ESE's works engine tuner

[Flettner]

Here is a 60.5mm piston, not finished outside. Thats why there is a lump on its head, to hold on to, to do the cut aways and piston ring groove. Material? magic.
https://youtu.be/MxyTBXiaFQw

[Flettner]

https://youtu.be/MxyTBXiaFQw
60.5 mm piston, clearly not outside finished yet.

[TZ350]

<iframe width="560" height="315" src="https://www.youtube.com/embed/MxyTBXiaFQw" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

What sorcery is hiding in here?......

[Flettner]

tried to put up a video but won't take.
So here is a picture instead, my new 175 piston, 60.5mm

[katinas]

Thanks Wob very much about this info, maybe we must to rise C before Europian final round
You are right, for accurate comparison test we must found right cylinder height for std piston and from this point start to test with rounded. But its even more pain.

Usual modification route is-
Work with bottom end (crank, crankase) then testing
Work with cylinder, then testing
Rounded piston, then testing

Add photo with another modification on C, crankcase step, its mimic to hydrodiode , we do this on SX50 and World Cup SX65, but still blind zone.
Maybe this coud help with full rounded piston, but we not tested.
I think for all of us would be very interesting to see your work results with sharp edge at C on much higher revs and power output engines than MX.

[jonny quest]

Thanks Wob very much about this info, maybe we must to rise C before Europian final round
You are right, for accurate comparison test we must found right cylinder height for std piston and from this point start to test with rounded. But its even more pain.

Usual modification route is-
Work with bottom end (crank, crankase) then testing
Work with cylinder, then testing
Rounded piston, then testing

Add photo with another modification on C, crankcase step, its mimic to hydrodiode , we do this on SX50 and World Cup SX65, but still blind zone.
Maybe this coud help with full rounded piston, but we not tested.
I think for all of us would be very interesting to see your work results with sharp edge at C on much higher revs and power output engines than MX.

I have lowered C port openings with epoxy. Maybe fully Radius piston and epoxy lowered C.

Entrance of C wider than cases works good. Any benefit from A and B entrance wider than cases?

[shnaggs]

I have lowered C port openings with epoxy. Maybe fully Radius piston and epoxy lowered C.

Entrance of C wider than cases works good. Any benefit from A and B entrance wider than cases?

Have wondered this myself...

[katinas]

Thanks for responce. The more information is on producer site.
http://sibaero.ru/%d0%b4%d0%b2%d0%b8%d0%b3%d0%b0%d1%82%d0%b5%d0%bb%d 0%b8/%d0%b4%d0%b2%d0%b8%d0%b3%d0%b0%d1%82%d0%b5%d0%bb%d 1%8c-sibaero-2r-i/
I nether see this engine working, only read information on Russian amateur aviation forum. Both cylinders are working (have the same themperature).
Hi,
On parallel two cylinders air cooled engines, aviators use isolation plate between cylinders to lower and maybe equalized cylinders temperature for both transfers sides. Without plate engine lost power.
Maybe this help.

[katinas]

I have lowered C port openings with epoxy. Maybe fully Radius piston and epoxy lowered C.

Entrance of C wider than cases works good. Any benefit from A and B entrance wider than cases?

Yes, on dyno entrance of C wider than cases add something on reed engine, but with rotary or piston ported maybe all goes in different way.

Minarelli scooter engines made with big step, aprox 3mm at A ex side wall and case.

[Mental Trousers]

DB Errors have been fixed. You can now view the thread images again.

[wobbly]

Katinas , I am tuning for a team in OZ champs till next week , but as soon as I am back I will try C duct step ( sides only first , then all 3 edges ).
Its a test I can do back to back on the dyno in probably 1/2 an hour , so really worthwhile if a sucess , no drama if its no use.
I have a new piston from Vertex to test with angled squish only - then flat top.
Once I have done this is I will CNC that piston with radius to test again , but with a sharp C edge and test C height as well.
As I said , with full radius the front side power was very good - exactly what you want in MX.
But using a radius with sharp C and dropping the cylinder essentially makes the C lower in timing - again good for front side power.
I am hoping that dropping the cylinder and grinding up the C with the sharp edge will give more everywhere - including into the overev.
Bastard 2T will make a fool of me im sure , but I have to try it.
I think if you add big ball nose radius on the duct entry wall you will see a gain - worth over 1/2 Hp in the kart engine.

[katinas]

Thanks you Wob for your clear reference.

Actually for World Cup we send boy with two reverse restrictions in C port (add sketch blue color where was grinded) because KTM 65 cylinder is relatively high. With shorter cylinder, shorter Lc, and just one step on case is enough. On dyno with 65 this add 0,3 hp with better midrange. We use grinded spark plug that Jan and Frits recommended and this again add mid range. But very interesting, it looks like plug works one number cooler that before grinding, maybe better flush..
At World Cup boy was only one, in the whole group, with std. KTM exhaust pipe, but for us it works very well.

But Lotte van Drunen, what a ride !!! She won both starts, amazing.

[jfn2]

Katinas
Did you test with just the overhang and then test with just the hydro diode. I wonder why the use of hydro diodes are not used on all the transfer passages for reversion? I also wonder if the placement of the diode makes a difference?

[dutchpower]

22 hp

cil. std. only exhaust port and aux. ports
And pipe

[katinas]

22 hp

cil. std. only exhaust port and aux. ports
And pipe

Yes this is Lotte. Congratulations for all team.

22 hp amazing, but how high is rpm.

Best what we see on our dyno 18.21 hp at 10861 rpm.

[katinas]

Katinas
Did you test with just the overhang and then test with just the hydro diode. I wonder why the use of hydro diodes are not used on all the transfer passages for reversion? I also wonder if the placement of the diode makes a difference?

First time we test on an engine just with the overhang and this itself gave 0.3 hp, but on the last engine we just add hydro diode and not measure this mod alone.

C is most unrestricted port for reversion on reed engines , shortest of all with nearly to vertical angle, very comfortable for ex gases and for back pressure from the pipe at wrong time. A and B usually shape have some restrictions, especially with sharp A B widows upper edges.

[jfn2]

Katinas:
Thank you very much for the info. Doing a very good job.

[ceci]

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=342497&stc=1&thumb=1&d=1563307439

katrinas, you are so kind to give information about who this graphic is and how it works (I do not have the possibility of copying and pasting the text into a translator).
It is a stratified loading system

Thank you so much

[DoldGuy]

Trying to understand this, in this case a cylinder reed motor...What can cause this?

Ignition Timing/Port Timing/Fuel Type/Reed Material & Thickness/Pipe/Compression/MSV???

Current motor stroked/bored/long rod/spacer plate has a lot of reversion requiring substantially leaner jetting & wanting to have an understanding of How & Why.

[dutchpower]

Yes this is Lotte. Congratulations for all team.

22 hp amazing, but how high is rpm.

Best what we see on our dyno 18.21 hp at 10861 rpm.

Thats very good Katinas

22 hp 12100

[katinas]

Hi, Ceci
This book is more about mathematics simulation of Two stroke process.

About 2.12 scheme

Mathematics simulation show that, hydro diode in trans ports, help to rise torque in the whole range, with the full open throttle . In practice this has proved itself by testing with 111cc engine bore 58mm stroke 42mm. Torque rise everywhere up to 20 percent.
Character of changed pressure in the crankcase, indicate about much lowered flow of exhaust gases to crankcase, when piston start rise up from BDC and trans windows still open.
Hydro diode have no influence on fuel consumption.

Add link where you can download whole book page by page.

http://padaread.com/?book=742&pg=1

[katinas]

22 hp 12100

Thank you very much.

[ceci]

Hi, Ceci
This book is more about mathematics simulation of Two stroke process.

About 2.12 scheme

Mathematics simulation show that, hydro diode in trans ports, help to rise torque in the whole range, with the full open throttle . In practice this has proved itself by testing with 111cc engine bore 58mm stroke 42mm. Torque rise everywhere up to 20 percent.
Character of changed pressure in the crankcase, indicate about much lowered flow of exhaust gases to crankcase, when piston start rise up from BDC and trans windows still open.
Hydro diode have no influence on fuel consumption.

Add link where you can download whole book page by page.

http://padaread.com/?book=742&pg=1

Excellent book, for my taste a real jewel.
The issue of load stratification if it is in the

http://padaread.com/data/djvu/97/b3/742/Dvuhtaktnye-karbyuratornye-dvigateli-vnutrennego-sgoraniya-V-M-Kondrashov-1990/24.png
http://padaread.com/data/djvu/97/b3/742/Dvuhtaktnye-karbyuratornye-dvigateli-vnutrennego-sgoraniya-V-M-Kondrashov-1990/25.png

[katinas]

Excellent book, for my taste a real jewel.
The issue of load stratification if it is in the



2.16 Kawasaki ex pipe
When ex gas temperature rise up, therm element 6 push part 4 closer to cylinder.

[TZ350]

342512

The sort of thing you find when your bike has taken a high speed lye-down in the kitty litter.

[F5 Dave]

Yeah that's not pretty. Lucky it wasn't on the Rotary side. But I wouldn't count out some injection from bouncing gravel. I really wouldn't.

[TZ350]

I will check that but after the race finised the bike did manage to quietly put lts way back to the pits.

[flyonly]

342512

The sort of thing you find when your bike has taken a high speed lye-down in the kitty litter.

What is the thermostat off?


Sent from my iPhone using Tapatalk

[katinas]

I am hoping that dropping the cylinder and grinding up the C with the sharp edge will give more everywhere - including into the overev.
Bastard 2T will make a fool of me im sure , but I have to try it.


Wob, restored C duration show 17,85 hp just at 10185rpm. mid power left the same, over rev little bit better. We never see that before on this particular engine ( previous best before World cup 17,33 hp). Today on track boy said that this is different engine.
Sorry, I will not be able to answer week or two.

Thank you very much

[TZ350]

What is the thermostat off?

Wobbly had some made, they hold the water temperature to about 45 deg C. if you are interested in one, PM him to see if he has any left.

There are a lot of posts on this thread about thermostats. To find them copy this line into your google search bar.

thermostat site:https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?

[F5 Dave]

Hey! How did you get one not anodised Garish Red?

[TZ350]

Hey! How did you get one not anodised Garish Red?

I brought some with a plain finish from Wobbly for the Team ESE Bikes.

[Tim Ey]

Just found out that the Edding 3000 permanent marker has a 15mm diameter and a d12.7mmX3mm regress at the endcap.
That might work out for some 15mm Clip fitting.
342513

Probably some of you folks can make anything from it.

[peewee]

got a small update guys. after the local machinist was taking so long , i sent the cyls to another place thats a yami twin expert supposedly :laugh:. still it was several weeks time but finally i have them back in my hands. top and bottom decks were machined flat and the bore is rough bore for now while i do the port grinding. unfortunately the machinist sort of stuffed the bores and went to 68mm (8gr heavier) instead of 66mm. so i have to relocate the ring peg once again and weld the hole in a new set of pistons. not the end of the world but a set back still. to keep the same pin height in 68mm diam and not go the blaster type piston, i had to use wsm. which i believe are rebadged wossner since the package says Germany. anyways the intake side has some small fingers hanging down, do you think theres any concearn they could break off or should i round those off alittle ?

[peewee]

so I started preparing the pistons today. a while back when working on the wisecos I discovered a very fast and good method of removing the ring pin. the dremel discs fit well in the groove and grind off the pin in seconds . if you try it, first practice on some old pistons to get familiar :niceone:

[Brett S]

If you're going to grind out anti rotation pin with a dremel, put the piston in the lathe and the dremel in the tool post so you have full control to not hit the bottom of the ring land.

Another option I've thought about but never done is to drill into the underside of the crown behind where the original pin ends and then push the pin in below ID of ring groove.

[TZ350]

.
PeeWee and Brett, I have tried before but made a mess of mine. So thanks for your great ideas about how to go about removing the pin.

[TZ350]

342535 342534 342537 342536

Some interesting pictures scraped from Ken Seeber's FaceBook page.

[jonny quest]

If you're going to grind out anti rotation pin with a dremel, put the piston in the lathe and the dremel in the tool post so you have full control to not hit the bottom of the ring land.

Another option I've thought about but never done is to drill into the underside of the crown behind where the original pin ends and then push the pin in below ID of ring groove.

But don't turn lathe on, just rotate the piston in lathe by hand the few degrees needed

[Haufen]

Depending on the height of the groove and the thickness of the disc, you can also use several discs on top of each other. I used to glue paper with superglue to the top and bottom side of the discs to protect the groove a bit, but if you have a calm hand it should work out without this, also.

[Brett S]

But don't turn lathe on, just rotate the piston in lathe by hand the few degrees needed

Sorry Yes don't turn lathe on.
A little fixture like this is handy, you will have to machine the seat each time to ensure concentricity if using for squish area.

[peewee]

i tried drilling the pin with all sorts of different bits in a drill press. regular drill bit, various carbide bits. mini dremel disc worked best and by far fastest method. this is just my conclusion. a small stiff fly cutter type of bit might work but i didnt have one. biggest problem i found is most bits i tried, just deflected sideways and buggered the ring groove. i had a fair bit of practice on old pistons. the main thing about dremel discs, do a few practice runs on junk pistons to ensure the groove doesnt get stuffed when its go time on the good pistons but dont over complicate it. :2thumbsup

[Frits Overmars]

A little fixture like this is handy, you will have to machine the seat each time to ensure concentricity if using for squish area.The accuracy of this method depends on front and back of the piston skirt being equally long. And due to the conicity of the piston you cannot check this with a machinist square.
Pistons with a desaxé pin bore, which occurs more often than you might think, won't help either.
My approach for such operations: pull a piece of tight-fitting inner tube over the piston and gently (but not too gently; it's not your sister) clamp it in the lathe.
This won't be sufficiently accurate for a complete ring groove fabrication, but it will do for the limited angle of rotation required to grind away the pin.

[Carel H]

block hook.


