I need to know as soon as on this one guys as the machine shop man is on hold until i can answer his question.

 

What should the Piston Skirt - Bore clearance be on Wiseco 88mm pistons.

 

Thanks.

from Z1's website:

 

http://www.z1motorsports.com/PDFs/Wisecopistons.pdf

cool thanks, those measurements what are they measured in?

inches (thousands of) 0.003 = 3thou

What is the standerd Nissan clearance?

 

Thanks Paul this has really helped me out.

LOL! that should read thousandths of an inch, you obviously dont want a 3 thousand inch clearance!! :D

stock nissan measurements:

 

N/A = 0.0006 - 0.0014

TT = 0.0010 - 0.0018

obviously dont want a 3 thousand inch clearance

 

lol, i dont know much but that would be some "slappy" piston and a damn large block!

Old thread I know but it shows I use search lol

stock nissan measurements:

 

N/A = 0.0006 - 0.0014

TT = 0.0010 - 0.0018

 

If stock clearance is only this how come wiseco's require 0.003" it seems huge!I have wiseco 87.5 mm to go into my block. I currently have a stock block which needs honing do I go oem spec or wiseco's 3 thou clearance. ?

Edited May 12, 201114 yr by hellraiser

It will be becuase of the 2618 low silicon alloy that Wiseco use for the Z32 application.

 

All pistons wether cast or forged are primarily made from a Aluminium and Silicon Alloy.

 

Silicon, among the strength and hardness properties it brings to aluminium also affects the amount of thermal expansion in the alloy.

 

The stock cast pistons will have about 12-14% silicon, whereas the 2618 alloy that Wiseco use only has 0.25%

 

So a low silicon forged piston will expand a lot more than a high silicon Cast piston. Which is why Forged engines can be noisy when cold, but once warmed up all the tolerances tighten up.

Edited May 12, 201114 yr by Yowser

Excellent thanks Dave. Also I have been doing a little measuring And I take it the clearance figures are measuring radius so you have to double it to get the true clearence for example:

 

My stock block has a piston skirt diameter of 86.95 mm

 

The block bores are around 87.046 mm

 

This gives a difference of 0.096 mm or 0.00377 thou for you old schoolers.

If I devide this figure it's bang on the Nissan spec of 0.0019 thou

 

When I measured the wiseco block it has a piston skirt of 87.405 mm

 

The block bores are 87.54 approx

 

This gives a difference of 0.136 mm or 0.0054 thou

 

Devided by 2 gives me 0.00268 thou which is right on spec for wiseco's 3 thou recommendation.

 

Does that sound right?

 

Also because i have such a nice stock block I was gonna use that for my build and get it bored to suit the wiseco's .

Edited May 12, 201114 yr by hellraiser

Can anybody answer this question, I have been very patient lol