So I'm sure this has been covered a bit before however ive not found any definitive answers that have enlightened me to my questions. As stated in the title I acquired some very lightly used 85mm, 9:1 wiseco pistons (w/ supporting 22mm wrist pins) and 150mm Manley Tuff H beam rods.

My question is about the 1mm offset that I have read the oem pistons and rods have. What is it exactly and Is this an oem parts thing only? Or does it apply to aftermarket? I know the aftermarkets I have are floating so again confusion on my part. TIA for any input.

 

the piston pin is offset in the piston.. .i.e. it doesnt go trough the centre of the pison but it is slightly offset to one side.. dont worry about it.. my wisecos have it too..
Has to do with side loading during expansion stroke..

 

Aaaaahhhh. So it applys only to press in then?

 

no, offset pins is a part of the design... used both by mitsubishi for OE pistons and on aftermarket pistons such as wisecos.. Has nothing to do with them being floating or pressed in... it just means it is not centered in the piston but moved to the side a bit.. (when you look at the pin head on)

 

I c I c. So this is something that's not even reely visible but more of a measured thing? Because looking at it just now I couldnt see what the picture described. With that then, how do I know which way to install the pistons in the block? Ive been told the dot on the top of the piston faces the pull side of the engine. Ive also heard to match up the intake valve reliefs. Well I have my intake valves and the reliefs match on both sides..

 

the bigger relief goes under the intake valves...

 

Correct. Dot points to pulley is what I recall.

 

Thanx much! Appreciate all the input.