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General Specifications from Brattons W/ Corrections

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  • General Specifications from Brattons W/ Corrections


    Camshaft bearing clearance .001 to .003
    Cooling system 3 gal.
    Connecting rod to crankshaft clearance .001 to .00336
    Crank rod pins 1.500 less 1 to 2 thousands for oil (1.498/1.499)
    Crankshaft bearing size 1.625 less 1 to 2 thousands for oil (1.623/1.624, subtract .010 or .020 or .030 for rods)
    Crankshaft end play .004
    Distributor point gap .018 to .022
    End play of water pump shaft .006 to .010
    Engine compression 76 PSI at sea level; at 5,000 ft. deduct 20
    Flywheel depth 1.123 distance from 12 hold surface to refinish surface
    Gas tank 1928-29 10 gal.
    Gas tank 1930-31 11 gal
    Oil see reply #9 5 qts. But only 4 1/2 will come out with an oil change.
    Oil Pressure 2 - 3 lbs. depending on the weight of the oil
    Piston to cylinders .002 note: see reply's #2&4 below .0035 -.0045
    Piston ring gap - lower ring .008 to .010
    Piston ring gap - center ring .010 to .012
    Piston ring gap - upper ring .012 to .015
    Main bearing clearance .001 to .0015
    Rear axle 1 1/2 pints
    Rod wrist pin bushing - Machine shop must expand ID of bushing in rod before honing to .0003 or 4
    Spark plug gap .035
    Steering gear 7 3/4 ox. for 7 tooth, 4 1/2 oz. for 2 tooth box
    Transmission 1 pint
    Timing gear backlash .004
    Tire pressure 35 PSI
    Valves in valve guides .001 to .0015
    Valve to tappet clearance .010 to .012 for all valves

    The following is a guide for torquing the different fasteners. Remember, if original fasteners are used, their tension loss is unknown due to the number or times they have been reused. Therefore, the torque measurement might need to be adjusted. It is recommended to use all new fasteners. See Nuts and Bolts article in How to Restore Your Model A, Volume 3.
    Axle housing to differential 35
    Camshaft nut see reply #2 below 50-60 ft lbs 100
    Connecting rods 35
    Crankshaft Pulley Nut 80
    Cylinder Compression on NEW engine - The cylinders should not vary more than 7 pounds between cylinders 64
    Flywheel 55
    Head - Torque up in three stages using correct sequence with final torque after engine is hot. 50 - 55
    Main bearing cap bolts 70 - 80
    Mainfold - exhaust 25 - 30
    Oil pan Hand Snug and Common Sense
    Pressure plate - use grade 5 bolts 25
    Rear axle shaft nut 100
    Timing cover 25
    Torque tube to differential 35
    Valve cover Hand Snug and Common Sense
    Water inlet 40
    Water neck - torque with caution 50
    Wheel lug nuts 50-55

    2-Tooth Steering Gear Specifications

    Turning Radius 17' (34' diameter)

    Steering Gear Ratio 1930-31, 13:1

    Steering Wheel Diameter 1930-31, 17"

    Pitman Arm Length 6-7/8" hole center to ball center

    Ball End Angle to Shaft 14°

    Sector Shaft Bearing Clearance .001"-.002"

    7-Tooth Steering Gear Specifications

    Turning Radius 17' (34' diameter)

    Steering Gear Ratio 1928-29, 11-1/4:1

    Steering Wheel Diameter 1928-29, 17-1/2"

    Pitman Arm Length 6-7/8" hole center to ball center

    Ball End Angle to Shaft 14°

    Sector Shaft Bearing Clearance .001"-.002"

    3 ~ Tudor's
    Henry Ford said
    "It's all nuts and bolts"

    Mitch's Auto Service ctr

  • #2
    I would like to add a caution about the piston-to-cyl wall clearance printed by Brattons.
    This may have been the original Ford spec. If so, please keep in mind that the stock pistons had split skirts

    Pistons are not made that way any more. There has been much discussion and over-discussion of this number for years elsewhere.
    George Miller, Jim Brierley and I, to name just 3 people, do not use this number and instead use a rule of thumb that has been around for decades:
    .001" per inch diameter of piston. George and Jim have built a lot of motors, more than I, but I have built quite a few. Personally I use .0035 on cylinders 1,2, and 3,and .004-.0045 on cylinder 4. There have been many challenges to these numbers, but typically by people who do not actually build motors and do not have to guarantee their work. There is another engine thread on here from the beginning that I started that discusses the unequal heating of the cylinders, and thus the unequal expansion of the pistons. Expansion at road temps must be considered unless you want to invite scored pistons and cylinders.. I have a wall full of them that I have removed from motors done elsewhere. To complicate matters, evidently some piston suppliers are including little slips of paper saying to set the clearance to .002-.0025. This is consistent with a modern motor, and equally clear is that the manufacturers are not aware of the peculiarities of the A motor.
    You have choices here: be as informed as you can be when you make them!

    An additional note about the torque of the camshaft nut: The legendary Dan McEachern states that 100 is too much and suggests something closer to 50-60 ft-lbs.
    Last edited by tbirdtbird; 06-13-2017, 08:18 PM.


  • #3
    tbirdtbird thanks for adding the additional information..
    if anyone else notices suspect content in the above sheet or has additional information to post not listed please add to this thread.
    we can then make the necessary corrections to the spec sheet itself.
    This is a starting point for an accurate list
    3 ~ Tudor's
    Henry Ford said
    "It's all nuts and bolts"

    Mitch's Auto Service ctr


    • #4
      I also think .002 is to tight. cylinder 3,and 4 will never make it. and 1 and 2 might not make it either. I agree with tbirdtbird
      Model A's do not have water jackets all the way to the bottom of the cylinders, and poor circulation on 3,4 cylinders.
      Last edited by George Miller; 06-14-2017, 06:19 PM.


