squish bands

[bwalker]

he's talking about residual oil in the crank case.
don't know what that has to do with squish bands

Nothing. It was mentioned in regards to a question he asked..

 

[bwalker]

we can talk theory all day and get nowhere

You can get nowhere by not understanding theory pretty easy.

 

[bwalker]

I'm thinking the experience that we have seen firsthand trumps theory.

But.........I've learned a lot by staying open minded.

Why is that you see race saws with removable heads?

 

[bwalker]

he's talking about residual oil in the crank case.
don't know what that has to do with squish bands

And residual oil is only a product of migration time.
As it pertains to the original question migration time is pertinent to the amount of oil actually lubricating a motor when milling.

 

[tickbitintn]

My guess would be that it's easier to machine the chamber the shape you want it out of a block of aluminum rather that what the factory gave (or didn't!) you.
Also for more area to dissipate heat.....

Sent from my XT1254 using Tapatalk

 

[bwalker]

My guess would be that it's easier to machine the chamber the shape you want it out of a block of aluminum rather that what the factory gave (or didn't!) you.
Also for more area to dissipate heat.....

Sent from my XT1254 using Tapatalk

Heat doesn't matter for a saw that only makes a few cuts in a race.
Your first guess is more in line with my thoughts with the caveat that you add the word "proper" in front of shape.

 

[Hedgerow]

My guess would be that it's easier to machine the chamber the shape you want it out of a block of aluminum rather that what the factory gave (or didn't!) you.
Also for more area to dissipate heat.....

Sent from my XT1254 using Tapatalk

And spark plug placement.

 

[tree monkey]

You can get nowhere by not understanding theory pretty easy.

i'm not arguing with you. I understand the theory.
the band is just too narrow on a small bore to be concerned about.
cutting them flat with a tight clearance will put more fuel in the chamber producing more power out of the fuel that's in there.

I agree with the theory on larger bores, the larger the bore is the higher squish velocity gets. and the need for a tapper

 

[Hedgerow]

Like the torroidal cut Terry posted. Squish area gets it moving toward the center, then the other forces it into flame front?
But don't know if it's for more efficient burn? or for burning more sheer volume? Both?

 

[Mastermind]

Why is that you see race saws with removable heads?

So that a better chamber can be used.

I never build race saws though, so again........that is not something that concerns me.

 

[Hedgerow]

So that a better chamber can be used.

I never build race saws though, so again........that is not something that concerns me.

Don't it make you wonder though?
Why all the inconsistencies from the factories in chamber design and wide variants in squish widths and spacing?
Manufacturing tolerances just not that tight? so they gotta build in a little more room for variance of machining and components?

 

[Mastermind]

The factory uses a cast band rather than a machined band........they can only get it so good like that.

 

[weedkilla]

I learned one thing a lot of saws ago.

If I try to incorporate what works on bikes and sleds into my saw building.......I end up wasting a lot of time.

Just about everything dumb I've got to own up to is because it's taken me too long to realise this.

 

[Brush Ape]

If I try to incorporate what works on bikes and sleds into my saw building.......I end up wasting a lot of time.

Just about everything dumb I've got to own up to is because it's taken me too long to realise this.

Just about everything dumb I've done was on bikes or sleds. Or trucks or women....

 

[bwalker]

i'm not arguing with you. I understand the theory.
the band is just too narrow on a small bore to be concerned about.
cutting them flat with a tight clearance will put more fuel in the chamber producing more power out of the fuel that's in there.

I agree with the theory on larger bores, the larger the bore is the higher squish velocity gets. and the need for a tapper

And you very well be right. I really have no expiereance fooling with the heads on any cylinder under 125cc.

 

[bwalker]

The factory uses a cast band rather than a machined band........they can only get it so good like that.

The head on a Redmax 8000 looks damn near like a bike head. I think the oems could get much better in this regard.

 

[bwalker]

So that a better chamber can be used.

I never build race saws though, so again........that is not something that concerns me.

Now the question is could a factory cylinder be machined to a better shape?

 

[Mastermind]

Now the question is could a factory cylinder be machined to a better shape?

I'm not too interested in chasing this topic around in a circle.

 

[bwalker]

Redmax 8000 head I mentioned above.

 

[bwalker]

I'm not too interested in chasing this topic around in a circle.

I'd go on record as saying I think a head design proper for the application would work very well on a saw and make more power than the crappy stock designs. I would also go on record as saying by virtue of the stock designs making the proper shaped head on a stock cylinder would be very hard. For one the combustion chambers are pretty large to start with. If you remove much material to reshape you do so at the expense of lowering compression. Since the compression is so low to start with its better to peruse that than a proper head design.
Make sense?