Cylinder design, reed valve homelite

[ILIKEHOMELITES]

I posted a thread a couple weeks ago with a picture of the 0.030" cylinder for my Homelite C9. As I was looking on eBay I found a cylinder (already sold) for a 1020xp saw and noticed that the skirt of the cylinder is different than the C9. It appears that the location of the intake ports is similar, but it has a complete diameter under it (see the pics.). From a porting perspective how does this change things? Is the design of the case different for the different designs? I understand that the diamters of the cylinder are different, my question is about the design.

1020XP cylinder

C9 cylinder

 

[hotshot]

I posted a thread a couple weeks ago with a picture of the 0.030" cylinder for my Homelite C9. As I was looking on eBay I found a cylinder (already sold) for a 1020xp saw and noticed that the skirt of the cylinder is different than the C9. It appears that the location of the intake ports is similar, but it has a complete diameter under it (see the pics.). From a porting perspective how does this change things? Is the design of the case different for the different designs? I understand that the diamters of the cylinder are different, my question is about the design.

1020XP cylinder

C9 cylinder

The C9 is an open port cylinder and the 1020XP is a closed port, so yes the cases will
be different in their designs. The C9 has the cylinder skirt cut out on the sides to help
feed the intake charge up into the transfers. The closed port cylinders tend to flow better
at higher speeds but are more expensive to manufacture. What's the 0.030" dimension referring to in your post?

 

[ILIKEHOMELITES]

The C9 is an open port cylinder and the 1020XP is a closed port, so yes the cases will
be different in their designs. The C9 has the cylinder skirt cut out on the sides to help
feed the intake charge up into the transfers. The closed port cylinders tend to flow better
at higher speeds but are more expensive to manufacture. What's the 0.030" dimension referring to in your post?

The cylinder on this C9 is 0.030" oversize. I had actually started a thread on that here because I had not seen an oversized 2 stroke piston (unless the jug is changed.) The theory is at some point it was bored, plated, and an oversized piston used. http://http://www.arboristsite.com/chainsaw/245548.htm The cylinder is gauled though and cannot be saved which lead me to my next idea - a sleeve. The sleeve would work best if I could design it like the XP cylinder and cut the air ports at the end of the intake runners, that way I could support the sides of the piston were the runners are now on the C9. It may end in disaster or wasted effort, but I believe it could work if I can adopt the XP design! Have any experience with this??

 

[john_bud]

A smart man once told me that he loved aluminum engines as anything was possible with modifying them. The only limitation is your imagination....




...and the size of your wallet.


Your thought are good, but will it cost more than a new saw to implement? I don't know, but guess it might.

 

[ILIKEHOMELITES]

A smart man once told me that he loved aluminum engines as anything was possible with modifying them. The only limitation is your imagination....

...and the size of your wallet.

Your thought are good, but will it cost more than a new saw to implement? I don't know, but guess it might.

You are right John, I would never pay someone to do this, but I have the ability and the equipment to do it myself though. I enjoy doing this kind of thing!
I have a limited knowledge of the finer points of 2 stroke design - I figured there are many here that have a much deeper understanding of the design than I (as I have already seen.)
Brad

 

[IEL]

I know a guy who made replacement pistons for a two man saw out of motor cycle pistons.

There is a lot you can convert and moddify.

 

[john_bud]

You are right John, I would never pay someone to do this, but I have the ability and the equipment to do it myself though. I enjoy doing this kind of thing!
I have a limited knowledge of the finer points of 2 stroke design - I figured there are many here that have a much deeper understanding of the design than I (as I have already seen.)
Brad

If it's just time... what's hold'n you back?

 

[ILIKEHOMELITES]

If it's just time... what's hold'n you back?

I need to figure out how I am going to design the sleeve... This is the advice I am looking for here. If I was to use a XP design in the C series saw would it work (and work well)? Would I need to modify in the case?


Brad