272xp, is it worth it?

[Dennbb]

So manufacturers hone the cylinder to crosshatch the cylinder surface so the piston rings bed in easily and then plate the cylinder to cover the crosshatching.... ........Do they(?), think about it???

There isn't any cross hatching in a plated cylinder. It's unnecessary. Cross

So manufacturers hone the cylinder to crosshatch the cylinder surface so the piston rings bed in easily and then plate the cylinder to cover the crosshatching.... ........Do they(?), think about it???

 

[Dennbb]

There isn't any cross hatching in plated cylinders. It's unnecessary. Cross hatching is used in steel or cast iron sleeves requiring a break in period to seat the rings and keep the cylinder from glazing . It's used in four strokes to keep the engine from burning oil.

 

[zzr1200]

Cross hatching is used in steel or cast iron sleeves requiring a break in period to seat the rings and keep the cylinder from glazing . It's used in four strokes to keep the engine from burning oil.

Or in used cylinders to remove bore glazing so new piston rings seat into the bore, very little point in fitting new piston rings in to un-honed glazed bore.

 

[Dennbb]

There's very lttle point in honing a plated cylinder which is glazed right from the factory because of the plating.

 

[Maintenance supervisor]

Everyone Hone away! I like buying "cheap " chainsaws.

 

[zzr1200]

There's very lttle point in honing a plated cylinder which is glazed right from the factory because of the plating.

A cylinder in a new engine block or chainsaw cylinder is not glazed, be it made out of cast iron, chrome plated, nikasil or titanikel.

Glazing is caused by oil/fuel and carbon from the combustion process being built up over time preventing the piston rings from sealing, generally once the piston rings/cylinder walls have become super smooth and rings have worn slightly which allows the glazing to take place, although there are bad operator practices that also promote glazing.

A cylinder ball hone breaks the super smooth surface which allows the piston rings to bed in correctly, the hone must be rotated in both direction to remove any glaze that has built up in the opens to the transfer ports.

Hence this is why used cylinders are honed.

2 stoke ported cylinders are honed for 2 reasons.

1. To glaze bust if it's a used cylinder.
2. To remove any last chance of a possible burr on the edges of the transfer ports which could damage the piston/rings. This should/would be carried out on a new or used cylinder assembly that has been ported.

The 3 stone sprung loaded type cylinder hones don't enter the transfer port so are useless for this application.

Sunnen Style Hones used by manufacturers to finish machine the surface of roughly bored cylinders to final size, these are also useless for chainsaw style cylinder as they also do not enter the transfer ports to remove possible edge burrs. also this type of hone can remove serious amounts of material from the cylinder wall if used incorrectly, by an un-trained person.