ESE's works engine tuner

[jfn2]

wobbly:
Thank you for the reply about the reeds and backups. What material are the backups made from and do you know what length they should be to the reed length? Are there different thicknesses for the backups? Also I see that the reed stops have a peculiar cut out to them. Or doesn't that matter? Thanks again.

[TZ350]

Enough motivation to stop procrastinating on the installation of a deto sensor. With a diameter of about 20mm at the mating side I am asking myself where to put it ideally (and where not to put it). As I run a paper gasket, I suppose somewhere on the water cooled cylinder would be nice, but there is not enough space available, except "on a stick" on one of the bolting areas for the head cover. Where du you guys put yours?

Attachment 294192 Attachment 294193

Attachment 294223

http://www.ebay.com/itm/Knock-gauge-...e9e926&vxp=mtr

Attachment 286854Attachment 286853

Det Sensor

Follow the links back for more details.

[jfn2]

TZ350:
In attachment 294193 is the blue wired piece glued to the copper plate a temp sensor?

[husaberg]

"There’s very little all the factories agree on, but engine rotation is one of them After sunshine, rain and fresh air, my favourite natural phenomenon is gyroscopic effect. This is because we wouldn’t be able to ride motorcycles without it. If you don’t believe me, try this next time you’re out riding: when you stop at a traffic light, don’t put your feet down. (And don’t send me the bill.) A motorcycle’s spinning wheels create gyroscopic effect that keeps the machine going straight. The more speed, the more gyro and the more stability. This is all good, unless you are racing. Most racers don’t give a hoot about straight-line stability: they’re happy to hold on like gorillas on the straights, just so long as the bike will turn left or right in the blink of an eye. And this is why all premier-class Grand Prix manufacturers – possibly for the first time in history – now run their engines backwards. It may also explain why Marc Márquez’s COTA and Argentina victories were so huge – bigger than any dry-track wins from last year. When an engine runs forward (like most streetbikes) its crankshaft rotates the same way as the wheels, thus adding to the gyro effect, which makes it more difficult to turn into a corner or change direction. The obvious way to reduce gyro effect is to reverse the direction of engine rotation, so the reverse-rotating crank reduces the total gyro effect created by the fast-spinning wheels. The beneficial effects on the dynamics of a motorcycle are significant: 2the bike will turn quicker and change direction faster; a huge consideration in modern racing when most racetracks are very tight and twisty. A reverse-rotating engine also reduces wheelies, because the crank’s torque reaction pushes the front wheel down during acceleration, rather than lifting it (although this is less important than in the days of two-strokes, when crankshaft inertia was greater.) However, nothing is for free in racing. If you run the engine backwards the engine needs an extra jackshaft to keep the rear wheel turning the right way. That shaft absorbs a significant amount of horsepower, as well as increasing engine weight and dimensions. In theory, a reverse-rotating crank also increases understeer in corners, making the bike run wide on the exit, which can prevent the rider from getting on the throttle. But presumably all these costs are worthwhile because this year Honda reversed the engine rotation of their RC213V, the first time they’ve run an engine backwards since the days of the 500s. The last time Honda went backwards was in 1987. The first NSR500, born in 1984, was a real handful, partly because its V4 two-stroke engine ran forwards. The torque reaction from the forward-rotating crankshaft lifted the front during acceleration, causing plenty of problems for riders who spent too much time fighting wheelies instead of thinking about the next corner. The NSR ran backwards from 1987 and won eight of the last 13 500cc titles."

A bit off topic and random but...

All true but the 3 cylinder NS500 ran backwards as well.
I should note however, when the Screamer was reintroduced in the later 90's they kept the Balance shaft as Doohan said it steered better with it in place, that balance shaft of course ran forward.
Nearly All the other GP500's other thean the swiss auto had twin contra rotating cranks


The Velo Roarer had twin cotra rotating crankshafts mounted accross the frame with a direct shaft drive it is said to have steered beatifully.
Attachment 326536Attachment 326535Attachment 326534
The MotoCzysz was a bike design that tried to minismise the gyro effect.
Attachment 326537
http://motoczysz.com/motorcycles/c1_prototype
Regardsless of crank rotation the biggest conributer to the gyro effect on a bike is as far as i am aware the wheels.
All the honda CR125,250,500 shared very similar fame specs, the smaller cranked turn far better due to it small crankshaft the actually CR500 willfully resists any changes in direction.

The direction of crank spin has a huge influence on the bikes stability on corner entry and exit.
This is the precession effect,and we tried it experimentally when arguing about the crank spin of the BSL500 design.
Get a bicycle wheel and hold it in front of you by each end of the axle, spin it forwards or backwards then try to turn the axle to the left or right.
The precession force is huge considering the inertia of a tiny bicycle wheel/tyre, one direction of spin and the wheel "falls " into the turn direction
Spinning the opposite way its all but impossible to get the axle to rotate left or right by hand at all.
The amount of resisting force involved is simply staggering when you try this.

Cameron missed that the NS500 had a Jackshaft but the rest dovetails nicely.

Enjoy, sorry about the words being cut of some of the scans, but i didn't do them. i only screendumped and tidied them up.
Note# The corporate pride mentioned, is not restrcted to the Japanese.
Ducati is a shining example. As is Porsche.

[Pursang]

A key issue with the direction of engine rotation is piston thrust on the cylinder wall.

in a forward rotating engine the major thrust side is the back wall of the cylinder.
(In 2 Strokes, generally cooler and better lubricated due to intake flow)

Peak Force can be in the order of 8,000N

This can be 10 times the force on the minor thrust side.

