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What does 4 bolt mean?

Discussion in 'The Hokey Ass Message Board' started by oldfart, Nov 17, 2011.

  1. 49ratfink
    Joined: Feb 8, 2004
    Posts: 17,860

    from California

    while we are on the subject of bolts, how come Chevy rear ends are measured in bolts and Fords are measured in inches? are 12 bolts bigger than 9 inches? what is the conversion factor? how many bolts to an inch?
  2. eaglebeak
    Joined: Sep 17, 2007
    Posts: 1,137


    My car is 6 bolts. I want to change it to 12 bolts so I can have a CB.
    What should I do?
  3. R Frederick
    Joined: Mar 30, 2009
    Posts: 2,660

    R Frederick
    from illinois

    Then you could get into splayed caps.
  4. I think when it comes down to telling about inches it is because you feel inferior. Little man syndrome or the like. :eek:
  5. Jooneeda 12 bolt conberter!
  6. Jay Tyrrell
    Joined: Dec 9, 2007
    Posts: 1,631

    Jay Tyrrell

    Agree 100%
    It is unbelievable the way some of you guys look down on someone because they might not know something. In the last little while things have gotten a little nasty with the way some of people treat others questions here on the HAMB. Get off your fucking high horse and help out a guy that wants to learn!
    Last edited: Nov 17, 2011
    Joined: Nov 22, 2005
    Posts: 7,591

    from SIDNEY, NY

    What I was getting at was that, for instance, 3970010 blocks came in both 2 and 4 bolt main form, but over the years, countless people have tried to convince me that the 4 bolt blocks were "special".
  8. 53sled
    Joined: Jul 5, 2005
    Posts: 5,819

    from KCMO

    happy birthday!
  9. Fenders
    Joined: Sep 8, 2007
    Posts: 3,922


    that's the way I felt when I went back to school after a few years working... if I had a question in class, I raised my hand and asked the professor... funny thing is, the youngsters all thought I was smart because I asked (and wasn't afraid to ask) questions...
    Go figure.
  10. Truckedup
    Joined: Jul 25, 2006
    Posts: 3,864


    It ain't the size or number of bolts,but the strength of the individual bolt.At any rate,the bigger the engine,the smaller the johnson,yes?:D
    Most street SBC have less than 400 hp and are never run wide open for more than 15 2 bolt main block with a cast crank should be ok.........
  11. Don's Hot Rods
    Joined: Oct 7, 2005
    Posts: 8,319

    Don's Hot Rods
    from florida

    We sometimes talk out of both sides of our mouths.............we say "there are no stupid questions" then we jump on a guy for asking something he doesn't know. Not cool. It might seem that every rodder out there would know the difference between a 2 and 4 bolt, but if you have never had any experience with them or had someone tell you the differences, how would you know?

    As long as I have been playing with cars I still find stuff I have no idea about and have to ask for help. For example, I have never degreed a cam, just installed them out of the box. So when I wanted to learn how I posted that question and got lots of help. I bet some more experienced engine guys thought everyone should know that one and that I am a real dumbass. But if you don't know something you just don't know. :)

  12. PB,

    You are the first person besides me that I have heard "307" (mine is a 1968 casting) in a sentence from without cursing it. It came along about the same time as the 350 and then GM killed the compression and choked it to death with bad heads which helps explain the bad comments about it but mine came rated at 220 HP which isn't anything to sneeze at. When someone asks me about the 350 (my 307) sitting under the work bench I have started telling them it is a stroked 283 which is essentially the truth. The 283 is 3.875(b) x 3.00(s) and the 307 is 3.875(b) x 3.25(s). So far everyone who has asked thinks it is really cool that I have a 283 stroker.
    Last edited: Nov 17, 2011
  13. You are correct 4 bolt blocks just have different clamping points. All of that is a pretty mute point if your engine is properly built. An engine won't come apart if you build it right. It isn't normally a block failure on our kind of engines anyway, normally a rod pulls in two or a piston busts or a valve gets dropped. Occaisoinally someone spins a bearing, that again comes from improper build technique or the engine is just too worn to be run very hard.

