ESE's works engine tuner

[Grumph]

I once spent quite a bit of time as a Technician working on a prototype vertical cyclotron at ANAC (1980's) and gravity did have a measurable effect on the particles being spun around. Gravity would detract energy on the up side and added energy (speed) on the down side. Talking with the Physicist in charge, the challenge was timing the pushes and pulls of the accelerating plates to coincide with the particles passing, it wasn't symmetrical.

Interesting...Having watched with some amusement the theorists speculating about balance, can i pose a question ?

What balance factor would you use for a vertical shaft engine ?

Given that in a motorcycle application where the cylinder is vertical or nearly so, the balance factor tends toward greater than 55% and where the cylinder is horizontal or nearly so, it is usually the reciprocal or less than say, 45%. This in order to have the out of balance forces acting vertically in relation to the ground as this plane has historically been shown to be more acceptable in use.

And Smitty, yes, I know a lot of your outboards are horizontally opposed twins and therefore sidestep the issue...

[Dutch Fisher]

Attachment 310107

Calculated or direct measurement?

No. of cyls (if >1, degrees of combustion separation?)?

[Frits Overmars]

Calculated or direct measurement? No. of cyls (if >1, degrees of combustion separation?)?

Calculated, 1 cylinder. Two cylinders with 90° combustion separation run much smoother. With 180° separation they only sound smoother but the torque fluctuation is almost as bad as in a single.

[seattle smitty]

[QUOTE=Grumph] Interesting...Having watched with some amusement the theorists speculating about balance, . . . . (end quote)

And it's not like these assymetrically balanced engines are some factory race-team secret. I have an ordinary 1973 Yamaha 125 MX engine, thousands and thousands made, and it has one balance hole quite markedly bigger than the other one. I always supposed that it had nothing at all to do with engine performance, and was that way because after testing Yamaha found that moving the direction of the shakes was less likely to break welds, or made the carburetor float-needle meter better, or something like that.

If that was true, then with a vertical shaft or any other arrangement, I would speculate (it's free!!) that rather than there being a formula, you test the engine, and if it is shaking itself apart, or if the carburetion gets weird at certain places, you cut-and-try different balance combinations. There undoubtedly are some rough guidelines used by the factories. Industrial plant maintenance techs have been using vibration measuring equipment for decades, and surely these have been adapted to factory engine development for almost as long.

[husaberg]

Reading some of the posts with th physics involved made my head hurt....just me?

This I do know different bikes with the same engines sometimes have different balance factors depending on the frame design and inclination.
Ie Nortons in Featherbeds or STD frames even I understand slimline featherbed vs Wideline.
I am referring to old pommy shitters here these were arrived at by trail and error to what was acceptable to the rider (what the pommies thought was acceptable at the time)
A cr500 vibes far more in an alloy frame than in a steel frame

I know for a fact that a old pommy shiiter I had (8e Villers FB Falcon) was un-ride able without a head stay (which was a piece of pipe crushed on the ends that tied the frame to a head bolt.)
With this silly head stay made and fitted on, it was fine. (By old pommy shitter standards.) the vibes I guess did not disappear but were transferred to somewhere else. Likely the flexible frame.
So I guess it was tuned out resonance wise or something?

[speedpro]

The asymmetrical balance holes could also be due to asymmetrical piston acceleration either side of TDC & BDC. Remember the gudgeon pins are not in the centre of the pistons but offset. This affects rod geometry and therefore piston acceleration approaching TDC and departing TDC, and BDC. If the acceleration is affected then so is the resultant force/reaction.
It'd be interesting to see a graph of forces with the usual offset gudgeon pin versus with a pin central in the piston.

[breezy]

"old pommie shitters", .... charming

[Grumph]

"old pommie shitters", .... charming

A technical term much used in the ex colonies.

Can also refer to elderly freedom campers of British origin....

