The Cross Performance 066 Top End

[stihl_head1982]

I have 2 in the field for quite a while have heard nothing they are in a cutters hands so no news is good news.

I tend to agree sir.

 

[MustangMike]

Well, a tiny step forward today. I got the log ready for testing! Keep in mind, no heavy equipment and I was working alone, just me and my Timberjack, but I got it up off the ground and put a round under it so I can start testing.

Likely will video the stock set up on Friday when I have a camera man available!

 

[Deets066]

Looky what came today

 

[Deets066]

Why do you guys put OEM in big bold letters?

 

[CJ Brown]

Why do you guys put OEM in big bold letters?

Because a chainsaw is the perfect Once Every Month replacement, duh!

 

[MustangMike]

I made some (awkward) progress today! Made some vids of the stock saw in the test Oak.

Did not have anyone to help me, so I duct taped my phone camera to a step stool.

Lessons learned ... Even though it is Gorilla Duct Tape, use lots of it, and, When you rush to get back into it, remember to cut straight!

The two vids should provide a baseline of the stock 066 w/muff mod & timing adv w/36" RSLH. (Note: you can time cut #2 by the sound).

 

[MustangMike]

I checked the squish on the stock saw and it was .028, then I started ripping it down.

I knew the piston was slightly scored the exhaust side, but now I know it was slightly scored on both sides!

But the rings were free and the scoring did not go all the way down the piston, and she still ran pretty good!

FYI, the jug came off easier than any other saw I ever did, bolts were kinda easy to break loose, and the cylinder was not stuck, came loose right away with the bolts out ... kinda baffled me! I'm used to fighting with em.

 

[David Young]

I made some (awkward) progress today! Made some vids of the stock saw in the test Oak.

Did not have anyone to help me, so I duct taped my phone camera to a step stool.

Lessons learned ... Even though it is Gorilla Duct Tape, use lots of it, and, When you rush to get back into it, remember to cut straight!

The two vids should provide a baseline of the stock 066 w/muff mod & timing adv w/36" RSLH. (Note: you can time cut #2 by the sound).

I use a cookie for a phone holder.
cut it a little thicker lay it down flat and then make a slot to hold my phone.

 

[MustangMike]

I knew the piston was slightly scored the exhaust side, but now I know it was slightly scored on both sides!

Does the scoring on both sides reflect poor fuel quality rather than a heat failure???

 

[MustangMike]

Looky what came today

How does your kit look???

 

[RI Chevy]

Just curious what oil ratio you use Mike? And is that the saw you use for milling?

Sent from my SM-G930V using Tapatalk

 

[mdavlee]

Does the scoring on both sides reflect poor fuel quality rather than a heat failure???

All the way around was probably a splash of straight gas at one time.

 

[MustangMike]

Just curious what oil ratio you use Mike? And is that the saw you use for milling?

Sent from my SM-G930V using Tapatalk

I run Amsoil Saber at 40:1, and no, this is my long bar saw. I have anther 066 Randy did for me just for milling.

 

[MustangMike]

I hope you are all ready for more info...

First, let me say that the Cross Cylinder and piston look REMARKABLY SIMILAR to the OEM ones.

We will start with the pistons:

Weight: OEM 3.1 oz Cross 2.9 oz
Both pins are 0.5 oz, but the cross pin is noticeably thicker (see pic).

Width at base: OEM 2.123 Cross 2.124 (likely just reflects wear)

Skirt width: OEM Front 1.356 Cross 1.363
OEM Back 1.345 Cross 1.376

(Note: Cross skirts are wider, and OEM has wider skirt in front, Cross has wider skirt in back)

Pin to top: OEM .670 Cross .665 (As best as I can measure, distance to squish band is the same on both cylinders at 3.194.)

Height: OEM Front 1.691 Back 1.695 Cross (both) 1.689.

 

[MustangMike]

I could not find any name on the Cylinder, so I assume it is just a Stihl, and it is an A cylinder.

The original piston is a KS A/B.

Here are some jug pics:

 

[MustangMike]

The OEM cylinder is 1 lb 8.2 oz, the Cross is 1 lb 11.3 oz. The most notable difference is the cooling fins on the Cross are thicker.

I need to try to measure the ports. I think the cross has larger transfers, and wider (but shorter) intake & exhaust.

I also want to try to fix that little defect on my intake port. I have never done any saw porting, so some advice would be appreciated. I'm thinking of just gently touching it with my 12 V chain sharpener with the diamond stone in it. Will this work???

Thanks, just can't see putting it together with this little defect staring at me! I can see (and feel) a little bulge in the port right before it reaches the cylinder, and and the shape of the inside of the port is irregular there.

 

[MustangMike]

More cylinder comments:

Measuring from the squish band, the Exhaust and upper transfers are lower (by about the same amount).

The intake is about 1/16 wider and the Exhaust about 1/32 wider.

The Intake opening is also lower.

Lower transfers are about the same size.

That is all I got!

Hope someone responds to my idea about playing with the intake port.

 

[huskihl]

More cylinder comments:

Measuring from the squish band, the Exhaust and upper transfers are lower (by about the same amount).

The intake is about 1/16 wider and the Exhaust about 1/32 wider.

The Intake opening is also lower.

Lower transfers are about the same size.

That is all I got!

Hope someone responds to my idea about playing with the intake port.

Show us a pic of the intake defect you're talking about.

Nice work so far

 

[dall]

i have one of these cylinders and there a couple places needing touched up from casting

 

[MustangMike]

I think I posted this before, but here it is:

Notice on the left of the pic it looks good, then in the middle and right of the port there is a bit of excess material.