Distributer Vacuum can

[Jack J.]

[Leif A.]

Re: Distributer Vacuum can

Jack,
Picture of my '67. At this attitude I have 14* initial timing (vac can disconnected). Vacuum cannister is equi-distant between coil bracket and intake manifold. I have plenty of adjustment both sides.

[Duke W.]

Re: Distributer Vacuum can

A common cause of this is incorrect installation of the gear. The dimple on the side of the gear should be pointing the same direction as the rotor tip. So you need to pull the distributor and check.

1. Verify that the wires are indexed IAW service manual requirements: #1 should be next to the right (pass. side) window edge and then CW in the firing order.
2. Move the balancer notch to the timing tap with the rotor pointing at #1 and set the notch at the initial timing value, NOT TDC!

3. Remove dist. and check gear dimple orientation. If not pointing the same direction as the rotor tip, tap out the roll pin far enough to rotate the gear 180 deg. and tap pin back in.

4. Hold dist. above the hole with the rotor tip pointing about 20 degrees to the right, which will orient the rotor tip to #1 on the cap tower. Then check dist. shaft flat orientation and turn the oil pump drive shaft to allow the dist. shaft flat to slip into the slot.

5. Now with the rotor pointing forward lower the distributor into the hole. As the gears engage the rotor will turn clockwise. If the base does not drop down to the manifold you will have to tweak the oil pump shaft. Depending on your experience, this may take several tries.

6. Once the base seats rotate the housing full CW, then CCW and using you eye or a ohmmeter, rotate until the points just barely begin to open. The timing should now be within a degree or two or where you set the notch on the balancer. This is called static timing the engine.

7. Snug the hold down bolt slightly so you can still move the distributor.

8. Start engine and set timing at below the start point of centrifugal advance. On mechanical lifter cams it may be impossible to get the engine to idle stable long enough to set intial timing. In this case use the Total WOT method, by setting it at 36-40 above the point of max centrifugal, which may be as high as over 5000, and in this case you need lighter springs. Centrifugal specs are in service manuals and the AMA specs.

9. Once initial or total WOT advance is set tighten the dist. hold down bolt and connect hose to VAC.

In the end the plane of cap window should be near normal to engine centerline and the VAC should be around midway between the manifold and coil bracket interference points as shown in the post #2 photo. If not, you're off a tooth or there is some other issue.

Duke