[husaberg]

"old pommie shitters", .... charming

I didn't want to confuse anyone that I was referring to cutting edge two stoke design.
So to clear it up for our British overloads I will hence force refer to them as "shitters"


Although it looks like you can get decent crankshafts for them now
http://www.feked.com/villiers-cranks...rod-197cc.html
http://images.classicbikepartscheshi...5-36782800.jpg
As opposed to what they had.
http://thumbs2.ebaystatic.com/d/l225...hlUszqy8qg.jpg
With bushed big end and little end.

[breezy]

I didn't want to confuse anyone that I was referring to cutting edge two stoke design.
So to clear it up for our British overloads I will hence force refer to them as "shitters"


Although it looks like you can get decent crankshafts for them now
http://www.feked.com/villiers-cranks...rod-197cc.html
http://images.classicbikepartscheshi...5-36782800.jpg
As opposed to what they had.
http://thumbs2.ebaystatic.com/d/l225...hlUszqy8qg.jpg
With bushed big end and little end.

bring on the world cup

[husaberg]

bring on the world cup

Yeah past history suggests they always go so well for old blighty............

Cricket
Third may be a tad optimistic old chap where did you guys finish again......
2 wins from six matches. VS NZ undefeated in 6 thus far.
http://www.mirror.co.uk/sport/cricke...ld-cup-5325955

Unless you mean the rugby.
NZ VS England Overall games 40 allblack wins 32. 1 draw

A century of New Zealand dominance has been punctuated by remarkable England victories. The 17 point margin in 2012 eclipsed the 13-0 win in 1936. Out of the blue England visited NZ in 1973 and won the test match 16-10, their first win in New Zealand. Ten years later they pulled off the first home win in 48 years by 15-9 and repeated the feat ten years later by the same score. They won twice in 2002 and 2003.
One of the 1997 matches resulted in a 26 all draw.
The rest of the matches have been won by New Zealand. The highest margin was 42 points in 1998 in Dunedin when England sent a depleted touring side to New Zealand.
The teams have met three times in World Cups, with New Zealand winning all three matches.

Soccer surely not..........

16 - New Zealand All Whites soccer team undefeated in World Cup
During the 2010 World cup in one of those strange statistical quirks the All Whites were the only unbeaten team in the competition with a series of three exceptional draws — including one against defending world-champions Italy.

Pretty sure you wouldn't have meant League either.
https://www.youtube.com/watch?v=jTwYICJ-nPc

Netball unlikey seeing as as well as NZ and er Trindad and Tobago have won more world cups than England as well.

What sports are left? yachting and rowing lol.
I understand NZ pretty dire at those.........
Although its astounding to consider Engand have been trying to win an Americas cup since 1851 and we managed on our what third go..........

[cotswold]

Thanks Tee Zee for letting me put the 50 on your Dyno, shame things went pear shape but fairly happy with the nearly 14, could you post the graph for me as I forgot to take a photo in my haste to get home and strip the bee atch.

[TZ350]

Sure, but it will have to be tomorrow when I get back into work.



There you go.

[breezy]

Yeah past history suggests they always go so well for old blighty............

Cricket
Third may be a tad optimistic old chap where did you guys finish again......
2 wins from six matches. VS NZ undefeated in 6 thus far.
http://www.mirror.co.uk/sport/cricke...ld-cup-5325955

Unless you mean the rugby.
NZ VS England Overall games 40 allblack wins 32. 1 draw

Soccer surely not..........


Pretty sure you wouldn't have meant League either.
https://www.youtube.com/watch?v=jTwYICJ-nPc

Netball unlikey seeing as as well as NZ and er Trindad and Tobago have won more world cups than England as well.

What sports are left? yachting and rowing lol.
I understand NZ pretty dire at those.........
Although its astounding to consider Engand have been trying to win an Americas cup since 1851 and we managed on our what third go..........

[peewee]

hey guys has anyone attempted to move the piston rings locating pegs with any sucess ? i heard people do it but it failed. surely there must be a way