Engine piston to bore clearance

[andyblackman777]

Hi,

I posted in the thread below but got no answers. 
does anyone know the stock piston to bore clearance. I have the service notes but can only see the acceptable bore size and piston size. 
this could possibly result in what I think to be a very tight clearance. Would be nice to know what’s should be before reassembly 

obviously aftermarket pistons will state the required clearances 

Thanks Andy 

[Thartje]

Andy what clearance are you coming up with?

I'm not sure I would whole heartedly trust the tolerances from the manual 😂 they have .0006" for a main bearing clearance in there.

 

[andyblackman777]

Im away from home so don't have all the specs with me. average clearance around .002" - .0025"

. Around half of the liners are oval with the clearance going out another .0005" on the thrust axis. All the pistons measure very  slightly undersize. The clearance sounds about right to me for a cast piston, however the oval is another issue.

[Thartje]

Are you ordering new liners? Oval wont help with ring seal.

[andyblackman777]

New liners and pistons would be the way to go. If there was no oval I would probably just run a glaze breaker through and assemble with new rings.

I only need stock pistons so it would be nice to know what the clearances should be before assembly. The service notes only have the range of sizes the components should be not a specific clearance .

[andyblackman777]

So I had the information all along........

I'd forgotten that the service notes have some specifications at the very beginning.

- piston/liner clearance           0.010 - 0.039 mm (0.0004 - 0.0015 in)

Sounds tight but I guess that is correct. Thoughts??