www.pit-lane.biz/t5121-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-4

http://www.pit-lane.biz/t4072-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-3-locked

http://www.pit-lane.biz/t3173-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-2-locked

http://www.pit-lane.biz/t117-gp125-all-that-you-wanted-to-know-on-aprilia-rsa-125-and-more-by-mr-jan-thiel-and-mr-frits-overmars-part-1-locked

NSR250 suspension tuning:- http://nsr-world.com/tuning/250-tuning/suspension/

NSR250 Engine Tuning:- http://nsr-world.com/tuning/250-tuning/engine/

Ed Tuck racing (NSR250):- http://edetuckracing.blogspot.co.nz/...5-pistons.html (http://edetuckracing.blogspot.co.nz/p/fitting-rm125-pistons.html)

http://www.twostrokeracelab.com/

http://www.2strokers.com/index.php?topic=184.0

[Lightbulb]

Below you'll see the 2002 version of the engine, the cylinder and the dyno with left to right the eddy current brake, the flywheel, the safety coupling, the engine and the quick-change exhaust pipe fixture.

Thanks for the reply. Do you have any plan or info on the dyno you made ?
I want to make one for testing a 6.5ccF3D engine and the 2.5ccFAI engine.
The 2.5 cc revs to about 41K but I want to see what happens if it goes to 43k compared to the 39-41 at present.
The problem is that with just trying different props etc it is hard to figure out where the real power is with which particular pipe .
Have you looked at real time crank case pressures with your engine work?
It is another fascinating aspect of looking at what happens in an engine. I also had pressure transducers on a pipe at different places as well.
It just gave me more questions than answers, and nothing lines up with all that I read about how tuned pipes actually worked. The only thing that correlated was the wave speed of the pulse. And even that varied depending on where the measurements were taken.But that is to be expected as the pressure and temperature changes effect the wave speed.
It is surprising how there does not seem to be very much difference in the induction and port timings between small engines and the bike gokart engines. What really surprised me on pipes was when the rules changed and silencers were added to the pipes, we saw a power gain in both the torque and the top end rpm, which in not what were expecting. I am assuming that we stumbled upon a helmholtz effect on the system.

Neil

[Lightbulb]

Has anyone heard of , or do they offset balance crank shafts?
What I am asking about , is when the crank is balanced but not assembled, does the crank pin sit at 1am to 1:30 on the side of the direction of rotation as to sitting at the 12 pm position? This is when looking at a crank when it turns in a clock wise direction.
Any info or experience would be appreciated.
Thanks,
Neil

[wobbly]

Welcome back Neil, no hear from you for ages.
Yes, I have been investigating offset balance just recently as I am involved with a crank made in USA for a 1200cc twin used for
Jetski freestyle engine.
The offset asymmetric balance crank seems to be smoother than the traditional setup, but i still havnt got my head around why this should be - it certainly is
in practice.

F5 - thanks for the music interlude,I already have the BlueRay and thought for a long time that Tools live version of No Quarter by Zeppelin was actually superior.
But I have just recently built the hell vinyl front end, and my youngest son bought me The Song Remains The Same.
On that the live in New York guitar shred is completely the most amazing thing I have ever heard.
Last time racing in Vegas i went to Maynards Merkin Winery, met the man and had a few samples over dinner, 2 lines off the bucket list.

Try this
https://www.youtube.com/watch?v=KtaMTIQuwA8&feature=youtu.be

[Flettner]

I know Rob Metkemeijer very well, Neil. We've done a couple of projects together, like introducing the first sleeveless cylinder in F3D pylon racing, on the 6,5 cc MB40 engine. That engine has been just about unbeatable for the past 13 years or so (I stopped counting).
Below you'll see the 2002 version of the engine, the cylinder and the dyno with left to right the eddy current brake, the flywheel, the safety coupling, the engine and the quick-change exhaust pipe fixture.

313774 313775 313776

PS: don't build an inertia dyno for these kind of revs unless you know what you're doing.

Having no piston ring is one hell of an advantage, look at that exhaust port!

[husaberg]

Having no piston ring is one hell of an advantage, look at that exhaust port!

I know MZ did experiments without them, but the materials of the time (at least those available to them) were not up to it then.

[Lightbulb]

Thanks Wobbly,
yeah it's been a while, I owe you a phone call or 2.
I suspect it has been around for quite a long time but just not talked about.
Some things are like that, like the use of submicron lathes to make some of the parts super
accurately round, or the use of other gear to obtain a round setup at operating temperature.
Like with the model engines, the biggest gains are the sealing from around 30 deg BTDC to 30 deg ATDC

Ringless model engines if the piston geometry is correct, can get away with just enormously wide ports all round,especially the exhaust.
Larger ringless engines have been tried but at 15cc seems to be the max in a high performance engine. After that, the rate of expansion with materials
becomes too great and the most common failure is a seized or picked up piston.
Neil

[nick gill]

Some 50's history you might find interesting....
Came across this FOS style symmetrical cylinder by Ydral a while back. I think it may be in part a design by Vincenzo Piatti, who patented his own scavenging patterns and designed many small bore two stroke engines for various manufacturers in the 1950's.
https://c1.staticflickr.com/1/341/19813694875_e9c3f6cf8b_b.jpg
https://c1.staticflickr.com/1/275/19191085244_69bdaa388e_b.jpg
https://c1.staticflickr.com/1/344/19625657670_fe9921bd29.jpg
This style crown is very Piatti:
https://c1.staticflickr.com/1/334/19787510536_a8c352c0a2_z.jpg

[husaberg]

Some 50's history you might find interesting....
Came across this FOS style symmetrical cylinder by Ydral a while back. I think it may be in part a design by Vincenzo Piatti, who patented his own scavenging patterns and designed many small bore two stroke engines for various manufacturers in the 1950's.
He also designed the Suzuki TSCC.




The other bit is for Grumph we mentioned a while back this guy i certainly never knew he would go to the evil side i guess he is in a way responsible for the Evil FXR150 as Well.
He knew Bugathi as well as co designing the TSCC.

http://twinspin-ec.com/Analysis Software.htm


Frits and Wob and Grumph have probably seen them but does anyone have a pic of the Italian designed by Vincenco Piatti
AMC England manufactured motors made for James/Francis Barnet etc.The ones with the funny piston head port cut outs to control the fuel air charge kind of like a non loop scavenged deflector.Pic posted below. but a bit hard to make out detail sorry.
Because i am pretty sure they were all transfer gully ports as well. Just a trench machined into the cylinder with no cylinder wall to support them. Although i understand the motor was a piece of poo it did have a radial finned head.
In the shed at my old mans there is modified Villiers Cylinder that cut through the sleeve entirely and used the pistons skirt for the outer wall of the cylinder.
I am certainly not suggesting it was a great idea but It was done for a time at least once. Probably not that successful other wise they would be more common..
Note these engine were under-square and had real long skirts.No short skirt for you there wob sorry


http://www.motorcycle-usa.com/289/540/Motorcycle-Article/Memorable-Moto-Francis-Barnett-Cruiser.aspx

[nick gill]

I think your google docs link might need a bit of tweeking there Husa, there's emoticons bursting out of it

[husaberg]

I think your google docs link might need a bit of tweeking there Husa, there's emoticons bursting out of it

Yes it was a quote of one of my posts about 4 years ago.
I can't get them to work but I have done what I could.
the patents held by him link will not work so anyone interested should look for themselves.

[nick gill]

does anyone have a pic of the Italian designed by Vincenco Piatti.........The ones with the funny piston head port cut outs to control the fuel air charge.......i understand the motor was a piece of poo it did have a radial finned head

Not sure if you're still keen Husa but I've got some more Piatti engine pics, having restored a few now. Yes they are long stroke poo (51x61) with finger ports, I can confirm that, but the symmetrical Ydral cylinder I posted earlier could be modified into a real winner I'm sure.
https://c2.staticflickr.com/4/3814/10619604314_e26c575406_b.jpg
https://c2.staticflickr.com/8/7334/10619764053_818f8d5980_b.jpg

Normally I won't touch billet, squeezed or forged 2T pistons, but for odd-ball restorations there's little other choice than to go billet. These are machined from Avional 2618 billet by Wossner Germany:
https://c2.staticflickr.com/4/3710/11660345046_5b7742e7c9_b.jpg

Sorry if all this hurts your eyes but hopefully there's something to be learned in studying the early stuff, especially cylinders like the air-over-water Noguchi Yamahas etc....

[Tim Ey]

The alloy plugs cant be weld retained ( but several pressed in dimples on the circumference helps ) so i press them in with around 0.03 to 0.05mm
interference.
The Mallory inserts can be retained by simply melting the crank material into the plug in a couple of opposite arcs on each side, so the press fit can be reduced
to 0.01 - 0.02 .
You have to be careful with this as I have had a crank web split out from the Mallory hole, to the wheel circumference ,as the press fit was too tight due to the
plug being slightly oversize.


Interesting thing to do!
I once fitted a tungsten insert that started moving in the crank, by deforming the edge of it with a center punch.
Sorry for my curiousity but I really do not like to weld on cranks: Has anyone a hint how high I must go with the press fit without using any special tricks? :innocent:

For some Numbers: I just got my calculater working:
The Force of my tungsten insert will be 16,2KN @ 15000RPM (WOW!)
Incredibly high - perhaps I calculated it wrong...
Radius of the Center: 32mm
Diameter of the Tungsten: 22mm

Space to the edge of the crank: 3mm (is this enough?)
Space to the neighbouring Tungsten: 2,5mm (same question here)

Cheers!
Tim

[TZ350]

Well that was Mt Wellington today, first of the points races for the new season, I had finished third overall in F5 last year. Today the track had dried out by lunch time but it was a bitterly cold wind all afternoon.

A grade again was :first::second::third: for the two strokes. Finishing order was Dave - Will - Nathaniel, race one and Dave - Nathaniel - Will, race two, with Garry a bit further back, maybe 5th and Rod a place or two astern of that. Rods bike sounded very sharp.

Great to see Speedpros tuning work running at the head of the pack. I was riding in F5. In the last F5 race, only Nathaniel and myself made it to the start line. It was supposed to be a 12 lap race but the Starter gave me a half lap head start and then held out the chequered flag after Nat had caught and passed me, didn't take long, short race .... :laugh:

[Frits Overmars]

Do you have any plan or info on the dyno you made ? Not on me, Neil.
The flywheel is the critical part. I can't remember which steel it was made out of, but the flywheel and both shaft stubs were made out of one lump. No holes, no shrink or press fits, no welding or glueing. The centrifugal tension concentrates on the center and if there is a hole there, you lose 50% of the permissible tension.

The eddy current brake brought problems of its own. The rotor inside is exposed to the same centrifugal force, but it can't be made of just any high-quality steel; it has to be ferromagnetic. Moreover it tends to heat itself up. Having it double as an impeller can generate a cooling air flow through the brake, but that generates about as much noise as the engine. And worse, that air flow distorts the amount of torque exerted by the brake on the load cell, unless the direction of the outflowing hot air is changed from tangential into axial by stationary vanes or drillings.

Some more pictures of the dyno:
313816 313815



The problem is that with just trying different props etc it is hard to figure out where the real power is with which particular pipe.True. Measuring with test props will you give just one point of the power curve per measurement; your engine will be worn out before the curve is completed.


...I also had pressure transducers on a pipe at different places as well. It just gave me more questions than answers, and nothing lines up with all that I read about how tuned pipes actually worked.Pressure measuring gives you the pressure at a given distance from the exhaust port, at a given point in time. With pressure waves coming and going in both directions, chances are that you are measuring maximum or minimum wave superposition values, or anything in between, which will only teach you to dedicate your time and energy to other aspects of the engine.


It is surprising how there does not seem to be very much difference in the induction and port timings between small engines and the bike gokart engines.Engine size does not figure in resonance phasing. The MB40 engine has 190°/130° timing, like you would expect from any decent two-stroke.

I don't recall the rotary inlet timing of the hollow crankshaft shown below but it will probably be something like 140°/60°. That may seem tame and it is; this is not a high-revving engine :msn-wink:. It doesn't exceed 35000 rpm and then the mean piston speed is only 23 m/s. Compare that to 26,3 m/s for an Aprilia RSA (or 54 m/s for a Ryger).
Anyway, I feel that this kind of shaft rotary inlet for model engines is a fashion thing more than anything else; I wouldn't be surprised if simple piston port induction would perform better (it would certainly flow better).
313817

[136kg136ps]

On a tangent,Wobbly is there a modern 250 or 300cc cylinder you would prefer for a supermoto or motard?
Looking to apply as much of what you,Frits and others have graciously shared.

[wobbly]

Having any sort of working press fit in a flywheel that has ANY hole only 3mm from the circumference is simply asking for failure to occur.
Simple rule of thumb for this is that TWICE that is needed.
All that occurs with insufficient material is that if the core of the wheel is still under say RC40 hardness the hole will elongate outward to the wheels circumference
and the press fit goes away - if the core is any harder the material will split outward from the hole.
Several USA tuning firms have done stroker cranks for Jetskis with only 4mm and they explode continually, even with only intermittent use as in Freestyling.
They botched the problem by welding them initially, but later they got a bit cleverer and made eccentric pins,and welded those - still a dumb solution.
It is FAR better to have a light fit in your Mallory and tig melt a couple of small arcs of weld for retaining it, than having to use any excessive press that automatically creates a stress concentration.

[wobbly]

I have never measured them but the best looking 250 cylinders I have seen are a GasGas and an older TM250MX

[peewee]

wob i havent got to engmod yet but i almost have the sides back on. it wont win any beauty awards but if it holds water ill be happy :laugh:

[husaberg]

Dunelt.

No crankcase.
High transfers.
313829313834
Oyster used to have one.
I have Pm' ed him for some info

I have thrown in a pic of the SPX piston single piston
313845

1,171,767. Two-stroke engines. B. HOOPER and J.E. FAVILL. March 3, 1967 [Dec.4, 1965], No.51564/65. Heading F1B. The pump part 15 of a stepped-piston twostroke engine forces the charge on the upstroke through port 32, controlled by a recess in the piston, into a receiver 30. Near the bottom of the piston downstroke, the top of the working part 14 of the piston re-opens port 32 to allow the charge to flow from the receiver 30 into the cylinder for scavenging and charging. The inlet passage 21 of the pump portion 15 is connected to a carburetter and contains reed valves 22 or a cam-actuated valve. The receiver 30 may comprise more than one chamber and the total volume of the receiver is at least three times the pump swept volume. In a multi-cylinder engine one receiver space 30 may serve two adjacent cylinders.


