Hello - since the distributor gear has an odd number of teeth, does it need to be installed correctly on the shaft to ensure proper alignment? I have seen gears with a dimple machined in them which I believe is oriented to align with the rotor tip, but the UHV distributor #1111188 that I am selling does not have any markings on the gear. Is there any alignment that I need to be concerned with? Seems like all the internal pieces will maintain proper alignment no matter what, so worst case is the distributor body requires slight rotation to maintain the same timing setting. Thank you for any information.

 

The distributor gear doesn’t care where it’s positioned on the cam. I have never counted the teeth, but since the cam and distributor are rotating at a 1:1 ratio the cam must have the same number of teeth.

 

Yes, I totally agree. I think the only purpose of aligning the gear dimple with the rotor tip would be to ensure you are able to achieve the correct initial timing setting with the vacuum can in the proper orientation and therefore clearance with the firewall. If the gear is rotated 180º, the distributor body would need to be rotated the equivalent of 1/2 tooth one way or the other to achieve the same initial timing setting.

 

I've decided the only purpose of the dimple was to ensure the gear was always oriented the same on the assembly line so that they could install the distributor in the engine using the same position and achieve a consistent timing setting every time. The gear has 15 teeth so each tooth represents 24º distributor degrees, or 48º crankshaft degrees. Since halfway around the gear is 7-1/2 teeth, if you install the distributor in the exact same location with the gear 180º off, you change the total crankshaft timing by + or - 24º which is a significant variation. I assume the timing was set using a light once the engine was running, but this would allow them to know they had a very close setting on initial startup.