ESE's works engine tuner

[Haufen]

How do you remove those caps? Can they be re-used?

[JanBros]

1. How is a chainsaw ballanced?

as a chainsaw is only supposd to run at max rpm or very close to it, it's pretty straightforward I would say : balance it so that it vibrtas the least at (close to) max rpm. all the other rev's do not matter much.

[Frits Overmars]

How do you remove those caps? Can they be re-used?

The decent way would be to blow the first one out using compressed air but you can also pry it out with an awl; the second one is easily pushed out from the inside with a screwdriver through the wrist pin. They are re-usable.

[AndreasL]

Thanks for the link and your work Moooools.

One thing though...

Wouldn't it be more convenient if the small end of the con rod was the one to be weighted?
This is a easy thing to measure with the crank still put together. Big end is not...

Maybe I have got it all wrong and if so, dont put any attention to this post.

I really need to sit down and see if I can get the effect of the cylinder angle in to excel.
Would be nice to have.

Maybe not exactly the same thing but any way...
TZ did some very good work documenting the process starting at page #70.
http://www.kiwibiker.co.nz/forums/sh...post1129264719

[Grumph]

Finally got back to this thread to see the talk about balancing. Yes, i asked because of personal experience. Horizontal cylinders in my experience require the reciprocal balance factor of those which are vertical. Aermacchis use around 25% Vs an upright single which is usually in the 65-75% range.

I disagree with Frits - vibration in the vertical plane is usually more acceptable to a rider (motorcycle not kart..) The figures talked about will give just this.
The only big engine i have experience with that broke this rule is the TR1 Yamaha 1000cc V twin. On checking the balance factor on it, it's down below 50% hence shakes fore and aft. On the road this translates to an odd "stretching out under you" feeling remarked on in period road tests.

So Mooloos, I'd build in a question to your data input - above or below an inclination angle of 45 degrees...And adjust the end result to reflect that.

But yes, there's still an awful lot of suck it and see involved....

[wobbly]

Sorry Grumph but your figures ( correctly ) directly contradict what you are saying about rider perception.
A Norton Manx is balanced to 80% as this extra bob mass reduces the vertical shake at the bars by opposing the piston inertia force
in the plane of the cylinder axis.
A kart engine is around 70% as this again reduces the vertical buzz that the frame cannot resist.
A horizontal cylinder needs only 35% as this generates more for and aft shake the rider does not sense as bad vibes at the bars.
The angled cylinders on say a RZ or TZ need high 50 % as they have a shake vectors in both planes and need cancellation for both
cylinder axes components - then the added complexity of having 100% primary cancellation in the cylinder vertical plane is ruined by
the addition of a rocking couple along the same axis.
The rocking couple is the same as the secondaries, nothing can be done to ameliorate them, apart from a balance shaft.
So - the numbers all indicate the need to reduce the vertical component of any out of balance forces, as it is this that a humans senses detest most.
If you read my analysis ( a personal fail of the first order ) of an RZ running at 90* phasing ( in Oddball Engines ) , and translate this into an even fire TZ750 the effects are the same.

Just to add another note on vibrating up and down,here are next years signings for Yamaha MotoGP

[Grumph]

We may have to agree to disagree, Empirically, the horizontal singles balanced to less than 50% still vibrate in a vertical plane - ie at right angles to the cylinder axis. If you balanced a manx to the same factor, I'd pick it would be very unpleasant cos it would shake at right angles to the cylinder axis - fore and aft. Which the mounts aren't designed for...
The reason for upright singles being around 65-75% for road motors is because historically this was the best compromise with the modified bicycle frames they had.
i'm not going to go to the guillotine for my opinions. lol. i'm quite prepared to be shouted down by those with the experience to argue.

[Lightbulb]

Frits,
Some where on the Kiwi biker you mentioned about the way a high speed
engine runs with very little acceleration from the tdc to ex opening,
but that the remaining piston momentum from ex open to bdc is where
energy is put into the stroke cycle.
Have you done or do you have any information about rotational
acceleration of 2 stroke single cylinder engines ?
What is the difference between an engine having about 192 deg of exhaust
timing compared to an engine with 196 deg exhaust timing for making top
end power?
I am asking these, as I have an old 1992 2.5 cc engine. It can turn the
same prop my 2011 engine does, but but will run 1100 rpm more. Working
backwards, the 2011 engine at 39000 to 39100 is about right for the pipe
length and 192 deg exhaust timing. The 1992 engine, turns that prop at
40200, but because of the 195.4 deg, should be doing about 39750 rpm
with it's pipe. The older engine is running 450 rpm in the over rev
situation.
If I have a hall effect sensor, am I likely to see something between the
two different engines, ?
Will I be able to see a loaded engine state and an under loaded engine
state if I recorded these and graphed the rotation from 4 points ?
Lots of questions I know,
Thanks for your time and input.
Neil

[wobbly]

Grumph - For fucks sake what drugs are you on " in a vertical plane - ie at right angles to the cylinder axis ".
A Norton Manx cylinder is vertical, the cylinder axis is therefore vertical - you get free blowys for life as well if I am wrong.
These are balanced at 80% - ask Ken McIntosh.
This reduces the vertical shake by opposing the piston ( vertical ) inertia forces, and stops the bars from shaking up and down.
Its like being a Greeny, how the hell can you save the planet when you are off it most of the time.