Hi John,

Might be an idea to go to the attached link and printing a copy of the front page of GB Patent # 1171767

The extract is from one of the patents that my colleague and I invented, is shown on the link. This is a two stroke engine with the induction process and the working chamber separated completely from the lubrication process. The lubrication to the piston is dependant upon piston ring technology as present four stroke engines thus preventing lubricating oil being part of the combustion process..

This is the single cylinder version which was derived from our original multi-cylinder version which foillowed the principle that with a two stroke engine it is essential to separate the working part from the lubrication system. The multi cylinder is more obvious in that one pumping chamber transfers into the adjacent working chamber.
This single cylinder version is less obvious but follow through with this description of the cycle.

As the piston moves down air or an air fuel mixture is pulled into the chamber with the larger diameter of the "stepped-piston" then on the up-stroke is transferred into the side reciever volume as the piston moves towards TDC. Then as the piston moves down again through side ports in the cylinder the charge contained in the receiver is transferreds to the cylinder volume above the smaller diameter of the piston. As the piston moves back towards TDC the charge is compressed to be followed by ignition.

The drawing on the patent indicate the working volume is identical to the pumping volume as is the receiver volume. So if one uses logical reasoning we have the following.

One volume is pumped into one volume and expected to be transferred into one volume. How can that work?

When we invented the engine we argued with ourselves that the engine could not possibly work yet our instinct said it would. Calculations could not prove one way or another but we submitted the patent application on the assumption that our instinct, as engine designers, was correct. The only way to prove it one way or another was to build a prototype. We did it on a shoestring as Bernard and I were self employed designing all kinds of things such as ice cream cone manufacturing machines ( I kid you not) other than engines to earn money, and in our spare time we designed engines in accordance with our thinking. I made all the necessary wood patterns, mainly from chipboard, at home. We had the castings made and the machining done and paid for. We "borrowed" certain parts from Villiers which had been taken over during our time self employed, and had become Norton-Villiers. When we finally had all the parts I assembled this prototype engine on the kitchen table at Bernard's house. This was a prototype single cylinder engine with a capacity of 150ccs and we had made twin reciever volumes from standard air cylinders with sealed movable by hand pistons , like large bicycle pumps, each 10 times the swept volume of the single cylinder engine. When ready we took this strange looking engine into the back garden, placed the engine on a concrete slab, wound a length of cord around the crankshaft pulley and then, making sure we had petrol getting to the carburettor, I pulled the cord and although the engine turned over, nothing happened. So I wound the cord around the pulley again then pulled again. The engine started and ran. We all danced around the garden as our instinct had proved to be correct, although we still had no idea why it worked.

We had been invited to cease being self employed and begin an Advanced Development department at Norton-Villiers by the new managing director of the new company based on a recommendation by the Managing Director of Cotton Motorcycles, Monty Denley, and the raft of patents we now had on new engine designs. The idea was that we would work on these new ideas of ours with the object of Norton-Villers producing the results of our research under royalty agreements. We duly returned to the Villiers factory where we had left some 12 months previously and began working on our single cylinder engine. Our work led us to discover the capability and the potential of our engine although we never managed to develop the theory of why it worked. We realized that in some way gas dynamics played a part, but we never did discover how they did. We found as we increased the reciever volume the power ouput of the engine increased. We gradually increased the reciever volume until we reached a volume of 5 imperial gallons, as we would utilize any suitable container in our experiments. So by using a 5 gallon container we were pumping a volume of 150ccs into a volume of 22730 ccs which then was transferred back into 150ccs of the working chamber of the engine.
Everything was going well until the 5 gallon container of gasoline/air mix exploded. Luckily although we were standing close to the engine controlling the Heenan and Froude dynamometer and parts flew everywhere bedding themselves in the noise reducing wall tiles, all the parts missed us. We had realized this was a possibility but the experiment was all important and finding the limit of the reciever volume was our aim. With air only and injecting the fuel into the combustion chamber was the solution and we knew that was the way to go. But events took over.

We wanted to made a prototype diesel engine version and experiment with increasing the ratio of working volume to pumping volume. And all manner of ideas, but the gods had different plans for us. Norton-Villiers had taken over the bancrupt AMC company that made Norton, Matchless and AJS motorcycles. AMC management had stated they had a new motorcycle engine all ready to be put into production and painted a rosy picture. The truth was totally different.
The engine was a terrible design so the new owners of Norton-Villiers needed a new motorcycle to replace the antiquated products. Bernard and I were approached by the Managing Director who had invited us to join the new company, and asked us if we would cease our work on our engines, form a design team that would have the task of designing a practical new motorcycle as otherwise there was no future for the company.

The end result was the Norton Commando, the prototype of which we did in three months.

When the dust has settled and the Commando was a success Norton-Villiers turned to thoughts of new future products. The company produced one of our engine designs in accordance with Hooper-Favill patents and production began. This engine was called the "Vertex". A verticle shaft lawnmower engine with a capacity of 150ccs, a two stroke but with differences defined by our patent. I have a brochure somewhere that state the engine is in accordance with Hooper-Favill Patents The company also approached the National Research Development Corporation ( NRDC) and an agreement for financial support was reached for a new motorcycle design using Hooper-Favill patents for the multi cylinder stepped piston engine. This came all too late to reach production as before development was finalized and the company ceased trading, which is long sad story in itself. The prototype motorcycle called the "WULF" is now in the British Motorcycle Museum in Birmingham.

My colleague and myself the re-formed our design and development company, rented test facilities and office space and continued our engine design consultancy. We continued development of our stepped piston engines and when the manufacturing machine tools and assembly line for the Vertex engine was purchased by a mower manufacturing company we became consultants to the company on the production and engineering side under conditions defined under a royalty agreement. The company was Mountfield Mowers of Maidenhead in Berks.

In 1978 I visited the US in an attempt to interest Briggs and Stratton and Harley-Davidson in our engine designs. This visit was done with the support of the NRDC and the end result was that Briggs were not interested in our engine ideas and neither was Harley-Davidson but Harley made an offer I couldn't refuse and because of numerous reasons I finally agreed to join Harley and my colleague and myself parted ways although we remained friends and through my efforts I was able to get three design contracts, two from Harley and one from another Wisconsin company for design work to be done by Bernard. Bernard continued with the design and development for many years and I always met with him during my visits to England. This ended suddenly when during a visit to England I had arranged to meet with him together with an ex Norton-Villiers colleague and we were to have lunch together. Our ex-colleague met me at our agreed meeting location with the sad news that Bernard had died suddenly.

So now to comments about the engine as part of the Deltic.

The need is to separate the power developing bit from the bit that need lubrication. The use of Stepped pistons would provide the answer. I have doubts about the use of the long con-rod for the second piston and I would guess it brings problems unique to it's use. Gear , chain or toothed belt might be worth looking at . Using stepped pistons, fuel injection and the uniflow two stroke design would produce a very light engine and using a single reciever for both pistons would be easy to do although work on gas dynamics would be necessary. The crank support bearings, big and small end etc. could be lubricated in the traditional manner as a four stroke engines and lubrication of the piston, both diameters would follow four stroke practice with compression, oil control and scraper ring technology. Any liquid fuel that could be injected into the combustion chamber could be made to work but the most efficient would be a using a diesel cycle.





313828

another variation on stepped pistons
http://patentimages.storage.googleapis.com/pages/US5797359-1.png
http://www.google.com/patents/US5797359

[oyster]

The dunelt I race is a sturmey archer 4 stroke. I do have a dunelt 250cc 2 stoke though, it has the double diameter piston giving the "supercharging". Around 1925 dunelt ran a 500cc like this at the IOM. It was a sidecar, prob needed to carry the huge amount of fuel!!!

[husaberg]

The dunelt I race is a sturmey archer 4 stroke. I do have a dunelt 250cc 2 stoke though, it has the double diameter piston giving the "supercharging". Around 1925 dunelt ran a 500cc like this at the IOM. It was a sidecar, prob needed to carry the huge amount of fuel!!!

Do you have any pictures of the internals of the Two Stroke Pete?

They used to run advertising with a little gimic of Professor Supercharge.
I will add some scans later

http://ww3.tiki.ne.jp/~hwata/Images/Hunslet/201110/ValveMotion.gif

[chrisc]

Because it's the cheapo solution. The crankshaft shown in my previous post is from the Honda RS250 production racer. The crank webs are forgings with the material distributed correctly for balancing. But that would leave a clobbered external shape, so a tin cover is pressed around the lot.
The crankshaft below is from the NSR500. That was a works racer; no tins there...
313758

Cranks with 'tins', are they able to be rebuilt without destroying the tins?
Is it false economy to try rebuild one of these types or cranks?

Sorry for the newbie questions, someone has to ask don't they? :sweatdrop


So here it is as simple as can it be made - NO STEP IS BEST - but this does NOT mean grind the duct to make it round OR bigger in any way....

Wobbly, I've been binging on the ESE thread again and only just realized how many times you have reiterated this point and the 75% triple, 90% single rule of thumb. In fact I found a mention of it back in 2011 of the ESE thread from yourself. Sorry for asking AGAIN instead of searching the thread. Always appreciate the time you all put into this thread, it's the best!

[190mech]

Ken Oconnor racing has a good video on rebuilding tin can cranks,he cuts the rod and pin in half for easy removal..

https://www.youtube.com/watch?v=hs5Au5rrlUw

[ken seeber]

The Honda 2 stroke has made it to Gizmag, a really good broad technology site with 6 to 10 new things daily. Of course, not as good as kiwibiker though. :laugh:

See http://www.gizmag.com/ and the feature is dated 19 July.

[Lightbulb]

Does anyone here know of a source for round bar in 300M steel or E4340AQ steel, something bigger than 16mm diameter
so I can have a go at making some steel rods. I am after like a 1m length or what ever they will sell, as long as I don't have to buy a mill run.
Thanks
Neil

[136kg136ps]

Thank Wob,I'll see what I can dig up on them.Thanks again bucketeers.

[Grumph]

Does anyone here know of a source for round bar in 300M steel or E4340AQ steel, something bigger than 16mm diameter
so I can have a go at making some steel rods. I am after like a 1m length or what ever they will sell, as long as I don't have to buy a mill run.
Thanks
Neil

My first call for that stuff used to be Atlas Steel here in ChCh but they've changed hands and dumbed down...still worth a call.
I have also used Special Steels & Metals Ltd again here in ChCh.
There must be someone in the Hamilton area, I know a guy who works for Les DeLacy who makes a lot of crankpins for classic motors. Les' core business is aircraft engineering for which they need access to the good materials...

[speedpro]

Heat Treatments might be worth a call as well. They have a huge machine shop making interesting stuff so may have a small pile of useful steel.

[teriks]

<snip>
The MB40 engine has 190°/130° timing, like you would expect from any decent two-stroke.
Some people run them close to 200° exhaust timing nowadays with good results.
Modified in the simplest way, shim under the cylinder.



I don't recall the rotary inlet timing of the hollow crankshaft shown below but it will probably be something like 140°/60°. That may seem tame and it is; this is not a high-revving engine :msn-wink:. It doesn't exceed 35000 rpm and then the mean piston speed is only 23 m/s. Compare that to 26,3 m/s for an Aprilia RSA (or 54 m/s for a Ryger).
Anyway, I feel that this kind of shaft rotary inlet for model engines is a fashion thing more than anything else; I wouldn't be surprised if simple piston port induction would perform better (it would certainly flow better).

I dont run the shaft intake myself, but have 138°/65° on file for that one.
Piston port, now that's an interesting thought, in my opinion mostly from a friction point of view.
Might have to visit that idea in Engmod...

[wobbly]

Does anyone have a PWK38 NON Airstriker carb that i could use for a dyno test on CR125.
Both PWM and PWK carbs are legal for SKUSA racing.
No one uses the old longer PWK so thats a good reason to try one.

For anyone still wondering about steps ( or not ) in the Ex or if a race plug is worth buying then this dyno sheet should
give you the idea.
Green is a straight round spigot with steps, brown is a CNC oval/round transition,red is the same transition but replacing the R7376-10
plug with what is commonly used alot in USA, a BR9EIX.
The transition needed 2 jets leaner to hit the same 650*C egt in the tests.
It might cost 4X the price but the race plug is the cheapest 1Hp gain in a box stock engine you can buy.

[F5 Dave]

Sorry just a 35 but I just stole the turret to fix a damaged needle jet on my 39A/S, same part it appears.

Wow that is a pronounced change in the transition modification. Don't suppose you have a before & after picture?

Why do you think there is an improvement with the racing plug? Appears after 11k onward where combustion pressure comes to a peak but continues well after indicating that it could well be a time of combustion product.

My experiments on a 40mm bore showed no improvement in my bike & 1hp on a mates which had a super flat & shrouded chamber, both were around 13hp at 12k back in the day. Recent tests have been similar but my experience with these plugs is minimal. Perhaps the tiny bore size underrepresents the improvement potential. Clearly in your case it is well worth it.

[wobbly]

Sure - here are the two manifolds.
The plug result just confirms that having a rare earth fine wire center AND a fine wire platinum ground electrode makes the ignition
power required to initiate ionization under heavy compressive loads is way less with the race plug , when compared to the simple iridium
plugs cast iron plank hanging off the side of the body.
The dyno doesn't lie - check the overlay at the bottom of the curves, near as damn it identical in the range where the plugs efficiency makes no difference.

[speedpro]

The plug result just confirms that having a rare earth fine wire center AND a fine wire platinum ground electrode

Funnily enough that is the configuration of the standard plugs in my car. Makes you wonder.

[F5 Dave]

Thanks. So the barrel was a convenient oval shape, I was expecting there to be some bored into the port to get to that point. But you said there was a step so that looks like a good comparison. . . . And largely like my barrel once I'd welded a new tunnel area in exposing the oval and leaving a step top and bottom, next test was to be a transition. Those results make me excited.

One wonders how far away from the piston this transition should be and effectively start the header.

[husaberg]

Dunelt again

seems a simple way to have No dirty crankcase nor any need to seal of the crankcase.
So if it was set up as a single without a wet crankcase would the inlet mixture actually be compressed twice.
once under the piston then again prior to entry into the transfers?

