Viewing 9 posts - 21 through 29 (of 29 total)
  • Author
  • #401852


    You can also order the “Wiring & Tune-up Guide”” here on the website via either “”Back Issues”” of Company Store””. Everyone should have a copy!

    Selection of any other items and shipping expense should dictate which way to order.

    These basic questions gets repeated often. Obviously we don’t do enough to let members know what resources are readily available.



    The OEM (Delco) rotor number is 37598–expect to pay at least $100 for a NOS. Aftermarket numbers that I have are Echlin RR-99 and Shurhit ID-30. Same rotor was used on all 1929s, 1930 models A & B (but not C), and 1931 models 41 and 42 (but not model 43).

    The REAL problem for these cars is replacement distributor caps, which were not made in the aftermarket, so your only option is Delco (same applications as above, distributor number Delco 668-E). The last NOS Delco cap I saw was priced at $1,500. Those caps also fit Duesenbergs, so some may be on the shelves of Big D owners. The good news is that the Pierce-Arrow Museum is almost ready to reproduce these caps–our point of contact is our man-of-many-hats Membership Chairman John Wozney.


    or you can use a Stude cap…….they are about 400 nos, getting harder to find…..doesn’t look correct.


    Any idea on a ballpark price for the reproduction caps that are in the works?

    Then we just need some repro UU2 carb bodies. :)


    Bill Lyons’ Onan p/n above is for .30mfd condenser. My 12 needs a .20-.25mfd range condenser. Does anyone have a p/n for the correct value? My Onan parts guy has only application info that does not show the mfd specs.

    Or, does anyone know that a .30mfd unit would be OK? That is, is there published literature that shows acceptable mfd ranges for our distributors?


    Unless you have factory coils and they are still functioning exactly in their original range, useing a thirty will be fine, as your more modern coils will be putting out more KV’s anyway. Drive it like you stole it! Ed


    The Onan part number for service in 1929-31 Pierces (possibly more) is 0312-0256 as identified by Greg Loftness (who once worked for Onan) in an old Service Bulletin. I believe these have the correct microfarad capacitance.

    Again for the 668-E distributor:

    From a 1932 AEA catalog:

    * contact arm Delco 813238 (2 each)

    * contact point, upper Delco 825452

    * contact point, lower Delco 820558

    From a 1938 Standard Motor Products catalog:

    Sets: 1 ea DR1823X plus 1 ea DR1929X

    Individual components: 2 ea DR118 + 1 ea DR123RH + 1ea DR129LH

    Studebaker distributor cap number is Delco 825430, BUT your plug wires will have to be longer because the Stude cap has conventional towers rather than the OEM stick-10-holes-in-your-thumb lay-in-wires 3-piece cap.

    I’ve used NORS points and modified Echlin/NAPA points, with good results from both. NORS points have fiber rubbing blocks (vs nylon for modern points) which wear more quickly–especially initially, so use an initial point setting of 0.022 or 0.021, which will quickly drop to .020 or .019 as the rubbing block wears to shape. I set the nylon rubbing block points at 0.020. When you Dremel off the vertical backing from modern points, it’s very difficult to get good point alignment on that set.

    Don’t let the perfect be the enemy of the good!

    It’s important with either type to pop the distributor cap periodically (say every 3,000 miles) and use a Q-tip to add some ignition lube to the cam for the purpose of extending the life of the rubbing blocks.


    It is also critical in keeping the points alive to make sure the spark plug gap is correct. I was burning points and getting misses because I thought I remembered the proper gap – and was wrong.



    The difference between the capacitor ratings is not significant. If you checked 20 of them, you would find the actual ratings to be as much as 50% off. Put in what you can find. If they are significantly off, you will find that, over time, one side of the points will transfer to the other. If, after many thousands of miles, that occurs, change the condenser. The goal is to get a good spark. If, as has been said in this thread, the system is clean, well grounded, and has components that work (coils, wire, points, condenser), all properly adjusted, the system should work.

Viewing 9 posts - 21 through 29 (of 29 total)
  • You must be logged in to reply to this topic.