1926 Buick with 1928 Buick distributor?

I have determined that I have a 1928 Buick distributor (Delco-Remy 640a) grafted into the generator housing (no. 317) of my 1926 standard coupe. The advance plate has been crudely welded to the distributor housing and there is no timing nut below the gear. In addition, the unit sits rather loosely in the generator endplate. (see photos)

My questions are why would someone do this? Is the gear teeth on the '28 the same as on the '26? How do I time it without the nut to loosen the gear? (The '28 gear is locked with a pin.)

Any insights on this would be welcome.

Bob,

A couple of reasons why someone would change distributors come to mind. The original one was pot metal and broke or became swollen in the end plate of the generator and wouldn't move and was broken when they tried to move it. Or they couldn't find a cap and rotor. The cap and rotor for the 28 distributor is readily available at reasonable prices. You can even use Chevy 6 cyl cap. I have attached some pictures of pages in the 28 shop manual that covers adjusting the distributor timing. I hope this helps

Sorry the first two pics are in reverse order.

Dave

Thanks Dave for posting the '28 shop manual pages and enlightening me on reasons a 1928 distributor would be used on a 1926.

After reading the pages and going over the illustrations, The part that is just wrong on my setup is the welded timing/advance plate. The one shown has an adjustable clamp to facilitate timing. Will look at fabricating a proper clamp plate. Page 20 indicates the the generators on a '27 and '28 are interchangeable, which means the gears would be the same. Still leaves the question about the no. 317 generator dist. gear being the same. Great info!

Bob,

Yer welcome. I don't know about the #317 Distributor gear but I'll bet that if you crank the the engine by hand enough times to get back around to #1 firing position and the rotor comes back to the same place then they are the same.

Dave

The casing for the 26 was made out of really crappy pot metal and it seems to be a relatively common occurrence of the whole thing basically binding tightly onto the generator shaft (and then shattering). I have both and the gear is identical on both of them and it was a straight drop in.

Thanks for the info hidden_hunter! It's good to know the gears are identical. My concern was that the gear geometry or location on the shaft was different.