Would you run this Cross cylinder as is?

[huskihl]

Stihl, among other reputable manufactures, made exhaust roofs sharper and flatter than that with great long term results, so I'm wondering why this guy is grinding on this thing to begin with.
I think it looked good out of the box.

An 034 super is the only one I've ever seen like that. It was a great runner, but also a smaller exhaust port

 

[brshephard]

She came out to 100/120/80 with .036 squish with a gasket.
102/122/82 .016 without.

Since I'm a hamfisted, dull chain running hack I'm gonna go no gasket to get torque.
I'll hand sand the squish and fill the intake to 78.

Here's my JB weld life hack:

Put it on a hot wood stove, it's ready to grind after about 45 minutes.

 

[wcorey]

Be ready for a battle doing the squish, these are plated pretty heavy.
And watch out if you plan on going deep, some of them have a lot of undercut on the wall.

 

[MustangMike]

Unfortunately, I agree with Bill, will be very tough to hand sand a plated squish band.

You may be able to get away with 16 squish, but I would raise the Ex to 100 or lower so you don't break recoil ropes!

 

[MustangMike]

I would also make sure you use a OEM wrist pin bearing, they are only $10 from most dealers, and a frequent problem on the kits.

 

[brshephard]

I would also make sure you use a OEM wrist pin bearing, they are only $10 from most dealers, and a frequent problem on the kits.

That's good advice. The original wristpin actually failed in this saw.

Here it is with the intake filled.


This cylinder was underplated a bit. I cut to .019. I have hand sanded a plated AM jug as well. Its a pain but it is doable.

 

[drf256]

Looks great.

 

[paragonbuilder]

She came out to 100/120/80 with .036 squish with a gasket.
102/122/82 .016 without.

Since I'm a hamfisted, dull chain running hack I'm gonna go no gasket to get torque.
I'll hand sand the squish and fill the intake to 78.

Here's my JB weld life hack:
View attachment 122759
Put it on a hot wood stove, it's ready to grind after about 45 minutes.

Are you sure your timing numbers are correct? I find it odd that they all moved the same degrees when dropping the jug 20 thou...

 

[Wonkydonkey]

Idk , & Just wondering? / learingDoes 20thou = 2*

 

[cus_deluxe]

Depends on crank angle, ports at different heights will have a slightly different change in duration than the others.

 

[Wonkydonkey]

Ahh I see, understand now, less just after tdc most at 90*

Thanks for the clarification

Cheers

 

[cus_deluxe]

Yep, theres maths to figure out exactly the change. I dont figure stuff that way, i just use the wheel. I could measure the same jug 3 times and get slightly different numbers lol.

 

[brshephard]

Are you sure your timing numbers are correct? I find it odd that they all moved the same degrees when dropping the jug 20 thou...

You're right, the transfers moved three degrees or so.
Around 119.5 to 122.5

I always round towards the number I want lol.

 

[brshephard]

Ahh I see, understand now, less just after tdc most at 90*

Thanks for the clarification

Cheers

Since my intake and exhaust have identical durations, they also have complimentary crank angles.

Dropping the jug would decrease the exhaust duration and increase the intake duration the same amount.

I think mdavlee said .0147"/ degree of exhaust. No idea how he got out to the ten thou place. Maybe he will chime in.

 

[wcorey]

Dropping the jug would increase the exhaust duration and decrease the intake duration the same amount.

Other way around...

 

[brshephard]

Fixed, thanks.

 

[brshephard]

Can anyone tell me the rod length on this saw?

 

[srcarr52]

Can anyone tell me the rod length on this saw?

I've measured them at 2.81".

 

[brshephard]

Thank you sir. Is this a center to center measurement or OAL?

 

[wcorey]

Coming from Shaun it's pretty safe to assume it's center to center.