If you want to reverse the rotation it might be wise to reverse the cylinder too.
And visa versa.

Cheers, Daryl.

[TZ350]

TZ350:
Is the blue wired piece glued to the copper plate a temp sensor?

No. My knock sensor had two wires coming out of it. I used one for the signal and earthed the other one. The elastic glue is for vibration/strain relief so the wire does not break. I am not sure now if the earth was really necessary maybe both were individual knock sensor wires and the earth is the brass body of the knock sensor.

[husaberg]

A key issue with the direction of engine rotation is piston thrust on the cylinder wall.

in a forward rotating engine the major thrust side is the back wall of the cylinder.
(In 2 Strokes, generally cooler and better lubricated due to intake flow)

Peak Force can be in the order of 8,000N

This can be 10 times the force on the minor thrust side.

If you want to reverse the rotation it might be wise to reverse the cylinder too.
And visa versa.

Cheers, Daryl.

Which is why Yamaha did it first with the jackshaft on the TZ250H and then later with simplier Reverse Cylinder, It certainly wasn't for its pretty inlets.
The added bonus is less friction through loss of power sapping jackshaft and the potential for straighter exhausts.
Two strokes will run in either direction regarless of cylinder orientation, lightly tuned ones occasionally do it unintentionally.
A side not (i just thought of) a lot of shaft drive bikes run in reverse direction, Yet no one ever says they steer better than there chain drive sibblings?

[wobbly]

I tested the reverse cylinder friction theory when doing the BSL500.
Having the cylinder mounted " backwards " that is with the thrust face over the exhaust port made a repeatable 0.3Hp difference.
But the transfer duct entries were not matched, so that probably accounted for the power change more than any frictional gain/loss
The pipe was the same for the tests, but would have been dead straight or heavily curved in each case when bike mounted.

Yamaha didnt put the jackshaft into the 250 H model due to friction, it was to reverse the huge reliability issue they encountered with the piston port geometry prematurely
killing pistons in the G version.

Re the reed backups,the setups used at present are close to 50% length in the case of the TM and the CR I have been working on.
But both have much stiffer tip force on the bottom petals.
Both use carbon backups that are around 2/3 the thickness of the main petals, but cut away in the 1/2 moon shape, so contact is made
only on the outer sides.
The TM has stops around 1/3 length, the CR has full length stops.

[jfn2]

About the reed backups. How much is the backup curvature and what is the magmalyte material and are the backups made of the same material? If so, is this materials frequency the same as carbon fiber per same length and same thickness?

[husaberg]

I tested the reverse cylinder friction theory when doing the BSL500.
Having the cylinder mounted " backwards " that is with the thrust face over the exhaust port made a repeatable 0.3Hp difference.
But the transfer duct entries were not matched, so that probably accounted for the power change more than any frictional gain/loss
The pipe was the same for the tests, but would have been dead straight or heavily curved in each case when bike mounted.

Yamaha didnt put the jackshaft into the 250 H model due to friction, it was to reverse the huge reliability issue they encountered with the piston port geometry prematurely
killing pistons in the G version.

.

Wob i was meaning I believe they later just reversed the cylinders rather than use the earlier jackshaft as it had (from memory) cost them a couple of HP.
I was aware of the short piston life of the g model.

The TZ twin for instance did the jackshaft to reverse the crank rotation only to increase piston life over a 100KM or so.
As i said in regards to the TZ750 to save cost. .

Husa was of course exaggerating about the piston mileage in the Yamaha TZ250G but apart from that I must agree with him on all accounts.
The TZ250G was remarkable. Power-wise its cylinder block was a big step forward, with better transfer ducts, smaller exhaust duct volumes and the huge inlet ports that were detrimental to piston life.
The following year Yahama reversed the direction of crankshaft rotation by means of the jackshaft, but we'd already found a much simpler solution: we reversed the cylinderblock on the 'G': piston problem solved.

In the Yamaha twins book there is quite a decent write up covering the TZs, that'swhere i got the 100 kms figure from
The H also from memory had beefier crankpins and a tighter press fit.

I am actually playing with a RD350 at the moment, i can't get over just how cramped the transfers are, Its amazing the TZs made any power at all in 350 form.

[Yow Ling]

Wob i was meaning I believe they later just reversed the cylinders rather than use the earlier jackshaft as it had (from memory) cost them a couple of HP.
I was aware of the short piston life of the g model.







In the Yamaha twins book there is quite a decent write up covering the TZs, that'swhere i got the 100 kms figure from
The H also from memory had beefier crankpins and a tighter press fit.

H model had 2 seperate cranks with a coupling in the middle , on the outside of the coupling was the output gear that drove the jackshaft. So the crank was but a distant relative to the early TZs

[husaberg]

H model had 2 seperate cranks with a coupling in the middle , on the outside of the coupling was the output gear that drove the jackshaft. So the crank was but a distant relative to the early TZs

Different stroke as well.
PS All the cranks were seperate as far as i am aware.
I will post what i have.

[husaberg]

The rest....

https://www.kiwibiker.co.nz/forums/a...p?albumid=4882

[adegnes]

Merry Christmas guys!

[peewee]

any you guys tried these cages ? seems like they would need to be special ordered and maybe that adds a lot to the cost

http://www.skf.com/binary/tcm:12-322...m_12-32271.pdf