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Re: [TR] distributor advance

To: triumphs@autox.team.net
Subject: Re: [TR] distributor advance
From: Tony Drews <tony@tonydrews.com>
Date: Thu, 27 Feb 2020 19:08:07 -0600
Delivered-to: mharc@autox.team.net
Delivered-to: triumphs@autox.team.net
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The springs should just change what RPM it takes to get to full advance 
but the full advance should be the same (weights against the stops).  
I'm a little unclear on how much you changed the timing, it sounds like 
you had to retard the timing after the spring replacement - this would 
also retard the "all in" timing, which would be what you're running at 
3200 RPM.  It's possible it's worse at 3200 now than it was before 
because the full advance timing is now less.

I don't run a street car so could be all wet...  When I check the timing 
I see what it is once the advance is all-in.  Wherever it ends up at 
idle is where it ends up, I don't really pay attention to the idle advance.

With 110 octane gas and decent compression (and a 4 banger, not a 6 
banger), I shoot for 32 degrees when the advance stops changing.  I'd 
think you'd want closer to 26 degrees with a street motor / pump gas.

Hope this helps...

Regards, Tony Drews

On 2/27/2020 5:48 PM, Peter Arakelian wrote:
> Have an early 71 TR6, still has the 41306 distributor with dual 
> vacuums, advance and retard.  Did a little work on my distributor, 
> wanted to check the function of the mechanical advance since I came 
> across a new set of advance springs. I know they are correct because 
> they are Lucas and the correct part number as listed in the Lucas 
> master catalog.
> the old springs were visibly different and softer.  The weight in my 
> distributor was marked 13 degrees.  After I changed them, my timing at 
> idle advanced 10-15 degrees.  I reset the timing to 8 BTDC.  I have 
> always run there.  I use the advance 'till it pings and back off 
> method. Have had it as much as 10 BTDC with no ping, but I prefer to 
> run at 8. My retard works correctly, because it passes the test -idle 
> increases 300rpm when pulled.  Still no ping under the test - high 
> gear, full throttle 30-50 mph.  And no ping accelerating at full 
> throttle from 70-80.
> Now...am I correct in thinking the car should run better at speed 
> (3200rpm)?  My thinking is that the timing is more advanced at that 
> rpm with the correct springs, than it was previously.
> Peter Arakelian
>
> ** triumphs@autox.team.net **
>
> Donate: http://www.team.net/donate.html
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    <p>The springs should just change what RPM it takes to get to full
      advance but the full advance should be the same (weights against
      the stops).  I'm a little unclear on how much you changed the
      timing, it sounds like you had to retard the timing after the
      spring replacement - this would also retard the "all in" timing,
      which would be what you're running at 3200 RPM.  It's possible
      it's worse at 3200 now than it was before because the full advance
      timing is now less.</p>
    <p>I don't run a street car so could be all wet...  When I check the
      timing I see what it is once the advance is all-in.  Wherever it
      ends up at idle is where it ends up, I don't really pay attention
      to the idle advance.</p>
    <p>With 110 octane gas and decent compression (and a 4 banger, not a
      6 banger), I shoot for 32 degrees when the advance stops
      changing.  I'd think you'd want closer to 26 degrees with a street
      motor / pump gas.</p>
    <p>Hope this helps...</p>
    <p>Regards, Tony Drews<br>
    </p>
    <div class="moz-cite-prefix">On 2/27/2020 5:48 PM, Peter Arakelian
      wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:DM5PR06MB356410FC7F24C3E3B8724E13C1EB0@DM5PR06MB3564.namprd06.prod.outlook.com">
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/><![endif]-->
      <div>Have an early 71 TR6, still has the 41306 distributor with
        dual vacuums, advance and retard.  Did a little work on my
        distributor, wanted to check the function of the mechanical
        advance since I came across a new set of advance springs. 
        I know they are correct because they are Lucas and the correct
        part number as listed in the Lucas master catalog. </div>
      <div>the old springs were visibly different and softer.  The
        weight in my distributor was marked 13 degrees.  After I changed
        them, my timing at idle advanced 10-15 degrees.  I reset the
        timing to 8 BTDC.  I have always run there.  I use the advance
        'till it pings and back off method. Have had it as much as 10
        BTDC with no ping, but I prefer to run at 8. My retard works
        correctly, because it passes the test -idle increases 300rpm
        when pulled.  Still no ping under the test - high gear, full
        throttle 30-50 mph.  And no ping accelerating at full throttle
        from 70-80.</div>
      <div>Now...am I correct in thinking the car should run better at
        speed (3200rpm)?  My thinking is that the timing is more
        advanced at that rpm with the correct springs, than it was
        previously.</div>
      <div>Peter Arakelian</div>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
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