Stock Appearing Race Saws

[Mr.]

Full circle crank and fins on the flywheel...

Just because it isn't your way doesn't mean it's the wrong way.

Marcel left his flywheels alone after so many saws. He did pretty good.

The saw will sit up and bark.

As far as the pin holing goes.... the major benefit I want is better strutural integrity. The guys who are good at it use them for balancing also.

Fred

So does pumping all that air about make it cut faster? Maybe more an endurance racing thing.

Amazing how sensative people get when anything is questioned.

There may only be one single fact in life, and that is "That there are no facts, even what we take to be fact is only but opinion or preception of what people observe. Some opinions are generaly well accepted, other are not."

You did not question. And I am not sensative(sic).

When I want to bring up a topic and not offend people, I try not being a **** first. Care to try?

Fred

 

[Mr.]

I do not think that removing some weight off of a flywheel is a bad thing. As long as the balance is the same. Tough to measure balance at 15k+ RPM.

Not alot of machines will spin it that fast, but I digress. The balancing must be every plane. if you only look at static balance you will probably disappoint yourself.

I really didn't want to meantion it, but if someone gave me a saw with a flywheel that looked like the lightened one earlier in this thread.... I'd buy a new flywheel.

Another function of any rotational mass is to store energy. A good analogy for that flywheel is a digital wave. I would be much more concerned with breaking a crank when twirling a barbell on my flywheel than when it is all nice and even. Wait that was two good analogies.

Fred

 

[drmiller100]

I do agree that the compressor is an extreme example, and that is exactly why I chose it. In that case it takes a huge amount of power to push a small amount of air out a very small area at high velocity in a very inefficient way,

Yes so does an electric fan, except we measure the work it does as kinetic wind energy. Air has mass and it takes energy to move it, the faster we move it, exponetially the more energy it takes to move.
.

you are using words you don't really understand. moving air takes no work, no energy.
ACCELERATING air, on the other hand, takes both.

a compressor is a very efficient pump for what it is designed to do. If there was a more efficient way to compress air, the free enterprise system would utilize it.

When all done, your fan blades on the flywheel are a compressor.

I'm betting the air from a chainsaw is on the order of 10 cfm. if you want to measure it, fill a garbage bag with air, start teh chainsaw, and use the fan to suck the air out. time it.
anyway, do the math on 10 cfm at 1 inch of water pressure.

it ain't much.

 

[timberwolf]

Would it have made it better if I used "???" instead of "...", gramar or spelling is not what I am good at.

You have always been picking at my posts from day one, I don't need to go and show where and how, I think that is well enough known. I think you get off on it, well what ever turns your crank, full circle or not.

If it is working for you stick with it by all means, when I get the chance I will put together my findings on the matter and you can take someting or nothing at all from it. Makes absolutly no difference to me.

 

[drmiller100]

"


Doug, All of the energy you are talking about goes to heat, it is just a matter of when.


So If I take the flywheel in the previously posted picture and do one cut with the stock flywheel and one with the modded one the proof would be evident in two ways.

If nothing else is touched then the wot rpm should increase.

Will the increase in rpm tell us how much power was released?

If I do a cut or three with the stock flywheel and one with the modded one
will there be a difference in cut times and in the wood rpm?

Buck

agreed there will be heat, but HOPEFULLY there will also be a few wood chips!!!!!

measuring horsepower by timing cuts for sure is a valid way to guesstimate power.

measuring the increase of horsepower by measuring free wheel rpm is mostly a wsste of time. pretty tough to do.

 

[Mr.]

Would it have made it better if I used "???" instead of "...", gramar or spelling is not what I am good at.

You have always been picking at my posts from day one, I don't need to go and show where and how, I think that is well enough known. I think you get off on it, well what ever turns your crank, full circle or not.

If it is working for you stick with it by all means, when I get the chance I will put together my findings on the matter and you can take someting or nothing at all from it. Makes absolutly no difference to me.

This is what you do. Come in guns blazing and then I'm a mean guy for not accepting it.

If you weren't trying to take a poke.......... next time leave some context clues.

I state stuff the way you made those statements when I want to inform people that 1. I know more than they do. 2.They are doing it wrong.

