Too much piston-bore clearance? Piston slap? Video

[Stevetheboatguy]

Just so you know. You really need to measure the piston at the skirt not the crown to check for excessive play. The crown is always undersized to compensate for expansion when warmed up. There is no such thing as a truly square piston. They are all a smaller diameter at the crown and slightly egg shaped. Once they warm up and expand they are more closely to true square. Cold they are anything but.

Steven

 

[cuinrearview]

Just so you know. You really need to measure the piston at the skirt not the crown to check for excessive play. The crown is always undersized to compensate for expansion when warmed up. There is no such thing as a truly square piston. They are all a smaller diameter at the crown and slightly egg shaped. Once they warm up and expand they are more closely to true square. Cold they are anything but.

Steven

You're lucky your name's not @ramrat

 

[67L36Driver]

Easy to tell on this one. [emoji2960]

Actual skirt clearance was .070”.

 

[popopboat]

Easy to tell on this one. [emoji2960]

Actual skirt clearance was .070”.

*Ring ding ding daa baa*

 

[popopboat]

Just so you know. You really need to measure the piston at the skirt not the crown to check for excessive play. The crown is always undersized to compensate for expansion when warmed up. There is no such thing as a truly square piston. They are all a smaller diameter at the crown and slightly egg shaped. Once they warm up and expand they are more closely to true square. Cold they are anything but.

Steven

Yep, at skirt its a tad bigger than than the thickness of double-sided razor, which means its around 0.006"-0.007"
But i guess it would be shame now, when im doing a complete rebuild of it, to cheapskate on pretty much most important component.
Ill just put aftermarket one, and as im not a heavy user, and im always using atleast 40:1 it will last me a long time.

 

[Wonkydonkey]

I had one just like that, except it had a hole in the front on my 044

Easy to tell on this one. [emoji2960]

Actual skirt clearance was .070”.

 

[popopboat]

View attachment 225672 View attachment 225673 I had one just like that, except it had a hole in the front on my 044

How about cylinder walls?

 

[67L36Driver]

How about cylinder walls?

The only ‘wear’ you get on them is when the piston seizes up and galls.

It’s crome plated.

 

[popopboat]

The only ‘wear’ you get on them is when the piston seizes up and galls.

It’s crome plated.

And from slapping?

 

[cuinrearview]

The only ‘wear’ you get on them is when the piston seizes up and galls.

It’s crome plated.

The plating will will wear too. Just at a slower pace. I work with coated and SS tooling every day that is worn but aluminum not much thicker than foil.

 

[Wonkydonkey]

How about cylinder walls?

i bought the saw as a working saw, I pulled the plug, it was grey. Pulled the muff and saw the piston.
Now it was a rebuild saw.
I clean the cylinder up .he mastermind way al is good
You can read my thread

 

[Wonkydonkey]

The thread is here

http://opeforum.com/threads/whats-saw-is-in-the-package-an-ooerr44-arctic.18349/