Machinist square. Had to look it up. Block hook smells Dutch.

[Frits Overmars]

Machinist square. Had to look it up. Block hook smells Dutch.Dankjewel Carel. Tried to look it up but couldn't find it. Corrected it now :niceone:.

[TZ350]

My approach for such operations: pull a piece of tight-fitting inner tube over the piston and gently (but not too gently; it's not your sister) clamp it in the lathe.
This won't be sufficiently accurate for a complete ring groove fabrication, but it will do for the limited angle of rotation required to grind away the pin.

My method is similar, I have had success using masking tape to make up for the taper in the piston. It is also possible by carefull positioning of the chuck jaws to compensate for the piston cam.

342545

I have had some success filling away the ring peg with a slim file with the teeth on the flats ground off. Carefully grinding the file to the ring width and slightly radising the edges to protect the sealing surfaces of the ring land worked well.

342544

The new peg was made from piano wire with it secured by bending the tip over into a hole like Yamaha did on their TZ's.

342546

[TZ350]

342548 342547 342549

I had problems with Weisco forged pistons. If they got over heated in my air cooled engine the original ring locating pin would move further into its hole and allow the ring to rotate. I needed to find a more reliable way of locating the ring.


Another option I've thought about but never done is to drill into the underside of the crown behind where the original pin ends and then push the pin in below ID of ring groove.

Brett's idea may work well, there seems to be plenty of room at the bottom of the Weisco pin hole to be able to punch the ring locating pin down a lot further.

[Carel H]

Don't forget soft jaws. Tight, concentric and scratch-free.

[Michael Moore]

As an aside, when using tiny drill bits you can bump up the stiffness with a single flute version. I used one of those in carbide to put some oiling holes in case-hardened linear shaft and there was a distinct lack of drama during the operation (much to my relief).

cheers,
Michael

[peewee]

for the hell of it, i just might pickup one of these to see how well it removes the pins on some old pistons.. in my mind im thinking it could be the bees knees. chuck it up in the drill press jaws and just plunge down. essentially the same as drilling but the cutter is flat on the end with teeth and solid carbide so deflection would likely be nil. should mill the pin away in no time

https://www.travers.com/4-flute-micrograin-solid-carbide-coated-single-end-mill/p/08-601-038/

[Brett S]

342548 342547 342549

I had problems with Weisco forged pistons. If they got over heated in my air cooled engine the original ring locating pin would move further into its hole and allow the ring to rotate. I needed to find a more reliable way of locating the ring.



Brett's idea may work well, there seems to be plenty of room at the bottom of the Weisco pin hole to be able to punch the ring locating pin down a lot further.

I suppose officially the hole shouldn't be deep enough to let the pin go down too far if the interferance fit is wrong..
I have had a customer with the issue before on a batch of IAME kart pistons and i suggested to work out where the end of the pin is(cut open a failed one to see pin length) and centerpop the underside of the crown to both stop the pin being able to go in any further and hopefully increase the interferance fit.
I never heard back from him to know if it fixed the issue.

[ken seeber]

I suppose officially the hole shouldn't be deep enough to let the pin go down too far if the interferance fit is wrong..
I have had a customer with the issue before on a batch of IAME kart pistons and i suggested to work out where the end of the pin is(cut open a failed one to see pin length) and centerpop the underside of the crown to both stop the pin being able to go in any further and hopefully increase the interferance fit.
I never heard back from him to know if it fixed the issue.

Jeez Brett, just where do you get all these good ideas from ????? :niceone:

[Frits Overmars]

The new peg was made from piano wire... That is my favorite source. The material is top notch, available in any diameter you need, and one string is enough to modify at least a hundred pistons.


I had problems with Weisco forged pistons.Did you misspell that name on purpose? Never mind, now I can divulge that I've never seen anything good coming from them, without having to worry about lawsuits.

[SwePatrick]

Funny thing,, you discuss moving the pin.
I have the latest days tested moving one my self as i can´t find desired piston needed for my setup.

I use a different approach, which i suppose is the 'best' way.
I use Spark erosion to remove old pin.
342559


This leaves me with totally untouched ringgroove.
And when pressing in a new pin i used my cnc mill, drilling a hole with a tungsten 1.5mm diam drilling mill.
And the pin i made from an shaft of a 1.55mm drillbit.
Small taper on the end that goes in first in the piston, then just press it in.
I made the pin go all the way down in the hole i drilled, and by that forcing it to NOT move inwards into the piston, and as my ring closes the gap it won´t let the pin move outwards either.

And, if worried about spark erosion might spark onto the sides of the groove, one can either paint the piston or mask it with some thin tape.

Rgds
Patrick

[SwePatrick]

for the hell of it, i just might pickup one of these to see how well it removes the pins on some old pistons.. in my mind im thinking it could be the bees knees. chuck it up in the drill press jaws and just plunge down. essentially the same as drilling but the cutter is flat on the end with teeth and solid carbide so deflection would likely be nil. should mill the pin away in no time

https://www.travers.com/4-flute-micrograin-solid-carbide-coated-single-end-mill/p/08-601-038/

I use a similar one, but,, be aware!
They need about at least 3000rpm and about at top 0.02mm feed per tooth.

[andreas]

I believe I'm right that the top model has more balancing effect per rotational mass than the lower, and thats what we want right?

[wobbly]

The efficacy of a balance shaft is dependant upon two factors = m x r.
If you take the whole mass as being at a single point then that mass at the radius squared is the rotational inertia.
In the diagram it would appear that the bottom shaft has more eccentric mass within the same outer radius , thus will
have more rotational ineria effect.

[andreas]

The efficacy of a balance shaft is dependant upon two factors = m x r.
If you take the whole mass as being at a single point then that mass at the radius squared is the rotational inertia.
In the diagram it would appear that the bottom shaft has more eccentric mass within the same outer radius , thus will
have more rotational ineria effect.

I'm not shure I followed, say lets design the two to do the same job- then the upper would give faster accelleration?

[wobbly]

Sure - less ineria = faster acceleration.
But either you balance the crank properly or you dont - cant have both.
A crank with no balance shaft simply moves the shake from the vertical to the horizontal plane as the balance % is increased.
Balance shafts can eliminate the shake altogether, if thats what you want or need,

[andreas]

Sure - less ineria = faster acceleration.
But either you balance the crank propderly or you dont - cant have both.
A crank with no balance shaft simply moves the shake from the vertical to the horizontal plane as the balance % is increased.
Balance shafts can eliminate the shake altogether, if thats what you want or need,

I Don't intend to compromise the balancing act in any way, just better designed. Damn my minimalism. It must have larger diameter/length/density, but the more centered excentricity I think could make it possible to lose some inertia.

[SwePatrick]

Andreas, Look at it simple..
You need the inertia(weight) to balance the cranks inertia.
No way around it, if you want to use a small diameter balanceshaft, it needs to be longer to reach the same inertia.
You need the mass in some configuration, and thereby you won´t gain any response however you do it.
Oh,, well one way it might be useful with a small diam, that would be the windage and hitting the oil should be less.

[andreas]

Andreas, Look at it simple..
You need the inertia(weight) to balance the cranks inertia.
No way around it, if you want to use a small diameter balanceshaft, it needs to be longer to reach the same inertia.
You need the mass in some configuration, and thereby you won´t gain any response however you do it.
Oh,, well one way it might be useful with a small diam, that would be the windage and hitting the oil should be less.

Yes, it might be a brain ghost after all. By the way I've seen your external dito, rather like it.

[Muhr]

Yes, it might be a brain ghost after all. By the way I've seen your external dito, rather like it.

centrifugal force is not linear in a given direction with different centers of mass so I would never leave stroke length with center of balance mass on a balance shaft.

[andreas]

Sorry aint got no cad, and don't wish to hijack the thread, but here is the straightforeward.

[SwePatrick]

Yes, the weight 180 degree from 'no weight' will have the most inertia, but.....

[andreas]

The efficacy of a balance shaft is dependant upon two factors = m x r.
If you take the whole mass as being at a single point then that mass at the radius squared is the rotational inertia.
In the diagram it would appear that the bottom shaft has more eccentric mass within the same outer radius , thus will
have more rotational ineria effect.

That's what I mean, instead of a half circle, you conentrate the mass closest possible to this single point- and loose some momentum. Or what am I missing.

[wobbly]

Here we are talking about two differing effects.
Rotational inertia is scalar - that is it has no directional vector , the larger the mass or the bigger the effective radius then the inertia
number gets larger.
Balance forces are a vector , that is a force created by the eccentric mass has a directional value about the center of rotation.
Thus whenver the balance factor is increased , by more mass added opposite the crank pin , then this added mass will increase the
rotaional inertia that has to be accelerated.
But , here is the kicker - reducing rotational inertia of a 2T crank can be counterproductive.
The lower value of inertia allows the crank to accelerate faster away from TDC due to the gas pressure of combustion.
This faster acceleration results in faster velocity thru BDC.
This effectively reduces the STA of the transfers, and in practice the effect is seen as a lack of overev power.
I first discovered this on a TM125MX , when I took off the ignition rotor and replaced it with just a timing disk.
The engine , that previously spun to well over 13,000 easily, now would not go past 12,000.
Later I discoverd that VHM and Honda both produced higher inertia cranks to be used with no flywheel when converting to total loss.
In our discussion of balance shafts the added inertia may in fact produce better performance due to the above effect.
But - the added inertia may also overcome any added porformace simply due to the extra power absorbed trying to accelerate the added mass.
How much inertia is too much ? - look at an Aprilia crank with many inserts of tungsten close to the outside of the crank discs.
That may be the optimum balance between acceleration rate - Vs overev power.
I think it was Doc Fleck at Queens that first documented this behavour - noting that a heavyer dyno flywheel appeared to make the engine
being tested to create more top end Hp by slowing down the " in cycle speed variation " behavour.

[andreas]

Here we are talking about two differing effects.
Rotational inertia is scalar - that is it has no directional vector , the larger the mass or the bigger the effective radius then the inertia
number gets larger.
Balance forces are a vector , that is a force created by the eccentric mass has a directional value about the center of rotation.
Thus whenver the balance factor is increased , by more mass added opposite the crank pin , then this added mass will increase the
rotaional inertia that has to be accelerated.
But , here is the kicker - reducing rotational inertia of a 2T crank can be counterproductive.
The lower value of inertia allows the crank to accelerate faster away from TDC due to the gas pressure of combustion.
This faster acceleration results in faster velocity thru BDC.
This effectively reduces the STA of the transfers, and in practice the effect is seen as a lack of overev power.
I first discovered this on a TM125MX , when I took off the ignition rotor and replaced it with just a timing disk.
The engine , that previously spun to well over 13,000 easily, now would not go past 12,000.
Later I discoverd that VHM and Honda both produced higher inertia cranks to be used with no flywheel when converting to total loss.
In our discussion of balance shafts the added inertia may in fact produce better performance due to the above effect.
But - the added inertia may also overcome any added porformace simply due to the extra power absorbed trying to accelerate the added mass.
How much inertia is too much ? - look at an Aprilia crank with many inserts of tungsten close to the outside of the crank discs.
That may be the optimum balance between acceleration rate - Vs overev power.
I think it was Doc Fleck at Queens that first documented this behavour - noting that a heavyer dyno flywheel appeared to make the engine
being tested to create more top end Hp by slowing down the " in cycle speed variation " behavour.

Highly interesting, thank Wobbly.

[Frits Overmars]

Balance shafts can eliminate the shake altogetherYep - if we employ two balance shafts per crankshaft, or the Husaberg-solution with balance weights on the crankshaft.
In our usual layouts there is a definite distance between crankshaft and balance shaft. This distance between a crank force acting in one direction and a balance force acting in the opposite direction causes a fore-aft rocking torque.
The balance shaft solution as used in the Aprilia RSA for example, with outrigger balance masses, allows the smallest distance between crankshaft and balance shaft center lines.
In the Husaberg approach this distance is zero, which in itself is perfect. But if you want to do this right, you'll need balance discs on both sides of the crankshaft and both these discs must rotate counter-crankshaft-wise, which will require a handful of gears.
342593 342594 342595 342596342597 342598

[SwePatrick]

When talking balanceshafts, i now run a verion in my engine like the aprilia type.
One weight on each side of crank as close as possible to the center och the crankshaft.

Is there any data recorded with or without balancer, how much power it steals?

[katinas]

Wob, your advise about restored C open duration, really helped at the race. Boy finished in the second place at the European Championship Mx65 final.
Many thanks.

[Flettner]

When talking balanceshafts, i now run a verion in my engine like the aprilia type.
One weight on each side of crank as close as possible to the center och the crankshaft.

Is there any data recorded with or without balancer, how much power it steals?
In my particular case, parallel twin cylinder, the difference of with or without a balance shaft is the difference between flying or not. Without, the vibration was so bad I was sure sooner or later the engine would crack the engine mounts and rip itself out.
Balance shaft in all my furure designs for sure.

[SwePatrick]

In my particular case, parallel twin cylinder, the difference of with or without a balance shaft is the difference between flying or not. Without, the vibration was so bad I was sure sooner or later the engine would crack the engine mounts and rip itself out.
Balance shaft in all my furure designs for sure.

Yes, i feel the same.
But when dynoing my engine before the race a couple of weeks ago(after adding the balancer) i had lost a lot of power, it might be something else i messed up(many other mods), but as it seized in the bigend i can´t get the answers just yet.
From 69hp to the rear wheel to 57hp(when it seized, but it was heading above 60hp)
I figure i might have lost 2-3hp on the balancer, but it would be interesting with actual numbers from someone that has seen the diffrence.

[wobbly]

Frits yes you are correct ( theoretically as always ) but in practice a single balance shaft with eccentric weights on each end
or a single long offset cut shaft has such a profound effect on vibration as too negate any issues such as rocking torques,
Perfect example is when I tried to run TZ400 at 90*.
This prety much eliminated the couple across the crank but created a resultant force ,partially from each pistons position relative to
each other , that buzzed the bars and seat so bad it hurt.
KTMs 250GP parallel twin engine ran at 90* with a shaft and as I knew the designer he allowed me to warm one up in the pit lane at Philip Island.
No discenible vibration at all.

