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Re: RE: Does 0.120" really get 9.5:1 compression?

To: Timothy Holbrook <tjh173@yahoo.com>, <6pack@autox.team.net>
Subject: Re: RE: Does 0.120" really get 9.5:1 compression?
From: Greg Dito <dito9561@bellsouth.net>
Date: Mon, 22 Dec 2003 17:14:33 -0500
Whoa! Maybe in theory.  But you cannot take as much off of the block as you can 
the head for the simple reason that you would be exposing the pistons above 
flush to the block.

There may be several reasons for decking a block, but one certainly is to 
assure a flat mating surface to the head.  To properly deck a block you first 
have to measure all pistons and find the highest at top dead center before 
taking the engine apart.  The difference between the top of the block and the 
highest piston, less a clearance height (.005"?), is the max amount to be cut 
from the block.  Realize a typical human hair is about .004" thick.  Cut below 
the highest piston height and it will crash into the head the first time you 
crank it.

Another purpose for decking the block is to assure near identical compression 
in all cylinders.  This must be done, though, by also insuring your connecting 
rods and pistons are the same length.  A practice more for the competition 
engine than a street engine.

Greg Dito
CD6250L




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