ESE's works engine tuner

[Hemi Makutu]

Scroll down a couple of entries - to the topic research paper: http://trans-motauto.com/sbornik/1-2015.pdf

[Hemi Makutu]

www.ktm.com/mx/250-sx-1/

Does that balance shaft do anything else, eh bro?
It has to be geared/timed 1-1, so is it maybe an ignition mount too?

[F5 Dave]

No solenoid, and really? Better than a Keihin? A dirty mikuni?

No one seems to have taken on Smartcarb.

[husaberg]

www.ktm.com/mx/250-sx-1/

Does that balance shaft do anything else, eh bro?
It has to be geared/timed 1-1, so is it maybe an ignition mount too?

A counter balance shaft might be okay for a generator side of things i had that idea myself, but i think it would be not so great for timing as it would have a fair bit backlash built in.thus the timing could be a little eratic.
The Aprilias had a pickup sensor built into the crank wheel as did the ROC/swissauto/pulse.

[Hemi Makutu]

TZ inline 4's used their 1-1 jackshaft for ignition on one end, & clutch pinion on the other...
Maybe Yamaha should've used that jackshaft as a balance shaft too..

[Hemi Makutu]

Sometime ago Hooser got me excited. Nah, nothing to do the (or his?) whole chicken thing, but labyrinth seals (see pic). HP just waiting to be unleashed?
So, got a Ø20*Ø35*7 teflon lipped seal and wrapped it with a paper strip, slid it over a crank and weighted it up so it was enough to overcome static friction and slowly rotate around the shaft with a 90 gm weight. (see pic).
Working backwards, this level of friction equates @ 14k rpm, to equal 0 .0226 kW. Stuff all really.
However, this is without and pressure acting on the seal. I guess the next step would be to mount 2 seals in a sleeve with varying applied pressures from within a drilling in the shaft. See pic. I guess one could do this based on crank angle vs pressure and do some sort of averaged calc of the frictional power over the full 360 deg cycle
Attachment 325069Attachment 325070Attachment 325071

Ken, 2T oil generally contains high levels of ZDDP ( zinc-phosphate) to compensate for the loss of TEL ( lead)
lube from road-legal petrol, if you were serious about a research project, you could sacrifice a top-end, & seal up
a crank-in-case ( having cut off the con-rod above the big-end, & sealed on a blanking plate) to test it,
back to back, all-metal lab' seal vs current teflon low-loss resilient-type, on a powered spintron set-up, eh...

[ken seeber]

Ken, 2T oil generally contains high levels of ZDDP ( zinc-phosphate) to compensate for the loss of TEL ( lead)
lube from road-legal petrol, if you were serious about a research project, you could sacrifice a top-end, & seal up
a crank-in-case ( having cut off the con-rod above the big-end, & sealed on a blanking plate) to test it,
back to back, all-metal lab' seal vs current teflon low-loss resilient-type, on a powered spintron set-up, eh...

Hemi, I was always under the impression that zinc and phosphorous were additives specific to 4 strokes as these acted to provide resistance to the high pressure scuffing in cam followers. Unfortunately both these are considered poisonous to catalysts, hence the need for good oil control. However as 2 stroke oils do not contain these, the typical crankcase scavenged total loss lubrication system is quite ok. Could be wrong though.
As to your suggestion, it does offer a method of holding the seals, although with bearing friction to be allowed for, but it does allow one to fit alternative sealing arrangements in.

[husaberg]

TZ inline 4's used their 1-1 jackshaft for ignition on one end, & clutch pinion on the other...
Maybe Yamaha should've used that jackshaft as a balance shaft too..

Yes they did but that was to minimise the width, they did a two up two down config likely more to lower costs.
The jackshaft costs HP, not and issue in 750 but not ideal for a 125.

[Hemi Makutu]

If you fact check, there were G.P. 125's which utilized jackshafts.
Yamaha went basic to stick a pair of twin 180 degree cranks into the 4s rather than go to 90 degree/even firing.

Note the length/wheelbase saving shaft-stacking done by KTM, so really,
- it would depend on the value of crank rotation/gyroscopic forces - if a crank turning in reverse to wheel was wanted.

[husaberg]

If you fact check, there were G.P. 125's which utilized jackshafts.
Yamaha went basic to stick a pair of twin 180 degree cranks into the 4s rather than go to 90 degree/even firing.

Note the length/wheelbase saving shaft-stacking done by KTM, so really,
- it would depend on the value of crank rotation/gyroscopic forces - if a crank turning in reverse to wheel was wanted.

JAW......... all over again.
The words used were not ideal. No such words as never used.
The TZ twin for instance did the jackshaft to reverse the crankrotation only to increase piston life over a 100KM or so.
As i said in regards to the TZ750 to save cost. PS Thanks for you imput James.

[Hemi Makutu]

Hemi, I was always under the impression that zinc and phosphorous were additives specific to 4 strokes as these acted to provide resistance to the high pressure scuffing in cam followers. Unfortunately both these are considered poisonous to catalysts, hence the need for good oil control. However as 2 stroke oils do not contain these, the typical crankcase scavenged total loss lubrication system is quite ok. Could be wrong though.
As to your suggestion, it does offer a method of holding the seals, although with bearing friction to be allowed for, but it does allow one to fit alternative sealing arrangements in.

Among the highest ZDDP additive counts for 4T oil is the H-D specific type, due to their high load rolling element
bottom ends, & high ring-land/bore contact friction long-stroke designs.

But feel free to check, 2T oils use it for the same reasons...

[koenich]

hey guys,

not a regular poster rather a reader. as it's off season now in Europe I'd like to build some pipes for my Conti RX356...

I stumbled upon this drawing in the thread, is it for 50cc Wobbly?

Diameters seem to be a bit bigger than usual but length is way more (usually I end up in the 670 mm range).

[Hemi Makutu]

JAW......... all over again.
The words used were not ideal. No such words as never used.
The TZ twin did the jackshaft only to increase piston life over a 100KM or so.
As i said in regards to the TZ750 to save cost. PS Thanks for you imput James.

As it happens, you've got a bit to learn yet, eh fella.. see the 1960's 4 cyl 2T G.P. 125s..

& as such see the 2-stroke thread current on the F1 Technical Forum, wherein the value of a even-fire multi 2T engine is discussed.
(Its in the engines, transmissions... section)

[husaberg]

As it happens, you've got a bit to learn yet, eh fella.. see the 1960's 4 cyl 2T G.P. 125s..

& as such see the 2-stroke thread current on the F1 Technical Forum, wherein the value of a even-fire multi 2T engine is discussed.
(Its in the engines, transmissions... section)

Thanks J.A.W.
Alas If only you could actually read what was posted rather than just trying to be a know it all.
Adds to ignore list. Suggest's all others do the same.

[Hemi Makutu]

Adds to ignore list. Suggest's all others do the same.

Off topic/zero value post or what, eh fella...

Ah well, I also "suggests all others " go back to discussing items of actual 2T technical merit

Husa will likely back edit his ludicrous statement claiming that TZ twins used a jackshaft to enable their pistons to last 100 Km...

( & meanwhile Husa's calling card of leaving a negative reputation ranking & "total dick" comment - says heaps about his limitations).