313861313862313863313864313865

Plus an internal drawing of the Garelli twingle
313866

[jonny quest]

Wobbly, who sells yhat manifold?

[wobbly]

This 125 engine only just cracks 40Hp so isnt really stressing the conventional ignition that much, but as soon as things get tough
the good plugs configuration makes a difference.
A low bmep engine with rezo spark would as you say make bugger all difference, as it simply doesnt need the extra grunt.
When you really stress the hell out of the system, as in the Aprilia where simply changing to a bigger coil made more power, or when running
big com on rich methanol engines the power difference can be really worthwhile.
Ages ago my best TM125MX kart engine went up 2Hp to around 50 when changing from a BR10EGV.

The manifolds for the 2001 CR125 I had 3 very different ones CNC made direct off my solid models.
I modified the best one by hand grinding,then got that digitized and remade properly.
Not a cheap exercise doing small runs and one offs, but I was a few favours owed by a CNC workshop manager.
But when you want to win a box stock World Champ class thats what you need to go to, the customer is smiling ear to ear at the moment,
but hasnt got the invoice yet.
Ive been thru 50L of C12 at $8 a litre on the dyno and I aint finished.

Still searching for a 38PWK - anyone

[Haufen]

Still searching for a 38PWK - anyone

I should have one somewhere that you can borrow, but it's located in Europe. I have no plans with it for the next 2 month or so, but I have no idea about shipping time and cost to NZ. But as long as the package is not too heavy, it's not overly pricey sending around the globe as far as I remember.

[jonny quest]

I figured it was one off... i have a couple of CNC machines. .. but sometimes it's cheaper to just buy them.

[F5 Dave]

Is there any rule of thumb for where the transition should be from the piston face?

A manifold could be as short as 50mm, but a PV arrangement could be considerably longer and at what point does one start the header or delay the process by doing transition in the manifold?

[husaberg]

I was looking for a short closed 54mm piston with a low crown height and came across this.
Its an old McCulloch
look the closed gudgeon /cover any ideas how this is done?
It appears to be missing one or only on one side.
http://www.ebay.com/itm/McCULLOCH-CHAINSAW-1-46-PISTON-AND-CYLINDER-54MM-/360321382696
313884313885

[F5 Dave]

That's lovely I think you should use it Husa. 2nd hand all the better.

[wobbly]

Already answered the question about the Ex duct and transition point.

http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130882629#post1130882629

[F5 Dave]

Ahh yes you certainly did, I was on holiday and pretty hungover whilst reviewing that & paying too much attn. to trying to be funny & not enough learning.

I read that as - assuming a 50mm bore one would start the header proper at 100mm, with the last 25mm as the transition.

Thank you again.

And my port is too short. But I can make it up with extensions. Story of my life.

[Lightbulb]

Thanks for the chat.

[ken seeber]

313908313909313910313905313906313907

A “ROUGH AS GUTS” EXPERIMENT Part 1

The question is, what happens when you:
1. Get a 100 cc ARC piston port kart engine, essentially very similar and with many interchangeable parts with the Yamaha KT100S kart engine, and connect an A port to atmosphere via a filled in passage to a flanged face. Height of the port is unchanged from the original engine.
2. However, when at TDC, there is a direct passage (something we don’t want, do we?) to the crankcase via the cut-out in the side of a regular piston
3. So we weld a small piece into this side of the piston to block it off and while we are there we’ll drill a series of holes into the rear of piston to vent thru the open piston port inlet so there’ll be no great pressure fluctuations in the crankcase


Part 2 coming

[ken seeber]

313911313912313913313914


A “ROUGH AS GUTS” EXPERIMENT Part 2

4. So there’s no influence due to extraneous cylinder connected volumes in the upper cavities of the blocked off transfer passages (1 * A & 2 * B), we fill these flush with Silastic
5. Then we bolt it all together with a carb, but with no exhaust system
6. Crank it over with a few squirts of oil into the crankcase, check it out and it is all nice and oily, as one would expect with a wet sump.
7. Fill the carb with fuel only (no oil), ignition on and crank it over.

Simple really and I did say “rough as guts”.

WODDAEWESREKKON happens then?

[Frits Overmars]

when at TDC, there is a direct passage (something we don’t want, do we?)If you keep that direct passage, the transfer windows can double as piston controlled inlet ports and you could feed a rear transfer port from the crankcase.
But since you don't want that, I assume that you wanted to completely exclude the crankcase from the mixture flow. I then also assume that there's a puddle of oil in the crankcase to keep the bearings happy. EDIT: only now did I see your second post: a puddle it is.
we’ll drill a series of holes into the rear of piston to vent thru the open piston port inlet so there’ll be no great pressure fluctuations in the crankcase.What's wrong with pressure fluctuations in the crankcase? The built-up pressure that tries to prevent the piston from moving down, will be helping it again on the way up. I anticipate a lot of pumping losses and a lot of oil mist escaping through those drilled holes.
To comfort you, here's a picture to show you that you're not the only one suffering from ludicrous ideas :msn-wink:.
313915

[husaberg]

If you keep that direct passage, the transfer windows can double as piston controlled inlet ports and you could feed a rear transfer
To comfort you, here's a picture to show you that you're not the only one suffering from ludicrous ideas :msn-wink:.


Frits if will indulge me to go back a few pages you will see I added a bit to my post 18608

There is a question in there that I think you can answer.

[Frits Overmars]

Frits if will indulge me to go back a few pages you will see I added a bit to my post 18608. There is a question in there that I think you can answer.I saw the added text, but I did not see a question....

[ken seeber]

If you keep that direct passage, the transfer windows can double as piston controlled inlet ports and you could feed a rear transfer port from the crankcase.
But since you don't want that, I assume that you wanted to completely exclude the crankcase from the mixture flow. I then also assume that there's a puddle of oil in the crankcase to keep the bearings happy. EDIT: only now did I see your second post: a puddle it is.What's wrong with pressure fluctuations in the crankcase? The built-up pressure that tries to prevent the piston from moving down, will be helping it again on the way up. I anticipate a lot of pumping losses and a lot of oil mist escaping through those drilled holes.
To comfort you, here's a picture to show you that you're not the only one suffering from ludicrous ideas :msn-wink:.
313915

No puddle, just creating an aerated mixture as in Honda's string trimmer crankcase to achieve muilti angle/position lubrication. Attempted to minimize the fluctuations in crankcase as we don't have an oil scraper at bottom of piston, otherwise it'd be sealed, maybe just with an external catch tank

PS. I've always liked the SWSports engine :hug: and do concede that, basically everything has been invented before.

[husaberg]

I saw the added text, but I did not see a question....

It was more a question from the guy that created the engine.........
Why does it go better the bigger the chamber is made, did you notice how big in Gallons the surrogate crankcase was.
I have a theory as to why. but most of my theories are pretty far fetched.

[Frits Overmars]

It was more a question from the guy that created the engine.........
Why does it go better the bigger the chamber is made, did you notice how big in Gallons the surrogate crankcase was.I had a hunch that this would be it:
We found as we increased the reciever volume the power ouput of the engine increased. We gradually increased the reciever volume until we reached a volume of 5 imperial gallons, as we would utilize any suitable container in our experiments. So by using a 5 gallon container we were pumping a volume of 150ccs into a volume of 22730 ccs which then was transferred back into 150ccs of the working chamber of the engine.My feeling was that they only used the piston pump to draw air through the carburettor and then dumped the mixture in a huge vessel, from where the engine could breathe as if it were the atmosphere. You know, the bigger the vessel, the smaller the pressure drop when the engine inhaled (did someone say 24/7?)
I was surprised that they could get away with a 5 Gallon volume. I would have expected the fuel to drop out because of the almost stationary state of the mixture in the vessel.

[Frits Overmars]

Attempted to minimize the fluctuations in crankcase as we don't have an oil scraper at bottom of piston.You could try fitting a reed valve inside-out at the inlet port. That would lower the average crankcase pressure and reduce the pumping losses.


otherwise it'd be sealed, maybe just with an external catch tank.Well well well...
313916

[cotswold]

ESE's number 1 works rider has scored herself a ride at Suzuka on board this Beast, moonlighting must be ok

[Martin1981]

Hello Everyone!

Frits and Wobbly,

i want to modify a Simson Cylinder (40mm Bore, 44mm Stroke) for daily use (not looking for big hp) and have 2 Questions regarding that:

1. Is a Combination of 150° Inlet Duration (Piston Port), 125° Transfer Duration and 170° Exhaust Duration okay or is there a Mismatch?

2. I will use a 20mm Carburetor, meaning a 314 square mm cross section area. the inlet port is 10,6 mm high and 28,6 mm wide, meaning about 303 square mm cross section area.

is it necessary or better if the inlet port area is bigger than the carburetor area? and if so, how much? i am asking because i could just shorten the piston inlet skirt to achieve the 150° duration and leave the port and it`s area alone. But what is better in your opinion? enlarging the port or shortening the piston? one could think enlargening the port is better but on the other hand shortening the piston skirt makes the edge of it stay away longer from the port and thus not disrupting the flow (if there is a flow) when the piston travells down from TDC.

Thanks in advance! (as usual, opinions of all other forum members highly appreciated!)

[husaberg]

I had a hunch that this would be it:My feeling was that they only used the piston pump to draw air through the carburettor and then dumped the mixture in a huge vessel, from where the engine could breathe as if it were the atmosphere. You know, the bigger the vessel, the smaller the pressure drop when the engine inhaled (did someone say 24/7?)
I was surprised that they could get away with a 5 Gallon volume. I would have expected the fuel to drop out because of the almost stationary state of the mixture in the vessel.

I was rather surprised it was that big, My own theory was that at lower rpm the tank was actually storing some pressure as well as mixture and as you said providing a large volume to breath from. It could have some very good emissions if used as FI engine, if it was storing unused low RPM pumped volume that might other wise be sent out the pipe.

[Muciek]

Hello Everyone!

Frits and Wobbly,

i want to modify a Simson Cylinder (40mm Bore, 44mm Stroke) for daily use (not looking for big hp) and have 2 Questions regarding that:

1. Is a Combination of 150° Inlet Duration (Piston Port), 125° Transfer Duration and 170° Exhaust Duration okay or is there a Mismatch?

2. I will use a 20mm Carburetor, meaning a 314 square mm cross section area. the inlet port is 10,6 mm high and 28,6 mm wide, meaning about 303 square mm cross section area.

is it necessary or better if the inlet port area is bigger than the carburetor area? and if so, how much? i am asking because i could just shorten the piston inlet skirt to achieve the 150° duration and leave the port and it`s area alone. But what is better in your opinion? enlarging the port or shortening the piston? one could think enlargening the port is better but on the other hand shortening the piston skirt makes the edge of it stay away longer from the port and thus not disrupting the flow (if there is a flow) when the piston travells down from TDC.

Thanks in advance! (as usual, opinions of all other forum members highly appreciated!)

But what are the rpm's that are You aiming for? You are want to use 2 transfers or more? Around 500 page there was link for Porting calculator You could use it for calculating STA's if You cannot afford engmod. As for pipe since You want very broad powerband I would try to play with origninal pipe but change the cone position and volume behind it to match the tuned lenght (the origninal DDR pipe it's vevey type, later ones and those made right now are other design as far I have seen)

[lodgernz]

As the Ex height has a big influence upon the trapped dynamic com, I use the trapped ratio.
For your air cooled 125 on AvGas a ratio of 7.4 will work reliably no matter where the port is.

Wobbly, can I assume the trapped ratio you refer to is the CR calculated from exhaust closing rather than the simple geometric CR based solely on swept volume?
If so, do you have a guideline for a water cooled 100 on 98 pump gas?

[wobbly]

The trapped ratio takes account of radical differences in Ex port height, but when dealing with your normal race engines
the Ex port is usually in a fairly small window of timing.
Thus your 100 on Avgas could quite happily go around 16.5 full stroke CR, 98 pump would be pretty much maxed out at 15.5.

Re Martins engine details, again I reiterate that without actually doing a proper analysis its all just wild gestimation that would serve no one any good at all.

[41juergen]

It will be interesting to see where you get too Juergen.
I'd love to see 80+ from my TZ250 (not TZR); while I have a few spare TZ barrels, much rather tinker (likely destroy) some of the 3xv sp barrels (given they are not rocking horse shit).
While you say the parts are exactly the same - there is a number of differences in the port layout and time areas.

Of course most of the parts are (slightly) different, but if you go into EngMod you will get a good advise were to look into. Most power you will get when following what Wob and Frits are praying about the exhaust duct, next is (surprisigly at least for me) the reed setup and finaly a bit the exhaust incl. the venturi at the end of the conus. The sim predicts a plus of 5 HP on that....
But finally only the dyno will tell you the truth. :2thumbsup

[lodgernz]

Thank you Wobbly. Useful advice as always.

[TZ350]

313942

On my way home I saw this pile of junk put out for the rubbish collection. I recognized that the crank was from a two stroke and grabbed it.

313943313944

Center main reed valve and split big end bearing and deflector top piston. My guess is, its from an old 2T Mercury V6 outboard.

313941313940

There had been an old Lola fitted with a 6 cylinder 2T boat engine, well it went pretty good so it was Banned of course ......

Possibly the most unusual T294 to have competed is Pietro Raddi's car, HU81, which is powered by a 2-litre Mercury engine from a powerboat.

http://www.lolaheritage.co.uk/history/register/t294/Raddi/t294_01.htm

FEDERACION ESPANOLA AUTOMOBILISMO: the first year they were looking, but the year after decide to change the rules, and write a new article in the GR6....ENGINE HAS TO BE 4T!. Because many drivers were claiming against me and the 2T's power."



More on the the stepped piston concept, looks like an existing 2T could be adapted to it Ok.

R&D of the novel concept of the stepped piston engine.

The primary objective of this project has involved a demonstration of the low oil consumption characteristics of the stepped piston engine. The support enabled the design and build of a single cylinder 150 cm3 SP engine and this is shown above as a modification to an existing motorcycle crankcase and gearbox assembly. The original 125 cm3 crankcase scavenged "base" engine can be seen below.

http://users.breathe.com/prhooper/mcycle.htm

[peewee]

finished the exh roof tonight

[Grumph]

There had been an old Lola fitted with a 6 cylinder 2T boat engine, well it went pretty good so it was Banned of course ......

