[6pack] Compression Ratio Calculation

[Derek]

Stan,

 

Have sent you a seperate email attaching a spreadsheet which details the
various heads fitted to the six cylinder range. According to the spreadsheet
the standard head fitted to the 74.5 is the "219019" and it is 3.5" thick.
The 219019 number is stamped onto the top face of the head on the manifold
side at the front of the engine. 

Hope that this helps.

 

Derek 

 

 

 

Date: Sat, 5 Jan 2008 02:21:06 +0000

From: "Foster, Stan" <stan.foster at hp.com>

Subject: Re: [6pack] Compression ratio calculation (Was Headers)

To: "6pack at autox.team.net" <6pack at autox.team.net>

Message-ID:

 
<7516319594FEBC47B1205CE87EEE54071AFE066122 at G3W0076.americas.hpqcorp.net>

      

Content-Type: text/plain; charset="us-ascii"

 

The TR6 compression ratio was gradually reduced over the years from 9.5:1
(UK

PI) to 7.5:1 in 1974 (US version). I realize that there was a change in head

at least once during that time but was all of the compression ratio
variation

achieved via milling the head to a desired thickness ?. Do we have head

thickness data for the various years and in particular my immediate question

is regarding the thickness of the standard 1974.5 circle B head.

 

Stan