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stock comp ratio 454 tbi?

Discussion in 'The Garage' started by big_truxx, Jun 25, 2005.

  1. big_truxx

    big_truxx 1/2 ton status

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    What's the stock comp ratio of an 89 tbi 454? If it makes any difference the original motor in an 89 crew dually scotsdale model :D
     
  2. LongIslander26

    LongIslander26 1/2 ton status

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    comp ratio

    It's probably in the neighborhood of 8-8.5:1. I can look into it further to get you an exact number.
     
  3. big_truxx

    big_truxx 1/2 ton status

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    that sucks. I was hoping it'd be up around 9 :( I know gm's specs for the 350 mr goodwrench was 8.5. I may have to rebuild the whole motor anyway so mightbe good to up the compression some :D 10:1 would be about right I think :D
     
  4. LongIslander26

    LongIslander26 1/2 ton status

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    Big Block rebuild.

    Zero deck the block and use flattop pistons, a thin head gasket, and watch your cam lift, that should get you in the ballpark.
     
  5. k20

    k20 3/4 ton status

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    7.9:1
    230hp @ 3600 rpm
    385ft/lbs @ 1600 rpm
     
  6. big_truxx

    big_truxx 1/2 ton status

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    I am thinking since it has 163k on it and was ran hot and quite possibly needs head gaskets, may as well tear it down and put a couple other parts in the rebuild when I can afford. I just played with my desktop dyno 2000 and with pocket porting and large valves, 10:1 comp, headers, summit 1300 cam, and with the 660cfm setting using dual plane setting for induction it brings up roughly 425hp and 500 lb ft tq.. :thinking: :dunno: doesnt seem like that little work would produce that much power but... I dunno.
     
  7. LongIslander26

    LongIslander26 1/2 ton status

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    454

    10:1 CR is going to require some high octane gas in Maine close to sea level, especially with a low duration cam which will raise your dynamic CR . What's the cam specs on that summit cam?
     
  8. big_truxx

    big_truxx 1/2 ton status

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    yer right. I forgot about that. :waytogo: Just ran a different parts list of 8:1 comp ratio, heads pocket ported w/ large valves and headers w/ the stock cam option and its up to about 325hp and 470 lb ft tq :D now assuming that in overheating the rings and all are still ok, that would work out very well w/ the stock tbi setup :)
     
  9. LongIslander26

    LongIslander26 1/2 ton status

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    454

    Looks like a stump puller to me! :saweet: :woot:
     
  10. big_truxx

    big_truxx 1/2 ton status

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    Location:
    Canaan, Maine
    Brand: Summit
    Product Line: Summit Camshafts
    Cam Style: Hydraulic flat tappet
    Basic Operating RPM Range: 1,500-4,000 RPM
    Intake Duration 050 inch Lift: 208
    Exhaust Duration 050 inch Lift: 218
    Duration at 050 inch Lift: 208 int./218 exh.
    Advertised Intake Duration: 266
    Advertised Exhaust Duration: 276
    Advertised Duration: 266 int./276 exh.
    Intake Valve Lift with Factory Rocker Arm Ratio: 0.475
    Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.500
    Valve Lift with Factory Rocker Arm Ratio: 0.475 int./0.500 exh. lift
    Lobe Separation (degrees): 112
    Intake Valve Lash (in): 0.000
    Exhaust Valve Lash (in): 0.000
    Computer Controlled: No
    Quantity: Sold individually.

    cam specs :D
     

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