rich7777

Does anyone know if you need to get a slight bore when using these pistons ? Or have a problem with them been to loose inside the bore ?

I'm having a debate with someone at the moment that says just because its a standard size pistons it doesnt mean anythink and they could be to loose in the bores.

I personally can not see a company like Nippon selling you somethink like this unless there fine. But what do you guys think ?

rick_rabies

lol.
first of all...what motor?
im guessing a bseries.
getting a hone and glaze wont hurt. but if you boring it at all. you will need the same size piston. an 81mm motor bored at all, 81mm pistons would be too loose. hone and glaze it and put 81mm in it and use good rings....your rings will seal it. slap your friend in the face...no dont. friends dont do that...

rich7777

It is a B16b engine, he is not my friend, so i guess its ok to slap him in the face with a wet fish ? ? Basically i'v changed the b16b pistons to NPR STD size pistons ( i have honed the bore) and he's saying its not that simple and i need to check the piston to wall clearence as it could be off. If they were bigger pistons fair enouth but std size ? ?

rick_rabies

yeah unles you officialy bored any metal out use std size.
slap him with a dead raccoon uterus.
but.......measure the bore. becuase after awhile the cylinder can become egg shaped...hence the honing.
and use the right rings and make sure to set the rings when you start up the car for the first time, fart

thumper64

It will run if you just throw new pistons in, but it's more of proper engine building technique to overbore the cylinders to ensure they are 100% round, and then hone them to the desired piston to wall clearance. Of course, lots of people just hone the cylinders and throw new pistons in...

Boring is like a rough cut and gets the hole close.
Honing is a more precise method of bringing cylinders out to the correct bore.
Deglazing just removes the glaze and allows the rings to seat better.
Glaze is when the rings rub against the cylinder walls and polish the surface. The cylinder needs to have the cross hatching to initially shape the rings to the right shape and also to hold oil and lubricate the rings as they rub against the walls.

rick_rabies

^what he said

rich7777

I understand about honing and boring, it if the standard size NPR piston will be ok in a standard size bore is what i'm bothered about.

rick_rabies

yup. youl be fine
now check out this video
http://www.youtube.com/watch?v=N8fsgs49r8U

rich7777

Ha Ha Ha.... Where did you get that video from rick ? or are you not rick ?

rick_rabies

rick was an imaginary solder in iraq with us.....long story

rick_rabies

if your going all motor.
thumper64 had 12.1 and 11.1 wiseco pistons at 81.5mm for sale
bore out .5mm and use those.