Katinas - once I have racing out of the way , the first thing I will be doing is to get a piston radius cut and lift the C the same amount
as the cylinder is dropped.
I have already fully optimised the timings , so this will be a good pointer for anyone trying this idea.
Then I will do the boost port duct step - and put the dyno sheets on here a s well.
Thanks for that idea.

[jamathi]

When talking balanceshafts, i now run a verion in my engine like the aprilia type.
One weight on each side of crank as close as possible to the center och the crankshaft.

Is there any data recorded with or without balancer, how much power it steals?

I tried this at Garelli.
Without balancer the engine gave 1,7HP LESS!
I just removed the drive gear, without 'opening' the engine.....

[SwePatrick]

I tried this at Garelli.
Without balancer the engine gave 1,7HP LESS!
I just removed the drive gear, without 'opening' the engine.....

*bollocks* i didn´t want to hear that ;)
I was hoping it was robbing power from me, now it means that i have fucked up ;)
But the balancer works just fine =)

[wobbly]

So in Jans case at Garelli , maybe the balance shafts added inertia was a case of the crank needing more inertia anyway.

[andreas]

Gordon Blair is Doc Fleck?

[husaberg]

Gordon Blair is Doc Fleck?

they are two people Robert Fleck and Gordon Blair, but they were both at QUB
https://www.researchgate.net/scientific-contributions/2003745089_Robert_Fleck
https://www.researchgate.net/scientific-contributions/2067762926_G_P_Blair

[andreas]

they are two people Robert Fleck and Gordon Blair, but they were both at QUB
https://www.researchgate.net/scientific-contributions/2003745089_Robert_Fleck
https://www.researchgate.net/scientific-contributions/2067762926_G_P_Blair

Makes better logic.

[jamathi]

[QUOTE=wobbly;1131137968]So in Jans case at Garelli , maybe the balance shafts added inertia was a case of the crank needing more inertia anyway.[/QUOTE

Some people were telling me I was crazy putting a balancer in a racing engine, as it would cost power....
6 years later Honda did it too.
And the others followed....
Around the year 2000 heavier crankshafts were tested successfully.
Aprilia did this on-track

[husaberg]

[QUOTE=wobbly;1131137968]So in Jans case at Garelli , maybe the balance shafts added inertia was a case of the crank needing more inertia anyway.[/QUOTE

Some people were telling me I was crazy putting a balancer in a racing engine, as it would cost power....
6 years later Honda did it too.
And the others followed....
Around the year 2000 heavier crankshafts were tested successfully.
Aprilia did this on-track

Hi Jan, I would have also thought it would allow you to use lighter engine casing and frame etc as it would need to be as strong to absorb the vibrations for a double benefit.
I remember an observation made decades before that on a MX bike with a World champ rider that it lapped the track faster with an effective silencer , not because it made more power, but the rider subconsciously backs off the throttle when its too loud.
I wonder if vibrations would have the same effect on the rider.

[katinas]

Once tested my Honda VF500 F2 without generator flywheel, to see how engine react to less inertia, with intention to put on smaller rotor later.
Immediately effects was very nice, the engine feels faster, riding through corners very light. Motorcycle became so lovely controllable with very nice on and off throttle feeling.
BUT………..some very terrible sound appear at 8000-9200 rpm interval. Its not vibration, but horrible metallic sound, like crank resonated with deformation without flywheel or something when torque rise up. It feels like engine broke down in minutes. From 9500 to 12000 all goes quite.
Then put on rotor again and bad sound disappear.

[husaberg]

Once tested my Honda VF500 F2 without generator flywheel, to see how engine react to less inertia, with intention to put on smaller rotor later.
Immediately effects was very nice, the engine feels faster, riding through corners very light. Motorcycle became so lovely controllable with very nice on and off throttle feeling.
BUT………..some very terrible sound appear at 8000-9200 rpm interval. Its not vibration, but horrible metallic sound, like crank resonated with deformation without flywheel or something when torque rise up. It feels like engine broke down in minutes. From 9500 to 12000 all goes quite.
Then put on rotor again and bad sound disappear.

The VF400/500 had a 360 Crank compared to the VFR series 180 is that right?

[Grumph]

The VF400/500 had a 360 Crank compared to the VFR series 180 is that right?

Pretty sure both the 400 and 500 camchain VF's were 180 degree cranks. But it's been a long while...

Katinas, I don't know what your noise was - but I built a VF500 to run in a speedway car without the alternator rotor. In fact, with that end of the crank cut off flush with the end main bearing. No problems with the lower end lasting. Only the idiot driver, unable to read traffic.

[husaberg]

Pretty sure both the 400 and 500 camchain VF's were 180 degree cranks. But it's been a long while...

Katinas, I don't know what your noise was - but I built a VF500 to run in a speedway car without the alternator rotor. In fact, with that end of the crank cut off flush with the end main bearing. No problems with the lower end lasting. Only the idiot driver, unable to read traffic.

You remember better than i did.
Def a 180 degree.
342633

[TZ350]

342635 342636

The first ever 30 rwhp four stroke F4 Bucket.

New valve springs and an adjust of the rev limiter and that power peak will carry on for another 1000 - 1500 rpm or so. Rev limited to 15,000 at the moment but this engine is proven to be mechanically good for 18.000 RPM.

[husaberg]

342635 342636

The first ever 30 rwhp four stroke F4 Bucket.

New valve springs and an adjust of the rev limiter and that power peak will carry on for another 1000 - 1500 rpm or so. Rev limited to 15,000 at the moment but this engine is proven to be mechanically good for 18.000 RPM.

wow unnaturally aspirated 104cc with 30hp:wait:
Very nice work
342637342638
PS you spelt FZR wrong

[katinas]

Husa, you are right, VF 400 500 is 360 crank.
VFR 400 750 is 180, the same configuration like on NSR 500 V 90 84-85-86, just 84 rotate backward.

Grumph, are you used original cdi or programmable, maybe without rotor, engine needed different ignition curve as piston velocity at TDC on compression phase slower than with flywheel. Maybe I need to play little with ignition timing, without rotor.

[Grumph]

Husa, you are right, VF 400 500 is 360 crank.
VFR 750 is 180, the same configuration like on NSR 500 V 90 84-85-86, just 84 rotate backward.

Grumph, are you used original cdi or programmable, maybe without rotor, engine needed different ignition curve as piston velocity at TDC on compression phase slower than with flywheel. Maybe I need to play little with ignition timing, without rotor.

Used original ignition. TCI - transistor controlled ignition - not CDI. Run battery powered as total loss. No change to the curve or limiter. Went very well on quarter mile dirt ovals.
You may be right about the crank configuration - it was some time ago.
The rotor itself has no effect on the balance factor of the crank. The rotor is balanced as a separate unit. i've never seen a bike crank where the add-on rotor assists or alters the balance factor. On the other hand, it's quite common in cars. A lot of American V8's and V6's have flywheels with assymetric weights to bring the crank into balance.
It's very common to ditch the alternator rotor on big fourstrokes used for racing. There's invariably enough crank inertia that changing ignition curves to compensate isn't necessary.

[katinas]

Used original ignition. TCI - transistor controlled ignition - not CDI. Run battery powered as total loss. No change to the curve or limiter. Went very well on quarter mile dirt ovals.
You may be right about the crank configuration - it was some time ago.
The rotor itself has no effect on the balance factor of the crank. The rotor is balanced as a separate unit. i've never seen a bike crank where the add-on rotor assists or alters the balance factor. On the other hand, it's quite common in cars. A lot of American V8's and V6's have flywheels with assymetric weights to bring the crank into balance.
It's very common to ditch the alternator rotor on big fourstrokes used for racing. There's invariably enough crank inertia that changing ignition curves to compensate isn't necessary.

Thanks, of course its TCI.
With or without rotor there is no vibrations on this engine, but just very bad sound from 8000 to 9200 rpm. without rotor.

Just remember, the first year with Moto2 CBR 600 engines, they had some broken con rods bolts, just because without heavy electric starter, engine vibration character changed. Later it was dissolved with new bolts construction or shape.

[guyhockley]

Yep - if we employ two balance shafts per crankshaft, or the Husaberg-solution with balance weights on the crankshaft.
In our usual layouts there is a definite distance between crankshaft and balance shaft. This distance between a crank force acting in one direction and a balance force acting in the opposite direction causes a fore-aft rocking torque.
The balance shaft solution as used in the Aprilia RSA for example, with outrigger balance masses, allows the smallest distance between crankshaft and balance shaft center lines.
In the Husaberg approach this distance is zero, which in itself is perfect. But if you want to do this right, you'll need balance discs on both sides of the crankshaft and both these discs must rotate counter-crankshaft-wise, which will require a handful of gears.
342597 342598

I heard from a team that road-raced a Husaberg that the balancer bearing was a constant source of trouble. Presumably due to it effectively running at twice engine speed.

[guyhockley]

342647


Interesting that this picture shows the 2 "right" ways to balance a tandem twin, 360 with counter-rotating cranks and 180 with both going the same way, yet the first KR250s reportedly were sent to Europe with counter rotating cranks at 180 and lots of vibration!

[Grumph]

Interesting that this picture shows the 2 "right" ways to balance a tandem twin, 360 with counter-rotating cranks and 180 with both going the same way, yet the first KR250s reportedly were sent to Europe with counter rotating cranks at 180 and lots of vibration!

And the road versions are also 180 deg phasing. Elsewhere on this site, there's a guy asking for help with a tuned road one. i've told him to get in touch with someone local to him who I know rephases them.

[husaberg]

I heard from a team that road-raced a Husaberg that the balancer bearing was a constant source of trouble. Presumably due to it effectively running at twice engine speed.

Husaberg balancer's got heavier in later years but they never installed a wider 2 row bearing until 2006
The Little ones had no issues with the bearing afaik, only the bigger ones. but the oe bearing is exceedingly expensive.
but You can surface grind a wider bearing to fit.

The earlier 2005 ones have to have bearings machined to fit as OE ones are not available but you can get a double row custom narrowed to fit.

PS why would the balancer bearing be running 2x crank speed?
it just runs in the opposite direction doesn't it?
342655

[lodgernz]

PS why would the balancer bearing be running 2x crank speed?
it just runs in the opposite direction doesn't it?

Inside race running forward at crank revs, outer race running backward at crank revs. Balls would be stationary wouldn't they?

[husaberg]

You remember better than i did.
Def a 180 degree.
342633


Husa, you are right, VF 400 500 is 360 crank.
VFR 400 750 is 180, the same configuration like on NSR 500 V 90 84-85-86, just 84 rotate backward.

Grumph, are you used original cdi or programmable, maybe without rotor, engine needed different ignition curve as piston velocity at TDC on compression phase slower than with flywheel. Maybe I need to play little with ignition timing, without rotor.

okay i had a duff picture it seems VF400
https://www.picclickimg.com/d/l400/pict/122909109702_/Honda-VF500-F-1983-Crankshaft-13310-MJ8-40.jpg

https://www.ebay.ie/itm/380757154367

https://www.youtube.com/watch?v=3AjRGTF8cSM

NC30
http://images.southafricanlisted.com/nlarge/vfr_400_nc30_crankshaft_20623114.jpg

https://www.youtube.com/watch?v=_sYIje17ZrI

but NC24
https://i.ebayimg.com/images/g/NZsAAOSwdSRaAUHD/s-l1600.jpg

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

[Frits Overmars]

why would the balancer bearing be running 2x crank speed? it just runs in the opposite direction doesn't it?
Inside race running forward at crank revs, outer race running backward at crank revs. Balls would be stationary wouldn't they?They wouldn't. The inside and outside races rotate at equal, but opposite speeds, right. But as their diameters are different, so are their circumferential velocities.
The circumferential speed of the balls' outsides equals the circ.speed of the outer race, and the circ.speed of the balls' insides equals that of the inner race, which is lower. So the balls and their cage 'slowly' move in the direction of rotation of the outer race.

[guyhockley]

Wa-a-ay back someone who was building a replica, I think, was looking for Clisby information. Don't think it adds anything much but just found this.

[katinas]

Husa, thanks for correction, very interesting, on third generation VFR 400 NC30, they return to VF 500 360 crank configuration and RVF 750 RC45 too

The third generation of VFR400R was the best known version, the VFR400R NC30. This model saw the introduction of the 360° crank firing engine, which is also known as the "big bang" engine. The tachometer red-line was also raised to 14500 rpm.

[speedpro]

They wouldn't. The inside and outside races rotate at equal, but opposite speeds, right. But as their diameters are different, so are their circumferential velocities.
The circumferential speed of the balls' outsides equals the circ.speed of the outer race, and the circ.speed of the balls' insides equals that of the inner race, which is lower. So the balls and their cage 'slowly' move in the direction of rotation of the outer race.

If you assign + and - values to the directions of the crank and balancer to denote direction of travel you get +1 and -1. The difference is 2 which as far as the bearing is concerned, being between the two rotating objects, is the speed of rotation. That is 2X the speed of one of them

[JanBros]

re-read what Frits wrote again, carefully. you are only looking at it from an rpm point of view, but that is not the true speed of the ball's. the ball's speeds depends on their speed vs the speed of their contact patch.

it's the same as both wheels ont the same axle in a car when going through a corner : let's say the car goes through a corner at 50km/h, measured at it's CoG. the inner wheel has to travel a smaller radius than the CoG and the outer wheel a bigger radius than the CoG. Automaticaly this means that the outer wheel is rotating faster (maybe 53km/h) than the inner wheel (maybe 47km/h, the difference depends on the radius of the corner) as it has to cover more distance in the same time to make the corner.

