66, 266, 268 piston confusion

Anyone know or have pics of the differences between these pistons? (Ahem.... JJ...) Baileys lists two different pistons, but it seems you can use either in the 268?? I have heard that there are some pin height differences, but no proof on that. I have a 66 jug I'm going to use on a project, and I'd like to use a windowed piston if it will work. Are the 266xp style pistons available anymore with the full circle skirt?

I'm curious to know the answer to this also. I just got in a fairly large lot of diassembled 266/268/272 family saws and I'm confused also.

Just for reference the piston and cylinder on the left is off of a 268. The crankcase on the right is a 266 along with the pistons. The diameter, wristpin location, and height of the pistons are the same.

Does your 66 jug have closed or open transfer ports? All the 66 pistons I've seen are slab-sided for open transfers.

JJ - to your knowledge is that the main difference between the 66/266 is the piston ad cylinder vs a 268?

The 268 is basically a 272 with a 50mm bore. So the intake block and manifold, air filter, carburetor, muffler, and clutch are all different than the 266. The 266 I think has more in common with the 162 than the 268. I'm not sure on the 66 but I'm almost positive it's an extension of the 61 Rancher and designed as a farm and ranch/homeowner style saw. Like I said, the 61 and 66 cylinders I've seen were open port, whereas the 266 and 268 cylinders are closed port.

Jacob J. said:

Does your 66 jug have closed or open transfer ports? All the 66 pistons I've seen are slab-sided for open transfers.

Click to expand...

JJ, yes the 66 cylinder I have is open port. I have compared it to my 272 cylinder, and do not see alot of difference. The only exception being some material seperating the bottom and top of the transfer on the 272 jug.

66 on left, 272 on right


272 transfer


66 transfer


I am NOT a porting expert, but I have seen a few cylinders where guys have removed the material between the upper an lower openings on an internally fed closed transfer like the 272. Wouldn't that make it essentially the same as the 66 transfer setup?

I guess what I want to know here is this: Are there any pin to crown height differences on the 61/66/266 sub-series vs the 268/272 sub-series. I do not have a 66 piston to check. I am wanting to use a 268xp piston the the 66 jug. I think the windowed piston will help quite a bit in the performance dept. The ports may get some attention also. Gotta say that those Gilardoni cylinders are very nice. I have only had 3 or 4 of those so far, and I am quite impressed.

I'm not sure on the crown height differences between a 66 piston and a 268. I don't have a 66 piston here to compare either.

The only reason guys remove the transfer bar in closed port cylinders is when they're building race saws that will be turning very, very high RPM for a short period of time. Removing the transfer bar for a worksaw is a step backwards. An open port saw can be made into a good runner though, it takes some measuring and careful porting.

bcorradi said:

Just for reference the piston and cylinder on the left is off of a 268. The crankcase on the right is a 266 along with the pistons. The diameter, wristpin location, and height of the pistons are the same.

Click to expand...

Hhhhmmmm that reminds me, I gota get me a 266 thin ring piston.

Jacob J. said:

I'm not sure on the crown height differences between a 66 piston and a 268. I don't have a 66 piston here to compare either.

The only reason guys remove the transfer bar in closed port cylinders is when they're building race saws that will be turning very, very high RPM for a short period of time. Removing the transfer bar for a worksaw is a step backwards. An open port saw can be made into a good runner though, it takes some measuring and careful porting.

Click to expand...

Am I on the right track wanting to use the windowed piston?

I need to move to Oregon.

I did get a locked up 61 today, so I can measure the piston in that and compare it to the 272. I'm going to check with Bcorradi on a 266xp jug also. He just divulged that he has a pile of that series in boxes.

B200Driver said:

66 transfer

Click to expand...

I'm a BIG fan of open ports and that 66 jug looks like it's flowing a BIG charge:jawdrop:

Well, a windowed piston would work ok, but you may experience some lag in the spool-up. It's a good experiment anyhow. I haven't played with open port cylinders much.

Another thing to note is that there are 2 different 268's- xp and non-xp, with closed and open ports.

willsaw4beer said:

Another thing to note is that there are 2 different 268's- xp and non-xp, with closed and open ports.

Click to expand...

Yes, with corresponding pistons. We never got any non-xp 268s here though, so I've never seen one in person.

My 268 is a non xp.

I figure someday I'll find a good deal on a 272 topend and throw it on there. :greenchainsaw:

I have always heard that a closed port cylinder was the best choice if youve got the option to use one. I would throw a 272 p&c on the saw myself if I was looking to make it a hotrod. Rick!

I have a non xp 268 late 90's. I put the 52mm top end on it from Baileys and it rips, it also has a muffler mod and will beat my buddies 371xp all day

Jacob J. said:

The 268 is basically a 272 with a 50mm bore. So the intake block and manifold, air filter, carburetor, muffler, and clutch are all different than the 266. The 266 I think has more in common with the 162 than the 268. I'm not sure on the 66 but I'm almost positive it's an extension of the 61 Rancher and designed as a farm and ranch/homeowner style saw. Like I said, the 61 and 66 cylinders I've seen were open port, whereas the 266 and 268 cylinders are closed port.

Click to expand...

I believe you are right, but can't really prove it!


Anyway, "268" can be two quite different animals!

The SE/XP/Special are closed port high performance saws - and the "plain" 268 is an open port design with quite a bit less power, made after the 272xp replaced the 268xp.
The 268xp was renamed 268 Special at that point, and only made for a short time........

As far as I know, the plain 268 was made in Brazil until a year or two ago, when it was replaced by a "detuned" version of the 272xp.


Edit;

I see now that some of the above had already been mentioned, but I let the post stay anyway........

The SE/XP/Special are closed port high performance saws - and the "plain" 268 is an open port design with quite a bit less power, made after the 272xp replaced the 268xp.
The 268xp was renamed 268 Special at that point, and only made for a short time........


I have a 268XP Special, closed port. Are you saying that they dropped the XP and just went to a 268 Special in the later years of production?......Cliff

Cliff R said:

I have a 268XP Special, closed port. Are you saying that they dropped the XP and just went to a 268 Special in the later years of production?......Cliff

Click to expand...

I believe that's what Troll is referring to and as usual I think he's spot-on. I don't remember seeing the 268XP on the shelf after the first of the 'westernized' 272XPs started showing up, which was right around the time I started working in the woods.

BTW I have a roll of those 268 Special top cover stickers if anyone needs one for free.