ESE's works engine tuner

[peewee]

Peewee, in addition to every advice that has already been given, and to which I fully subscribe, I'd like add two points.
1: Make the cut as close to the rear axle as can be combined with inserting internal strengthening profiles of the correct length.
2: Can't you add some form of triangulation? That would kill two birds with one stone: much less stress on the welds and a much stiffer fork.

early on, I had thought about using 6mm thick plate and welding a arch on the bottom side of the arm like the photo. similar to what they would do in a differential housing to stiffen it. problem is, I wasn't sure how necessary it was but extra strength never hurts I guess and I could still weld it on. I assume this is what you meant by triangulation ?

[wobbly]

The Modena reed thing was in answer to Greg85.
Pretty crap power for the supposed very latest design in KZ engines, maybe thats why Roland is no longer working for them.

[Lightbulb]

I have a piece of balsa wood with the shim sticking out at 45 deg. So it pokes through the port on the edge of the piston. I move it slowly til you see want to move. I then lock up the crank shaft, and can then use a depth mic to get the height. I was using a plate in the back and a screw pushing through to the flywheel. My newest one is a plate that locks the crank by the prop washer and a cup plate that pulls against the crank and onto the crankcase from bearing seat. Fairly crude but works and is portable. So I can hold it to the light etc to see what is going on. I have the other shim sitting on the bottom of an other piece of balsa wood also for the transfer ports. But I am finding that a led light in the transfer port and looking at that is just as good and no added calculations are needed. The best idea I had was locking the crank in position so I can measure the heights. Due to the interference fit of the piston at TDC, I take all my measurements based off BDC. I have 0.200 inch liner shim I use when measuring the stroke. That way I am not pushing the piston through the interference fit zone. I find this helpful when doing the induction timing. Bike pistons are a lot more difficult because of the clearance they have at the piston top and the chamfer/break they have on the edge of the crown, as well as the curved crowns.
Neil

[Larry Wiechman]

The Modena reed thing was in answer to Greg85.
Pretty crap power for the supposed very latest design in KZ engines, maybe thats why Roland is no longer working for them.

Didn't Roland develop a version of Frits' 24/7 reed cage?

[Greg85]

The reed block in the Modena seems like a good idea to split the flow and direct it toward the transfer entry area.
But the problem as I see it is that bending the flow sideways like that will immediately cause a flow reduction in total.
And this ignores the fact that a large amount of the flow in a normal " square " reed block, flows over the outer sides, not just thru the curtain area at the tip.
I have a picture of a reed with the opposite idea, this gives the side spill over flow room down the sides to flow along the reed box side walls toward the transfer entries.
Two other things, it appears to make good mid power, but falls over in the top end.
Does that reed have a soft petal on top and a stiff petal on the bottom - TM use the same petals now ( soft ) but use two stiffeners on the bottom.
The other thing to look at would be a spacer between the stiffeners and the main petals, some reed makers use this idea along with cutting away the to reed
near the clamp to soften it.

PS - now do you know why not one fast Modena is being used in the 1st 3 rounds of the Euro Champs - all TM KZ10C , maybe two Vortex.

Thank you for the answer wobbly, reed petal is 0.36 is bottom 0.25, yes roland abandoned the project v-flow the engine I had originated from the homologation (prototyp) after modena my sent standard reed box and the new casing I had not so long ago that I have not tested yet but by changing the old cylinder casings I arrived at something nice..but I lost the low regime has to do with the new, yes wobbly I know tm is for me anyway the best engine of the world I have 3 with the last tmkz10c black

[Frits Overmars]

Didn't Roland develop a version of Frits' 24/7 reed cage?

Yes he did, amongst other projects that would never get the blessing of the FIM-CIK governing body, like fuel injection: far too sophisticated


Rolands 24/7 version was not fit for sale to the general karting world anyway: too complicated. The FIM-CIK has forbidden any form of electronics except ignition
(it's a miracle that they don't insist on flintstone ignition), so Roland had to find a mechanical way of actuating the reeds.
He used a cam on the crankshaft which required that the reeds' inertia and movement path were kept to a minimum. Hence the two carbon fibre reeds, whereas a servomotor would have enabled the use of a much simpler single reed. But servomotors are electrickery...