[lodgernz]

They wouldn't. The inside and outside races rotate at equal, but opposite speeds, right. But as their diameters are different, so are their circumferential velocities.
The circumferential speed of the balls' outsides equals the circ.speed of the outer race, and the circ.speed of the balls' insides equals that of the inner race, which is lower. So the balls and their cage 'slowly' move in the direction of rotation of the outer race.

True. However, each ball, although hardly moving geographically, will be rotating at twice the revs it would in a normal single-direction bearing arrangement with one race fixed and the other rotating.
Maybe that's what killed them?

[Grumph]

True. However, each ball, although hardly moving geographically, will be rotating at twice the revs it would in a normal single-direction bearing arrangement with one race fixed and the other rotating.
Maybe that's what killed them?

I'd suspect that what kills them is lubrication failure - balls against cage.

[flyonly]

How did Aprilia turn the rotary valve on their engine? The rotary valve that is replacing the normal reed inlet.

I have seen a picture of an engine which is driven by belts off the clutch but wasnt sure if it was an Aprilia or not

[wobbly]

The Aprilia had its balance shaft across the front gear driven on one side then a bevel drive on the other side.
This drove a small shaft up over the main bearing cavity below the transfer duct entry cutout , and into the back of the offset RV.

[husaberg]

How did Aprilia turn the rotary valve on their engine? The rotary valve that is replacing the normal reed inlet.

I have seen a picture of an engine which is driven by belts off the clutch but wasnt sure if it was an Aprilia or not

Have a look here. close to 600 pics
https://www.kiwibiker.co.nz/forums/album.php?albumid=4839

[jamathi]

How did Aprilia turn the rotary valve on their engine? The rotary valve that is replacing the normal reed inlet.

I have seen a picture of an engine which is driven by belts off the clutch but wasnt sure if it was an Aprilia or not

No belt, that was decided from the beginning!
Gear driven from the balancer shaft.

[Frits Overmars]

Gear driven from the balancer shaft.
342660342661

[Frits Overmars]

each ball, although hardly moving geographically, will be rotating at twice the revs it would in a normal single-direction bearing arrangement with one race fixed and the other rotating.They would, if inner and outer race both had the same diameter, which is physically impossible. As it is, the balls will be rotating at more than twice the revs they would make in a conventional crankshaft bearing.
342663
The picture on the left shows the conventional situation: the yellow inner race, fitted on the crankshaft, rotates counter-clockwise, while the blue outer race is stationary.
The circumferential velocity Vi at point A of the inner race equals inner_rpm x radius CA.
Point B of the red ball is stationary, resting against the outer race. So the circumferential velocity at point A of the ball equals ball_rpm x ball diameter AB.
As there is no slip between inner race and ball, both these circumferential velocities must be equal:
inner_rpm x CA = ball_rpm x AB
ball_rpm = inner_rpm x CA / AB

The picture on the right shows a stationary yellow inner race with the blue outer race rotating clockwise around it.
The circumferential velocity Vo at point B of the outer race equals outer_rpm x radius CB.
Point A of the red ball is stationary, resting against the inner race. So the circumferential velocity at point B of the ball equals ball_rpm x ball diameter AB.
As there is no slip between outer race and ball, both these circumferential velocities must be equal:
outer_rpm x CB = ball_rpm x AB
ball_rpm = outer_rpm x CB / AB

Now we superimpose both situations. The inner race rotates CCW and the outer race rotates CW. Total ball_rpm becomes:
ball_rpm = [inner_rpm x CA / AB] + [outer_rpm x CB / AB]

inner_rpm and outer_rpm are opposite, but both are equal to engine rpm, so:

ball_rpm = engine_rpm x (CA + CB) / AB


I'd suspect that what kills them is lubrication failure - balls against cage.I'm not sure, but you may have nailed it Grumph.

[Haufen]

No belt, that was decided from the beginning!
Gear driven from the balancer shaft.

Did you happen to measure the power consumption of the gear drive for the disc? For example by running the engine non-fired on the dyno with and without the shaft?

[Frits Overmars]

Did you happen to measure the power consumption of the gear drive for the disc? For example by running the engine non-fired on the dyno with and without the shaft?What would that have told you Haufen? The friction of the disc mainly depends on the pressures working on its surfaces, and those are mainly influenced by gasdynamics. No firing engine = no gasdynamics. And the same goes for the friction losses in the bevel gears that are mainly dependent on the power being transmittted through them.

Calculations were performed on the disc drive, in order to determine the required diameter for the drive shaft. The outcome was the 8 mm shaft that has been the cause of a number of engine failures during races, because the calculated friction torque was not nearly as high as the neglected torque peaks, necessary to accelerate or decelerate the disc during gear changes.

[lodgernz]

They would, if inner and outer race both had the same diameter, which is physically impossible. As it is, the balls will be rotating at more than twice the revs they would make in a conventional crankshaft bearing.
342663
The picture on the left shows the conventional situation: the yellow inner race, fitted on the crankshaft, rotates counter-clockwise, while the blue outer race is stationary.
The circumferential velocity Vi at point A of the inner race equals inner_rpm x radius CA.
Point B of the red ball is stationary, resting against the outer race. So the circumferential velocity at point A of the ball equals ball_rpm x ball diameter AB.
As there is no slip between inner race and ball, both these circumferential velocities must be equal:
inner_rpm x CA = ball_rpm x AB
ball_rpm = inner_rpm x CA / AB

The picture on the right shows a stationary yellow inner race with the blue outer race rotating clockwise around it.
The circumferential velocity Vo at point B of the outer race equals outer_rpm x radius CB.
Point A of the red ball is stationary, resting against the inner race. So the circumferential velocity at point B of the ball equals ball_rpm x ball diameter AB.
As there is no slip between outer race and ball, both these circumferential velocities must be equal:
outer_rpm x CB = ball_rpm x AB
ball_rpm = outer_rpm x CB / AB

Now we superimpose both situations. The inner race rotates CCW and the outer race rotates CW. Total ball_rpm becomes:
ball_rpm = [inner_rpm x CA / AB] + [outer_rpm x CB / AB]

inner_rpm and outer_rpm are opposite, but both are equal to engine rpm, so:

ball_rpm = engine_rpm x (CA + CB) / AB



Frits, thank you for this analysis, but I think there is an error.
You appear to have omitted the factor 2*PI in the calculation of the circumferential velocities of the inner and outer races, and the factor of 1*PI in the circumferential velocity of the balls. The PI cancels out of course, but because you have used the diameter of the ball rather than its radius, the factor of 2 is not cancelled.
If I'm right, the final equation is:

ball_rpm = engine_rpm x 2 x (CA + CB) / AB

Or maybe not...

[flyonly]

Is the a recommended volume calculation for a still air box for a given CC capacity or carb inlet size?


Sent from my iPhone using Tapatalk

[Michael Moore]

the calculated friction torque was not nearly as high as the neglected torque peaks, necessary to accelerate or decelerate the disc during gear changes.

An engineer at Tilton Engineering (clutches) told me that their first go at specifying a clutch for the Wittner Guzzi racer didn't work (too small) because they'd ignored the torque spikes seen a a large displacement twin cylinder race bike.

cheers,
Michael

[jamathi]

Did you happen to measure the power consumption of the gear drive for the disc? For example by running the engine non-fired on the dyno with and without the shaft?

No, never!

[jamathi]

What would that have told you Haufen? The friction of the disc mainly depends on the pressures working on its surfaces, and those are mainly influenced by gasdynamics. No firing engine = no gasdynamics. And the same goes for the friction losses in the bevel gears that are mainly dependent on the power being transmittted through them.

Calculations were performed on the disc drive, in order to determine the required diameter for the drive shaft. The outcome was the 8 mm shaft that has been the cause of a number of engine failures during races, because the calculated friction torque was not nearly as high as the neglected torque peaks, necessary to accelerate or decelerate the disc during gear changes.

The problem of breaking shafts was solved by fitting a shock absorber.
Something like old English bikes had....

[jonny quest]

A shock absorber to the hub of disk valve?

[husaberg]

A shock absorber to the hub of disk valve?

A shaft the correct dimensions and materials.
Old daigo and pommy ohc shitters often had waisted shafts but they only turned at half engine speed at half the revolutions.
342670 342669
I would muse that it allows them to act as a torsion spring rather than saving weights
Much like these ATV axles?
342668
later...........

3) Design is another very effective method of increasing axle shaft durability. The two different designs are waisted and non-waisted. In most applications a waisted design is a superior design. What waisted means is having a section of the shaft that has a smaller diameter than the minor spline diameter. The objective of this is to give the axle a larger section that it can twist instead of concentrating this twisting on a very small section of the shaft. The ability to twist allows the shaft to absorb greater torque and shock loads. We have done a substantial amount of development using both computer modeling and destructive testing and have discovered that the design of the waisted portion of the axle shaft is critical to gaining the maximum benefit of from it. Factors such as the length, diameter and radiuses have a significant impact on the effectiveness.

later again Grump told be Colin Chapman once decided to use a real thin steering shaft, sure enough it turned out to be zstrong enough not to break, but added a whole extra revolution to the steering lock in twist.:innocent:

[Frits Overmars]

Frits, thank you for this analysis, but I think there is an error. You appear to have omitted the factor 2*PI in the calculation of the circumferential velocities of the inner and outer races, and the factor of 1*PI in the circumferential velocity of the balls. I only needed the relation between those circumferential velocities, so there was no need to calculate each of them in meters per second.


The PI cancels out of course, but because you have used the diameter of the ball rather than its radius, the factor of 2 is not cancelled. The diameter AB of the ball is the radius with which point A circles around point B in the left picture and with which point B circles around point A in the right picture.

[lodgernz]

I only needed the relation between those circumferential velocities, so there was no need to calculate each of them in meters per second.

The diameter AB of the ball is the radius with which point A circles around point B in the left picture and with which point B circles around point A in the right picture.

Ah. Think I've got it now. Gnarly.

[RZ350]

Greetings people,

I am looking for pointers to get more hp from RZ350. First item to change is the ignition system with a goal of reducing the mass on the l/h crank which i assume means swapping to total loss?????

my ears are open...

Cheers

[Haufen]

What would that have told you Haufen? The friction of the disc mainly depends on the pressures working on its surfaces, and those are mainly influenced by gasdynamics. No firing engine = no gasdynamics. And the same goes for the friction losses in the bevel gears that are mainly dependent on the power being transmittted through them.

More than enough to get an idea about the friction penalty of the rear disc of the RSA vs the side disc of the RSW. The gasdynamics should be quite comparable between those two engines, and as long as the disc is driven by the shaft and the throttle open (assuming a warm engine run down with cut ignition), the load on the bevel gears should be quite realistic, too.

Of course there are better and more precise ways to find out about the friction penalty, but Jan already said that he did not have the tools / test equipment available to calculate e.g. FMEP.

[andreas]

Greetings people,

I am looking for pointers to get more hp from RZ350. First item to change is the ignition system with a goal of reducing the mass on the l/h crank which i assume means swapping to total loss?????

my ears are open...

Cheers

A tz 350 portmap might help. Also, rd lc 125 reeds fit with a minimum of grinding and are much bigger than the yz 85's that ppl like to use.

[Muhr]

ball_rpm = engine_rpm x (CA + CB) / AB



ball_rpm = engine_rpm x 2 x (CA + CB) / AB

Or maybe not...

you both mean maybe?
Ball RPM = Engine RPM * ((CA + CB * 2) / AB)

[TZ350]

First item to change is the ignition system with a goal of reducing the mass on the l/h crank which i assume means swapping to total loss?????

my ears are open...

Cheers

Follow this link, a lot of info on how to make a light weight battery less ignition. 12V Generator plus Digital Ignition.


329021

How to make a decent light weight racing 12 Volt generator stater for the Suzuki GP/TF/TS RG50 from a Lifan after market magneto kit. We have spun these to 14,000 rpm plus on the dyno and they have proved reliable on the track.

[F5 Dave]

Greetings people,

I am looking for pointers to get more hp from RZ350. First item to change is the ignition system with a goal of reducing the mass on the l/h crank which i assume means swapping to total loss?????

my ears are open...

Cheers
Decent pipes, PWK28mm carbs, bit of port work, job done. Ignition will be fine to that point.

[RZ350]

Thanks F5 Dave

"Decent pipes, PWK28mm carbs, bit of port work, job done. Ignition will be fine to that point."

JL pipes, Vforce4 reeds, zeeltronic mapping ignition/pv controller. Standard 26mm carbs 320main. I am at "that point" so i want to drop the rotor weight to protect the crank before i push for HP.......

I have the standard RZ rotor approx 410g and 125mm dia and would like to reduce that to something smaller and lighter.

QUESTION??

If i swap a 410g 125mm rotor for a 410g 95mm rotor, the weight is the same but what would be the effect of the smaller diameter?

Cheers

M

[Frits Overmars]

ball_rpm = engine_rpm x (CA + CB) / AB
ball_rpm = engine_rpm x 2 x (CA + CB) / AB
Or maybe not...
you both mean maybe?
Ball RPM = Engine RPM * ((CA + CB * 2) / AB)No........

[F5 Dave]

I still have std rotor on my 100hp,350 (500cc) it's fine and makes for nice road manners. But yes reducing the diameter will achieve the effect of increasing acceleration of flywheel, at least while unloaded. Increasing the acceleration of a vehicle has other inconvenient forces to overcome which horsepower will be required.

[Grumph]

I still have std rotor on my 100hp,350 (500cc) it's fine and makes for nice road manners. But yes reducing the diameter will achieve the effect of increasing acceleration of flywheel, at least while unloaded. Increasing the acceleration of a vehicle has other inconvenient forces to overcome which horsepower will be required.

I actually have an aircooled RD350 racebike here at present - to which someone has adapted an RD400 rotor and ignition.
It wouldn't have been my preference. Very heavy. I'm sympathetic to RZ350's desire to lighten the mass on the crank end.
The owner of this one has no budget to progress it so it's likely to be for sale.

