[6pack] Ignition Timing

[Irv Korey]

On Wed, Sep 22, 2010 at 2:48 PM, COLIN THOM <colinthom at shaw.ca> wrote:

> Hi Gang..what's the verdict on ignition timing? Here are the details: 270
> deg. duration cam with 108 deg lobe separation, stock rocker arm ratio,
> compression upped to 10 :1...maybe a bit higher, vacuum system disabled,
> running 86 octane smoothly enough, Pertronics...no points, Lucas high-output
> coil.  I'm getting some occasional back firing through the carbs when
> pulling away from a dead stop and am trying to figure out what's causing it.
> Currently the timing's set at about 14 deg BTDC at 825-850 rpm then idle is
> upped to 900-ish, which seems to have helped a bit.
>


Is the backfire a recent development? If so, check out the plug wires. I
just went through the same thing last week with a similar engine
configuration, and it was the wires. They only had about 1500 miles on them,
and they were pricey (Magnecors), but 2 of them had already failed.

HTH,

Irv Korey
74 TR6 CF22767U
Highland Park, IL