[TR] Tuning question and 1 oil question

[Jeff Scarbrough]

At 08:33 PM 5/20/2010, Anthony Cascio wrote:
>list,
>While we're on the subject, I run my TR3A at 5 BTDC, and get spark 
>knock. Should I try 8 to 10 BTDC?

Increasing BTDC will advance the timing...the spark will occur 
earlier in the cycle (because the Before number is larger).  This is 
likely to make the knock worse...the knock is caused by the premature 
ignition of the air-fuel charge.

Other things can cause knocking/pinging/pinking - little bits of 
glowing hot carbon in the cylinder, for instance - but try retarding 
the timing instead.  Maybe 2 BTDC?

>I have been blaming the gas that's available in Ga,

Me too.  The stuff is lousy.

>  I am also thinking of changing to Pertronix.

I'm interested in the replies to this one.  It ~should~ make timing 
more reliable, but won't fix a worn-out distributor shaft.


Jeff Scarbrough      75 TR6 x 1, 76 1500 x 2, 78 1500 x 1, 80 1500 x 0.5
http://www.fishplate.org/vehicles/
Corrosion Acres, Georgia         #354