There was a single seat special built here in NZ, I think for our domestic 1500cc formula. OMC V4 powerhead from memory.
I never saw it run but i've seen it written up, I'm sure Husa could find the info. Car may have been called the Spider...

[husaberg]

There was a single seat special built here in NZ, I think for our domestic 1500cc formula. OMC V4 powerhead from memory.
I never saw it run but i've seen it written up, I'm sure Husa could find the info. Car may have been called the Spider...

Id rather post pics of Colin Listers V engines.

[Flettner]

313911313912313913313914


A “ROUGH AS GUTS” EXPERIMENT Part 2

4. So there’s no influence due to extraneous cylinder connected volumes in the upper cavities of the blocked off transfer passages (1 * A & 2 * B), we fill these flush with Silastic
5. Then we bolt it all together with a carb, but with no exhaust system
6. Crank it over with a few squirts of oil into the crankcase, check it out and it is all nice and oily, as one would expect with a wet sump.
7. Fill the carb with fuel only (no oil), ignition on and crank it over.

Simple really and I did say “rough as guts”.


WODDAEWESREKKON happens then?

Well what? Bets please, on what the outcome might be;)

[Flettner]

313942

On my way home I saw this pile of junk put out for the rubbish collection. I recognized that the crank was from a two stroke and grabbed it.

313943313944

Center main reed valve and split big end bearing and deflector top piston. My guess is, its from an old 2T Mercury V6 outboard.

313941313940

There had been an old Lola fitted with a 6 cylinder 2T boat engine, well it went pretty good so it was Banned of course ......

Possibly the most unusual T294 to have competed is Pietro Raddi's car, HU81, which is powered by a 2-litre Mercury engine from a powerboat.

http://www.lolaheritage.co.uk/history/register/t294/Raddi/t294_01.htm

FEDERACION ESPANOLA AUTOMOBILISMO: the first year they were looking, but the year after decide to change the rules, and write a new article in the GR6....ENGINE HAS TO BE 4T!. Because many drivers were claiming against me and the 2T's power."



More on the the stepped piston concept, looks like an existing 2T could be adapted to it Ok.

R&D of the novel concept of the stepped piston engine.

The primary objective of this project has involved a demonstration of the low oil consumption characteristics of the stepped piston engine. The support enabled the design and build of a single cylinder 150 cm3 SP engine and this is shown above as a modification to an existing motorcycle crankcase and gearbox assembly. The original 125 cm3 crankcase scavenged "base" engine can be seen below.

http://users.breathe.com/prhooper/mcycle.htm

Yes, they might well want to ban twostrokes, especially now with the new found clean burn and LOADS of HP!
I think that's a straight six (your parts you found)

[TZ350]

Straight six, yes I think you are right.

313957

[seattle smitty]

The crank in the photos is from a Mercury inline six, but (guessing) about fifteen years and one design-generation newer (early '70s) and with 40-50% more displacement than the red Mk78 (about 1958) in the photo. The car has a V-6 that's a good ten years newer yet. If you're into this old stuff, the last generation of crossflow Mercs was called "Direct-Charge;" google that term for photos of the somewhat unusual piston.

On Pg. 78 of The Bucket Foundry thread is some talk about an oddball outboard project; Flettner, I think the crank you picked up might well be the one that Dick Austin is using in his homebuilt motor (which however is loop-scavenged, not crossflow).


(LATE EDIT) Oops, not Flettner, TeeZee!!!! Sorry!

[Lef16]

Hello guys
Frits has already explained about port directions and axial angles.
Aprilia A-ports had about 28* axial angle and B ports had 7*.What about the opposite?
I was watching old Yamaha cylindes(B ports directed upwards and A ports are perpendicular) I was wonderining what effect will these axial angles have with A ports having more duration (no exhaust power valve).
Cheers!

[wobbly]

All latest generations of engines with normal stagger ( A port first ) have the same axial relationships as the Aprilia.
Flat A ports are long dead.
Welding the roof corner is needed in the Yamaha B port to flatten it out as it goes into water, the A port simply needs epoxy
to fill in the top radius and increase the upward tilt.
The C port is always in the 50 to 60* range, depending upon the end use, the bore/stroke, and the port width in relation to the B width.

[Flettner]

The crank in the photos is from a Mercury inline six, but (guessing) about fifteen years and one design-generation newer (early '70s) and with 40-50% more displacement than the red Mk78 (about 1958) in the photo. The car has a V-6 that's a good ten years newer yet. If you're into this old stuff, the last generation of crossflow Mercs was called "Direct-Charge;" google that term for photos of the somewhat unusual piston.

On Pg. 78 of The Bucket Foundry thread is some talk about an oddball outboard project; Flettner, I think the crank you picked up might well be the one that Dick Austin is using in his homebuilt motor (which however is loop-scavenged, not crossflow).

The rod with the beam, page 78? That's a rod, and I am using a crank from, a 250 four 4T to make an oil less twostroke. Will be using the FOS concept (sort of). It's being machined out of solid plate as I wright. Is using a "leagal" pressurised crank case.

[ken seeber]

Well what? Bets please, on what the outcome might be;)

I can understand that many of you have been holding your breath, just waiting, so, to avoid any further suffocations, I am happy to say it works.
However , working to the level of 70 hp @ 18k, it might take a tad more effort. There's some weird phenomena going on that I've gotta get my head around. But after that, I'm going for 80hp. :violin: Sorry Harry.

[breezy]

I can understand that many of you have been holding your breath, just waiting, so, to avoid any further suffocations, I am happy to say it works.
However , working to the level of 70 hp @ 18k, it might take a tad more effort. There's some weird phenomena going on that I've gotta get my head around. But after that, I'm going for 80hp. :violin: Sorry Harry.

Ken ,any chance you could be more specific?? or are you holding yourself back because of legalities :bleh:

[Flettner]

Anyone here friends with BRC karts? I'm after one of their pistons, for the sleeve engine. 24mm crown height from the gudgin pin center.

[Lef16]

Welding the roof corner is needed in the Yamaha B port to flatten it out as it goes into water, the A port simply needs epoxy
to fill in the top radius and increase the upward tilt.
I think epoxy is also good for inner radii!Does it work?Did you test it?
What brand should I trust?
Cheers

[Haufen]

Ken ,any chance you could be more specific?? or are you holding yourself back because of legalities :bleh:

I think I got something here. Remember, the RSA had a carburetor from the garden sized 43mm and 54hp @ 13000 rpm. Then along comes the Ryger with 18000 rpm and a carburetor from the garden sized 30mm. Now in Ken's picture, guess what's there! Exactly, an even smaller carburetor from the garden! This can not be coincidence! I can not say for sure which number there is on the carb, but if it's anywhere near the 19 I think I could decipher on that carb, then this thing should have the potential for triple digits, for sure!
:eek5::rockon:

[husaberg]

Anyone here friends with BRC karts? I'm after one of their pistons, for the sleeve engine. 24mm crown height from the gudgin pin center.
try rick he is spanering Superkarts with a Aprilia clone DEA?

Hello all, great forum, great to see a bunch of enthusiest sharing ideas, knowledge & encourigement

My question, can anyone assist with the direction to the page where Frits Overmars mentioned, fuel pump type / site link, pressure ect upon the Aprillia

Cheers all, keep up the great sharing of a common interest, Without competers we all LOOSE

[Frits Overmars]

Anyone here friends with BRC karts? I'm after one of their pistons, for the sleeve engine. 24mm crown height from the gudgin pin center.Neil, the man to talk to at BRC engineering is Riley Will: http://www.brcenginc.com/contact.html
Other possibilities are
Andrea degli Esposti of DEA, deaengineering@gmail.com
and
Francis Payart of FPE, f.p.e@wanadoo.fr.

You can give those guys my regards, and they may still help you :msn-wink:.
Francis is even a kiwibiker forum member, so you could send him a PM, but I don't know how often he takes a look here.

24 mm from gudgeon pin center to tip sounds familiar. The Aprilia RSA and RSW had either 24 mm or 21 mm.
Try Asso and Vertex in Italy; both of them supplied the Aprilia racing pistons.

[peewee]

wobbly you ever tried this stuff ? i got some the other day as i figure now the cylinder is located 6mm higher and wider sides with the pieces i welded over the water jackets it puts the head and cylinder much closer to the fuel tank underside. a heat barier on the fuel tank bottom couldnt hurt i guess

http://www.ebay.com/itm/DEI-010396-2-SELF-ADHESIVE-REFLECT-A-GOLD-HEAT-WRAP-BARRIER-TAPE-15-FEET-ROLL-/281255854588?hash=item417c27c1fc&vxp=mtr

[Flettner]

Neil, the man to talk to at BRC engineering is Riley Will: http://www.brcenginc.com/contact.html
Other possibilities are
Andrea degli Esposti of DEA, deaengineering@gmail.com
and
Francis Payart of FPE, f.p.e@wanadoo.fr.

You can give those guys my regards, and they may still help you :msn-wink:.
Francis is even a kiwibiker forum member, so you could send him a PM, but I don't know how often he takes a look here.

24 mm from gudgeon pin center to tip sounds familiar. The Aprilia RSA and RSW had either 24 mm or 21 mm.
Try Asso and Vertex in Italy; both of them supplied the Aprilia racing pistons.

Thank you, again.

The sleeve engine has been sitting waiting for me to build a piston, so I decided to build a blank and see what was required (no drawings, the engine just evolves as I go), to my good fortune it would seem I can use a ready made piston (as above request) but just modified a bit. This has put the sleeve engine "back on the burner" as it were.
This is NOT the oil less engine as this sleeve engine will consume a lot of oil I think (like the Crecy).

[wobbly]

For smaller jobs J B Weld is a great epoxy for ports.
Better for bigger filling jobs is Devcon F.

I have used the same type of reflective tape around kart fuel tanks, and airboxes to stop heat buildup - seems to work fine but have
not used the gold stuff before.

[husaberg]

Thank you, again.

The sleeve engine has been sitting waiting for me to build a piston, so I decided to build a blank and see what was required (no drawings, the engine just evolves as I go), to my good fortune it would seem I can use a ready made piston (as above request) but just modified a bit. This has put the sleeve engine "back on the burner" as it were.
This is NOT the oil less engine as this sleeve engine will consume a lot of oil I think (like the Crecy).

Piston pour TM K7 e Vortex, TM 10050
not quite
313974
http://www.superkart.it/index.php?main_page=index&cPath=92_108


these I think might be 25mm
you will gain the rest offset boring the pin housing
http://www.ebay.com/itm/otk-tony-race-go-kart-new-54-00-125cc-rok-vertex-piston-kit-14mm-18mm-pin-height-/252037482178
http://i.ebayimg.com/00/s/NDgwWDY0MA==/z/e2EAAOSwg3FUnO8c/$_12.JPG

http://www.ebay.com/itm/go-kart-vertex-125cc-53-95mm-engine-piston-14mm-pin-14mm-pin-height-crg-birel-/251785163967?hash=item3a9f90b4bf

[TZ350]

Still searching for a 38PWK - anyone

Think I found one, Wob if you are still looking for one and if this is what you want, PM me.

313987313988313989

[peewee]

i think this is the same stuff jan used. it works pretty good and cheap as peanuts. consistency is like putty so you can do alot of build up http://www.ebay.com/itm/Green-Stuff-1-x-36-Kneadatite-Blue-Yellow-Epoxy-Tape-/110796692779?pt=LH_DefaultDomain_0&hash=item19cbff5d2b

[peewee]

frits can you comment on the texture of all the surfaces inside the crankcase and cylinder of the rsa ? from what ive seen they all appear to be pretty smooth but i dont recall anybody saying for sure.

[Frits Overmars]

frits can you comment on the texture of all the surfaces inside the crankcase and cylinder of the rsa ? from what ive seen they all appear to be pretty smooth but i dont recall anybody saying for sure.Everything in there is pretty smooth, but there is no hi-gloss polishing anywhere. The cylinder already comes quite smooth from the foundry; the port windows are hand milled to a template, the exhaust duct and the radius from the duct to the cylinder bore are CNCd and some areas like the transfer duct entries are slightly polished
(click three times on the cylinder picture below to see the surface structure).
The cases are completely CNCd but not polished. In case you were expecting sand-blasting or golf-ball dimpling or suchlike: there isn't any. Only the inner and outer disc valve covers have a distinct structure, but that has nothing to do with gas flow; it serves to reduce the viscous friction.
313993 313994 313995

[ken seeber]

Frits,
As a non-loaded question, how many 125 RSW and RSA engines were ever produced and what quantities ever got sold to private teams/individuals?

[husaberg]

<iframe width="554" height="310" src="https://www.youtube.com/embed/piVnArp9ZE0" frameborder="0" allowfullscreen></iframe>

As an aside the noise effects for the running millennium falcon were are Merlin powered P51 Mustang.

[Frits Overmars]

how many 125 RSW and RSA engines were ever produced and what quantities ever got sold to private teams/individuals?I haven't got the faintest idea Ken. I always kept as far away from commercial things as I possibly could. And so did Jan.

[husaberg]

Frits,
As a non-loaded question, how many 125 RSW and RSA engines were ever produced and what quantities ever got sold to private teams/individuals?

In the Stuff frits posted or on the aprilia web site that Frits linked at some time there is a list of engine numbers for diferent years. A clever man could add them up.

[ken seeber]

A clever man could add them up.

Hooser, that's why I asked. :innocent:

[husaberg]

Hooser, that's why I asked. :innocent:
Ten ...................

Thanks, Mental; everything seems to be fine now. So here they are again:

http://www.kiwibiker.co.nz/manual/Aprilia-1.zip (http://www.kiwibiker.co.nz/manual/Aprilia-1.zip) (6.8 MB)
http://www.kiwibiker.co.nz/manual/Aprilia-2.zip (http://www.kiwibiker.co.nz/manual/Aprilia-2.zip) (8.3 MB)
http://www.kiwibiker.co.nz/manual/Aprilia-3.zip (http://www.kiwibiker.co.nz/manual/Aprilia-3.zip) (9.2 MB)
http://www.kiwibiker.co.nz/manual/Aprilia-4.zip (http://www.kiwibiker.co.nz/manual/Aprilia-4.zip) (7.2 MB)
http://www.kiwibiker.co.nz/manual/Aprilia-5.zip (http://www.kiwibiker.co.nz/manual/Aprilia-5.zip) (5.6 MB)

I can't remember where the Aprilia race website info is?
Edit yes I can
http://www.serviceaprilia.com/public/racing/scheda.asp?SubPath1=02_Parts%20and%20Manuals/02_2-stroke/Rs%20125%20GP&Contafile=1
In 1989 25 replicas 250's were sold
In 1992 Aprilia sold 40 RSV250's
Around the same time Honda Sold 150 RS250's and 500 RS125
If I take a guess then I would say no more than 125-135 or so 125's would have been made per year?