[Muciek]

For older aircooled ones I have made replacement from GY6 150W one (weights around 800g if I remember correctly). Need to fab the backing plate and taper reduction and since there is no place for 2nd sensor (street setup with cover ect ect , maybe for racing and custom cover You could fit 2 ) I have tig welded a strip of steel for 2nd cylinder on the rotor. If someones need a 60W (a lot lighter) they can go for the ones from scooters without sensors, they give 2 sparks per rev.
342675342676

[Pursang]

Thanks F5 Dave
"Decent pipes, PWK28mm carbs, bit of port work, job done. Ignition will be fine to that point."

JL pipes, Vforce4 reeds, zeeltronic mapping ignition/pv controller. Standard 26mm carbs 320main.

I am at "that point" so i want to drop the rotor weight to protect the crank before i push for HP.......
I have the standard RZ rotor approx 410g and 125mm dia and would like to reduce that to something smaller and lighter.

QUESTION?? If i swap a 410g 125mm rotor for a 410g 95mm rotor, the weight is the same but what would be the effect of the smaller diameter?

Based on some very brave assumptions a 0.41kg x 95mm (external) rotor will have about half the Moment of Inertia of a 0.41kg x 125mm one.

Is this a Good Thing? You will need to test it in your particular application!

What F5 Dave said re: acceleration, and also the recent discussion here, about lack of inertia in an engine restricting top end and over-run.
As far as protecting the crank.... Imagine the loads on the crank and bearings with No flywheel effect present, how low do you want to go?

Mountains of info online re: tuning RZ350's (and the whole family). Everything has been done and tested, 1000 times before.
Be wary of some the Banshee info, Lots of those people just like spending heaps and heaps of money!!

Changing ignition doesn't seem to be a priority. Some recommend welding the crank for road racing.

When you say "push for HP" do you mean more revs or more torque in the standard rev range?

Here is a nice list of progressive performance options .https://wilsonperformance.net/services/rz350-ypvs/

cheers, Daryl.

[41juergen]

That's how I did it to my RZ, I made another plate, changed the taper on the crank, mounted the whole generator setup of a TZ250 3TC to it and use a Zeel incl. a TPS. The generator was rewinded as I run the ignition energy out of the battery, no seperate coil needed.

342680342681,

[Muhr]

No........


:scratch:Ok you don't refer to how fast it rotates around its axis but how fast it travels around the bearing clockwise.

Edit: well that's not the case, sorry
I'm lost!:Oops:

[RZ350]

When you say "push for HP" do you mean more revs or more torque in the standard rev range?

Still trying to add the quote to the reply.....

The bike is a F2 pre-89. I have a motor prepared by wobbly for someone else for road use i bought on Trade me that gives 57hp from 8,500 to 10,500. (Too slow)

I want more power and slightly higher revs. I have a second motor under reconstruction ( left side crank nearly touching case when opened up)
and want to lighten the load by shedding the rotor weight. I dont want to stroke the crank

We fitted a powerdyno race ignition to a TZ350a/b motor and it ran well and the rotor weight was 190g from memory. I have been thinking about fitting the powerdyno and then working on trying to trigger the YPVS controller running from a battery. Also thinking about taking the magnets out of the standard rotor (thats got to shed a fair chunk of weight) and then run a zeeltronic with PV on total loss battery and use the yamaha pick up (or whats required) to trigger off the existing lugs on the standard rotor.
Would like some discharge rates on batteries to get my head around battery size ....(wind turbine?????)

cheers
M

[sispeed]

Also thinking about taking the magnets out of the standard rotor (thats got to shed a fair chunk of weight)
A friend tested this and reverted it due to no or negative effect. So I would not recommend that
Regards Siggi

[Grumph]

Would like some discharge rates on batteries to get my head around battery size ....(wind turbine?????)

cheers
M

It's not the discharge rate you need - it's the running current draw of your Zeeltronic. A big 4T running a basic Dyna on total loss draws around 1.6 amps.
For our short races, I find a 6 AH battery is sufficient for a days racing. Next time you fire up the one with the Zeeltronic, put a multimeter in circuit for a baseline on current draw.

I'm surprised no-one is shouting Ignitech.

[wobbly]

Total loss is not the answer when using a digital cdi , as they perform best when paired with a charging system running at 14,2V minimum.
The best rotor to use is a 800g 100mm unit as used on dozens of smaller Jap copy engines.
The output can be increased in many cases by winding the redundant ignition source coil bobins with extra 12V windings.
Then you machine a small area on the outer face and heat slip fit a thin ring onto this - enabling the simple 3 lobe setup for an Ignitech
to trigger two cdi differentially from a single trigger ( mounted in the stock case pocket area. )
This gets rid of using twinspark per rev, that fires both plugs at the same time.
Using this simple setup gives the best inertia compromise for the big twin has plenty of sprk power using RGV250 coils, and of course
the Ignitech has the PV servo control onboard,

[F5 Dave]

Ahh, ok it's a racebike. That wasn't clear


I replaced my older zeel with ignitech just easy. (Old zeel on shelf if keen)

Mine as it came had TZR reedblocks and PWK28s. Massive improvement over std setup.

You'll need to rebuild the crank with decent stuff if you want to rev higher. You can buy stroked cranks of various quality (research) . It isnt a bad idea as it gets you closer to square which brings benefits beyond just the cc increase.

I sold my Toomey pipes to Sam down in chch, I don't think he ever got around to putting them on. There will be much better pipes but depends upon the budget. Managed 70hp so they aren't total dross.

[TZ350]

I'm surprised no-one is shouting Ignitech.

12Volt AC Scooter/Pitbike type of generator, Voltage rectifier/regulator with a 25Volt/2500uF capacitor and Sparker DCCDIP2 Race"Ignitec" is our setup of choice.

No battery required and it still runs a power valve ok. Just push and go.

When tested, at 13,000 rpm, with one channel of the CDI running the Ignitech was drawing 1.5A so a twin I guess would be 3A. At idle it was 0.2A.

With a CDI the current draw goes up with RPM as the capacitor is being charged more often.

With a normal inductive ignition the current draw goes down with rpm as the points are closed on average for less time.

[wobbly]

Just looked at PowerDyno for RD/LC/TZ - wouldnt run it if they gave at away.
2* of retard from 6 to 12,000 - joke.

[husaberg]

Just looked at PowerDyno for RD/LC/TZ - wouldnt run it if they gave at away.
2* of retard from 6 to 12,000 - joke.

This is the trace i have seen for the race ignition ie no lighting Vape ie formally called Dowerdyno
http://www.powerdynamo.biz/deu/systems/7101/advance.gif

Oh you are right. they use the same unit and curve for all their race ignitions it seems.

Rex caunt is back in business they used to maake an race only ignition for the Yamaha twins
342695

Honda MB50
MB5 ignition
Ignition timing "F" mark 19 +or- 3 degrees BTDC @ 3000 rpm
Full retard 10 +or- 5 degrees BTDC @ 7000 rpm

http://www.carmoelectronics.co.uk/index.php?main_page=product_info&products_id=564
http://www.carmoelectronics.co.uk/pictures/ignition-set/Yamaha%20TZ-RD-YR-YD-ignition-curve-STK-043.jpg

PVL
https://www.ebay.ie/itm/PVL-Twin-Ignition-for-2-Cylinder-180-for-RD-250-350-with-Adapterplate-/152877764266?hash=item2398398eaa
https://cdn11.bigcommerce.com/s-8b7e9eowlk/images/stencil/1280x1280/products/80792/281150/PVL_Ignition_System_2__39978.1549910590.jpg

HPI
https://www.hpi.be/item.php?item=210K176
https://www.hpi.be/curves/210_curve_2c_130_full.png

electrix world
https://www.electrexworld.co.uk/acatalog/STK-043.pdf
https://lh3.googleusercontent.com/ndp6yin0fQx0LWjkexsXbpXAs1_Qsfubdh_1tsHNUnl4u_KE1P KZKxRsOjgVPHjUkt-BUx4=s170

Poewer spark programmable TCI
https://www.power-spark.de/index_en.html
https://www.power-spark.de/images/Lieferumfang_1ie.jpg

[flyonly]

Dry Clutch for 50cc

Has anyone tried fitting a dry clutch to get out of the oil drag? What would you use as a donor if you were trying to fit one?

[jbiplane]

This is automatically tuning system FAI EFI for 4-stroke. Just start and play by throttle few minutes to calibration.
https://www.ebay.com/itm/FAI-motorcycle-scooter-buggy-moped-UAV-EFI-engine-Electronic-Fuel-Injection-kit-/273178456487
Seems should be simple and elegant way use it on 2-strokes?

[TZ350]

This is automatically tuning system FAI EFI

Automatically tuned, how?

[husaberg]

Automatically tuned, how?

I would think lamda like a holley efi

[F5 Dave]

Nanobots


(tiny elves proved not to be up to the task)

[TZ350]

I would think lamda like a holley efi

It does not seem to have any O2 sensor with the kit.

[husaberg]

It does not seem to have any O2 sensor with the kit.
my guess is it generic pics or its tucked in behind ,its listed in the blurb..........

Initialization

If your engine works well with the kit,please ignore this,in case of following situation,you may need the initialization:
1.Your engine works not very well.
2.Oxygen sensor is newly mounted.
3.ECU is replaced.
4.Injection assembly is replaced

009 oxygen sensor fault.
https://www.ebay.com/itm/FAI-motorcycle-scooter-buggy-moped-UAV-EFI-engine-Electronic-Fuel-Injection-kit-/273178456487

its also in a photo
https://ae01.alicdn.com/kf/HTB1H1tHQFXXXXbTXVXXq6xXFXXXl/222044071/HTB1H1tHQFXXXXbTXVXXq6xXFXXXl.jpg


FAI USER MANUAL


The 3 oxygen sensor seat is welded to the front end of the exhaust pipe, the exhaust pipeand the installation of the oxygen sensor installed. (welding standard chart)

The FAI injector in the EFI system has two interfaces, one is the supply port (Language), an oil return port (exhaust port, with fine) fuel switch pipe and exhaust pipe, no anti reverse. Avoidexcessive pressure, tubing is bent or curved around too much, otherwise it will lead to the oilpipeline is blocked or accumulated in a large number of bubbles. Especially the exhaust oil return pipe to ensure the above to ensure a smooth upward from the bubble.

[flyonly]

This is automatically tuning system FAI EFI for 4-stroke. Just start and play bt throttle few minutes to calibration.
https://www.ebay.com/itm/FAI-motorcycle-scooter-buggy-moped-UAV-EFI-engine-Electronic-Fuel-Injection-kit-/273178456487
Seems should be simple and elegant way use it on 2-strokes?

Where would you put the O2 sensor on a 2 stroke? Middle or stinger cone?


Sent from my iPhone using Tapatalk

[TZ350]

my guess is it generic pics or its tucked in behind ,its listed in the blurb..........
009 oxygen sensor fault. https://www.ebay.com/itm/FAI-motorcycle-scooter-buggy-moped-UAV-EFI-engine-Electronic-Fuel-Injection-kit-/273178456487

its also in a photo

Good spotting, I didn't see that. Wide or narrow band O2 sensor and what air/fuel ratio or lambda would the CPU be automatically tuned to?

[husaberg]

Good spotting, I didn't see that. Wide or narrow band O2 sensor and what air/fuel ratio or lambda would the CPU be automatically tuned to?

No idea but as its for a foul stroke so i guess stoich.
pretty sure one of those you used had a autotune function?

[TZ350]

Where would you put the O2 sensor on a 2 stroke? Middle or stinger cone?

I put mine in the rear cone near the stinger.

342708

[TZ350]

pretty sure one of those you used had a autotune function?

Problem with any auto tune for a two stroke is accounting for the oxygen in the short circuiting air.


342709

The cylinder can have a perfect air/fuel mixture trapped inside when the exhaust port closes but the O2 sensor still thinks it sees a lean condition. The effect varies depending on TPS and RPM and whether its on the pipe or not. The best result is at WOT and peak torque where there is maximum trapping efficiency and the least short circuiting. Every where else is worse.

You can have a target air/fuel map for the ECU to aim at. But for every RPM vis TPS position on the map the air/fuel ratio to look for is still pretty much a guess. In my experience the motor can be running perfectly but the indicated air/fuel ratio can be anything from 18:1 to 10:1 and changes continuously as the load and rpm changes.

[husaberg]

Problem with any auto tune for a two stroke is accounting for the short circuiting air.


342709

The cylinder can have a perfect air/fuel mixture trapped inside when the exhaust port closes but the O2 sensor still thinks it sees a lean condition. The effect varies depending on TPS and RPM and whether its on the pipe or not. The best result is at WOT and peak torque where there is maximum trapping efficiency and the least short circuiting. Every where else is worse.

You can have a target air/fuel map for the ECU to aim at. But for every RPM vis TPS position on the map the air/fuel ratio to look for is still pretty much a guess. In my experience the motor can be running perfectly but the indicated air/fuel ratio can be anything from 18:1 to 10:1 and changes continuously as the load and rpm changes.

Frits sumed it up
insert quote here.

So you are aware that a Lambda sensor cannot tell you at all if a mixture is rich or lean. It can only tell you whether there is oxygen present in the exhaust gases.
Scavenging losses at low revs as a result of washed-through mixture will make sure of this oxygen presence. And misfiring because of an overly-rich mixture can enhance this presence even more, so enrichening the mixture at low revs may well worsen the 'lean' situation.
There are three things you can do about it. The first is copying Flettners cylinder with variable transfer timing. The second, somewhat simpler option, is to shift down when the engine threatens to drop out of its power band. The third option is to get an engine without a power band (and without two-stroke power),
a so-called foulstroke or Falschtakter :msn-wink:.

.


And how is this system going to detect a lean condition? An O2-sensor cannot do that; it can only detect the presence of unused oxygen in the exhaust gases.
If the mixture is so rich that the engine misfires, that O2-sensor will detect O2 and then this wonderful system will enrichen the mixture even more. Been there....
...

