Grade 12 head bolts

[Deleted User]
[Deleted User]
edited November -1 in HUDSON
Does anyone know if its Ok to use grade 12 head bolts, instead of the standard grade 8 ?



The reason I ask is because all my engines seem to have a mixed bag of head bolts, showing up to three different markings, which makes the head look a little "backyardish", if you know what I mean.



I'm thinking maybe grade 12 bolts, in the gold colour plated (cadmium ?) should look quite good, since they have the 12 little raised "spokes" on the head, indicating their grade, and maybe one could use them without paint, and not have that chipping problem with the torque wrench squashing the paint on the heads while retorquing a couple times in the first 1000 miles or so.



Or are they too brittle or too hard ??



silverone

Comments

  • [Deleted User]
    [Deleted User]
    Dale Cooper sells the correct bolts with the correct head pattern for your engine.
  • [Deleted User]
    [Deleted User]
    51hornetA wrote:
    Dale Cooper sells the correct bolts with the correct head pattern for your engine.



    Yes, I have a new set here from Dale, but they are black, and will need painting, which will lead to scuffing and chipping while torquing, unless I guess one paints the head bolts again, after a retorque or two and a few hundred miles.



    I guess I could use grade 8 gold coloured plated bolts too.



    Just knocking around an idea. Maybe never will try it --- and just go with the norm.



    silverone.
  • [Deleted User]
    [Deleted User]
    On previous Hudson engines I have touched up the bolts with a brush and they look great can't tell unless you crawl in the engine compartment with a magnifying lense which I warn you I will do when I see you at the meet in July. And don't worry I will be wearing my Doc Hudson slippers so I won't scratch anything.
  • [Deleted User]
    [Deleted User]
    seems to me that bolts and their related threaded parts are made to be torqued to their yield point to be effective as they were designed. new cars use head bolts that are torqued to the point of actually stretching beyond being re-usable. so what im trying to say is use what is recommended. maybe you could have the tops of the heads actually chrome plated, just the hex part. . . . . it certainly could be done but im not aware of how the chemicals would react to the strength of the bolt head. . .
  • TwinH
    TwinH Senior Contributor
    Well,I used studs but didn't worry about what the nuts looked like.

    I used a chrome acorn cover. They'd work on bolts too,and if that's

    too much flash just squirtem with engine paint.

    Hudsonjan06005.jpg
  • [Deleted User]
    [Deleted User]
    51hornetA wrote:
    On previous Hudson engines I have touched up the bolts with a brush and they look great can't tell unless you crawl in the engine compartment with a magnifying lense which I warn you I will do when I see you at the meet in July. And don't worry I will be wearing my Doc Hudson slippers so I won't scratch anything.



    Doc Hudson slippers are pre-approved '51, but if you show up with Sally slippers
    well, --- that's another thing. Somehow I don't think I'll have to worry about that happening, thankfully. :-)



    I guess I sort of solved my own problem today, by going down to the local bolt supplier and checking out the grade twelve bolts in that size. Turns out they're a shade longer than the stock ones, so decided to stay with the proven stuff.



    However, now I've turned up another question. Some of my engines have flat washers under the head bolts, and some do not. I assume the washers allow the bolt to torque up a bit smoother, because I can't see any other reason for a washer. Dave's engine came without washers, but what was factory stock ??
  • Unknown
    Unknown
    Hardened washers will help to spread the torque load over a larger area, won't let bolt dig into head, specially on aluminum heads. You could also use a flanged head bolt with a hardened washer, a set for small block chev will fit the 7/16 size, speed or performance shop found. Hudsonly Lou Cote
  • Unknown
    Unknown
    grade 12 bolts are way overkill,so are grade 8. Originals were grade 5!
  • [Deleted User]
    [Deleted User]
    thanks you very much. . . and here is a very complete web site that explains the nuts and bolts of nuts and bolts. . . .

    http://www.pirate4x4.com/tech/billavista/NutsandBolts/Nuts&Bolts_signed.pdf
  • PAULARGETYPE
    PAULARGETYPE Senior Contributor
    I Didn't Think Grade System Was Used As It Is Now Back In The 50's
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