And in answer to Neils question about the piston acceleration from TDC to EPO.
Frits analysis was based on an a calculation with an error of over a factor of 2 regarding peak cylinder pressure in the Aprilia.
I certainly dont want to even begin to second guess, or criticize Frits in public, but the assumptions leading from this error are plainly wrong
as i alluded to previously in this thread.

The answer re EPO is that down at 190 we have huge superposition that allows a very wide band of usable torque production.
But ultimately this approach finally runs into good old physics, and is simply incapable of generating sufficient blowdown to even begin to approach
the peak numbers able to be generated at 200*.
BUT - To make this scenario work over a usable broad band every trick in the bag is needed, a servo PV and PWM powerjet along with digital ignition enabled spark retard.
All the things you dont have.

[Moooools]

So Mooloos, I'd build in a question to your data input - above or below an inclination angle of 45 degrees...And adjust the end result to reflect that.

But yes, there's still an awful lot of suck it and see involved....

Hmmm, the outputs would be a bit too subjective I think. I will get a plot going of horizontal vs Vertical vibrations so that you can correlate an existing engine vibration 'feel' to a ratio between vertical and horizontal vibrations.

Will do a balance shaft too. But have to get through a few exams first. Unfortunately balancing only takes up 5 pages of content out of 300 or so in my next exam so not much of an excuse to keep working on the spreadsheet.

[Grumph]

Grumph - For fucks sake what drugs are you on " in a vertical plane - ie at right angles to the cylinder axis ".
A Norton Manx cylinder is vertical, the cylinder axis is therefore vertical - you get free blowys for life as well if I am wrong.
These are balanced at 80% - ask Ken McIntosh.
This reduces the vertical shake by opposing the piston ( vertical ) inertia forces, and stops the bars from shaking up and down.
Its like being a Greeny, how the hell can you save the planet when you are off it most of the time.

While I have ridden bikes where the balance was so bad you were off the planet most of the time, i don't think you saw the point i was making.
I said, if you balanced a manx (upright cylinder) to the same factor as a horizontal cylinder motor, it would shake at right angles to the cylinder axis...IE fore and aft. i can tell you as fact that a horizontal single balanced to 25% still has a vertical (in relation to the ground, ie at right angles to the cylinder axis) vibration. The trick is getting it to an acceptable level - as is the case with whatever cylinder configuration you choose to use.
I'm well aware of the factor Ken uses as i've discussed more than one of Kens cranks with Barry Lynch here who has done a few....

I'm out of this argument. carry on.

Edit - If sammy miller ever brings the F model Horizontal single manx out here, we must ask him what the balance factor is....and if he wants a blowy...

[Flettner]

as a chainsaw is only supposd to run at max rpm or very close to it, it's pretty straightforward I would say : balance it so that it vibrtas the least at (close to) max rpm. all the other rev's do not matter much.

I think with chainsaws they just rubber/spring mount them (from the handle) as much as possible. You know, just let the bugger shake!

[mr bucketracer]

i must ask brian thomas

[husaberg]

I think with chainsaws they just rubber/spring mount them (from the handle) as much as possible. You know, just let the bugger shake!

Back in the old days before the antivides there was a fair few people who lost fingers from the saws not from the chain but from the vibration destroying the blood supply to the fingers they used to call it white finger or wimpy fist.
People operating Jack hammers used to get it as well but those things were at least designed to vibrate.
https://en.wikipedia.org/wiki/Vibration_white_finger

[wobbly]

Sure thing, you are out, but the bottom line is that vertical shake reduction really is the aim of the balance factor
chosen to work with the chassis natural resonance.
Saying vertical shake is a non issue is simply bollocks.
And in all cases of a near vertical cylinder this necessitates a highly overbalanced crankshaft ( around 80% Manx, less for a "road " single ) to nullify the vertical component.
You disagreed with Frits on this and I am fully defending his assertions.
So I have now also disagreed with him about his graphical analysis of rod force resultants, due to combustion pressure magnitude Vs mechanical inertial forces.
Im cringing awaiting the sky falling in on my head.