[TZ350]

.
Yes, auto tune is not so straight forward with a two stroke.

[jbiplane]

.
Yes, auto tune is not so straight forward with a two stroke.
I saw at least perfectly working autotune systems
2-stroke 3w model engines
2-stroke Stihl 500 chainsaws and cutters
Mixture lean on medium rpm and rich on high revs

Zhejiang Fai Electronics Co. have 2-stroke solutions as well
http://www.freepatentsonline.com/6964263.pdf

Some additional info
http://fuyangdali.com/en/product/33.html
http://3moon-house.com/upload/201607/18/201607181739542500.pdf

[Pursang]

I put mine in the rear cone near the stinger.

342708

What about using a Hydrocarbon or CO or CO2 sensor here instead of looking for O2?
Any of these would be a better indicator of fuel mixture/combustion efficiency.

For a race engine a base level of hydrocarbon would indicate that you have sufficient fuel to consume all the O2 available.
For road use aiming for max CO2 would ensure complete combustion. (and the possible wrath of concerned citizens).

Cheers, Daryl

[SwePatrick]

Lubrication and cooling bigend connectionrod.

As my bigend seized i´m about to rebuild it with a fresh rod, but i´m thinking maybe leave the axial plates/discs on the bigend and guide the rod in the piston instead.
I figure i might loose some friction also, and by this not build as much heat in the bigend.
And when having no axial plates/discs there are more space to cool it and lubricate it.

Is it a good idea?

[TZ350]

What about using a Hydrocarbon or CO or CO2 sensor here instead of looking for O2?

Hi Daryl. I had not thought of that. I wounder if its a practical possibility .... interesting....:scratch:

[diesel62]

What about using a Hydrocarbon or CO or CO2 sensor here instead of looking for O2?
Any of these would be a better indicator of fuel mixture/combustion efficiency.

For a race engine a base level of hydrocarbon would indicate that you have sufficient fuel to consume all the O2 available.
For road use aiming for max CO2 would ensure complete combustion. (and the possible wrath of concerned citizens).

Cheers, DarylI found putting the sensor there gives bad readings. I think the gas is too turbulent. Works better at the end of the stinger as there is no reversion

Sent from my SM-P555 using Tapatalk

[TZ350]

i´m thinking maybe leave the axial plates/discs on the bigend and guide the rod in the piston instead. Is it a good idea?

The Suzuki RGV250 did this and I used one of their Rod kits in my single cylinder 125 for years, it worked well.

342710

The smaller washers next to the rod are used to centralize the bigend bearing. The rod centralizing washers can be seen on the little end pin.

[TZ350]

I found putting the sensor there gives bad readings. I think the gas is too turbulent. Works better at the end of the stinger as there is no reversion .

Muffler end or the cone end of the stinger? I think Wobbly has talked about doing it that way too.

[diesel62]

Muffler end or the cone end of the stinger? I think Wobbly has talked about doing it that way too.Outlet of muffler. I made an adapter so it didn't impead the gas flow. Just make sure you don't have any air leaks between muffler and expansion or stinger

Sent from my SM-P555 using Tapatalk

[Muhr]

No........




I'm lost!:Oops:

Tricky but obvious when you see it!

https://vimeo.com/353145011

[wobbly]

After testing every position of Lambda sensors I found the most consistant results are had placing it right at the start of the
perf in the muffler.
This seems to " average " the reading over several cycles.
At the mufflers other exit end the sensor is contaminated with fresh air , being pulsed back and forth by the wave action
reflecting off atmosphere.

[Pursang]

I wonder if its a practical possibility .... interesting....:scratch:

Interesting discussion paper on High Temp Gas sensing for Automotive use, including 2 Strokes:
https://www.researchgate.net/publication/263009979_Solid-state_gas_sensors_for_high_temperature_application s_-_a_review

If anyone can possibly do it practically, I'm sure you can.

Wobbly, what sort of temperatures are present at the start of the muffler?
If under say 600C, current sensor technology is more than up to the task.

Cheers Daryl

[jamathi]

Lubrication and cooling bigend connectionrod.

As my bigend seized i´m about to rebuild it with a fresh rod, but i´m thinking maybe leave the axial plates/discs on the bigend and guide the rod in the piston instead.
I figure i might loose some friction also, and by this not build as much heat in the bigend.
And when having no axial plates/discs there are more space to cool it and lubricate it.

Is it a good idea?

Yes, a very good idea!

[Muhr]

https://usercontent1.hubstatic.com/6245674.jpg
why is not a MAF sensor a good option?

[TZ350]

why is not a MAF sensor a good option?

Probably would be if it was at the entrance to a large well sealed air box.

It would probably work particularly well with a multi cylinder like the Suter MMX500 road racer.

[Pursang]

Use the MAF as a 24/7 flap valve??

Cheers, Daryl

[Pursang]

These Guys:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=2ahUKEwjhxKSltvrjAhXFbCsKHaC_BvwQFjADegQIAxAC&url=https%3A%2F%2Fwww.ama-science.org%2Fproceedings%2FgetFile%2FZwZkZt%3D%3D&usg=AOvVaw0dLw8gQuazkdvCb41UXgS8
Used one of these:

https://docs-emea.rs-online.com/webdocs/15a6/0900766b815a66d8.pdf

In the stacks of wood stoves, far outside its rated operating temp, for 150 mins, with results not dissimilar to dedicated industrial units.

Cheers, Daryl.

[andreas]

Lubrication and cooling bigend connectionrod.

As my bigend seized i´m about to rebuild it with a fresh rod, but i´m thinking maybe leave the axial plates/discs on the bigend and guide the rod in the piston instead.
I figure i might loose some friction also, and by this not build as much heat in the bigend.
And when having no axial plates/discs there are more space to cool it and lubricate it.

Is it a good idea?

Would like to see your evaluation on this, if you proceed.

[yatasaki]

Lubrication and cooling bigend connectionrod.

As my bigend seized i´m about to rebuild it with a fresh rod, but i´m thinking maybe leave the axial plates/discs on the bigend and guide the rod in the piston instead.
I figure i might loose some friction also, and by this not build as much heat in the bigend.
And when having no axial plates/discs there are more space to cool it and lubricate it.

Is it a good idea?
RG500 has same arrangement. Be careful with washers material and arrangement as upper bearing is wider than rod.
Hi everybody, been occupied for time beeing with racing, broken arm, racing WITH broken arm, and v16 diesel burned crankshaft

[Pursang]

I wonder if its a practical possibility .... interesting....:scratch:

Might be Rocket Science:

https://ntts-prod.s3.amazonaws.com/t2p/prod/t2media/tops/pdf/LEW-TOPS-112.pdf

NASA is looking for partners to develop & use these in new applications.

Bleeding Edge 2 Stroke technology might be appropriate, after all there is a technical bonding link, way back to Walter Kaaden, V-1 & 2's & WW2

cheers, Daryl.

PS. Don't mention the War! I did once... but I think I got away with it!

[Pursang]

Hydrocarbon sensors available in NZ for less than 20 Kiwi Dollars.

http://www.etech.kiwi/4310-gas-sensor-hydrocarbon/

At that price you could replace them after each Heat (pun intended).

Cheers, Daryl.

[peewee]

RG500 has same arrangement. Be careful with washers material and arrangement as upper bearing is wider than rod.
Hi everybody, been occupied for time beeing with racing, broken arm, racing WITH broken arm, and v16 diesel burned crankshaft

most conventional engines has the guiding discs on the big end but suzuki had several engines with guiding discs on the small end as well. if you remember the lt250 and lt500 qaudzilla

[husaberg]

most conventional engines has the guiding discs on the big end but suzuki had several engines with guiding discs on the small end as well. if you remember the lt250 and lt500 qaudzilla

As was the RGV250
https://www.oemmotorparts.com/fiche-l/SU4_-2077792.png

[SwePatrick]

RG500 has same arrangement. Be careful with washers material and arrangement as upper bearing is wider than rod.
Hi everybody, been occupied for time beeing with racing, broken arm, racing WITH broken arm, and v16 diesel burned crankshaft

I´ll modify the piston to accept the rod with correct clearance, as is now, the rod is wider then inside of piston ;)

[SwePatrick]

Successfully relocated pins:

https://forumbilder.com/images/2019/08/12/rings.jpg

[husaberg]

https://www.youtube.com/watch?v=YKoWqTQ2woQ

[Pursang]

.
.
EFFEN Football!!?? :shit:

Is this the ESEsWET Jumping the Shark Moment? :facepalm:

http://www.freakingnews.com/pictures/113000/Motorcycle-Jumping-a-Shark-in-a-Pool--113201.jpg

Cheerless Daryl.

[41juergen]

May be some of you have seen that, I like it...:Punk:

http://forum.2temps.fr/viewtopic.php?f=8&t=19432

[SwePatrick]

When designing a crankshaft, Lesson number one: Do NOT exaggerate the interferencefit, sometime somebody maybe want to rebuild it.
Quite disappointed now as the bolt wouldn´t move when pressing with a shitload of force(over 40tonnes).
And the material around the lighteningpockets on the inside collapsed instead.

342752

Sad day.

[F5 Dave]

Oh. That's upsetting

[TZ350]

.
If the big end and rod are completely ruined the trick is to hold the rod in a vice. And cut through the rod and big end pin with a disk grinder. Then you have the two flywheel halves to deal with separately. Much easier to place one crank half in the press to press the remains of the pin out.

[guyhockley]

Presumably it took a lot, or excessive, amount of force to assemble it in the first place, and was difficult to align?

[SwePatrick]

It was almost impossible to align the crank i noticed earlier, it took very high forces to get it to move just a couple of thousands of a millimeter.

[Ocean1]

.
If the big end and rod are completely ruined the trick is to hold the rod in a vice. And cut through the rod and big end pin with a disk grinder. Then you have the two flywheel halves to deal with separately. Much easier to place one crank half in the press to press the remains of the pin out.

I once had a similar problem, compounded by a lack of intelligence in failing to support crank halves immediately surrounding the pin and over enthusiastic use of a very large press. Better tooling might have worked, but experience with similar assemblies suggested another approach. Pushing the end of a shaft swells that end and increases the radial pressure against its bore, I've felt this many times where it takes more force to remove a shaft than it took to initially install it, in some cases the increase in force is indeed enough to distort the shaft beyond it's elastic limit, at which point you're buggered.

One solution is to make the pin hollow, (which is common enough) but not for its full length. Pressing against the bottom of this pin hole is effectively the same as pulling it out, which slightly stretches it, microscopically reducing the diameter, the opposite effect of applying force to the upper face. The force required to disassemble the shaft where I first used that design is about 60% of the original with the same fit.

[husaberg]

The mother country had this stuff sorted years ago:innocent:
342753342754342755

[TZ350]

342758

The Yamaha KT100 kart engine used steel plugs inserted in the end of the big end pin to expand it and lock it in place.

To disassembly it, before pressing, you drilled one plug out and then tapped the other side out with a pin punch.


Pushing the end of a shaft swells that end and increases the radial pressure against its bore, I've felt this many times where it takes more force to remove a shaft than it took to initially install it, in some cases the increase in force is indeed enough to distort the shaft beyond it's elastic limit, at which point you're buggered.

One solution is to make the pin hollow, (which is common enough) but not for its full length. Pressing against the bottom of this pin hole is effectively the same as pulling it out, which slightly stretches it, microscopically reducing the diameter, the opposite effect of applying force to the upper face. The force required to disassemble the shaft where I first used that design is about 60% of the original with the same fit.

I like Ocean1's approch very much.

[andreas]

Why not disassemble it from the other dirction, one half at the time?

[Michael Moore]

The problem of breaking shafts was solved by fitting a shock absorber.
Something like old English bikes had....

It appears that the twin cylinder Seadoo model 580 2T that takes the rotary valve drive from between the cylinders has a spring on the drive shaft that may let the skew gear float a bit which might serve as a damping device.

cheers,
Michael

[ceci]

If the sleeve thing doesn't work, we will just lower the exhaust ports and re cast as an FOS cylinder.


Sorry, I'm curious, your new project is related to this statement.

[husaberg]

It appears that the twin cylinder Seadoo model 580 2T that takes the rotary valve drive from between the cylinders has a spring on the drive shaft that may let the skew gear float a bit which might serve as a damping device.

cheers,
Michael
When Jan said lik a pommy i was thinking this, it could be the same set up but with the cam so steep and the spring that is so strong it cant go to the next slot in the cam changing the timing?
342763

[jbiplane]

https://www.youtube.com/watch?v=YD1suLdczv8&feature=youtu.be
Dont consider it as advertisiment. I going to make smaller version baced on this. The first OPEN SOURCE Tuner Studio compatible Stm32 based engine management system. Unlike Microsquirt or Speeduino it is "real time" system which will allow got max of your engine.

[philou]

Hello,

Do you have pictures of the v4 swissauto?

Other than the one that have seen it everywhere

For example the open crankcase

[Muhr]

When designing a crankshaft, Lesson number one: Do NOT exaggerate the interferencefit, sometime somebody maybe want to rebuild it.
Quite disappointed now as the bolt wouldn´t move when pressing with a shitload of force(over 40tonnes).
And the material around the lighteningpockets on the inside collapsed instead.

342752

Sad day.


I have no problem with small crap throwing campaigns directed at me. but leave him out thank.

[TZ350]

[video=youtube;YD1suLdczv8] The first OPEN SOURCE Tuner Studio compatible Stm32 based engine management system.

I like that its Tuner Studio compatible and open source. Can you tell us more about its features please.

[husaberg]

Hello,

Do you have pictures of the v4 swissauto?

Other than the one that have seen it everywhere

For example the open crankcase

Here is all i have.
https://www.kiwibiker.co.nz/forums/album.php?albumid=4833

[jbiplane]

I like that its Tuner Studio compatible and open source. Can you tell us more about its features please.

