Date:         Mon, 3 Mar 2003 17:57:49 -0800
Reply-To:     Tom Young <tomyoung1@ATTBI.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Tom Young <tomyoung1@ATTBI.COM>
Subject:      Re: [T2] A cc'ing the heads question-answered
Comments: To: Stan Wilder <wilden1@juno.com>
Content-Type: text/plain; charset="iso-8859-1"

----- Original Message -----
From: "Stan Wilder" <wilden1@juno.com>
To: <tomyoung1@ATTBI.COM>
Cc: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, March 03, 2003 4:04 PM
Subject: Re: [T2] A cc'ing the heads question-answered


> One side came out as 53.8 cc's and 52.4 cc's.
> The other side measured at 56.8 cc's and 56.7 cc's.
> Tom Young                       '81 Vanagon
> ----------------- Clip -----------------------
> Your measurements are exactly why I measure deck height with the heads on
> the engine by crushing a thin brass tube as the piston comes over TDC.
> The height below the barrel to the piston isn't relevant if I've got
> .028 + clearance.

I have to admit, I don't understand what you're saying here.  To be clearer,
I can't visualize what you're describing when you say "the height below the
barrel" (I'm interpreting "barrel" to mean "cylinder") "to the piston."

I cc'd the heads using a Plexiglas plate that fit exactly where the top of
the cylinder meets the head.  Next, I'll measure the deck height, without
any shims, using a piece I've machined out of 1/2" aluminum plate that will
serve as the "head" and allow me to torque the head nuts sufficiently.  At
that point, once I add in the piston dish, I've got my compressed volume and
can calculate, and adjust, CR accordingly.

You're technique of getting deck height by crushing a thin brass tube seems
to have merit, (though, I wonder about "springback" of the tube after
crushing) but I don't understand why you think it's a superior system.  What
additional accuracy, information, what ever, do you think you're getting
from your techique vs. the one I'm using?



> Are you going to try to match them up?

Probably not.  After measuring deck height I'll try matching small heads
with big deck heights and then shim things until they're roughly equivalent.
---------------------------------------------------------------
Tom Young                       '81 Vanagon
Lafayette, CA 94549         '82 Westfalia
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