[Frits Overmars]

In 1992 Aprilia sold 40 RSV250's. Around the same time Honda Sold 150 RS250's and 500 RS125.I wouldn't be surprised if sales went up a bit after 1995 when Jan Thiel joined Aprilia :first::first::first:etc...

[RAW]

In 1988 aprilia made 30 250cc race bikes
In 1992 aprilia made 40 250cc race bikes manufactured
Thus I'm sure there after there were greater numbers of units made up until a point when racing numbers began to fall.
How many of each model is made now 2015

[husaberg]

I wouldn't be surprised if sales went up a bit after 1995 when Jan Thiel joined Aprilia :first::first::first:etc...

Maybe but I think Max won the Championships that year but Max's bike I think you have said had Non Thiel (AVL?) Cylinders if I am not mistaken.
Aprilia had won the 125s the year before for I think the first time with Sakata But Honda won it the next two years with Aoki
I do know that in 1993. A Honda RS125 cost 6000 Pounds and An Aprilia Cost 16000 pounds.
Then again none of the Hondas that were competitive didn't have big $$$ spend of cases and suspension and A and B kits. The B kit was 19000 pounds in 1993 so god knows what the A Kit cost.
The ADM cases to also for a cassette box were about 10000 pounds.

Yet a year later the Honda B kit was only 2500 pounds and the RS125 had gone up to 8000 pounds.

[RAW]

I have the paperwork from 1992 when the 1992 model Aprilia 250cc & the 1991 model 125cc upgraded to 92 specs I now own we're purchased. I will look at the costs from back then but I'm pretty sure the 250 was $96,000 Aus dollars. The combined total for the 2 bikes in 1992 was $130,000 Aussie dollars.
125cc was ridden by Allesandro Gramingi or Gabriel Debbia for Team Italia as pictured, note a young Lorris Caparossi in the background.
313999313998314000314001

[RAW]

Sorry all. But how do I rotate the pictures ?

[Frits Overmars]

Maybe but I think Max won the Championships that year but Max's bike I think you have said had Non Thiel (AVL?) Cylinders if I am not mistaken. You're right. But I was talking about 'after 1995'.


Aprilia had won the 125s the year before for I think the first time with Sakata But Honda won it the next two years with Aoki.Which I proudly remember, because Aoki's Team Molenaar bikes were prepared by Hans Spaan, using my FOS dyno hard- and software.
Then, after two years of glory, Aoki was relieved by a young Italian called Rossi, using engines, developed by a Dutchman called Thiel.


none of the Hondas that were competitive didn't have big $$$ spend of cases and suspension and A and B kits. The B kit was 19000 pounds in 1993 so god knows what the A Kit cost.The A-kit couldn't even be bought with money alone. Honda had to think you were worthy of it.
The last A-kits went to Team Gresini and Team Molenaar and it turned out that the last B-kits (that had, in contrast to the A-kits, no power valve) were better than the last A-kits. In hindsight, the best part of these Honda kits was their ignition: much stronger than the weak RS125 standard spark box of that era.

[husaberg]

Sorry all. But how do I rotate the pictures ?

Busting all those Aussie stereotypes Rick.
314008314009314010314011

[Flettner]

Frits, why does the back port (boost port) always need to point upward at an angle. As you said the FOS cylinder has a stable gas flow (plume) even if one port is blocked off. With modern cylinders the transfers are starting to tuck right in under the exhaust, so the transfers could all be arranged as in your FOS cylinder with the rear port having much more effective area because it doesn't have to be at that upward angle?
I've changed one of my engines to have a rear port just like a side port, it went very well, perhaps I just thought it went better:rolleyes:?

[F5 Dave]

Sorry all. But how do I rotate the pictures ?

I thought, Whoa, cool display. . . . oh hold on.



Lionel Richies Bikes? (sorry I hated that song).:rolleyes:

[peewee]

wobbly just so i understand. is this how the exh spigot should look ? i made a 5mm spacer which i might or might not use depending what engmod says but if i use it then the aux tunells will have a smoother transition to the main port. this engine seems to have a rediculously short main exh tunell. likely because there wasnt much room at the front of the chassis im sure. also the cylinder is at the machine shop getting the bore straightend back out and the gasket surfaces machined flat. should have it back by friday i hope then bolt it on the crankcase and start engmod

[wobbly]

NO - the aux tunnels should be ground outward at the flange face, then smoothly transition into the round
exit of the spigot.
This pic is of a KZ2 kart cylinder, and the spigot is tapered on the OD, allowing the extended aux width.
The Aprilia is similar but as far as I know they never had a proper smooth transition within the spigot - all the
pics I have seen still had steps.

[Lightbulb]

Blended exhaust, this is what I made for our 6.5cc engine, the reduction at the oval is 75% of the projected exhaust area. I did not take into account curvature of the liner, radius 10.19mm. The shape to oval takes place over a distance of 7mm at the shortest part, about 10 mm at the corners for the top and outer edges of the exhaust. The pipe header is 15.0 mm diameter, and the oval is 15mm wide and 9.9 mm high. From the oval to the diameter, That part was turned as a taper from 15mm to 9.9 mm diameter. Then I just used a 3/8 endmill to make a slot through the assemble cutting an oval 9.9 x 15.
You can see from 1 picture the shape of the exhaust and the faceted looking blend, but that is the cad. Then you will see the round to the oval and the bottom area that has a small step.
I tried an adapter that was like a wire cut from the oval to the diameter 15mm header. But there was no measureable power gain or any benefit from the extra work compared to the turned taper and an oval slot put through.
The oval to round is over a length of about 20 mm or so. It's not a motor bike but the idea really does work. I can't tell you why exactly that it works though. Hopefully this will be of some help to someone.

314026

[husaberg]

Ten ...................


I can't remember where the Aprilia race website info is?
Edit yes I can
http://www.serviceaprilia.com/public/racing/scheda.asp?SubPath1=02_Parts%20and%20Manuals/02_2-stroke/Rs%20125%20GP&Contafile=1
In 1989 25 replicas 250's were sold
In 1992 Aprilia sold 40 RSV250's
Around the same time Honda Sold 150 RS250's and 500 RS125
If I take a guess then I would say no more than 125-135 or so 125's would have been made per year?


I wouldn't be surprised if sales went up a bit after 1995 when Jan Thiel joined Aprilia :first::first::first:etc...
(These are customer bikes)

In 1988 aprilia made 30 250cc race bikes
In 1992 aprilia made 40 250cc race bikes manufactured
Thus I'm sure there after there were greater numbers of units made up until a point when racing numbers began to fall.
How many of each model is made now 2015



Jan Thiel Pitlane
The most time was spent narrowing the bridges in the exhaust duct.
These could not be CNC machined:the inside was unreachable.
Preparing for plating took about half a day.
And preparing for dyno testing another half day.
A cylinder 'untouched' after plating would give 1,0 to 1,5 Hp less.
All cylinders destined for 'works' riders were dyno tested.
And reworked in case of missing HP.
We could dyno at maximum 3-4 cylinders a day.
Difference between 'best' and 'worst' cylinders was about 0,4 HP.
There were 2 people grinding cylinders daily.
I only did necessary corrections personally.
There were 2 dyno's working every day.
About 300 cylinders were made every year.
And apart of this we also constantly tried to improve HP.
Mostly batches of 30 cylinders were cast, 25 'as before' and 5 with small changes.
Between casting and dynoing took about 3 month's time.
We also dynoed replated cylinders.
They were almost never as good as new one's!

So I would say maybe my guessed numbers might be pretty close.
Putting mine and Raws together we have
Thus far we have using mine and rick information (feel free to add anyone)
In 1988 aprilia made 30 250cc race bikes (First year of the V twin)
In 1989 25 replicas 250's were sold
In 1990 40 250
In 1991......
In 1992 Aprilia sold 40 RSV250's

[Frits Overmars]

Frits, why does the back port (boost port) always need to point upward at an angle. As you said the FOS cylinder has a stable gas flow (plume) even if one port is blocked off. With modern cylinders the transfers are starting to tuck right in under the exhaust, so the transfers could all be arranged as in your FOS cylinder with the rear port having much more effective area because it doesn't have to be at that upward angle?I've changed one of my engines to have a rear port just like a side port, it went very well, perhaps I just thought it went better?In the FOS cylinder there is a stable axial scavenging column (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130452977#post1130452977) centered in the bore, rising up until it collides with the cylinder head.
This collision has two effects. There will be a pressure rise in the head which will slow the flow down; the pressure inside the rising column will rise and the column will expand in diameter, pushing the spent gases that surround it, into the four exhaust ports surrounding the bore.
The second effect of the collision is that the axial column mushrooms in the head and flows down along the walls of the bore, pushing the spent gases that were clinging onto the bore, towards the exhaust ports.
In a conventional cylinder this axial scavenging column is supposed to cling to the rear bore wall. This clinging gives it extra stability and at the same time helps to scavenge the spent gases in that rear area. If the rear transfer port doesn't have that upward angle, it has much more effective area, as you say, so the flow exiting from it can be so much stronger that the axial scavenging column doesn't get a chance to cling to the rear bore wall. The spent gases in that area will no longer be washed out and they have nowhere to go because unlike in the FOS cylinder, there are no exhaust ports in the rear wall of a conventional cylinder.
So although this better-flowing rear transfer port may bring more fresh charge into the cylinder, it may also cause less-effective scavenging, leaving more hot, polluting spent gases in the cylinder. The net result may be positive or negative, depending on your cylinder layout.

Jan Thiel has tested every imaginable port configuration and the Aprilia layout as we now know it was the end result. But things may well be different in your cylinder.
I'd say: reduce the axial angle of the rear transfer port until it does not improve power any more (it will certainly improve piston cooling). And if you overdo it, you can easily increase the axial angle again with some epoxy, or narrow the rear port, which will have a similar effect.

[Frits Overmars]

Blended exhaust, this is what I made for our 6.5cc engine.Neil, here are some pictures showing the birth of the 1999 MB40 exhaust duct. The first pic shows a points cloud of the duct, from the rectangular blowdown area to the circular duct end, generated by a CFD program that I wrote over 25 years ago, which explains the crude appearance.
The second picture shows a solid, generated by SolidWorks out of that points cloud. The third picture shows one complete copper electrode and a number of cut-up electrodes, used for shaping the inside of the prototype's exhaust duct by means of electro-erosion. The final pic shows the mould for the exhaust duct wax cores.
314168314165 314166 314167

[Lightbulb]

Thanks Frits, So in the case of the MB LS not sure if it in production yet, is there any restriction and then back up to the header area ?
Nice work, it would have been fairly well the limit of cad software at the time I would think.
With the really wide over the top of the rear transfer port exhaust, how much better or what does that do compared to the narrower port that does not go over the top of the rear transfers ?
Are the rear transfer ports still inclined at 20 deg from horizontal ?
Having the looped shape in the transfer passage, jug handles I call them, what is the advantage as compared to normal model design with just the ports without the curved shape.? Lots of questions I know, just an enquiring mind.
Sometimes very small attention to the right detail makes quite measureable improvements to an engines overall performance.
What material would you recommend for a crank shaft?
Thanks again, Neil

[Frits Overmars]

Thanks Frits, So in the case of the MB LS not sure if it in production yet, is there any restriction and then back up to the header area ?There is still a tiny unintentional step at the bottom:
314169

With the really wide over the top of the rear transfer port exhaust, how much better or what does that do compared to the narrower port that does not go over the top of the rear transfers ?That is a damn good question Neil. I had sleepless nights figuring out why that MB engine reacted so differently from other engines. I finally came to the conclusion that this engine needs exhaust gas recycling, although in the case of a two-stroke we'd better call it exhaust gas retention.
The methanol droplets that are added to the inlet air flow, are so coarse, and there is so little time to mix them with the air, let alone let them evaporate completely, that the combustion becomes better when the mixture is pre-heated by some left-behind exhaust gas. So this engine can have too much blowdown time.area. The exhaust port is not as wide as it was in the prototype anymore.


Are the rear transfer ports still inclined at 20 deg from horizontal ?No; the scavenging column was moving too fast compared to the piston speed of this engine. Aiming the B-transfers more toward each other took some velocity out of that column. Their axial angle is in the region of 10° now.


Having the looped shape in the transfer passage, jug handles I call them, what is the advantage as compared to normal model design with just the ports without the curved shape?'Normal model design' as in stone age sleeved cylinders, you mean? :devil2:
The most important part of a transfer port is its inner radius. And this means the smallest radius you can find anywhere in the duct; with a sleeve chances are that there is a sharp edge somewhere, which means: R=0.
Make that inner radius bigger and the port will not only flow better but also better deliver the charge in the direction that you want.

But this was not even the main reason for the sleeveless MB cylinder. In the normal (stone age) model cylinders there is a bronze or alu sleeve with a slip fit in the engine casing, and contact between sleeve and casing leaves something to be desired. And in practice oil will creep between sleeve and casing, so heat transfer from the sleeve to the outside world leaves everything to be desired. The sleeve heats up, and the piston heats up even more because it cannot get rid of its heat.
Then the piston material softens, the crown may collapse unless it is made very thick (and heavy), and the piston fit within the bore that is extremely important with ringless pistons, will quickly deteriorate.

A second improvement was the use of RSP material that retains its strength at high temperatures. A special alloy was developed for the MB pistons and the minimum orderable quantity is such that I'm sure you can have some if you approach Rob Metkemeijer.



What material would you recommend for a crank shaft?That's a question you should put to Rob; I never concerned myself with the crank. All I contributed was the suggestion to use ceramic balls in the bearings.
The inner race is ground on the crankshaft so we can leave away the inner ring and use a bigger diameter inlet, and we use the cage and the outer race from a normal steel bearing. The ceramic balls cost about 1 € apiece and the bearings live forever.