Please visit forum https://rusefi.com/ and https://rusefi.com/forum to understand better
Your comments at https://rusefi.com/forum/viewtopic.php?f=4&p=34177#p34177 highly appreciated

[guyhockley]

Hello,

Do you have pictures of the v4 swissauto?

Other than the one that have seen it everywhere

For example the open crankcase

Got this one showing the bottom/rear case, although there's a bit of the top/front case behind it.

[TZ350]

342775 342776

Playing on the dyno with Cotswold and Chambers. Cotswold's new 50cc F5 Bucket, 16 rwhp.

[F5 Dave]

That's indeed a good effort. Is that with the honda barrel?

Edit, oh hold on is this the one from his other thread?

[RAW]

Exhaust port should be what Wob

[philou]

Got this one showing the bottom/rear case, although there's a bit of the top/front case behind it.

Thanks you :)

[flyonly]

Have any of you guys fitted a dry clutch to a wet clutch bike or modified you bike to run a wet clutch dry.

What did you adapt? How did it go?


Sent from my iPhone using Tapatalk

[F5 Dave]

I knew someone who tried something along those lines on a customer's VF1000 when they were new. The dry sump was less than successful. He left that line of employment thereafter. :innocent:

[koenich]

Have any of you guys fitted a dry clutch to a wet clutch bike or modified you bike to run a wet clutch dry.

What did you adapt? How did it go?
Didn't do but thought about it for my Derbi 50cc engines. High likely you'll need a longer transmission primary shaft, some mods to the clutch basket to get a sealing surface and a new clutch cover...wasn't worth the effort for me since you'd need quite a few special parts made (read $$$).

[katinas]

Run battery powered as total loss. No change to the curve or limiter. Went very well on quarter mile dirt ovals.
It's very common to ditch the alternator rotor on big fourstrokes used for racing. There's invariably enough crank inertia that changing ignition curves to compensate isn't necessary.

Tested much smaller alternator from Honda CRF 450 2012 on VF500 F2 and bad sound, that appears without rotor, almost gone. Engine goes much faster, than with heavy std rotor.
CRF 250 400 rotor magnets are very powerful, looks like neodymium.

[_____]

@Katinas:
That looks nice! Is it a 1:5 cone? Do you know the start diameter? That looks like it might fit my Aprilia RS250 :Police:

Cheers Chris

[guyhockley]

There have been discussions on here about balance shafts and crankcase volume/compression ratio - this kind of touches on both. it's a Cisco Motors engine for nanolights and paramotors, so not quite as highly tuned as bucket racers, maybe...

Basic Specs:

"ENGINE : Two - Stroke Single Cilinder
CYLINDER : Aluminium with nichel treated
barrel w/6 scavenge ports
BORE x STROKE : 51 X 47 mm
DISPLACEMENT : 175cc
COMPRESSION RATIO : 12:1
INTAKE : By 6 blade reed valve in crankcase
CARBURETTOR : Walbro WB series
MAXIM POWER : 20 KW / 8000 rpm
MAX ROTATION 8100 giri
MAX TORQUE : 22 Nm / 7700 rpm
STARTER: Electrical
TRASMISSION : Belt 508 PV-14G
REDUCTION : Pulley 1/2,6 (Optional 1/2,8 1/3)
SUPPORT ENGINE : 4 Silent-Block radial
FUEL : Unleaded NC 623-02 R.O.N. 95
addition 3% oil syntetich
Coil recharge battery 0.8 ah/hour"


Comment on the balance shaft version weight difference:

"WEIGHT: Engine complete 14.9 KG
WEIGHT: Engine complete of Balance shaft 15.3 KG"

Not much of a weight difference?

Design comment:

"THE SYSTEM
For this model with the belt reduction the engineers have developed a very clever solution that uses the lubrication of the mix to 3% for the pair of gears and bearings to rolling at high speed.
Inside the engine the measures remain unchanged with an increase in the weight very limited but with the vibrations reduction of 70%"

Looking at the exploded drawing it does look as if the balance drive shaft gears and the needle bearing are fed pre-mix inside the case with quite a large space carved out. They don't quote any performance difference between the two crankcase versions...
The other thing that puzzles me is that the ball bearing on the other end of the shaft seems to be outside its oilseal?

All quoted bits from:

http://www.ciscomotors.com/prodotti/engines/c-max-e-175.htm

[Frits Overmars]

"the engineers have developed a very clever solution that uses the lubrication of the mix to 3% for the pair of gears and bearings to rolling at high speed."
All quoted bits from: http://www.ciscomotors.com/prodotti/engines/c-max-e-175.htmI wonder: did their engineers really develop this very clever solution, or did they just do their reading and adopt a setup that worked fine on moped engines 50 years ago? (not for a balance shaft, but for their primary reduction).
By the way, your link does not seem to work.

[Tim Ey]

The real mystery is how they manage to get 175cm³ out of bore 51 x stroke 47
(In my universe thats 96cm³)

[husaberg]

There have been discussions on here about balance shafts and crankcase volume/compression ratio - this kind of touches on both. it's a Cisco Motors engine for nanolights and paramotors, so not quite as highly tuned as bucket racers, maybe...

Basic Specs:

"ENGINE : Two - Stroke Single Cilinder
CYLINDER : Aluminium with nichel treated
barrel w/6 scavenge ports
BORE x STROKE : 51 X 47 mm
DISPLACEMENT : 175cc
COMPRESSION RATIO : 12:1
INTAKE : By 6 blade reed valve in crankcase
CARBURETTOR : Walbro WB series
MAXIM POWER : 20 KW / 8000 rpm
MAX ROTATION 8100 giri
MAX TORQUE : 22 Nm / 7700 rpm
STARTER: Electrical
TRASMISSION : Belt 508 PV-14G
REDUCTION : Pulley 1/2,6 (Optional 1/2,8 1/3)
SUPPORT ENGINE : 4 Silent-Block radial
FUEL : Unleaded NC 623-02 R.O.N. 95
addition 3% oil syntetich
Coil recharge battery 0.8 ah/hour"


Comment on the balance shaft version weight difference:

"WEIGHT: Engine complete 14.9 KG
WEIGHT: Engine complete of Balance shaft 15.3 KG"

Not much of a weight difference?

Design comment:

"THE SYSTEM
For this model with the belt reduction the engineers have developed a very clever solution that uses the lubrication of the mix to 3% for the pair of gears and bearings to rolling at high speed.
Inside the engine the measures remain unchanged with an increase in the weight very limited but with the vibrations reduction of 70%"

Looking at the exploded drawing it does look as if the balance drive shaft gears and the needle bearing are fed pre-mix inside the case with quite a large space carved out. They don't quote any performance difference between the two crankcase versions...
The other thing that puzzles me is that the ball bearing on the other end of the shaft seems to be outside its oilseal?

All quoted bits from:

http://www.ciscomotors.com/prodotti/engines/c-max-e-175.htm


Same set up as a nsr125 other than it overlaps without breaking into case, with the bearings thats why i assume the mag side is run wet on the NSR125.
342830342831
Although one 50cc i seen on here by a Dutchman used sealed bearings.

[wobbly]

Having the balance shaft inside the primary case increases the displacement from 96 to 175.
Haha , bloody obvious in another dimension.

[wax]

When it comes to ignition system who here has played with a trigger wheel versus the normal single lump on the flywheel. So a higher resolution. It would seem to me with a full revolution before the system gets to read again that the speed would have changed and thus the timing would be incorrect, where as a higher resolution would be a lot better.

[Carel H]

That's the "n" or "n-1" question. N being current rpm. With a small lump you use the n-1 data for timing and generate the next n-1.

But the lump can be widened and both sides can be used. On the picture you see the first edge to trigger the calculation of "n" and corresponding ignition delay. the second edge starts the delay for the spark.

Made it, worked like a charm, never run it on an engine. But I thought it to be more theoretically correct.

[katinas]

@Katinas:
Is it a 1:5 cone? Do you know the start diameter? That looks like it might fit my Aprilia RS250 :Police:

Cheers Chris

Yes Chris, cone is 1/5.
Original, Rgv/Rs 250 SAPC engine, flywheel rotor is lightest and smallest from all group of street 250/500 2 strokers and Crf 250/450 EFI(2009-2019) rotors is just fractionally smaller and with multiple short lumps.
Better would be use much smaller Crf 250/450 Carb (2002-2008 add photo ) alternator with long lump easily modified if needed for Rs/Rgv.
Very likely that total loss or smaller rotor together with longer con rod, help a little to mask usual Rgv/Rs power dip at 8000rpm, as piston goes faster through BDC, with less inertia flywheel and longer con rod ( say 110mm vs 106mm on Rgv).

Rgv/Rs SAPC OD-106mm. Inside –90mm.
CRF250/450 (2009-2016) OD- 90mm. Inside-78mm. neodymium ( multiple lumps ) stator inside 32mm
CRF250/450 (2002-2008) OD 75mm. Inside-63mm (two lumps one long and one short add photo ) stator inside ?
CRF450 (2017-2019) OD- 102mm Inside- 90mm neodymium
CR 125 only 2004 stator, with thick wire, generated low voltage OD -75 mm Inside- 63mm stator inside -27mm ( But with CR s alternators it would be more work to adapt, as stator arranged to engine side like on first generation Rgv VJ21, not on cover like SAPC Rgv/Rs)
VF 500 OD- 136mm. Inside-115mm

With Honda CR 125 2004 (low voltage 12v plus and very likely Crf 250/450 2002-2008 just opposite stator location ) 8 poles stator and two plates, its easy to make alternator for V2 90 engine( add photo). Tested on NS 250 and works fine with two 2004 Cdi KSRA with inside voltage converters, but it must work with programmable Ignitech or Zeeltronic too. With two plates it is possible adjust different timing for both cylinders just in seconds at testing..
CR 125 2002-2003 and 2005-2007 alternator stator with 4 poles ( middle voltage type 70v plus) not worked for V90 two cylinders with two std Cr 125 cdi . Not tested with CR 125 2001 and older, 8 poles high voltage alternators.

[41juergen]

Hi guy's,
when doing a radius to the transfer entry as shown in the pic, do I need to replate the cylinder? I thought that should be not nesseccary as long the plating was not damaged while grinding, right?

342838

[husaberg]

Yes Chris, cone is 1/5.
Original, Rgv/Rs 250 SAPC engine, flywheel rotor is lightest and smallest from all group of street 250/500 2 strokers and Crf 250/450 EFI(2009-2018) rotor is just fractionally smaller and with multiple short lumps.
Better would be use much smaller Crf 250/450 Carb (2002-2008 add photo ) alternator with long lump easily modified if needed for Rs/Rgv.
Very likely that total loss or smaller rotor together with longer con rod, help a little to mask usual Rgv/Rs power dip at 8000rpm, as piston goes faster through BDC, with less inertia flywheel and longer con rod ( say 110mm vs 106mm on Rgv).

Rgv/Rs SAPC OD-106mm. Inside –90mm.
CRF250/450 (2009-2018) OD- 90mm. Inside-78mm. ( multiple lumps ) stator inside 32mm
CRF250/450 (2002-2008) OD 75mm. Inside-63mm (two lumps one long and one short add photo ) stator inside ?
CR 125 only 2004 stator, with thick wire, generated low voltage OD -75 mm Inside- 63mm stator inside -27mm ( But with CR s alternators it would be more work to adapt, as stator arranged to engine side like on first generation Rgv VJ21, not on cover like SAPC Rgv/Rs)
VF 500 OD- 136mm. Inside-115mm

With Honda CR 125 2004 (low voltage 12v plus) 8 poles stator and two plates, its easy to make alternator for V2 90 engine( add photo). Tested on NS 250 and works fine. With two plates it is possible adjust different timing for both cylinders just in seconds at testing..
CR 125 2002-2003 and 2005-2007 alternator stator with 4 poles ( middle voltage type 70v plus) not worked for two cylinders. Not tested with CR 125 2001 and older 8 poles high voltage alternators.

Cheers i am not totally sure but i believe a lot of the later KTM and Husky 2t have a Very similar size mag flywheel from the same maker Kokistan not sure re the taper but it should be able to cross reference off Electrix and HPI sites

You can find the lighting output stators quite cheapo if you go aftermarket.
pretty sure the electric start ones are straight DC 100W to about 200W
http://www.cafehusky.com/threads/08-cr125-with-ktm-125-lighting-stator-howd-ya-do-that.2755/
https://www.rmstator.com/en_ww/products/stator-for-ktm-sx-xc-xc-w-144-200-250-300-2007-2016-rms010-101534
https://www.trailtech.net/hard-parts/stators/ktm-stator-kits
https://www.electrexworld.co.uk/acatalog/STK-147.html

[Frits Overmars]

when doing a radius to the transfer entry as shown in the pic, do I need to replate the cylinder? I thought that should be not nesseccary as long the plating was not damaged while grinding, right?
342838Right, sort of. When grinding, there will always be some plastic deformation of the underlying aluminium, causing tension in the adhesion between the nickel and the alu. So don't put too much force on the grinder and finish the transition between nickel and alu with a diamond file.
Luckily there will be no piston ring running over this transition. Modifying the port edges, especially the exhaust port top edge, will require more subtlety.
In the latter case, it is advisable to radius the exhaust top edge before plating, and finish it with a diamond file after plating.

[F5 Dave]

Cheers i am not totally sure but i believe a lot of the later KTM and Husky 2t have a Very similar size mag flywheel from the same maker Kokistan not sure re the taper but it should be able to cross reference off Electrix and HPI sites

You can find the lighting output stators quite cheapo if you go aftermarket.
pretty sure the electric start ones are straight DC 100W to about 200W
http://www.cafehusky.com/threads/08-cr125-with-ktm-125-lighting-stator-howd-ya-do-that.2755/
https://www.rmstator.com/en_ww/products/stator-for-ktm-sx-xc-xc-w-144-200-250-300-2007-2016-rms010-101534
https://www.trailtech.net/hard-parts/stators/ktm-stator-kits
https://www.electrexworld.co.uk/acatalog/STK-147.html
I have an electrex on my gasgas, appears good quality, however didn't need lots of power so just the 2k3, same as ktm.

