Topic: installing oversize pistons

[hymodyne]

hi,

I've got my engine broken open to deal with a valve spring issue, so I thought about replacing the psitons and rings while i'm at it. I found these on ebay:
   
   Description          
Set of four, complete with Piston, rings, clips and wrist pens, S4 (1.00) over, Piston number on the boxes= 13049-323-000 Ring number13051-323-014 Great for that rebuild, should fit all the early 500-4s low reserve

and wondering what would be involved with installing them. Would I have have the cylinders machined?

hym

[Dennis]

Those pistons are 1.00 mm oversize sometimes called 4th over. I'm guessing that your bore size is different and will require boring and honing in a machine shop.
What size is your bore?
Has the engine ever been opened prior to this problem?
Why do you want to replace the pistons anyway? Is there something wrong with them?
I personally would hesitate at boring so large if it was not necessary due to bore damage.
Others may have a different opinion on that.

[cd811]

yea only bore when ya have to
if your going for more hp'ya won't gain much that way
plus
check then double check on parts availability!!!!!!!!
I aquired a motor with bored top end and it was a big challenged to find rings!!