[seattle smitty]

In Husaberg's thread above quoting Jan Thiel's reminiscences, Mr. Thiel states that re-plated cylinders nearly always made less power than they previously did. Why? Was any way discovered to avoid this? Many racers have to re-plate their cylinders eventually; how should this be done for best results?

[senso]

Maybe when they remove the old plating some "pieces" of the old one are now embedded into the cylinder and cause a higher thermal resistance?

[Lightbulb]

Thanks Frits, alot now makes more sense.
If an engine had the transfer port not go to BDC, but instead were only to about 20 to 30 deg BBDC, are there any negative effects as a result of this?
ie how some engines have astep at the exhaust at BDC, what would happen with the transfers at that same bottom height.
I am still not sure about the porting thing, mainly due to the shifting of the bottom edge as the port effectively as the piston moves past.

The bottom step, do you think this is like an anti reversion step and helps the engine to pipe up and overall easier to run and set a mixture ?

I have seen on model engines where a sleeve that has alot of chrome on it, do not perform as well as a sleeve that only has a very minimal layer of chrome. My take is not only the thermal change, but the amount that builds on the inner edge of the port must be directing the flow enough to be having a negative effect. I did not get onto the port and clean it back out to the original cut shape.
Neil

[Martin1981]

I remember Jan said that when the old worn plating was removed before replating, there was also a little bit aluminium removed (unintentionally and not avoidable?). And Jan said that this is not good.

[Bert]

That's a question you should put to Rob; I never concerned myself with the crank. All I contributed was the suggestion to use ceramic balls in the bearings.
The inner race is ground on the crankshaft so we can leave away the inner ring and use a bigger diameter inlet, and we use the cage and the outer race from a normal steel bearing. The ceramic balls cost about 1 € apiece and the bearings live forever.

Using the steel outer casing and cage is a damn good idea. My little experiment with 100% ceramics didn't quite go to plan... And my neck still hurts from the high side...
I concluded the mess was created by side loading of the bearing (but likely to be wrong).

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=265496&d=1340517996

[Flettner]

In the FOS cylinder there is a stable axial scavenging column (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130452977#post1130452977) centered in the bore, rising up until it collides with the cylinder head.
This collision has two effects. There will be a pressure rise in the head which will slow the flow down; the pressure inside the rising column will rise and the column will expand in diameter, pushing the spent gases that surround it, into the four exhaust ports surrounding the bore.
The second effect of the collision is that the axial column mushrooms in the head and flows down along the walls of the bore, pushing the spent gases that were clinging onto the bore, towards the exhaust ports.
In a conventional cylinder this axial scavenging column is supposed to cling to the rear bore wall. This clinging gives it extra stability and at the same time helps to scavenge the spent gases in that rear area. If the rear transfer port doesn't have that upward angle, it has much more effective area, as you say, so the flow exiting from it can be so much stronger that the axial scavenging column doesn't get a chance to cling to the rear bore wall. The spent gases in that area will no longer be washed out and they have nowhere to go because unlike in the FOS cylinder, there are no exhaust ports in the rear wall of a conventional cylinder.
So although this better-flowing rear transfer port may bring more fresh charge into the cylinder, it may also cause less-effective scavenging, leaving more hot, polluting spent gases in the cylinder. The net result may be positive or negative, depending on your cylinder layout.

Jan Thiel has tested every imaginable port configuration and the Aprilia layout as we now know it was the end result. But things may well be different in your cylinder.
I'd say: reduce the axial angle of the rear transfer port until it does not improve power any more (it will certainly improve piston cooling). And if you overdo it, you can easily increase the axial angle again with some epoxy, or narrow the rear port, which will have a similar effect.

Makes sense, I just imagined you could massage the plume to be right up the back of the cylinder. FOS it is then.
Although I have got a design that opens a back set of exhaust ports but only at blowdown time then reverts to a tansfer when needed, to keep the cylinder wall acting as a plume guide still.
But the oil less and sleeve engine need to be finished first.

[Frits Overmars]

If an engine had the transfer port not go to BDC, but instead were only to about 20 to 30 deg BBDC, are there any negative effects as a result of this? ie how some engines have astep at the exhaust at BDC, what would happen with the transfers at that same bottom height. I am still not sure about the porting thing, mainly due to the shifting of the bottom edge as the port effectively as the piston moves past.An exhaust window that does not extend all the way down to BDC may be beneficial in that there is less tendency for the transfer flow to make a U-turn directly into the exhaust. Transfer windows that do not extend down to BDC will have a little less angle.area and the transfer flow may show less tendency to cling to the piston crown once the piston timing edge is below the window floor.


The bottom step, do you think this is like an anti reversion step and helps the engine to pipe up and overall easier to run and set a mixture ?A bottom step will somewhat impede backflow, which may only be desirable outside the power band, and it may kick the backflow upwards so it is concentrated against the exhaust duct ceiling. That will make it easier for the backflow to slip over the rising piston and into the cylinder. But raising the whole duct floor will do that too, and even more effectively.

Removing a step, either top or bottom, almost always has a negative effect because in will increase the duct volume. Avoiding steps by way of utilizing adapters, like Wobbly has comprehensively explained here, is recommendable. A small duct volume will help the engine to pipe up. That is one more reason to raise the duct floor.


I have seen on model engines where a sleeve that has alot of chrome on it, do not perform as well as a sleeve that only has a very minimal layer of chrome. My take is not only the thermal change, but the amount that builds on the inner edge of the port must be directing the flow enough to be having a negative effect. I did not get onto the port and clean it back out to the original cut shape.
The thermal influence of the chrome layer thickness is negligible in comparison to the thermal resistance at the transition from sleeve to cylinder and from cylinder to air or to liquid coolant.

The build-up of chrome or nikasil around the port edges is very disturbing to the flow and should be removed. Ideally the port edges should be radiused prior to the plating process and the plating itself should be carried out with an eye on the amperage. A high current means that the plating will take less time, so the performing company will tend to turn the current up, but it will also cause a more severe build-up around the port edges.

[senso]

Using the steel outer casing and cage is a damn good idea. My little experiment with 100% ceramics didn't quite go to plan... And my neck still hurts from the high side...
I concluded the mess was created by side loading of the bearing (but likely to be wrong).



Is that a DTR engine?
If so they are know for having very,very bad castings and machining, I have seen one that the bearing bores where not aligned, but a couple thousands eccentric, it ate crankshafts lol.

[peewee]

NO - the aux tunnels should be ground outward at the flange face, then smoothly transition into the round
exit of the spigot.
This pic is of a KZ2 kart cylinder, and the spigot is tapered on the OD, allowing the extended aux width.
The Aprilia is similar but as far as I know they never had a proper smooth transition within the spigot - all the
pics I have seen still had steps.

wob mine will look like your pic. have you forgot why i welded ears to the sides of my exh spigot :msn-wink:. the spacer (which isnt finished yet) was simply so the aux tunell could have a more gradual transition into the spigot, as the main exh tunell seems unusually short on this engine.

[peewee]

frits i cant recall if i asked you this before but on the rsw drawing it shows the radiuses of all the ports. did you say the radius values were a percentage of the bore diameter ? i want to start making some templates this weekend is why i ask.

example: on the A port inner wall it says near the bottom is R20, middle is R22 and near the top R16. so if the bore is 54mm then these values would represent R20=10.8mm, R22= 11.88mm, R16= 8.64mm ? to apply this strategy to my engine i can simply use these R22, R20, R16 percentages of my bore ?

[Bert]

Is that a DTR engine?
If so they are know for having very,very bad castings and machining, I have seen one that the bearing bores where not aligned, but a couple thousands eccentric, it ate crankshafts lol.

Close, TZR125 but all the same really.

[mr bucketracer]

Using the steel outer casing and cage is a damn good idea. My little experiment with 100% ceramics didn't quite go to plan... And my neck still hurts from the high side...
I concluded the mess was created by side loading of the bearing (but likely to be wrong).

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=265496&d=1340517996you gave it to much blow up time:laugh:

[husaberg]

you gave it to much blow up time:laugh:
314185
He lost his marbles.............Think about it:innocent:
He must now have rocks in his head.

Anyway MZ's
click on them 3 times

[Frits Overmars]

on the rsw drawing it shows the radiuses of all the ports. did you say the radius values were a percentage of the bore diameter ?Peewee, the short answer is: no, I didn't. But I suppose you'd rather have the long answer.


example: on the A port inner wall it says near the bottom is R20, middle is R22 and near the top R16. so if the bore is 54mm then these values would represent R20=10.8mm, R22= 11.88mm, R16= 8.64mm ? to apply this strategy to my engine i can simply use these R22, R20, R16 percentages of my bore ?Let's keep it simple, Peewee. If a radius in any drawing is stated as, for example R20, then it means 20 mm, not some percentage of anything.
Moreover, the RSW drawings that you refer to, were the drawings that I could release at that time; they were not the RSA drawings.
Things have become even simpler since then: in the RSA cylinder the inner walls of the A-ports have one constant radius of 22,6 mm. If you wish to convert that to a percentage of the 54,5 mm RSA stroke (not the bore), be my guest.

There are some radii that I have quoted as being a certain percentage. They are the radius at the top edge of the main exhaust port (6% of the stroke) and the radius at the top edge of a radiused piston (8% of the stroke). But you cannot use these values just like that because they are not simply tangential at both ends, as you can see in the picture of the radiused piston below.
314189

[seattle smitty]

The build-up of chrome or nikasil around the port edges is very disturbing to the flow and should be removed. Ideally the port edges should be radiused prior to the plating process and the plating itself should be carried out with an eye on the amperage. A high current means that the plating will take less time, so the performing company will tend to turn the current up, but it will also cause a more severe build-up around the port edges.

But is this what Mr. Thiel was talking about (in the quote from Husaberg's post)? Presumably he would have known about these issues already, and taken appropriate measures to get the best outcome on cylinders to which he had originally done a lot of hand detailing. In other words, if a racer has a good but worn cylinder, and takes all the precautions you describe, is there any reason the re-plated cylinder won't work just as well as it did originally?

[Frits Overmars]

But is this what Mr. Thiel was talking about (in the quote from Husaberg's post)? Presumably he would have known about these issues already, and taken appropriate measures to get the best outcome on cylinders to which he had originally done a lot of hand detailing. In other words, if a racer has a good but worn cylinder, and takes all the precautions you describe, is there any reason the re-plated cylinder won't work just as well as it did originally?Well, Jan did take all possible precautions and the re-plated cylinders didn't work just as well as they did originally. So yes, there must be a reason.
Before re-plating the old plating is removed in a chemical bath that seems to eat into the aluminium as well. The cylinders have a more or less porous look when they come out of this bath. They seem to have lost weight and density and apparently they don't like it.

[breezy]

314211[QUOTE=Flettner;1130886856]Makes sense, I just imagined you could massage the plume to be right up the back of the cylinder. FOS it is then.
Although I have got a design that opens a back set of exhaust ports but only at blowdown time then reverts to a tansfer when needed, to keep the cylinder wall acting as a plume guide still.
But the oil less and sleeve engine need to be finished first

[Haufen]

There are some radii that I have quoted as being a certain percentage. They are the radius at the top edge of the main exhaust port (6% of the stroke) and the radius at the top edge of a radiused piston (8% of the stroke). But you cannot use these values just like that because they are not simply tangential at both ends, as you can see in the picture of the radiused piston below.
314189
Now that's interesting, what's the reason / benefit of them not being tangential at both ends?
Is re-adjustment of the port timings needed after the piston has been radiused? Like dropping the cylinder half of the value of the radius, afterwards? I think such a modification might also behave like a raised barrel, but with the benefit of a better flow coefficient of the ports.

[Frits Overmars]

what's the reason / benefit of them not being tangential at both ends?For the radius at the top edge of the exhaust port a practical reason is that it would be quite difficult to get it perfectly tangential with the curvature of the cylinder bore. And for both the exhaust edge radius and the piston edge radius, making them completely tangential will not help the flow.
Both pictures below will show that a full tangential piston edge radius would take away so much of the edge that the ring groove would need to be relocated.
With the piston in BDC it would also create a deeper trough between piston and bore which would create turbulence instead of helping the flow cling to the piston crown. And when the piston is half-way in front of the port and the flow is bumping against it, that lower bit of tangential radius won't make a difference, whether it is there or not.
314215 314214




Is re-adjustment of the port timings needed after the piston has been radiused? Like dropping the cylinder half of the value of the radius, afterwards? I think such a modification might also behave like a raised barrel, but with the benefit of a better flow coefficient of the ports.If you just radius the piston edge, you will increase the port timing and improve the flow. Improving the flow is fine; increasing the timing is not always desirable.
We could drop the cylinder until we have the same angle.areas as before the radiusing, but that does not take the improved flow into account.
What we really ought to do, is include the flow coefficient in the angle.area calculation. But that is beyond the scope of engine simulation programs like EngMod; it would require true 3-dimensional CFD.

[2T Institute]

Frits,
As a non-loaded question, how many 125 RSW and RSA engines were ever produced and what quantities ever got sold to private teams/individuals?

I doubt RSA engines were available over the counter, likewise RSW, a new RSA engine was 130,000 Euro and they chucked in a top of the line 125cc racing motorcycle with it :msn-wink:

[peewee]

Peewee, the short answer is: no, I didn't. But I suppose you'd rather have the long answer.

Let's keep it simple, Peewee. If a radius in any drawing is stated as, for example R20, then it means 20 mm, not some percentage of anything.
Moreover, the RSW drawings that you refer to, were the drawings that I could release at that time; they were not the RSA drawings.
Things have become even simpler since then: in the RSA cylinder the inner walls of the A-ports have one constant radius of 22,6 mm. If you wish to convert that to a percentage of the 54,5 mm RSA stroke (not the bore), be my guest.

There are some radii that I have quoted as being a certain percentage. They are the radius at the top edge of the main exhaust port (6% of the stroke) and the radius at the top edge of a radiused piston (8% of the stroke). But you cannot use these values just like that because they are not simply tangential at both ends, as you can see in the picture of the radiused piston below.
314189

thnx frits. maybe i asked you about the exh window radius and thats where i remember it being a percentage of something. since ive got 82mm stroke and the inner wall at the bore is likely much longer than the rsa, i suspect the 22.6mm will be far to sharp of a radius. do you happen to recall the wall length at the bore like in my pic ? if i know that value then maybe i can calculate the same radius to my cylinder, unless you know a easier way as i was never a math expert. judging from the rsw drawing which may be far different than the rsa, i estimate the wall length at the bore to be about 36mm. does that sound about right ?

