Timing 383

[65coronet]

The following is the specs on my car.

1969 383 BORED .030
TRW PISTONS
1975 452 HEADS WITH SUPER COMMANDO/MAGNUM SPRINGS
SUPER COMMANDO/MAGNUM CAMSHAFT
WINDAGE TRAY
ASSEBLY BALANCED
HIGH VOLUME OIL PUMP
HOLLEY 700 DOUBLE PUMPER
HIGH OUTPUT ELECTRONIC IGNITION
CHROME CONTROL BOX
SPIRAL CORE PLUG WIRES
ACCEL SUPER COIL

It also has a mechanical advance.

My question is: HOW THE @$%^ DO YOU TIME A MECHANICAL ADVANCE UNIT?????????????????????

Thanks for any help!

[Jims451]

To set the "total" mechanical timming you need either the timming tape that glues to the dampner or (preferred) a dial advance timming light.

Either way you need to be able to read the timming at around 35 to 40 degrees.

Almost all the distribitors (except the lean burn units) have "mechanical" advance, some also include the vacuum advance unit.
The mechanical advance uses weights and springs to control the rate of advance. As engine RPM increases, the weights use centrifical force to overcome the return spring tension and this movement of the weights increases the mechanical advance. The total amount of mechanical advance "in the curve" is controlled by stops in the distribitor.

At idle, the return springs inside the distribitor keep the weights from swinging out, so there is no (or very little) mechanical advance at idle. As engine speed increases the mechanical advance will increase to a point where it is up to the stops. The RPM it takes to get full mechanical advance depends on the tension of the springs, but usually by about 3,000+ RPM most distribitors will be at full mechanical advance.

So, to set "Total Mechanical advance", remove the vacuum advance vacuum line (if equiped), and bring the engine RPMs up to about 3,000+ RPM (you will actually see when the timming marks stop advancing.) Now you can adjust the distribitor for the total timming, usually around 36 degrees?

[65coronet]

Jims451

Thanks man, I appreciate that. You should have seen my face when I set up my timing light. I was wondering how the heck the coronet started let alone run so well when I saw where the timing mark was. HA!!!!!

Thanks again!

Jeff