Fred

 

[buck futter]

I really didn't want to meantion it, but if someone gave me a saw with a flywheel that looked like the lightened one earlier in this thread.... I'd buy a new flywheel.


If you found it to be poor, I would be more offended that you would let me potential damage a saw or myself then my feelings.

Why would you do this and what is so horribly wrong? balance? it has been reviewed.

have you ever run a saw with a broken fin on the flywheel?

Have you ever seen a woods saw with so much dirt and crud in it that 1/4 to 1/2 of the fins are gone.

Or have you ever seen a broken crank caused by one?

Go over to R saws and look at the flywheel on Brians 359 that was spinning up at 18k and I think the crank is still ok.


how about the propeller on an air plane? They don't stay balanced and it is imperative that they stay running.

I don't think it is as much of a issue of rotational mass as it is the fans wind resistance. How much do each of the aluminum fins weigh?

 

[Danger Dan]

This is what you do. Come in guns blazing and then I'm a mean guy for not accepting it.

If you weren't trying to take a poke.......... next time leave some context clues.

I state stuff the way you made those statements when I want to inform people that 1. I know more than they do. 2.They are doing it wrong.

Fred

Yep, All you did was post a picture of a saw you have for sale and you got ambushed, (egos at work). It will make me think twice about posting photos or videos of my stuff, not that it's in the same league, but this is a tough, (critical) crowd.opcorn:

btw, looks like a cool saw umpkin2:

 

[Mr.]

I really didn't want to meantion it, but if someone gave me a saw with a flywheel that looked like the lightened one earlier in this thread.... I'd buy a new flywheel.


If you found it to be poor, I would be more offended that you would let me potential damage a saw or myself then my feelings.
Not poor, just different than my thinking
Why would you do this and what is so horribly wrong? balance? it has been reviewed.
I'll take a pic of a flywheel I had lightened. It seems to me that the most advantageous material to remove is that which is furthest from the crank centerline. How much resistance could half a fin left between the magnet's make?
have you ever run a saw with a broken fin on the flywheel?
Yes it had two broken fins when I was done.
Have you ever seen a woods saw with so much dirt and crud in it that 1/4 to 1/2 of the fins are gone.

Or have you ever seen a broken crank caused by one?
I've seen bearings ruined by off balance flywheels.
Go over to R saws and look at the flywheel on Brians 359 that was spinning up at 18k and I think the crank is still ok.


how about the propeller on an air plane? They don't stay balanced and it is imperative that they stay running.
I'm not a pilot, I am an old hotrodder that has seen engines roar to life after being balanced. There is hp in balancing.
I don't think it is as much of a issue of rotational mass as it is the fans wind resistance. How much do each of the aluminum fins weigh?

Okay?

 

[timberwolf]

This is what you do. Come in guns blazing and then I'm a mean guy for not accepting it.

Follow me here for a moment.

I come in on the thread and make an observation, based from what I have seen the fins on a fly wheel are pretty soon to go in the life of a race saw. Many of the bike saws have no cooling system what so ever. Up until that point I watched the thead, but kept out of it, it was your babby, but the fins and full circle crank just caught me as odd.

So I said this

Full circle crank and fins on the flywheel...

I can't see how you have taken this is rude, I did not say you were FOS, or say that someone did not know what the were doing,

Come in guns blazing

Hardly.

Then here is your reply

Just because it isn't your way doesn't mean it's the wrong way.

Did I miss something? I never said anything about it being wrong at that point or it wasn't what I would do. You drew those conclusions based on what i don't know, and it goes on from there, got to admit at that point I got my back up.

Anyway this could go on for a long time yet to no end. So I will try to be more careful when entering into the hen house, as not to have feathers fly all over and mess up the egg laying.

As to removing the fins, I have cut about a 1/4 lb off flywheels no problems, knock on wood. I just make an effort to remove metal in very even amounts and loacations on both halves of the flywheel.

 

[Mr.]

Anyway this could go on for a long time yet to no end. So I will try to be more careful when entering into the hen house, as not to have feather fly all over and mess up the egg laying.

[\QUOTE]


Hen house???

Hell, how big the roosters get where you come from?

Funny that you call us hens after you recoil from hurt feelings.