      • #5
        #4 cylinder on Old Datsun 210s ran HOTTER, scoring the cylinder & valve seats falling OUT! They "improved" the seats, by center punching around them! Piston problem was solved with a quick polish on the skirts, with a strip of EMERY cloth----Whatever WORKS!!!----LOL
        Bill Greasemonkey


        • #6
          On page 375 of the service bulletins it mentions the rear axle holds 1 1/2 quarts. These are some of the discrepancies i mentioned about in the past.
          snyders 1 1/2 pints
          brattons 1 1/2 pints
          macs 1 1/2 quarts
          service bulletin 1 1/2 quarts
          Tams 1 1/2 quarts

          I just filled a diff on a 31 and it took 1-1/2 pints
          3 ~ Tudor's
          Henry Ford said
          "It's all nuts and bolts"

          Mitch's Auto Service ctr


          • DaWizard
            DaWizard commented
            Editing a comment
            Mitch, if the exact amount known is needed, why not take and fill each place as described and drain into a measuring cup? I think a 3 cup measuring cup would work well for this as a pint is only 16oz or 2 cups, which would make 1.5 pints 3 cups. That seems to be about the amount in the trans, and less in the rear end.

            Just a thought. Personally, I don't believe anything is measured in "quarts" except the crankcase oil.
            Last edited by DaWizard; 06-20-2017, 12:11 PM.

          • Mitch
            Mitch commented
            Editing a comment
            can you do it and report back thanks

          • DaWizard
            DaWizard commented
            Editing a comment
            Mitch, I would be tickled pink to do that for you IF I only had a lift to get the car off the ground, but alas, laying on my back on the driveway gives me great pains, to say the least. Perhaps next time I get the car "serviced".

        • #7
          I've never measured, but just fill until it's ready to come out the fill hole.
          If the SERVICE BULLETINS make a mistake, it is usually corrected in the bulletins for the following month.


          • Mitch
            Mitch commented
            Editing a comment
            sometimes it's nice to know how much quantity one needs to buy and have on hand before changing out the fluids.
            i would like to have the above list accurate, but as i remember i believe the quarts is correct.

        • #8
          ANYONE remember when Sacramento Vintage showed a pic of V-8 plug wiring, showing the R/F as # 1 cylinder? I helped several Guys to get their V-8s RUNNING!----NLOL
          When contacted, Sac Vintage sed, "YEP, we've got to get that corrected"!!----"YES, but WHEN"!!!
          Bill Wiringmaster


          • #9
            We put some water in the dipper tray that had been removed from the oil pan and it held one quart of oil. So adding four and 1/2 quarts is going to over fill the oil pan. When I change my oil, I only add four quarts and the dip stick registers just below the F mark.


            • Mitch
              Mitch commented
              Editing a comment
              Thanks Dave there are a few other variables that can effect the exact amount. Sludge in the oil pan and the little bit that is left in the valve chamber are two of them

            • DaWizard
              DaWizard commented
              Editing a comment
              Hey Dave or Mitch, when you fill the oil through the vent tube, does it also fill the dipper tray?

            • Mitch
              Mitch commented
              Editing a comment
              Wiz yes it does

          • #10
            WHISKEY can be bought in QUARTS!--------Back to "HIGH NOON" movie------Know why it's called a SHOT of whiskey?---The whiskey cost 25 Cents, a bullet cost 25 Cents, if a saddle BUM wuz broke, he traded a BULLET for a DRINK!--BULLET=SHOT!
            The Dog duzen't get it!---LOL
            Bill Sober


            • #11
              OK Bill, lets line them up till we figure out the meaning, or the real meaning. I had to look this one up. Many ideas.

              (Alcohol is still sold by weight in some countries. A lead shot (or musket-ball) was a convenient weight for measuring a single serving on a simple balance scale; Start with two empty glasses that balance, put the shot on one side, fill the glass on the other side until the scale balances)

              (it might be more general than that, in French you say boire un coup [that's the same word as un coup de feu i.e. a shot].
              The explanation seems to be "a shot" is the amount of liquid you can drink at once, at a go, i.e. d'un seul coup.)

              (The use of shot in the context of a measure of liquor; usually with the drink being specified, e.g. a 'shot of rum', suggests that the drink is being 'shot' into the glass. As such it goes back to the earliest meaning of the word (c.1000): a rapid movement or motion.

              The first example in the context of alcohol that has been recorded is:

              1916 R. Lardner ‘Champion’ in Coll. Short Stories (1941): Midge [...] aroused the napping bartender by slapping a silver dollar on the festive board. ‘Gimme a shot.’)

              (The use if the word 'shot' has been attested etymologically as far back as 1676, meaning "drink of straight liquor".

              Going back this far, the name comes from the glass the drinks are served in as opposed to any trading of bullets - small vessels were filled with fine lead shot and used to clean and store quills - hence 'shot-glass'.

              Still, this is not to suggest an alternative etymology occurred around swapping bullets for whisky, but the term had been around a lot longer than bullets themselves so it certainly isn't the original etymology, besides, as far as i'm aware, whiskey was a much more precious commodity than ammunition for the 'tombstone legends', and it would have cost you more than a few bullets to get wasted!)

              I think we better debate what oil to use.


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