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Re: Cam is broken in

To: Btp44@aol.com, 6pack@autox.team.net
Subject: Re: Cam is broken in
From: Timothy Holbrook <tjh173@yahoo.com>
Date: Tue, 20 Apr 2004 09:58:55 -0700 (PDT)
Berry,

I never knew that the curves differed so much!  I had wondered why
other listers had told me once that they reach full advance at around
2500rpm, but I don't hit full advance until redline.  Thanks very much
for clearing up that mystery for me!


However, I have to disagree with you on the static settings.  I have
verified with two separate strobe lights that my dizzy has 20 degrees
of mechanical advance (just as all other TR250/6 dizzies, to my
knowledge).  On my dizzy, this 20 degree advance progressively
increases from idle through to redline.  I assume that on the other
dizzy's, the advance curve is a steep line from idle to 2500 or so,
then a flat line after that. 

Therefore, even though my dizzy advances more slowly, I still have to
keep 10 degrees of static advance in order to get a full 30 of total
advance (I limit myself to 30 degrees total advance due to increased
CR; stock engines run about 34 degrees total, and therefore run 14
degrees static).  I have never seen a Triumph workshop manual that had
different static timing setting specs based on year of manufacture.

However, I wonder if any power gains can be had from switching to a
dizzy with the more aggressive advance curve...  Anyone played around
with this?

Tim Holbrook
1971 TR6

--- Btp44@aol.com wrote:
> Tim-All TR6 dist curves are not created equal. I was looking at a
> Bentley 
> manual at the various dist. specs. and noticed that the dist. used on
> 71 cars 
> (41352) is quite different. The static timing is 4 deg BTDC and does
> not reach 
> max advance of 26-30 deg until 5600 rpm. Most of the other dist.
> start with 
> about 12 deg static, advance quicker, and have less total advance.
> The PI cars 
> start with 11 deg, and reach max advance of 12-16 deg at only 2600
> rpm. I guess 
> the bottom line is that using 10 deg. static timing on the 71 dist.
> will give 
> too much total advance, if the compression has been increased.
> Berry Price 
> 



        
                
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