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Technical "Modern" HiPo 289

Discussion in 'The Hokey Ass Message Board' started by Flattop Tiki, Nov 20, 2020.

  1. Flattop Tiki
    Joined: Apr 14, 2019
    Posts: 35

    Flattop Tiki

    Hello to all!

    Looking at building a hot 289 for light duty racing, and long-term Carrera Panamericana ambitions.

    With that in mind I'm limited to stock displacement and stroke, iron heads, and 600cfm 4bbl max. Oh, and to top it off, race requires you to run 87-91 octane pump gas.

    With all that being said, the best bet seems to be building a sort of "modern" HiPo 289. I'm not looking for peak HP, but more so a durable little block that pulls strong to redline, say 6000-6500rpm max.

    Looking for input on heads/camshaft, with build specs as follows:

    289 stock crank and rods
    Late Model 302 Block
    OEM hydraulic lifters
    Hi-Rise Dual Plane Aluminum Intake
    Tri-Y headers (to fit 1962 Meteor)
    2800-3000lb race weight
    Toploader/Super T-10
    3.55-3.73 Rear Gears

    I'm leaning towards bonestock, GT40 iron heads (1.84/1.54 valves), with some seat and bowl work. Coupled with a custom ground cam from Ed Curtis.

    Any suggestions or wisdom regarding camshaft duration, compression (static/dynamic), and head selection are all appreciated!
     
    loudbang likes this.
  2. Go roller cam.Later 302"s came with them I believe {Chevy guy}.Makes a bit more HP,and no worry of cam break in.
     
    Deuces and loudbang like this.
  3. OzyRodder
    Joined: Dec 11, 2012
    Posts: 300

    OzyRodder
    ALLIANCE MEMBER

  4. Do you have to run stock cylinder heads? If not Ed Curtis would be the man to design the cam and head combination. If yes then be advised that the GT 40P heads have a unique spark plug angle. Not a problem if you are building your own headers.
     
    loudbang likes this.

  5. Aren't you giving up one of the main advantages of the 289? It's ability to rev to 7K+ without harm when assembled right is well known, and you don't need a bunch of exotic parts to do it. And with a manual trans and those rear gears I'd give serious thought to a single-plane intake too.
     
    MUNCIE, loudbang and seb fontana like this.
  6. caper
    Joined: Jun 12, 2009
    Posts: 36

    caper
    Member
    from Cape Cod

    Check out Windsor Jr. iron heads - used them on a 289 I had in a 65 GT350R clone. Stout motor.
     
    loudbang likes this.
  7. Flattop Tiki
    Joined: Apr 14, 2019
    Posts: 35

    Flattop Tiki

    Forgot to mention in the initial post, 100% going with a roller cam. Solid vs Hydraulic will be up to the cam grinder.

    Already in contact with Flowtech, recommend the Dart Iron heads. Only concern there is I don't want to have "too much" head, and lose torque for top end.

    Stock plugs would be nice

    Single plane and 7000rpm are all fine and dandy, I'm just concerned with losing low end torque just for a bigger horsepower number.

    Spoken with guys who have run 289/302s in La Carrera, they recommended building a reliable, torquey motor vs a high winder.

    If you think I can have my cake and eat it too in regards to hill climbing torque and flat out horsepower, I'm all ears!
     
    loudbang likes this.
  8. Torque will be good with a 4 speed and 3.55 or 3.73 gears but will not garner that much top end speed. In other words cam and mild heads should be geared to 5500 RPM and below. Much more that that and revving it to the moon will not yield very much more noticeable power. Compression and a good spark curve will be required to gain the most from a combination like this so be sure to invest in some dyno tuning time. Keeping RPM's below 6000 will help insure longevity and reliability of the engine and parts. What is your anticipated top speed and for how long will that be attained? Like a 1/2 mile straight or longer.
     
    loudbang likes this.
  9. TCTND
    Joined: Dec 27, 2019
    Posts: 271

    TCTND
    Member

    If allowed be sure to use an oil accumulator (Accusump, Moroso, etc.) and definitely a better than stock oil pump drive rod.
     
    loudbang likes this.
  10. deathrowdave
    Joined: May 27, 2014
    Posts: 2,748

    deathrowdave
    ALLIANCE MEMBER
    from NKy

    Main cap girdle , roller block ,x grind cam , springs ,GT40 heads ,roller rockers , dual plane Edlebrock Performer RPM , 4180 series Holley carb (635 CFM vac secondaries ) ., KB pistons , recurved point ign., headers .This is the combination in my 32 , I dare say it’s making more than 271HP that the stock HP made . It will spin like a chain saw ! I do not drive my car hard any more , the old Harley is for that . It’s there if I want or need to .
     
    loudbang likes this.
  11. Marty Strode
    Joined: Apr 28, 2011
    Posts: 6,289

    Marty Strode
    Member

    In your lead in post, you mention stock 289 rods. If you mean anything but Hi-Po, they have 5/16 rod bolts, and torque to 19-24 lbs. I would buy aftermarket rods, with 3/8 bolts.
     
    HemiDeuce, ottoman and loudbang like this.
  12. deathrowdave
    Joined: May 27, 2014
    Posts: 2,748

    deathrowdave
    ALLIANCE MEMBER
    from NKy

    Personal friend purchased a GT 350 H , raced it from day one , 8K redline , not one issue with a rod bolt . He still owns the car today , still stock crank and rods in the block after many hard years of twisting it up hard . OEM HP was totally different from production , 289 . If you going to build all out race engine , many many things can be up graded and should be to modern standards . A fun engine can be built on the cheap with a bit of looking for the correct off the shelf stuff . That little V8 will take all you can give it all day long in stock form .
     
    loudbang likes this.
  13. seb fontana
    Joined: Sep 1, 2005
    Posts: 7,206

    seb fontana
    Member
    from ct

    Just where do you want the torque to be? Max is going to be close to 5k, with a decent 6500 hp. What you expecting with a 2.875 stroke? T5z 5speed with .075 fifth replacement [if you can find a set] or.80 [readily available] and rear gears to suit, that's what gears do, multiply torque. Chocolate cake please.
     
    loudbang likes this.
  14. finn
    Joined: Jan 25, 2006
    Posts: 930

    finn
    Member

    The hi po 289 had 3/8” rod bolts and broached caps, not the standard 5/16” bolts. Boss 302 engines had the same hipo 289 rod forging, but milled spot faced caps, eliminating the stress risers from the broaching.
     
    Deuces and loudbang like this.
  15. Before everyone thinks that the HP rods are a requirement for a reliable motor, keep in mind the NHRA Super Stock racers that run 289s. They don't use the Hipo motor, they use the lo-po 4V version (class weight breaks are based on advertised HP) as they can get just as much power with less weight out of those given the class rules. They are required to use stock 5/16 rods (at least one has to be bone stock) and they routinely rev these well beyond 6K. I recall a guy a number of years ago setting a class record in the high 9s... he was buzzing it at close to 10K at the finish line...
     

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