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Re: 83mm/86mm Heads

To: "shrack04@netzero.net" <shrack04@netzero.net>,
Subject: Re: 83mm/86mm Heads
From: TeriAnn Wakeman <twakeman@razzolink.com>
Date: Sat, 03 Sep 2005 06:34:06 -0700
> I visited Steve Newell, the Newell boys and the Newell TR4's this summer.  We 
>looked at the head off of Steve's early TR4.  It looked like a TR3 head from 
>the top (no flat area above the #1 intake port), but from the bottom it looked 
>like a TR4 head (with the cast in chamfers).  I've not read of a head made 
>like this.  It must of been cast during the change of design.  Any one else 
>seen heads like this?  I'm just a curious kinda guy.  Kent Shrack TR3a

Steve has an interesting cylinder head.  When I first put my head 
diagram together I was allowed to spend a day browsing through a wall of 
TR2 through 4A heads at a British car wrecking yard that was big on 
Triumphs.  I went through well over 40 cylinder heads, each marked with 
the model they came off of, measuring each one and marking them down in 
my notebook. In my research I did not come across a head like Steve's. 
His head seems to be the last TR3A (83mm standard fittment)casting that 
had been machined for 86mm pistons.  This head is a question that will 
probably never be answered.  Was the factory just using up castings on 
hand during the transition?  Was this an official configuration for a 
short time at the beginning of TR4/3B production?

A sample size of 40+ cylinder heads seems like a large number today but 
compared to Triumph production it is only the smallest of a random cross 
sample.

Randall questioned the engine numbers I had for the heads.  Those 
numbers came from Moss and TRF catalogues. I merged them for the chart 
in the hopes that their research was fairly close.  Randall, Do you have 
better numbers as to which head fits which engine to share?

Sorry the chart isn't prefect but it was the best I could do given the 
resources I had access to in the mid '80's.  I'll add Steve's head to my 
chart.

TeriAnn




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