Fred

 

[timberwolf]

There we go again, I never said you were hens, they don't call it a rooster house do they?

Anyway this could go on for a long time yet to no end.

Sorry, Nothing here has hurt my feelings.

I will leave you to it. Like I said when I get the time I will post what I have found on this.

 

[Mr.]

Dictionary.com Unabridged (v 1.1) - Cite This Source - Share This
in·fer·ence / Pronunciation Key - Show Spelled Pronunciation[in-fer-uhns, -fruhns] Pronunciation Key - Show IPA Pronunciation
–noun 1. the act or process of inferring.
2. something that is inferred: to make rash inferences.
3. Logic. a. the process of deriving the strict logical consequences of assumed premises.
b. the process of arriving at some conclusion that, though it is not logically derivable from the assumed premises, possesses some degree of probability relative to the premises. c. a proposition reached by a process of inference.

You learned your math from somewhere. Don't pretend you didn't sit in an English class.

Fred

 

[timberwolf]

"Anyway this could go on for a long time yet to no end."

 

[Mr.]

Okay, now that we have the men seperated from the boys......

What do you guys think about a full circle crank in a stock appearing saw?

I've sat and listened while people talk about large crankcase volumes being good for a pipe motor. There may be truth to that, but I've yet to hear an arguement that convinces me that a tight crankcase isn't the gold standard in muffler saws.

Thoughts?

Fred

 

[buck futter]

low porting numbers.

 

[Dennis Cahoon]

I've yet to hear an arguement that convinces me that a tight crankcase isn't the gold standard in muffler saws.

Thoughts?

Fred

You won't!.....at least from me.

 

[Crofter]

Okay, now that we have the men seperated from the boys......

>Snip>

Thoughts?

Fred

Not much doubt about the intent behind that statement! Lol!


Thoughts on base volume; here goes and since I have no emotional attachment to them, give em a rip! I dont think there is a simple rule that makes the smallest possible base volume capable of the maximum output, but rather needs to be juggled around to mesh with other changes we make when modding. Depending on where the crankcase volume to displacement ratio is to start with, there is no doubt there are situations that will show gain from stuffing. Does that necessarily mean it was the best move or could some other things have been changed instead that would have netted more gain?

At relatively low rpm a relatively small crankcase volume clearly will give more performance for a given displacement as opposed to a loose one. Resonance of the combined base and intake runner, and the ram effect, is not a large factor here but as rpm is pushed up, time area and duration of transfer and intake must increase and the number of degrees of effective pumping time for intake must, of mechanical necessity, decrease. Resonance and the effect of momentum and inertia on port blocking and stuffing, starts to become more a factor in the limits of the mass of the trapped charge. The actual weight of the charge trappped in the base, not its volume is what we can harness. Next the requirement to transfer it up above the piston will need a different strategy depending on actual mean average pressure during transfer time. back to the same question of the fan vs the air compressor. Look at the transfers on an 026 and a 346 for that comparison.

If you doubt the power of the resonance and combined inertia momentum factor in charging then explain how two stroke engines have been designed to run with no crankcase scavenging, simply piston ported intake and exhaust with no reeds in either. No piston force affects the induction. It will only give full power at the tuned rpm and it must be force induced for one cycle to start but it clearly shows the effect.
The tight crankcase is a double edged sword. It limits ram induced charge because its smaller capacity causes pressure to rise quicker and reject rammed charge, though it is more effective in creating transfer velocity.

Stroke to bore ratio
Reed Vs piston ported
Large displacement engines Vs small
Piped Vs muffler

How do each of these factors affect what base volume to displacement ratio will give the maximum output (not necessarily the most flexible or usable)

 

[buck futter]

so a 359 top on a 357 bottom will be the best combination for a muffler saw.



Man

 

[Crofter]

Probably as a work saw; but as a stock appearing race saw cutting three thousand or so rpm higher, maybe not. I know some fellows have done just that experiment but you have to be carefull that you do not do some other things at the same time that skews results. If your 359 cylinder was ported to give the max output on the larger case volume, it would no longer be at its best when you change to the smaller volume with the 357 crank. To be fair towards proving the effect of case volume itself, it would have to be retuned for max output on both setups.