    Now when you start throwing a heavy load of Nitro at one it is an entirely different game. that is why those guys don't use stock blocks any more. Not many of us are going to be dosing with nitro I am afraid.


    Any of them can be built it is just a matter of knowing what you are doing. TRW actually makes a higher compression piston for a 307, I used to know the number maybe someone can find one in a book. Stroked 283s were actually popular way back when. The bore to stroke ratio is real close to that of a 383 Chevy, so theoretically it could be considered a smaller version of the 383.

    Bore to stroke ratio is a very important part of engine building, I prefer an engine that is bore heavy myself but a lot of fellas prefer a long arm instead. A lot of it depends on what you intend the engine to do.

    I have a 307 in my '61 Willys, I tell everyone that it is a 283 they dont' know the difference. It is a good engine for the little crawler makes all it torque right off idle.
    Last edited: Nov 17, 2011
  14. outlaw256
    Joined: Jun 26, 2008
    Posts: 2,023


    bingo beaner!! i wont pay the price difference between a 2 bolt and a 4 bolt,but i will pay the machine shop to splay my blocks. a lot of arguements on that one.but no matter i still prefer a splayed block.
  15. The last time I was dosed with Nitro was in the back of an ambulance on the way to the hospital in full arrest. I will pass on that thanks.

  16. The Ol' Man had angina and carried Nitro pills. He asked me if I wanted one once and I said I dunno will it make me see colors? He just laughed and said leary couldn't make you see colors you color blind SOB.

    We used to have a lot of fun, workin' and playin'.
  17. 49ratfink
    Joined: Feb 8, 2004
    Posts: 17,860

    from California

    I have 12 bolts. I don't understand what you are referrring to. my 1 ton van has 14 I think. I don't feel inferior, I feel EXferior.:confused:
  18. traffic61
    Joined: Jun 15, 2009
    Posts: 1,479

    from Owasso, OK

    Didn't Emily Litella do a bit about having your cap splayed? Or was it neutered?
  19. Dan in Pasadena
    Joined: Sep 11, 2009
    Posts: 854

    Dan in Pasadena

    EXACTLY right!

    Geez guys, some of you think you came out of the womb knowing what 4 bolt mains are? Kudos that the guy has the stones to say to a group of supposed "experts", "Hey, why is this called this or that?"

    Do NOT stop asking. Screw everyone else that needs to give you crap for it.
  20. ford didnt want to confuse chevy guys that can only count to 12, with using a tape, JUST JOKEING GUYS LOL
  21. sickytwisted
    Joined: Feb 2, 2009
    Posts: 139


    I thought that the original question was good. A lot of people, especially beginners don't know what a 4 bolt is. I'm not calling anyone a rookie but isn't this whole forum to help each other? It's helped me a lot.
  22. mysteryman
    Joined: Apr 20, 2011
    Posts: 252

    from atlanta

    ( this is not true for answers).ive ran both 2 and 4 bolt blocks never had an issue with either one.ive heard 4 bolts are stronger??any pictures out there of 2 bolt blocks that have failed due to only having 2 bolts.
    Joined: Mar 30, 2010
    Posts: 3,254


    Everybody likes a little one likes a wise ass. ( I LIKE BIG ONES TOO)
  24. Pop-Rodder
    Joined: Oct 6, 2011
    Posts: 325


    Much has been said about no stupid questions only stupid answers etc; however, it's been my often learned experience that-- the only stupid question is the one you don't ask!
  25. rjaustin421
    Joined: May 1, 2009
    Posts: 337


  26. Drive Em
    Joined: Aug 25, 2006
    Posts: 1,748

    Drive Em

    "4 bolt main" is a cruise night engineer's lingo describing his small block.
  27. Engine man
    Joined: Jan 30, 2011
    Posts: 3,476

    Engine man
    from Wisconsin

    He has almost 900 posts.
  28. rixrex
    Joined: Jun 25, 2006
    Posts: 1,433


    I'm still not too sure what "limited slip" differential means...
  29. striptnut
    Joined: Mar 5, 2011
    Posts: 90


    Thank you!.
    Last edited: Nov 17, 2011
  30. Can't a chicken cross the road without having its motives questioned?

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