[F5 Dave]

Oh stop it. I want to ride my 300 again. Those effortless wheelies, torque laden pull out of slop.
Sigh. Being broken sucks. Gravity is a harsh mistress. Alcohol helps. And yes I know it's only 5 o'clock.

[peewee]

might as well sell that old thing. be a new 300 engine about this time next year. not sure what kind of internal changes it has as only exterior photos have been posted so far

[Flettner]

Neil, the man to talk to at BRC engineering is Riley Will: http://www.brcenginc.com/contact.html
Other possibilities are
Andrea degli Esposti of DEA, deaengineering@gmail.com
and
Francis Payart of FPE, f.p.e@wanadoo.fr.

You can give those guys my regards, and they may still help you :msn-wink:.
Francis is even a kiwibiker forum member, so you could send him a PM, but I don't know how often he takes a look here.

24 mm from gudgeon pin center to tip sounds familiar. The Aprilia RSA and RSW had either 24 mm or 21 mm.
Try Asso and Vertex in Italy; both of them supplied the Aprilia racing pistons.

Thank you, phoned a guy in Canada, who said you need to contact a guy called "Wizzar" in Australia who said you need to contact Vertex NZ (where he gets his pistons) so I have an H size piston on the way, three weeks delivery! Now all I have to do is save up to pay for it:facepalm:

[husaberg]

thnx frits. maybe i asked you about the exh window radius and thats where i remember it being a percentage of something. since ive got 82mm stroke and the inner wall at the bore is likely much longer than the rsa, i suspect the 22.6mm will be far to sharp of a radius. do you happen to recall the wall length at the bore like in my pic ? if i know that value then maybe i can calculate the same radius to my cylinder, unless you know a easier way as i was never a math expert. judging from the rsw drawing which may be far different than the rsa, i estimate the wall length at the bore to be about 36mm. does that sound about right ?

RSA kind of looks a lot like a RSW other than the cooling and cylinder fixings.
Whilst here maybe detail changes in the Exhaust ports the radius look similar.
[R RATED]https://lh4.googleusercontent.com/-Ua19WSZgRcE/Uc972BkRgrI/AAAAAAAAANo/uSGrLOpJLmc/w800-h800/OLK.jpg[/R RATED]


if you are wanting to replicate the Aprilia then get your welder out again some more and weld some fill onto the outside of the transfers so you can recreate the swooping organic cures of the transfer passages.
Then again if that pic is your twin (which I think it is)I doubt you have the room but, on the KTM single you do

[F5 Dave]

might as well sell that old thing. be a new 300 engine about this time next year. not sure what kind of internal changes it has as only exterior photos have been posted so far

My gg is an 07. SSS YZ forks, haven't ridden a better bike for me. Should be able to ride end of the year. Enjoy it while you can.

[wobbly]

The Aprilia drawings I have show the inner wall length as 37.2mm - but does not show the hand finished ball nose radius
on the intersection with the bore,thus I would estimate the length at 34.2,mm with an R3 radius on top of this at the duct entry.

[Frits Overmars]

since ive got 82mm stroke and the inner wall at the bore is likely much longer than the rsa, i suspect the 22.6mm will be far to sharp of a radius. do you happen to recall the wall length at the bore like in my pic ? if i know that value then maybe i can calculate the same radius to my cylinder, unless you know a easier way as i was never a math expert. judging from the rsw drawing which may be far different than the rsa, i estimate the wall length at the bore to be about 36mm. does that sound about right?Let's do it the easy way, Peewee. The RSA has a 54,5 mm stroke and a transfer duct inner radius of 22,6 mm. Yours has a 82 mm stroke, so if you wish to maintain the RSA proportions, your radius should be 82/54,5 x 22,6 = 34 mm.
And if we assume an 'inside leg' of 36 mm for the RSA transfer duct (I haven't got the exact dimensions with me, but 36 mm sounds about right), then yours will need to be 82/54,5 x 36 = 54,2 mm.

[Frits Overmars]

phoned a guy in Canada, who said you need to contact a guy called "Wizzar" in Australia who said you need to contact Vertex NZ (where he gets his pistons) so I have an H size piston on the way, three weeks delivery! Now all I have to do is save up to pay for it:facepalm:I forgot to tell you: don't mention Aprilia; it will make prices go up. I suppose you did ask Wobbly about all those 54 mm kart pistons?

[husaberg]

Thank you, phoned a guy in Canada, who said you need to contact a guy called "Wizzar" in Australia who said you need to contact Vertex NZ (where he gets his pistons) so I have an H size piston on the way, three weeks delivery! Now all I have to do is save up to pay for it:facepalm:
bump...........

Piston pour TM K7 e Vortex, TM 10050
not quite
313974
http://www.superkart.it/index.php?main_page=index&cPath=92_108


these I think might be 25mm
you will gain the rest offset boring the pin housing
http://www.ebay.com/itm/otk-tony-race-go-kart-new-54-00-125cc-rok-vertex-piston-kit-14mm-18mm-pin-height-/252037482178
http://i.ebayimg.com/00/s/NDgwWDY0MA==/z/e2EAAOSwg3FUnO8c/$_12.JPG

http://www.ebay.com/itm/go-kart-vertex-125cc-53-95mm-engine-piston-14mm-pin-14mm-pin-height-crg-birel-/251785163967?hash=item3a9f90b4bf

[seattle smitty]

But is this what Mr. Thiel was talking about (in the quote from Husaberg's post)? Presumably he would have known about these issues already, and taken appropriate measures to get the best outcome on cylinders to which he had originally done a lot of hand detailing. In other words, if a racer has a good but worn cylinder, and takes all the precautions you describe, is there any reason the re-plated cylinder won't work just as well as it did originally?


I persisted in this question because some of the top alky outboard racers report much faster wear of factory Nikasiled cylinders than the bikers see. Maybe this is a consequence of the different fuels . . .

[JanBros]

anyone looking for a cheap porting tool, I'd recommend looking at dental handpieces. thought already a while about buying something like this :

http://www.ebay.co.uk/itm/Dental-Lab-35K-RPM-Marathon-Micro-motor-N3-Contra-Angle-Straight-Handpiece-Burs-/381242079696?var=&hash=item58c3cc79d0

but as my dad is a retired dentist and now has plans to move to a smaller house, he's old aquipment needs to go and asked a 90° piece to try out (he still used them for his modelling trains :yes: , and still has loads and loads of burs/drills/polishing stones/... :banana: ).

it works with a compressor so I just used a preasure regulator and stuck the tube in it

https://lh3.googleusercontent.com/JQLvnsMFfSdnTllOGnyoDaZd-hmY7VInCuRncubGVFw=w640-h480-no

could go to about 2bar before the original hose starts to blow up and gave it a try with a mill in it. the cut-out in the 2mm thick iron plate was done in about 2-3 minutes :

https://lh3.googleusercontent.com/xLqCkgI0z_vR4wh_3kPy0TORNhkyMfNxlaruMgQOcgE=w640-h480-no

to show how easy it is to get in the transfer ports : this is in a 39mm moped cylinder :

https://lh3.googleusercontent.com/LrKJ-eqVt9UMd6plEsBrJzZq0_oiufC2iJfSFLirG1A=w640-h480-no

https://lh3.googleusercontent.com/vA753wphsN3uaCFd_BymfgH967DMaq7ILLWXZebeC6s=w640-h480-no

when pushing to hard, the drill stops turning , and the bigger the diameter the less power you have before it stops. with the sanding stone in the picture, you won't be able to take away much material (only tried in on the iron casted cylinder, might be more of use in an aluminium cyl), but small diameter mills like in the first picture are realy usefull, and the sanding stones with bigger diameter can than be used to make the surface more even.

China-made dental pieces like this can be bougth very cheaply on ebay (for example http://www.ebay.co.uk/itm/5pcs-NSK-Style-Dental-Fast-High-Speed-Handpiece-4-Hole-Push-Button-Turbine-4-H-/271594999768?hash=item3f3c52cfd8) . they probably won't last as long as much more expensive brand equipment, but at 10£ a piece worth a try. there are also pieces whith heads that can turn to give you different angles. you'd have to source the part to connect the hose to the piece but maybe the china-ebayer can supply it to. or you could go for an electric like in my first link.

[Frits Overmars]

I would not recommend dental hand pieces, Jan. In my experience they are too fragile for cylinder work. The bevel gears in particular won't survive very long.
I once got a box of used dental handpieces for free and used them to modify a 125 cc cylinder. When the cylinder was done, the box was empty: all five sets worn out.

What I will recommend, albeit in a sturdier form, is the swivel head. It's great; it will enable you to get to every imaginable spot.
314276

[peewee]

keep your eyes on ebay. ive seen alot of used foredom stuff for cheap. the only piece i havent been able to find cheaply is the 90* but if you can buy everything else dirt cheap then full price for the 90* shouldnt break the bank

[Yow Ling]

keep your eyes on ebay. ive seen alot of used foredom stuff for cheap. the only piece i havent been able to find cheaply is the 90* but if you can buy everything else dirt cheap then full price for the 90* shouldnt break the bank

There is also Foredom stuff on Aliexpress, it is all counterfeit and rubbish. The only upside is if you order it you get your money back and can keep the motor flexshaft and toolholder, this process takes a little extra time.

[TZ350]

page 1250 ....

If you are looking for 2T tuning technical information I have found this thread is best read backwards, ie start at the last page and read back towards the beginning.


Transfer Port theory

There are also over 7000 images on this thread, use "Thread Tools" to view them and then click through to the original post about them.


Use Google so to search this site use an ordinary search phrase and after it add

site:www.kiwibiker.co.nz (http://www.kiwibiker.co.nz/)

for example

Frits priceless site:www.kiwibiker.co.nz (http://www.kiwibiker.co.nz/)
or
Frits pisa site:www.kiwibiker.co.nz (http://www.kiwibiker.co.nz/)

the same will work for other sites with the appropriate site address

Mick

A lot of the decade pages have collections of quotes and links to other interesting things.

Page 1250 Links List
Page 1240 2T development Software, Port Theory, Interesting Sites
Page 1230 Compression Ratio, Ex duct shape and length, Fancy spark plugs.
Page 1220 Reed Valve Petals, Oxygen Sensors, Exhaust duct step at the pipe flange.
Page 1210 Ignition Trigger Woes, EngMod 2T and Blow-Down, Fuelling Curve.
Page 1200 Frits on power spread and the ratio of the maximum and minimum points in the power band.
Page 1190 No data, but lots of talk about what the Ryger engine might look like.
Page 1180 Frits on 2T fuel consumption. M50 cylinder portmap and EngMod2T analysis.
Page 1170 Engine/Gearbox oils and bearings. Transfer duct shape and optimal Ex port timing.
Page 1160 Frits - Engines need large crankcase volumes, Power vis Handling.
Page 1150 Serious talk about crankcase volume.
Page 1140 Measuring the transfer duct length, Ignitec, Expansion chamber design, Trombone pipe.
Page 1130 Team GPR Edgecumbe Videos …. Cooling 2T’s …. 3xEx vis T port,
Page 1120 Crank Balancing, Ceramic Coating, Plugs, Piston Edge chamfers, RS125 pipe dimensions.
Page 1110 TeeZees progress on the EFI thing with the Beast.
Page 1100 No Data but some talk about pickups and EngMod 2T transducer position in the pipe.
Page 1090 Links about the Detonation Sensor and Temperature Data Logger.
Page 1080 No Data, the plenum is protested, Frits on Blowdown and Transfer window height.
Page 1070 Exhaust Duct shape, Kawasaki and BRC EFI dyno videos.
Page 1060 No Data but page talk about Port shape and Flow in a duct on this page.
Page 1050 EngMod2T setup talk about pipes, transfer ports and the TubMax graph.
Page 1040 Basics of pipe design and how to influence where the point of maximum depression occurs.
Page 1030 Racing at Greymouth, its well worth a look to see Team GPR in action.
Page 1020 Pipe dimensions, Seattle Smittys hydroplanes. Husaburgs piston link.
Page 1010 Suspension Tuning.


