57 312 pinging to much

[ACESPACK]

Good evening,
I have a new issue.  Now that the valves are quite, timing is set at 6 degrees at idle 45 degrees at 2,500, I have noticed the motor pings quite a bit even when not under any load. Cruising at 65mph and just barely give a bit more fuel it rattles.  The fuel is 89 grade.
Before I started playing with it to get it better (what was I thinking) the timing was advanced at idle to 9 degrees; but it only seemed to ping with your foot stuck way in it or on a grade.  Could this be caused by the valve adjustment; or the air bleed adjustment on the car (AFB)?   I have heard on the 57's there is some need for testing the timing at three different points on the balancer pulley.  If this is true, could someone shed some light.

Thanks much,

Jack

[hiball3985]

Depending on how accurate your timing mark is, these old balancers are known for the outer ring slipping over years of use. Is the 45 degrees measured with the vacuum advance attached and working? You should only have about 36 degrees total with the vacuum advance disconnected, The distributor should have 26 mechanical advance + 8-10 initial. With the 312 compression you may need to run a premium fuel or back off the timing.. The fuel we get today is nothing like it was in 57....

[ACESPACK]

Thanks for the reply.  I didn't check the advance without the vac; I will do so.  With the vac I thought it was supposed to be 45 degrees (wonder where that came from).  Also, the dwell is at 32 but according to the 57 Manual it should be no more than 28.  Not sure that's enough to cause the issue but worth a look.  The pulley slipping is another good thought.  With regard to the gas, no doubt it is crap. Thanks again.

[hiball3985]

The vacuum advance will add another 10 degrees, but getting a total of 45 at 2500 rpm is a little high. Some of the newer replacement vacuum cans can be adjusted, it takes a small allen wrench through the nipple were the hose attaches. You could try having it come in at a little higher rpm. I remember reading on one of the Yblock sites about the 57 dist having to much mechanical advance and curve also, I run a 62 distributor that only has 24 mechanical and a slower advance curve vs the 57 26, and 10 initial for a total of 34. I've set the vacuum to start at 3200 rpm and run on 89 octane with no problem. Good luck, it takes some experimenting depending on the fuel in your area..