ESE's works engine tuner

[husaberg]

Consider it done!

Ages ago (I think but could be wrong)either 2Tinsitute or Ken Seeber suggested a cheaper alternative for small quanities of a tunsten alloy.
it was on Ebay for these things
http://www.abc-pinewood-derby.com/weights.php
http://pinecar.woodlandscenics.com/s...m/P3915/page/1
http://www.maximum-velocity.com/tungstencylinders.htm
http://www.ebay.com/itm/Incremental-...-/322004729139

You could also check out your local angling/fishing store.

[adegnes]

Ages ago either 2Tinsitute or Ken Sebbler suggested a cheaper alternative for small quanities of a tunsten alloy.
it was on Ebay for these things
http://www.abc-pinewood-derby.com/weights.php
http://pinecar.woodlandscenics.com/s...m/P3915/page/1
http://www.maximum-velocity.com/tungstencylinders.htm
http://www.ebay.com/itm/Incremental-...-/322004729139

You could also check out your local angling/fishing store.

Thank you!

[speedboy]

With free shipping:
https://www.aliexpress.com/item/New-...b-ab5af59265c8

[adegnes]

Low inertia of the crank/variator and no flywheel makes the situation WORSE, due to lack of mass damping.

This is exactly what I thought too. I also thought that the unbalance of the rotary valve could be of significance in an engine like mine with the low inertia crank and no flywheel.
I'll bring the balance factor up to 60% and hope that it isn't...

Thanks for all the help!

[adegnes]

With free shipping:
https://www.aliexpress.com/item/New-...b-ab5af59265c8

Thanks for the link!

[adegnes]

Found this small program(sorry if it's been posted before) that can help with visualising how different balance factors affect the engine.

http://www.tonyfoale.com/index.html - choose freeware and balance factor analysis.


20% - Around where my crank was out of the box, vibrated alot!


38% - current state, vibrates but better than 20%(but too much for the carb)


60% - what Wobbly is suggesting, and by looking at the radar plot I think I understand why(maybe), it seems to be the most "balanced" option.


80%



One thing I noticed is that with "With secondaries" checked, 60% is what gives the lowest max force, not 50%.
Can someone explain what the "secondaries" are?

[husaberg]

One thing I noticed is that with "With secondaries" checked, 60% is what gives the lowest max force, not 50%.
Can someone explain what the "secondaries" are?

http://www.tonyfoale.com/Articles/En...ineBalance.pdf

n a single cylinder engine, the secondary forces provide us with a harder problem to solve. The concept of balance factor is applied to the crankshaft is not relevant in this case, because by definition, the secondary forces vibrate at twice the rate of the crankshaft rotation. We could add a balance shaft that rotates at twice the engine speed but that would only replace the in-line forces with lateral ones, as in the case of 100% balance factor with primary forces. However, if we used two counter-rotating balance shafts, geared so they ran at twice the speed of the crankshaft, then we could in fact, eliminate the secondary forces. As we shall see, four cylinder engines suffer badly from secondary forces

http://www.freestudy.co.uk/d225/t9.pdf

[adegnes]

thank you great sir!

[wobbly]

Yes, if you do an an analysis of common bore/stroke/rod ratios the balance factor that minimizes overall force
transmitted from the crank to the frame is always overbalanced, centered around 60%.
This also helps the relatively smaller force generated at 90* by the rod mass acting at its C of G comprised of some of the reciprocating
mass opposing the added mass opposite the pin.
This is not always taken into consideration in some balance programs.

[peewee]

maybe its to soon to ask this question but what do you guys think of the new 250sx engine with counterbalancer used in ktm and Husqvarna motorcycles ? anyone got a peek inside to see whats different from previous generations ? im hoping theres plenty of potential for more power ? really the only info ive found is the generic stuff on the ktm and husky websites. was thinking of picking up the Husqvarna model but still undecided

[Niels Abildgaard]

The late MZ consumer bikes of DDR were not balanced for oscillating forces at all.
Engine/transmission block rear end was connected to frame via a steel-rubber bush that allowed rotation but not translation.
The front end that is cylinder crank and carb was alloved to go up and down antiphasing piston.
There is a very soft rubber block between cylinder head and the big single rectangular frame pipe.
I have driven a 300 ETZ for 80000 km at near max rpm and never had anything or myself being destroyed from vibration.
http://www.motorstown.com/images/mz-etz-251-07.jpg

[Niels Abildgaard]

Another source or heavy metals is a used/blunt carbide endmill.
Machine shops have them in kilograms and if they also have a wire EDM machine discs are nearly free.
Density is 14.6 gram per ccm.

[adegnes]

The late MZ consumer bikes of DDR were not balanced for oscillating forces at all.
Engine/transmission block rear end was connected to frame via a steel-rubber bush that allowed rotation but not translation.
The front end that is cylinder crank and carb was alloved to go up and down antiphasing piston.
There is a very soft rubber block between cylinder head and the big single rectangular frame pipe.
I have driven a 300 ETZ for 80000 km at near max rpm and never had anything or myself being destroyed from vibration.
http://www.motorstown.com/images/mz-etz-251-07.jpg

Interesting!
Sounds like quite a trip!
Rubber mounts could help if it is still acting up after the rebalancing.

Another source or heavy metals is a used/blunt carbide endmill.
Machine shops have them in kilograms and if they also have a wire EDM machine discs are nearly free.
Density is 14.6 gram per ccm.

Thanks for the tip!

[wobbly]

With no attempt at cancelling the crank oscillating forces internally, then the cases/bearings are being severely hammered
even if it cant be felt by the rider due to some clever isolation techniques.

[peewee]

wob on the yami twins would I gain anything worth while if i reverse the water flow and take it from the rad to the top of the head at the front of the cylinder then weld on some spigots as low as I can at the cylinder rear just above the reed blocks ? this is how some of the older ktm water flowed. I could also weld up the rear water passage holes in the head so it forces it to go over and around the exh port before exiting at the rear. guy I know has a cnc so it shouldn't be much trouble to do up a impeller with reverse fins, then ill just flip flop the water hoses at the radiator.

I thought of keeping the current water flow direction and using a electric trailtech fan but they said I would need to do a DC conversion and who knows what else then install a battery