Page 1000 has a lot of useful information and links. http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page1000?p=1130773139#post1130773139



Page 990 Blowdown STA, Ex porting plated cylinders, port layout and port angles.
Page 980 No links list but there is talk about spark energy and EGT
Page 970 Fuel - Oil and EGT talk
Page 960 Wob - Fuel and Oil Talk and Crank inertia.
Page 950 Its all about exhaust blow down …..
Page 940 Fixers 50cc adventures – ports & heads – Wob talks about Bad Gas.
Page 930 Frits 50cc pipe – Husburgs large links list, parts books, steering head brgs
Page 920 Big links list, allsorts. Tokoroa GP videos.
Page 910 No links list but the page is about fitting a 12V generator stator.
Page 900 Frits thoughts on O2 sensors – EFI Fueling theory – Wob on EGT
Page 890 DIY Foundry tips – EFI data – Detonation Management (tec paper) – more EFI
Page 880 Big list of Flettners Foundry posts and pictures.
Page 870 YZ & Bighorn Dyno results – Dyno Vids and EFI talk
Page 860 Air cooling and ducting and Carb air inlets, next page Greymouth Race
Page 850 1st run of the EFI Beast
Page 840 Husaburgs big links list on Power Jets – High temp epoxy and Ex port dam.
Page 830 Plugging piston pins – Cyl Heads (no radius) and Plug to Piston distance.
Page 820 Det sensor & Ignitec setup – Exhaust port dam – Boost Bottle – Insulating Paint
Page 810 Links – about Razing the Exhaust port floor
Page 800 Link to dyno graphs for the YZ & BigHorn EFI Bikes & a lot of EFI stuff
Page 790 Car & bike museum pics _ Wobs pipe.
Page 780 Setting up an IgniTec DC-CDI-Race-2 ignition – Big list of links.
Page 770 Wobs views on triple ex ports – first run of the EFI YZ250
Page 760 Port Angles – lots of Pipe design info – Fast model aero engine.
Page 750 Case Com – Basic 2T tuning – BigHorn EFI
Page 740 Case Vol – Deto – Inlet Length – Over rev deto.
Page 730 Pipes – Deto – Lambda – Temp probes – CrankCase CR – Variable headers.
Page 720 Inlet tract length – GP125 service manual – Picture of how to read a plug + Wobs comments
Page 710 Fuel and Power Jets - EGT and CHT - Crank build
Page 700 Talk about wide and low transfers – Case volume and dyno graph – det and Lambda sensors.
Page 690 Pipe talk and ideas about making mufflers.
Page 680 Talk about the Trombone pipe and more of Frits and Wobs views on pipes.
Page 670 Pipes – blowdown STA numbers – Trombone pipe.
Page 660 Lots of links on pipes – Ariel Arrow – and CVT
Page 650 Links – Frits and Wobs views on pipes – CVT transmissions – 30 vis 24 carb dyno graph
Page 640 Links to Wobs views on pipes – crank balance factor – connecting a laptop to the Ignitec
Page 630 More of Wobs views on pipes – Frame & wheel weights – correct O ring grove sizes
Page 620 Links to Cooling Water Flow – Case Comp and Pipes – Setting up 2T carburation.
Page 610 Simulation packages – combustion efficiency – transfer ducts – chamfered exhaust top edge.
Page 600 Books that can be down loaded and Frits talks about why 190 Ex duration is so good.
Page 580 No links but page is about mounting carbs and the 24mm pumper carb & 28hp dyno graph.
Page 570 No links but the page talks about carburation – emulsion tubes and pilot jets.
Page 560 No links, the page is mostly about 96 vis Av gas with dyno test.
Page 550 No links list but the page is mostly about TZ400 build and cranks and rods.
Page 540 No links, the page is mostly about Wobs success with the 400 project.
Page 530 Ignition – setting up det sensors without a dyno – wings inside reed valves – poly quad head
Page 520 Mostly about what some wheels weigh, ATAC valves and crank stuffers.
Page 510 Bucketracers general Links List
Page 500 Bucketracers links list of how to make a mid 20’s hp Suzuki GP125




Page 490 The Trombone, Ex port resonance and Transfer port stagger.
Page 480 A vid of the Trombone, transfer timing and hot gases entering the transfers because of insufficient blow-down for the rpm.
Page 470 Blow-down STA ... Specific Time Area.
Page 460 No list but the page talks about Boost Bottles.
Page 450 Links to the basic info for building a 30+ hp Bucket.
Page 440 No list, page talks about power and air correction jets.
Page 430 Carb inlet lengths and crankcase volumes.
Page 420 Transfer ports and the importance of the up swept angles, the Leaning Tower of Pisa principle explained.
Page 410 Rolling road dynos, main and power jet ratio.
Page 400 Links to the basic info for building a 30hp Suzuki GP125 Bucket engine.
Page 390 Links to Frits collection of Aprilia stuff.
Page 380 Transfer duct shape and STA's.
Page 370 No list but the page talks about Jan Thiel and racing 50's.
Page 360 Frits chamber calculations formula.
Page 350 PJ switching, Wob and crank shaft balance.
Page 340 Muriatic Acid, main brg float, Husburgs con rod dimensions.
Page 330 No list, page talks about expansion chambers, race gas.
Page 320 High temp silicon, Yama Bond, crankcase sealing, air solenoids Vid clips of Mamola.
Page 310 Copper for cooling, sprockets for cooling, steering head brgs.
Page 300 How to determine STA numbers.
Page 290 B/E dimensions, delivery ratio, Honda Ex Step, stinger nozzel
Page 280 Aprilia RSA port layout explained, pumper carb, links to gluing up the GP cases.
Page 270 Link list on how to make a decent high 20's hp Suzuki GP125 Bucket engine.
Page 260 Over rev cough and what it means, Mallory metal for crank balancing.
Page 250 27hp from a 1978 Suzuki GP125
Page 240 Aprilia RSA cylinder stuff.
Page 230 Porting Calculator and a lot of other useful tech links.
Page 220 RG50 part numbers, 2-stroke carb atomisers explained
Page 210 Page is mostly about the results from the TRRS
Page 200 Simple 18 hp Suzuki GP Bucket engine using a RG250 pipe.

Etc ...

On Page 500, Bucket has links to how Team ESE built their 26, 28 and 31 hp engines:- http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page (http://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page600)500

[peewee]

I dont know anything about counterfiet foredom stuff but I wouldnt be suprised. The chinese are well known for poorly reproducing many thing.

[Lightbulb]

EBM is electron beam melting or also called electron beam manufacturing. Instead of a laser they use a high power electron beam to melt/fuses the metal powder together building up in layers. One of the largest privately owned machines is here in NZ in Auckland.
facebook pictures are here, https://www.facebook.com/pages/Zenith-Tecnica/605151476263222?sk=photos_stream
their website is here, http://zenithtecnica.com/
a company that makes the machines is here, http://www.arcam.com/

Anyway, I am posting this to let people know about the new technology and about the new electron beam polishing as well. This is different where it takes an existing something and then reworks the surface to give a mirror finish to like a sand blast finish based on a 3d surface model.

Yeah it is expensive, but the advantages will be the ability to make things with very good detail in areas that traditional casting just does not allow.
I am contemplating about making an engine case this way for a 6.5cc race engine. If all goes well, I should be able to incorporate features that can never be achieved by casting and more importantly, be able to have very accurate repeatable transfer and exhaust port shapes at a level of accuracy just not achievable any other way.
More types of materials will be available in the near future, with the ability to vary the materials density as well leads to some exciting things to come.

If the project takes off and I can make it happen, where would be the best place to make a write up with pictures etc if anyone else is interested?

Sorry to be putting thread off its great line.
PS this is in no way to detract from what people are currently doing with cores and casting, I see it merely as another tool to get what you want.

Neil

[TZ350]

If the project takes off and I can make it happen, where would be the best place to make a write up with pictures etc if anyone else is interested?

Postings here about the development of your 6.5cc race 2T engine would be very welcome and interesting.

[wobbly]

I have had a special close ratio gearset made for a TZ350 that uses the NOVA 1st,2nd,3rd set for a YPVS and stock RD400
for the rest.
All the dogs have been undercut,and the new TZ style gears are all modern 3 dog engagement.
But the RD400 has 2 gears with 6 dogs.
I have been told that the trick to enable faster changes with these is to shorten 3 of the dogs by 1.5mm.
This gives quicker initial engagement, but full locking once the gears have slid together.
Sounds brilliant - is it ?

[peewee]

well i got the cylinder back from the machine shop and all things considered i think it turned out well. theres now plenty of room for modification of the A ports and the aux exh window can likely be much bigger than i originally thought. the downside is it had to be over bored slightly to get it straight again but thats not a huge deal as i can have a over size piston in a few days. next time ill watch the heat alittle closer but for my first attempt at something like this i think it was a sucess. almost forgot to mention but the exh floor is 5mm higher than bdc now

[Grumph]

I have had a special close ratio gearset made for a TZ350 that uses the NOVA 1st,2nd,3rd set for a YPVS and stock RD400
for the rest.
All the dogs have been undercut,and the new TZ style gears are all modern 3 dog engagement.
But the RD400 has 2 gears with 6 dogs.
I have been told that the trick to enable faster changes with these is to shorten 3 of the dogs by 1.5mm.
This gives quicker initial engagement, but full locking once the gears have slid together.
Sounds brilliant - is it ?

Probably....
It sounds very similar to the old practise of "double backlashing"...Olde Timey boxes often used gear teeth as engagement dogs. Race practise was to cut back every second tooth so as to offer a bigger target for the incoming sliding gear to find. I've done this myself on a Triumph box in the early years of the Classic register. Not good practise where there's a huge amount of torque going in but it lasts well enough.
You are checking for engagement of all dogs - usually using engineers blue ?

[Frits Overmars]

I have been told that the trick to enable faster changes with these is to shorten 3 of the dogs by 1.5mm. This gives quicker initial engagement, but full locking once the gears have slid together.Sounds brilliant - is it ?Gear change velocity mainly depends on 2 things (and the rider's boot size isn't one of them).

1: How the shift drum is held in its various positions:

Drilled pits in the drum circumference + spring-loaded ball = bad;
once the ball is out of a pit it will just stand on the drum circumference, doing nothing until the next pit shows up; the rider must be sure to fully rotate the drum. A quick dab on the shift lever can easily result in an unwelcome neutral.

Star-like cam on the drum shaft + spring-loaded swivel + roller = good;
once the roller is over the top of a star point, it will want to roll into the next valley, so it will help the rotation of the star and the drum. The rider only needs to rotate the drum halfway to its next rest position; the roller and the star will do the rest.

2: The relation between the total angular length of the dogs and the total angular length of the recesses.

Obviously a dog must be angularly smaller than a recess but even then it often happens that a dog is pushed against the adjacent gear between recesses. Then the relative rotation between the dog and the adjacent gear must cover a certain angle before the dog can enter the recess. As the relative rotation velocity between adjacent gears is rather low (the closer the gear ratios, the lower this speed) this may take some time.
It won't help if you shorten all dogs but one; the remaining long dog will play the decisive role.

Small-angular dogs and big-angular recesses will speed up the shifting but will cause a lot of backlash. But if the number of recesses is twice the number of dogs, the chance that a dog directly encounters a recess is doubled without the disadvantage of the large backlash.
the new TZ style gears are all modern 3 dog engagement. But the RD400 has 2 gears with 6 dogs.Come to think of it: the smaller the angular angle that a dog has to slide along the adjacent gear before it can enter a recess, the faster will be your shifts. So what you need is many small-angular dogs. This is beginning to look like a car synchromesh...

[Frits Overmars]

EBM is electron beam melting or also called electron beam manufacturing. Instead of a laser they use a high power electron beam to melt/fuses the metal powder together building up in layers. facebook pictures are here, https://www.facebook.com/pages/Zenith-Tecnica/605151476263222?sk=photos_stream their website is here, http://zenithtecnica.com/ Neil, as I have some experience with Selective Laser Melting (SLM), I was curious about the differences between laser melting and electron beam melting.
Zenith Tecnica has committed itself to Electron Beam Melting (EBM) technology.With Additive Manufacturing (AM), parts are built by successively melting thin layers of metal powder together. AM enables the manufacture of complex parts that cannot be made by any other manufacturing process – this immediately creates design freedom and cost-efficiency benefits. The EBM build speed is considerably faster compared to other metal powder AM technologies.I could not find any explanation as tho why EBM should be preferable to SLM and neither could I find an explanation as to why it should be faster.
The build speed with all metal power AM technologies depends on the size of the puddle of molten metal that is created by the laser beam or the electron beam.
For fine detailing you want to keep this puddle small which limits the amount of beam energy that can be applied. In other words: you cannot increase the build speed by just using a stronger laser or a stronger electron beamer; you must also shorten the melt time per point and move the beam quicker from one point to the next.

Next: Zenith-Tecnica claims "No residual stresses - no distortion". In theory this may be true - if your product is symmetrical and if you have two melting beams operating simultaneously at opposite sides of the product.

I'd be interested to hear Zenith-Tecnica's comments on the above points.


I am contemplating about making an engine case this way for a 6.5cc race engine. If all goes well, I should be able to incorporate features that can never be achieved by casting and more importantly, be able to have very accurate repeatable transfer and exhaust port shapes at a level of accuracy just not achievable any other way.If you plan to produce an engine casing with integral cylinder, you are right. But at MB we stepped away from integral cylinders because bolted-on cylinders are not only easier to produce but also much more user-friendly. For example we can inspect a piston without the need to remove the engine from the model airplane.
The MB cylinders are cast via the lost wax method and the duct and port qualities are every bit as good as could be achieved with Additive Manufacturing.


If the project takes off and I can make it happen, where would be the best place to make a write up with pictures etc if anyone else is interested?I hope my above comments didn't put you off; I would be very interested to read about your adventures.

[Lightbulb]

Thanks for the encouragement and interest.
It is a risk taking on a new project with new technology. I know I will be learning a lot from the process and what the possibilities are going to be.
Yeah, they are not giving away much on how their process and works. A lot that they do, is not published for commercial reasons I assume.
I have a meeting with them tomorrow to find out more about the process, costings etc and material options. Over the phone they sounded quite interested in my project and I am also very curious about what they can do. So I will share what I can after the meeting tomorrow.
Neil

[Bert]

Frits,
As a non-loaded question, how many 125 RSW and RSA engines were ever produced and what quantities ever got sold to private teams/individuals?

Question for Ken (strike pistons).

Does the Strike PS001 have enough meat around the pin to enable it to be re machined to a 15 or 16mm pin??

With all the MOMs rule changes it now means I can shelve the YZ100 pistons that I current use in favour of a higher quality Kart piston...

[Lef16]

Hey guys,check this one!!
Give emphasis on the 90mm center to center rod.
I guess that if crankcase don't communicate with tranfers,a long rod isn't needed for bigger case vol!

[Muciek]

Number of ducts :11 , 1ehx that's interesting. So they should be racing next year or there is a chance to see them this year?

[AndreasL]

11 transfers and 1 exhaustport!!!

Is it high position transfer ports we see around/above the export?

Very interesting!

Thanks Lef16 for sharing.

[nick gill]

I could not find any explanation as tho why EBM should be preferable to SLM
So I'll share with you what I learned quoting some EBM projects through Zenith.
1) Materials - You can't use aluminum ! Which is really annoying isn't it.....
Aluminium has a vapour phase temp too low for EBM. Basicallly If you tried to do it, you'd inadvertantly create a kind of vapour deposition vaccuum metaliser, coating the entire cabinet in aluminium.
Most materials EBM'd are stainless steel, titanium, or inconel. I believe copper based alloys would be possible, and probably Tungsten. Rocket engines and acid pumps and that kind of thing are what tends to get built in the main.
2) Distortion is controlled with a proprietary method of modelling 'fins' and webs onto the parts to balance them thermally during the build. These are sort of 'stitched' onto the part, and are broken away once the part is completed. This controllled cooling enables much finer forms than can be achieved with SLS. Remember we are talking about titanium and inconel here. SLS of aluminium may not have these distortion issues, but Ti certainly does.
3) Resolution and surface texture is comparable to SLS. Porosity should be much lower but is a compromise with build speed.

I have a ti project coming up soon that will go to Zenith. I'll share it with you if it is successful.