[6pack] Compression Ratio Calculation

[Foster, Stan]

The gentleman who is doing the machining for my motor also asserts that zero
decked engines develop more torque.

He is going to CC my cylinder head to my desired CR btw.

Stan


-----Original Message-----
From: 6pack-bounces+stan.foster=hp.com at autox.team.net
[mailto:6pack-bounces+stan.foster=hp.com at autox.team.net] On Behalf Of
Navarrette, Vance
Sent: Monday, January 07, 2008 1:03 PM
To: Shawn J. Loseke
Cc: 6pack (6pack)
Subject: Re: [6pack] Compression Ratio Calculation

        Shawn:

        Raising the compression ratio by decking the block will get you
more power than raising the compression the same amount by milling the
head.
        The reason is that with a decked block the piston comes closer
to the head, increasing "squish". This creates more turbulence and fuel
mixing in the chamber, for a more thorough burn. The closer the piston
comes to the head, the more squish you get, right up until the piston
crashes into the head and your new motor is reduced to scrap metal.
        If you are hot rodding an engine and are pulling the block,
ALWAYS get your motor zero decked if your head has any squish area on
the head (Some motors have no squish at all, like the old Chrysler Hemi
motors and some Japanese 4 valve designs). If you have no squish area,
then it is a waste of time. But most motors have a squish (sometimes
call "quench") area designed in so you should go with a zero deck
height. This is why Kastner instructs you to deck the block (although he
does not say why) when prepping your motor. David Vizard also strongly
recommends it in his engine building books.

        Confucius say "Learn the ways of the Zen masters, oh
grasshopper, and you will go fast"

        Vance