Re-Sleeving Stihl Nikasil Cylinders ?

[RiverRat2]

As best I can measure (it's harder then it looks..), when Stihl says 60mm bore, it's 60mm within a handful of 10,000ths... The pistons are undersized appropriately.

The OEM 088 piston has a cast steel disc above the top ring. In addition to heat dissipation, the disc protrudes beyond the piston diameter to assist in blocking the combustion from the top ring. Any bore clearance needs to take this into account. I'd measure a new OEM cylinder and match that..

I'll try to cut one in half tomorrow and post a pic to show the construction.

If he gets the OEM piston and sends it with the cylinder they (US Chrome) will get it (the newly plated bore) finished to the right size.... We run a bunch of their work,,,,,,,

 

[2wheels]

If you want to get that stud out, weld a nut on to it.

I also noticed your scoring marks on the cylinder. I the past with problem cylinders, I have drilled 2 small holes on the piston skirt, just below the exhaust port to lube and cool that area.

 

[Lakeside53]

If he gets the OEM piston and sends it with the cylinder they (US Chrome) will get it (the newly plated bore) finished to the right size.... We run a bunch of their work,,,,,,,

Yep...

Now I'm not sure about the disk protruding anyhow. I just looked at two old 084 and 088 pistons and it doesn't seem to. Mahle sure builds a nice piston..

 

[bwalker]

When sleeving a coated cylinder with a steel/iron sleeve heat transfer problems often result. This causes seizers. I know this because I ran into this problem first hand on a MX bike motor and a snowmobile.

 

[RiverRat2]

They are not going to sleve it

When sleeving a coated cylinder with a steel/iron sleeve heat transfer problems often result. This causes seizers. I know this because I ran into this problem first hand on a MX bike motor and a snowmobile.

just removing the damaged old plating and replating the bore and honing to match the OEM piston...They do All of our 2.5 liter outboard drag Motors

 

[bwalker]

US Chrome does excellant work FWIW.

 

[Timber_Hitch]

Ordered a OEM Stihl 088 mag piston today OUCH !!! :deadhorse: Lake has alot of experience and caused me some concern so I bit the bullet 120.00 dollas. When I get the piston I am going to send it with the cylinder to Scott of US Chrome and I should end up with a great saw.

 

[Lakeside53]

Dont forget.. you still have to find out why it failed the first time...or you'll be back with a scored piston..

New OEM cylinder gasket (the bump points DOWN), and a full pressure test is in order. Also, look at the carb closely, pressure test the fuel line and change the fuel flter (OEM only..). 088 have rev limiting coils so adjustment is tricky...


Do you have a service manual?

 

[RiverRat2]

Man that sounds familiar!!!!!

Dont forget.. you still have to find out why it failed the first time...or you'll be back with a scored piston..

New OEM cylinder gasket (the bump points DOWN), and a full pressure test is in order. Also, look at the carb closely, pressure test the fuel line and change the fuel flter (OEM only..). 088 have rev limiting coils so adjustment is tricky...


Do you have a service manual?

Great advice though!!!!!! Keep up tha good work Andy,,,,

You tha man,,,,