7 replies to this topic

[dow62]

Rebuilding engine, all info on piston crowns the same timing chain end 71.578 ,Sp 0.05 clutch end ,on all four. On the underside of piston looks like No2 180 degrees out, number on bottom 070 149 clutch end on 1,3 and 4 but on timing chain end on No2 (upside down though) Whats right crown info or underside info or nothing to worry about ?

Attached Files

•  013.JPG   27.64K   9 downloads
•  014.JPG   27.44K   6 downloads
•  022.JPG   26.71K   7 downloads

Edited by dow62, 16 February 2014 - 06:02 PM.

[coopdog]

Never heard of a piston being the wrong way around before :/

Don't think they can be

[dow62]

Thanks, all the info on tops of pistons read the same way round (left to right looking at engine from front). Engine been honed and crank polish, new shells and rings fitted, all turns over ok. Just from under side No2 piston look 180 degrees out to the rest or that ones right, and the other three are wrong !

[adam_93rio]

Pretty sure there's no difference, a piston is round and needs the same amount of movement of the con rod on each side of it

[Jordie]

You can get pistons that are offset to suit certain specifications of engines, hence some pistons are marked FRONT.

 

This isnt about how round the piston is, they are all round, but the piston could be dished differently to suit application.

 

 

As above.

 

If the piston isnt offset dished or marked front etc, it should be fine

[dow62]

Thanks Jordie, no arrows or offset dish, if i get my finger out might see me at the Metro Centre cruise nights this year ! (or next year !!!)

Thanks for all replies, Martin.

Edited by dow62, 16 February 2014 - 09:15 PM.

[phil hill]

It's my understanding that pistons are handed.  The gudgeon pin isn't actually in the centre of the piston, but offset slightly, so they should all be the same way round.

 

I'm sure either AC or Cooperman will confirm.

 

Phil.

[Gremlin]

I thought they were handed as they have a thrust face