[_____]

Rgv/Rs SAPC OD-106mm. Inside –90mm.
CRF250/450 (2009-2016) OD- 90mm. Inside-78mm. neodymium ( multiple lumps ) stator inside 32mm
CRF250/450 (2002-2008) OD 75mm. Inside-63mm (two lumps one long and one short add photo ) stator inside ?
CRF450 (2017-2019) OD- 102mm Inside- 90mm neodymium
CR 125 only 2004 stator, with thick wire, generated low voltage OD -75 mm Inside- 63mm stator inside -27mm ( But with CR s alternators it would be more work to adapt, as stator arranged to engine side like on first generation Rgv VJ21, not on cover like SAPC Rgv/Rs)
VF 500 OD- 136mm. Inside-115mm

With Honda CR 125 2004 (low voltage 12v plus and very likely Crf 250/450 2002-2008 just opposite stator location ) 8 poles stator and two plates, its easy to make alternator for V2 90 engine( add photo). Tested on NS 250 and works fine with two 2004 Cdi KSRA with inside voltage converters, but it must work with programmable Ignitech or Zeeltronic too. With two plates it is possible adjust different timing for both cylinders just in seconds at testing..
CR 125 2002-2003 and 2005-2007 alternator stator with 4 poles ( middle voltage type 70v plus) not worked for V90 two cylinders with two std Cr 125 cdi . Not tested with CR 125 2001 and older, 8 poles high voltage alternators.

Thank you so much! This is all very helpful!
One question left: are you certain about the outer diameter of 63mm on the '04 CR125 stator? Because I know that a lot of kokusan rotors (also the Magneto LFS from Ignitech) have 59-60mm stator diameter?!


Hi guy's,
when doing a radius to the transfer entry as shown in the pic, do I need to replate the cylinder? I thought that should be not nesseccary as long the plating was not damaged while grinding, right?

342838
I agree with Frits, i would also add a polishing finish to the transition of plating to alloy. On that cylinder my #1 priority would be to fill the sharp lathing edge with 2k epoxy, starting from the red mark.

[katinas]

Yes Chris, Cr 125 Denso stator outside dia is 60mm. 63mm is inside rotor dia.
I am not sure, but looks like Kawasaki, on Kx 125 1998-2000, use low voltage, 75mm rotor alternator (with rectifier). like cr 125 2004.

Husa, thanks for good info.


Not in theme, but how nice, eye catching pipe on this record, Edvard Stelling Lithuanian legend, model. I cant believed, he made cylinders with Nikasil plating in 1979.
https://www.youtube.com/watch?v=NBxFWEG0Fp0

[TZ350]

342844

Jim and his daughter will be returning to the Aus salt next year and their bikes will be equipped with a couple of smart carbs.

342845

I am looking forward to seeing how these little beauties go on the dyno.

The hope is, that the carb as setup on the dyno holds its tune at the salt without having to make any altitude or RAD adjustments when they get there.

[F5 Dave]

Hope they are lighter than the preproduction billet ones. They are like a block of stone.

With speed attempts one would think a section of flat over rev would be a real advantage as you reach the point of power required to push top achievable speed. A fixed gear and a power curve that drops off could be a serious limitation we dont typically see on racetracks.

I made a solenoid PJ conversion for a carb (RGV) that could fit where the KX125 one couldn't. Never ironed it out but given time and less issues elsewhere that's what I'd try again.

So far smartcarbs haven't offered up the elixir promised on dirtbike forums I've seen. Big improvement seems to come on bikes that have dreadful needles stock.

[TZ350]

.... eye catching pipe on this record, Edvard Stelling Lithuanian legend, model. I cant believed, he made cylinders with Nikasil plating in 1979. https://www.youtube.com/watch?v=NBxFWEG0Fp0

Incredible work, very impressive.

[41juergen]

Thank you so much! This is all very helpful!
One question left: are you certain about the outer diameter of 63mm on the '04 CR125 stator? Because I know that a lot of kokusan rotors (also the Magneto LFS from Ignitech) have 59-60mm stator diameter?!


I agree with Frits, i would also add a polishing finish to the transition of plating to alloy. On that cylinder my #1 priority would be to fill the sharp lathing edge with 2k epoxy, starting from the red mark.

@Frits: Thank's a lot, of course will follow the advise of the wise man! :yes:

@_____ Thank's for you comment, you mean like this? BTW: what's your name, may be you want to fill out your profile at bit more? :confused:

342849

[katinas]

Incredible work, very impressive.

Rob, I am too amazed and really enjoy when see someone working all they life with the strokers. As I hear they designed all engine parts, then manufactured them in Saint Petersburg ( Russia), and then do all final “secret” job at home. Nowadays Estonians are fastest almost in all five classes. Add some drawings from very old, 1980 speed car model book.

I didn’t know is it true, but hear the story that long time ago in soviet union road racing championship, someone used piston without ring together with bronze liner, and if they succeeded to fired up the engine from pushing start, they always won.

Rob are you tried on your rotary valve 110 cc engine, piston with side cuts, as low as they masked A and B transfer windows, when piston is at TDC?

[TZ350]

.
Very interesting pictures. One with a "Turbo" impeller and the other Rotary valve. Beautiful workmanship.

[TZ350]

Rob are you tried on your rotary valve 110 cc engine, piston with side cuts, as low as they masked A and B transfer windows, when piston is at TDC?

This is a view of the piston at TDC. It exposes the top of the "A" and "C" ports and partially exposes the "B" port. Is that what you mean.


342853

[Flettner]

this piston could be well suited to the side port concept.

[Frits Overmars]

Add some drawings from very old, 1980 speed car model book.Very interesting pictures Katinas. Especially the compressor engine made me wonder. Some coarse reverse-engineering of your drawings yielded very oversquare engine dimensions of 29 mm bore and 15 mm stroke (the second engine, with the bigendpin-driven rotary disk, yielded a more conventional 24,5 mm bore and 21 mm stroke). The compressor impeller has a 46 mm diameter.
Assuming a piston speed of 22 m/s, the compressor engine would rev to 44000 rpm. The various angle.areas would not allow decent breathing at those revs, but let's ignore this for now. But a 46 mm Ø compressor impeller would need to spin at least five times as fast to do any good....
Now this old Gilera-sketch comes to mind:
342865

[andreas]

Why the fascination over long rods (not the brand)? Far as I know a short rod has a slightly cleverer trigonometral order, and crank case volume can be increased in other ways?

[TZ350]

Why the fascination over long rods (not the brand)? Far as I know a short rod has a slightly cleverer trigonometral order, and crank case volume can be increased in other ways?

My fascination is practicality.

I use a long rod, actually the longest I can find because it is practical and suits my purpose.

I needed a long rod so I could fit the cylinder hold down adapter plate. As well as the extra long rod the crankcase volume was also increased by slimming down the flywheels as much as I dared and spacing the crankcase halves 12mm further apart. So all in all there was a huge increase in crankcase volume. It is hard to see how I can increase the case volume anymore but I am open to suggestions. Also the long rod reduces side thrust friction, which appeals to me, although I am not sure how much that matters in practical terms.

342889 342890 Possibly the Worlds most modified Suzuki GP100. https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page1680?p=1131032879#post1131032879

[husaberg]

its not a fascination or a fashion it has practical benefits, aside form the lessening of thrust on the piston It also increases the piston dwell both near Top Dead Center, Which can improve combustion efficiency.

[andreas]

Practicality, is my fascination.

I use a long rod, actually the longest I can find because it is practical and suits my purpose. I needed a long rod so I could fit the cylinder hold down adapter plate. As well as the extra long rod the crankcase volume was also increased by slimming down the flywheels as much as I dared and spacing the crankcase halve further apart by 12mm so all in all there was a huge increase in crankcase volume. Also the long rod reduces side thrust friction although I am not sure how much that matters in practical terms.

342889

Aha yes, to suite a bastard build everything is permitted and endorsed. I'm talking about the young knights who "long rod" their perfectly good engines. I mean short rod would allow for, not so much in the end but still, better gas exchange.

[katinas]

This is a view of the piston at TDC. It exposes the top of the "A" and "C" ports and partially exposes the "B" port. Is that what you mean.


342853

Yes Rob , this photo. It would be very interesting to try piston that fully masked trans windows at TDC. Then transfers ports, some time, start work like tube with closed one side, as increase fluctuation (separately from moving down piston) between under piston space and transfers ports ends, from the moment when rotary disk close intake to the point when trans windows start open.

Testing with reed valve engines, shows power increase and over rev, when piston side cuts was raised as much as possible ( not to weaken std pistons) This help increase flow to transfers ports directly from reed valve. Add photo with three different Honda RS pistons side cuts (latest model on left side) and similar on NSR500V two cylinder pistons. But the rotary disk and piston ported engines maybe wants opposite.

[andreas]

its not a fascination or a fashion it has practical benefits, aside form the lessening of thrust on the piston It also increases the piston dwell both near Top Dead Center, Which can improve combustion efficiency.

Does it really increase dwell at bdc? I think the opposite. At least it stays a comparatively shorter time in the bottom half of the stroke.

[TZ350]

... photo with three different Honda RS pistons side cuts and similar on NSR500V two cylinder pistons. But the rotary valve and piston ported engines maybe wants opposite.

I had not thought about the side cuts at TDC and did not realize there were differences in the RS pistons. I use a second hand RS125 piston in an old road bike NSR250 barrel. Our racing class rules allow the RS piston but not the RS cylinder. The TZ piston in your third picture is interesting.

[andreas]

TZ I seriously like your engine.

[husaberg]

Does it really increase dwell at bdc? I think the opposite. At least it stays a comparatively shorter time in the bottom half of the stroke.

no, I said the opposite.:innocent:
342894

[andreas]

[QUOTE=husaberg;1131140261]no, I said the opposite.:innocent:

[katinas]

Very interesting pictures Katinas. Especially the compressor engine made me wonder. Some coarse reverse-engineering of your drawings yielded very oversquare engine dimensions of 29 mm bore and 15 mm stroke (the second engine, with the bigendpin-driven rotary disk, yielded a more conventional 24,5 mm bore and 21 mm stroke). The compressor impeller has a 46 mm diameter.
Assuming a piston speed of 22 m/s, the compressor engine would rev to 44000 rpm. The various angle.areas would not allow decent breathing at those revs, but let's ignore this for now. But a 46 mm Ø compressor impeller would need to spin at least five times as fast to do any good....
Now this old Gilera-sketch comes to mind:
342865

Frits, your accuracy is 99 %. Engine with the bigendpin-driven rotary disk is 1970 E.Gusev 9,95cc engine 24 mm bore 22 mm stroke, crank big end 7mm (crank and rod material 12crni3) with 1.5 mm rolers, main shaft 10mm, rotary valve steel 0.3 mm. The engine was modified through years until 1980 and maybe more and ended with reed valve..
Compressor engine is more experimental for 10cc class. From the text impeller just for 10 cc engine, 45 mm diameter, 27000-28000 rpm just little help and can work only with pipe. For effective small impeller work it require very high rpm.
Add other drawings from this book. When car model moving so fast on circle, side force help to reduce piston force to cylinder wall or increase if spins in wrong direction.

Latest worrying stories with rounded piston and hydro diodes. One father from 50 cc (add power graph) wanted to stop his son on the track at training when he started to jump like others with 85 cc. Other father from 65 cc put 2 teeth smaller rear sprocket, because boy cant hold on the bar when accelerating.

Really Thanks.

[TZ350]

Yes Rob , this photo. 342898

The good old TZ. This one has an aftermarket clutch basket that completely encloses the plates, good idea. I remember being hit with bits of broken TZ friction plates during really savage standing starts. Full throttle and moderate the revs with the clutch. The friction plates would crackup and bits fly out between the outer clutch fingers. The bike would keep going but two or three friction plates would be missing bits.

[katinas]

With shorter rod, piston goes faster through TDC and slower through BDC. Without higher piston side foce and lower under piston volume this changes all other things - ex and trans timing, needed different ignition timing, compression rise if use the same Ex duration like with longer rod, gas dynamic through crankcase and transfers changes at intake and transfer phases. Shorter rod is more aggressive on reed petals, when piston goes through TDC, and maybe on rotary engine intake needed close earlier.
Honda on NSR500V used 123 mm rod with 68 mm bore and 68.8 mm stroke, very short ( like 97.4 mm rod with 54.5 mm stroke ), but maybe because no left space for 500 2V 100 degree engine. From one 250 cc cylinder power 69 hp at 10250 rpm.

[katinas]

The good old TZ. This one has an aftermarket clutch basket that completely encloses the plates, good idea.

Remember one mechanic, with absolutely destroyed this type of basket in his hands, from, if remembers correctly, Antony West V2 Honda NSR500V at 2001 Brno GP.

[wobbly]

Honda stuck with short ( 104,105 ) rods for years , but the last champ winning 250 had a longer ( 109 ) rod.
It would have been changed for only 1 reason - power.
Theoretically the short rod has longer dwell at BDC , but in my opinion the long rod with more dwell at TDC and the reduced bore
friction from rod angularity has more advantages than downside.
Going back to the questions I missed a few days ago ( been racing in OZ ).
The Denso ignitions starting from around 2000 are all the same basic hardware - 60mm stator and 12V output , and 1-5 taper.
There was a change to a one piece fully machined rotor , and this also has NdFeB magnets.
A 4 coil stator with these magnets makes the same power as an 8 coil with the older Ferrite magnets.
And that 8 coil stator with the good magnets will produce over 4A , enough for a DCCDI P2 running both CDI .
Lastly the radius on the bore edge / transfer duct entry.
I have ground dozens of these with a simple carbide rotary tool for roughing , then polished up with bonded cotton mounted points.
Never had chrome chipping or any issues at all.