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Engine Re-build

Discussion in 'The Garage' started by 83ChevK5, Oct 14, 2003.

  1. 83ChevK5

    83ChevK5 Registered Member

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    I am re-building a sb350 bored 40 over im lookin at cam and lifter set-ups and im not to sure what to get or where from. I've been looking at one from Jegs its a comp cam extreme 4x4. what duration should i look for i need good low end torque. Any suggestions? I also have a strange noise question. I just fixed my cracked frame at the gear box and installed a frame gusset from auto fab. now i have a slight tick noise from around the gear box any ideas on what it might be! /forums/images/graemlins/confused.gif

    /forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gifRyan /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif
     
  2. SUBFAN

    SUBFAN 1/2 ton status

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    Low end torque you say? The best thing you can do for it yjen, is install a stroker crank....A small version of the X-treme 4x4 camshafts will produce lots of low torque in this set up....

    Money willing, try and go with a roller cam. Running several combinations through Desktop Dyno helped sell me on the roller cam idea....Should have bought a roller 350 instead of the 400....
     
  3. sled_dog

    sled_dog 1 ton status

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    I've heard comp cams says not to idle too much with their roller lifters. So if I went Roller I'd try and get a like Vortec 350 without intake or anything. Then I'd have a 350 with roller cam and vortec heads. Had a chance at one for like $350, should have bought it /forums/images/graemlins/frown.gif If I had to do it again I'd go with a 383 and a Comp Cams 4x4 cam. Smallest duration will be best torque. I'd still like to go 383 but I'd have to remove my motor and tear it all down to get it machined so thats not happening.
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    DD2K is apparently a little optimistic on the gains for a roller cam. Guy with a 383 in a Monte Carlo (runs mid 12's) has a roller cam, and comparing DD2K's results with his estimated HP based on ET, plugging it in as a hydraulic flat cam got him the closest to what his ET was saying his HP was.

    The difference on the exact same cam in DD2K is pretty darn large, when in reality, most of the gains to be had from a roller come from the different profiles you can run, not the efficiency of the roller lifters, although those don't help.
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    [ QUOTE ]
    I've heard comp cams says not to idle too much with their roller lifters

    [/ QUOTE ]

    My crane rollers say the same thing. Don't believe there is a difference in the oiling of a stock SBC with or without roller lifters, so I'm guessing the aftermarket warnings are based on the link bar design.

    Wish I would have gone with a newer block too. /forums/images/graemlins/frown.gif Live and learn, eh?
     
  6. sled_dog

    sled_dog 1 ton status

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    [ QUOTE ]


    Wish I would have gone with a newer block too. /forums/images/graemlins/frown.gif Live and learn, eh?

    [/ QUOTE ] Wouldn't be living otherwise.
     
  7. SUBFAN

    SUBFAN 1/2 ton status

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    Yes the rollers do seem like quite a large jump on DD2000....It is interesting too that carb size to them has little effect on output also. Add in a roller cam and sequential port FI and watch the numbers really jump!

    I really didn't see a huge difference in using a 400 block vs. just going the 383 route either. For cost a roller block turned into a 383 seems the way to go for one nice SBC....
     
  8. MOABDADC22

    MOABDADC22 1/2 ton status

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    [ QUOTE ]
    what duration should i look for i need good low end torque. Any suggestions?

    [/ QUOTE ]

    The best suggestion I can give is.........call different cam companies and tell them what you are looking for. You will find that most companies are very helpful in helping choose the correct cam for your rig. /forums/images/graemlins/thumb.gif
     
  9. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    You must take into account several factors. Such as gearing ( transmission , transfercase , tire size etc. ), intended rpm range, carb/fuel inj. size and flow, exhaust etc. But a good rule of thumb is for low end torque that you can feel FORGET all the hot rod stuff and run something not more than a step or two over stock. Most stock replacement cams even have more power than FACTORY cams did!
     
  10. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    I have a 400 bored to 406 and I am running comp cams 268H high energy cam. According to DD2000 I am making 355HP@5,000rpm and 455ft. pounds of torque@ 3,000RPM. I think that is a pretty torquey combo. /forums/images/graemlins/thumb.gif
     

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