piston instal problem

[twofourzeroSX]

ok im having a hell of a time rebuilding my motor and i dont know why...

I cant get the pistons in...i have brand new rings on my old pistons, all put on correctly. i put the ring compressor on the piston and set it flush against the block, tap the piston down. it goes down all the way until the compression ring. the compression ring SORDOF goes in the cylinder but i cant tap the piston down. what is wrong? there is no ridge on the cyl. wall or nething. im getting frustrated!!

[AmoebAssassin]

Are you using assembly lube, and are you tightening the piston ring compressor all the way? Make sure there are no burrs on your cylinder walls.

[bardabe]

assembly lube is amust. make sure the piston rings are ligned to FSM spec. and make sure that there is no gap betwen the piston ring compressor and the block. it has to be absolutley flush otherwise the piston rings tend to jump or expand. tape them in sofly but quick they should go in fine unless your block is f*ck*d. (trust me I rebuilt mine already)

[ILikeMy240sx]

yeah, putting in the pistons into the block is a PITA. It makes things much easier if you have one of those tapered piston ring compressor but I doubt you do. I found out that the oil rings always pop out and causes the piston to not go any further. Make sure your ring compressor is flush with the block and tap on the piston pretty quickly. They will pop in eventually.

[FAST-DATSUN]

To save yourself a lot of trouble have a local machine shop do the assmbly to make sure its done right.......

[twofourzeroSX]

ok if u guys want a good laugh here it is... i had the 2 compression rings backwards. i figured that the directional ring would be on top and the non directional would be in the middle...wrong. the groves in the piston are different sizes.

now i know... MOLLY rings ALWAYS on top!