66 401 specs

Discussion in ''Da Nailhead' started by 66elctra, Oct 26, 2002.

  1. 66elctra

    66elctra Member

    Can someone send me or suggest a link to find the engine specs for my 1966 401 (electra)? I am looking for all specs, cam, valves, lifters, ect. I am using a computer dyno program to decide on what type of cam, and other upgrades I will be doing in the rebuild of this motor.
     
  2. Dan K

    Dan K Well-Known Member

    I don't want to sound trite, but I think a 66 shop manual is the best investment you can make. I has all of the specs, and tells you how to take it all apart, put it back together, and what to do if you don't know what that funny sound is. I use mine almost daily.
     
  3. Babeola

    Babeola Well-Known Member

    Engine Specs

    Mr. or Ms. 66 Electra,

    There is some general data on the 66 401 here (bore + stroke, compression): http://home.san.rr.com/oldways/nailhead/buick.html . There are specifications for the 66 401 head cc, total valve lift, valve size, rocker arm ratio, compression and carburetor here: http://www.nhra.com/tech_specs/engine/blueprints/BUI-66.rtf . Be careful of that 123 cc cylinder volume value. That is the NHRA minimum. Stock heads may be closer to 130 cc chambers.

    The manual is a good place to find most of this information, but it does not include some of the information, like flow #s and camshaft specifications, that is necessary to use an engine analyzer program. Below is some more information that you may need.

    Average Intake Flow at Lift of Several Stock Nailheads (1.87 valve) at 28 of Water:
    .100---.200---.300---.400---.500---.600
    53.4--110.2--157.0--180.4--190.4--196.0

    Average Exhaust Flow at Lift of Several Stock Nailheads (1.50 valve) at 28 of Water:
    .100---.200---.300---.400---.500---.600
    47.0---78.5--103.5--116.9--120.2--122.7

    Stock Cam Specifications for the 66 401:
    Intake duration ---- 295*
    Exhaust Duration -- 295*
    Intake lift ----------- .431
    Exhaust Lift -------- .431
    Lobe Separation - 114*
    Overlap ------------ 67*

    The following approximate stock 401 measurements may also be useful: rod length center to center 6.22, stock compression height 1.93, dome volume (estimated) - 53 cc, gasket thickness - .015 or .038, gasket diameter - 4.41, and the standard distance from the deck to the piston of about .055 for a standard deck height of 10.025. This should get your program up and running.

    Cheryl :)
     
    Last edited: Dec 8, 2002
  4. BuickStreet

    BuickStreet Well-Known Member

    Good to see another 66 Electra being lovingly looked after. Got any Pics?

    As far as cams go, I didn't think we had much of a choice. Are there many to choose from? If you find a good source of hop-up parts for these motors be sure to post some links and let us know what you find.

    Bill S.
     

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