[Frits Overmars]

I had thought about using 6mm thick plate and welding a arch on the bottom side of the arm like the photo... I assume this is what you meant by triangulation ?

Hardly; I was thinking more like this:

[Haufen]

Yes he did, amongst other projects that would never get the blessing of the FIM-CIK governing body, like fuel injection: far too sophisticated


Rolands 24/7 version was not fit for sale to the general karting world anyway: too complicated. The FIM-CIK has forbidden any form of electronics except ignition
(it's a miracle that they don't insist on flintstone ignition), so Roland had to find a mechanical way of actuating the reeds.
He used a cam on the crankshaft which required that the reeds' inertia and movement path were kept to a minimum. Hence the two carbon fibre reeds, whereas a servomotor would have enabled the use of a much simpler single reed. But servomotors are electrickery...

Thanks for the pictures. Can you also tell us about the results? Or can you invite Roland so that he can tell us? I am sure we'd all be eager to listen.

[Haufen]

I dynoed my old 132cc honda 44hp to the sprocket = 0.33hp per cc
I dynoed this 211cc kawa to 71.35hp to the sprocket = 0.33hp per cc

Are those both single cylinder engines? If so, then your skills might have improved a lot without you even noticing.
In my opinion, 0,33hp per cc is really a lot for the 211cc engine. Not so much for the 132cc. But bigger displacements are always more difficult to get to high specific power outputs.

[Niels Abildgaard]

I feel at this point all my tricks up my sleeve is getting used.

I dynoed my old 132cc honda 44hp to the sprocket = 0.33hp per cc
I dynoed this 211cc kawa to 71.35hp to the sprocket = 0.33hp per cc

In both engines i dunno what to do next *lol*
And i see a red line here, at 0.33hp per cc my knowledge is the limit.

Rgds.
Patrick

Power is a port area thing.It is better to compare power per piston square cm.

An Aprilia RSA was 55 horsepower on 23 square cm equal to 2.4

The Honda thing 44 divided by 24 equal 1.8 and the Kawa 71 divided by 32 equal 2.2 horsepower square cm piston

It is a shame that 125 engines for karts and bikes have to be single cylinder.
A 100 ccm twin can do the same and be a much nicer engine vibrationwise.

[SwePatrick]

Are those both single cylinder engines? If so, then your skills might have improved a lot without you even noticing.
In my opinion, 0,33hp per cc is really a lot for the 211cc engine. Not so much for the 132cc. But bigger displacements are always more difficult to get to high specific power outputs.

Yes,, both single cylinders

The 211cc engine is running on Methanol, the 132cc was running unleaded 98.
I have actually now dynoed 72.91 as peak.
Sorted out some fuelissues.

[Frits Overmars]

Thanks for the pictures. Can you also tell us about the results? Or can you invite Roland so that he can tell us? I am sure we'd all be eager to listen.

I think I already did tell, some time ago.
With the same obligatory 30 mm carburettor, the 24/7 engine produced 5 hp more than the standard engine, and revved 500 rpm higher.
The injected engine had good driveability; anything more would be for Roland himself to reveal.
I could invite Roland to tell us here but I'm not sure if he has sufficient English. We always speak German when Italians are listening, and vice versa (Roland is from Süd-Tirol, the German-speaking part of Italy). Besides, he is always pressed for time. And when he finds some time, he gives lectures to interested youngsters.

[Frits Overmars]

Power is a port area thing. It is better to compare power per piston square cm.

That is true if you wish to compare thermal load on the pistons, Niels. If you want to judge the sophistication of an engine, it is customary to compare Mean Effective Pressure values. That involves some calculation, but there is also an easier approach: horsepower per cc per 1000 rpm.
No matter which approach you choose, 71 sprocket-HP out of a 211 cc engine, even when it is running on methanol, is quite respectable.

[Jannem]

Let's see if I can delete this...

[wobbly]

Any program for comparing ports must compensate for for both the axial and radial angles.
Port chordal width * height is pretty much useless for anything meaningful.
Its the effective FLOW width* height * cosine up angle* open period ( for Specific Time Area ) that is used in EngMod.