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304 ci 8BA… Too big?

Discussion in 'Traditional Hot Rods' started by sluggo1936, Nov 13, 2013.

  1. sluggo1936
    Joined: Feb 28, 2012
    Posts: 46

    sluggo1936
    Member
    from Colorado

    Is a 304 too big for an 8BA? I don't know the in's and outs of flatheads, I've just heard things from guys talking and me asking questions. I'm concerned about the block cracking between the pistons and heat issues, longevity of the engine, etc. I'm putting in a 400jr & 2x2 97's. It's going in a 31 roadster, probably driven with the hood off most of the time. I've heard a 286 might be the way to go… I just don't know, so I though I'd ask you guys.

    Thanks…
     
  2. Bearing Burner
    Joined: Mar 2, 2009
    Posts: 937

    Bearing Burner
    Member
    from W. MA

    I think that 296ci is as big as you can feed and exhaust and that is with bigger valves a lot of porting and relief. 276 is much more practical,reliable and cheaper.
     
  3. A 304 is possible using an 8BA block provided you have it sonic tested first. Ask to have it tested at multiple points on each cylinder as some are thinner at the top.

    The alternative is to sleeve the block ad then boring to 3 3/8" and using a 4 1/4" crank from Scat or Eagle.


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  4. sluggo1936
    Joined: Feb 28, 2012
    Posts: 46

    sluggo1936
    Member
    from Colorado

    Thanks. I'm sure there are some 304 HAMBers out there. I'd like to hear your thoughts. Given some of the issues with a large motor, I'm leaning towards 276-286.

    Thanks again for replying!
     

  5. acme30
    Joined: Jun 13, 2011
    Posts: 192

    acme30
    Member
    from Australia

    Whilst it can be done better to save yourself the grief and the cash and go with the smaller cubes

    My 2 cents
     
  6. I run a 304 but its in the dragster and solid block, but I love the blown 5/16 x 4 in the ICT for a dialy driver and its on its 13th year after build.......
     
  7. HotRodMicky
    Joined: Oct 14, 2001
    Posts: 1,772

    HotRodMicky
    Member

    I run a 304 in a street roadster
    No problems with etc.
    But!!!! Have the block sonic tested first!!!!!
    Core shift can cause problems and wont allow for the big bore

    I would get a Scat 4 1/4 x 3 5/16 balanced kit .
    Makes 296ci

    You will have problems feed the 304 with two 97s
    A 296 might work
    A 284 will work , have a friend running the combo
     
  8. GMC BUBBA
    Joined: Jun 15, 2006
    Posts: 3,385

    GMC BUBBA
    Member

    Use a 4 1/4 crank and a 304 is no problem...I have one on the stand right now.
     
  9. oldsman41
    Joined: Jun 25, 2010
    Posts: 1,545

    oldsman41
    Member

    I will probably get hell from some of these guys but why not look for a Lincoln motor instead. little there will go a long way.
     
  10. woodypecker
    Joined: Jan 23, 2011
    Posts: 300

    woodypecker
    Member

    Go small and you will be happier unless you race with your buddies.
     
  11. 34hemipu
    Joined: Jan 12, 2006
    Posts: 145

    34hemipu
    Member

    Or if you have a blower.
     
  12. sluggo1936
    Joined: Feb 28, 2012
    Posts: 46

    sluggo1936
    Member
    from Colorado

    No hell yet... I've already purchased the 8BA block.




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  13. flatheadpete
    Joined: Oct 29, 2003
    Posts: 10,210

    flatheadpete
    Member
    from Burton, MI

    My old T roadster ran a 276 and it ran really well. Never any big cooling problems or other flathead 'problems'.
     
  14. 36tbird
    Joined: Feb 1, 2005
    Posts: 1,084

    36tbird
    Member

    Messing with flatheads, I think that the emphasis should not be cubes but transmission if you're talking about a street motor. Aim for a combo where 65 to 70 cruise is about 2400 to 2600 rpm. 2 cents.
     
  15. sluggo1936
    Joined: Feb 28, 2012
    Posts: 46

    sluggo1936
    Member
    from Colorado

    Thanks for all the input. I'm going with a 8BA 276 2x2 with a 400jr...


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  16. sluggo1936
    Joined: Feb 28, 2012
    Posts: 46

    sluggo1936
    Member
    from Colorado

    ImageUploadedByH.A.M.B.1392753231.284883.jpg ImageUploadedByH.A.M.B.1392753254.936677.jpg ImageUploadedByH.A.M.B.1392753280.697490.jpg ImageUploadedByH.A.M.B.1392753307.667094.jpg ImageUploadedByH.A.M.B.1392753332.305744.jpg


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  17. tubman
    Joined: May 16, 2007
    Posts: 5,850

    tubman
    ALLIANCE MEMBER

    If you do this, budget for heavy duty springs, helper springs, and coil-over shocks. These are HEAVY engines.
     
  18. Russ Gaylord Fontana
    Joined: May 12, 2007
    Posts: 58

    Russ Gaylord Fontana
    Member
    from Home

    I can only say I hope you enjoy the 400jnr as much as I do:D
     
  19. sluggo1936
    Joined: Feb 28, 2012
    Posts: 46

    sluggo1936
    Member
    from Colorado

    That's good to hear! I've never driven one, just heard them. A lot of research & opinions tell me it's the way to go. Should be on the road late spring. Can't wait!


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  20. seb fontana
    Joined: Sep 1, 2005
    Posts: 7,153

    seb fontana
    Member
    from ct

    A friend put together a 286 [3-3/8 x 4] with wiend cheater heads and tri power and 400jr cam..t5 and 3.08 rear gear..30/31 roadster..Really runs great, very eager with throttle response..Maybe not fast or quick but fun to drive!
     
  21. thirtytwo
    Joined: Dec 19, 2003
    Posts: 2,641

    thirtytwo
    Member

    I think a 3 5/16 bore x 4 stroke is probably the "Happiest "flat motor ... One with stock cam in a 3w 32 highboy 3.00:1 gears 39 trans. pulled good got 20mpg with 2- 97s.... Put a 400jr. In it ... car pulled hard... Mpg went down to about 14 .... But it sure sounded good ...

    I have a 3 3/8x 4 1/8 now with a 3/8 potvin cam runs real good but it doesn't like traffic a whole lot ... I would have been happier with a smaller bore... I'm not sure i can really notice the bigger stroke if you find a cheap orig. 4" merc crank ... I'd go that route... If your buying a new scat crank... Flip a coin I guess... I think I'd stick to 3 5/16 bore on a street car though
     
  22. Big bore flatheads are kool, blown flatheads are way cooler, and not as pricey as you might think.

    Flatheads dont like to breathe - force feed em ;)

    The difference ? Night and day.

    My 2c
     

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