RB25DET piston question??

[JonPowell]

On top of all the pistons there is a dot(I am assuming that it indicates the front of the piston) and a number(I am assuming that it indicates the cylinder it should go in). What I am wondering about is in cylinder 1 the piston says 1, cyl2 says 2, cyl 3 says 3, cyl 4,5 and 6 say 2. Is this normal or an indicationt hat someone has been in the motor before and changed the last 3 pistons? I am not sure what to think about this as the motor is supposed to have only 18000 origional miles and I cant see a reason to change the pistons(when everything else is stock on the motor) at such a low milage.

Thanks for your input,Jon

[Nathan]

From what I understand Nissan has several different piston sizes to choose from for all their engines...(they are VERY close together). After they prepare the block they check to see EXACTLY which size fits the best. Perhaps they number each different size and thats why yours are different numbers. I could be totally off base here, thats just what I remember hearing so dont take it as gospel. I sure hope it doesnt mean someone has been in there changing pistons on an 18,000 mile engine

[FAST-DATSUN]

the number indicate the .0001 size to insure a exact fit of the piston. There a number some where beside the cylinder to indicate its size and what piston should be installed..