i just got a b16a from a friend, and its just the short block... but i noticed that i could move the pistons around a lil bit(the motor is assembled), like so much that i can prolly fit my fingernail between the cylinder wall and piston. he told me it was put together like that for turbo purposes... but ive neer herd of somethin like that.

now the motor was boosted before on like 15 psi and it ran flawless.... didnt smoke or anything. but i wanna see what you guys say about the whole pistons being about to move around a lil bit....

BTW the block is bored to 84mm with GE Sleeves and cp pistons and all that good stuff...
i just havent seen a motor before that the pistons had play in them....

SHOOT ME YOUR THOUGHTS OR KNOWLEDGE

 

anyone?

 

Pistons are cold. Once the engine is warmed up they will expand slightly and the gaps will be gone.

 

ight that sounds good.
anyone else have any input?

 

the tops of the pistons are smaller due to them bein exposed to the combustion temps.... the higher heat expands the tops more than the bottoms.... u will always see larger gaps looking at the tops of the pistons when they are assembled in the block.... the clearance that counts is at the bottom of the pistons ( the piston skirts )..... they are probably around 3-4 thousands clearance since its a turbo motor.... that amount of clearance will feel like alot when u move the piston side-to-side, but it takes lots of skill and experince to judge by feel..... hope this helps.... since u say it runs good, u shouldn't be worried... it sounds ok to me.....

 

At room temp there should be between .0035"-.0045" piston to wall clearance. Also your sticking your finger nail in near the top but the place to measure would be near the bottom of the piston skirt and in several places up and down the bore. All of these measurements can't be taken with the block assembled, so either take it apart or cross your fingers.

 

X2...The pistons need some room in there for clearence they are not supose to be butted right up against the walls...Heat=expansion

 

all the info is gunna help me sleep tonight lol

 

Depending on what Piston your using. I got some Custom Rlz pistons from Tony he advised to clearance them 5.5 thous. to prevent the almighty Black death. Used mine last year and love them, still running strong! If no scars on the walls, Your good to go! Once it warms up, it will expand and tighten the clearances up.