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Desktop Dyno Anyone?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Stoopalini, Jan 24, 2005.

  1. Stoopalini

    Stoopalini 1/2 ton status

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    Would someone with Desktop Dyno be willing to run the numbers on a motor I am putting together?

    I can e-mail or post the specs if someone is willing.

    Thanks,
    Thomas.
     
  2. BranndonC

    BranndonC 3/4 ton status

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    i think i still have it installed, i dont know too much about motors yet, but give me the specs and i'll throw them in if i can
     
  3. Stoopalini

    Stoopalini 1/2 ton status

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    Thanks!
    • 355ci 4-bolt main factory roller block w/ one piece rear main seal
    • 6" rods with 6" style pistons
    • 1.94 intake valve and 1.50 exhaust valve sizes
    • 9.5:1 compression ratio
    • Comp Cam part # 08-500-8
    • 1.5 Roller rockers
    • GM Roller lifters
    • Edlebrock Performer dual plane intake manifold
    • 750cfm quadrajet carb
    • Hooker super competition shortie headers
    • Full exhaust with 2.5" pipe
    • Stock ignition
    Thomas.
     
  4. BranndonC

    BranndonC 3/4 ton status

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    sorry, i cant find the right places to enter all that info, the program i have is only 1 meg in size (small) i can email it to you if you want
    its desktop dyno 2000
     
  5. Stoopalini

    Stoopalini 1/2 ton status

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    I wasn't sure how much info you would need for the program, so I just included everything I could think of ;)

    Thanks for trying,
    Thomas.
     
  6. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    max HP is 396 at 5500rpm
    max TQ is 425 at 4000rpm

    [​IMG]
     
  7. sled_dog

    sled_dog 1 ton status

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    don't know what you did but there is no way that motor is making that much power, no way at all.

    Desktop Dyno 2000 is tiny and easy if you know the real specs. Guys too often say, oh yeah my heads or cam are equal to that.

    I ran the numbers and came back with 312 HP @ 4500RPM, 446 ft-lbs @ 2000 RPMs. But mind you that Desktop Dyno is really screwed up when it comes to roller camshafts. The torque is far highre than it would be really.
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    yep. Calculate the engine with a hydraulic flat tappet with the roller cam specs.
     
  9. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    i have airflow files for a few heads. i put in the 882 heads and got this. also the timing i set at 10* BTDC

    this is what i put in
    chevy 350 .030 over
    882 heads 1.94 intake 1.5 exhaust valves
    9.5 compression
    750 cfm at 1.5"HG
    dual plane manifold
    small tube headers with mufflers
    highperformance street cam, roller lifters, seat to seat timing
    .480 intake .488 exhaust lift
    IVO 21 IVC 57
    EVO 68 EVC 16
     
  10. sled_dog

    sled_dog 1 ton status

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    I recommend never touching the timing thing on Dyno 2000. I plugged in his actual cam specs and used a set of untouched 882 flow numbers and came up with just a little over 300. And when I adjusted the timing up like you do it dropped well below 300.
     
  11. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    no matter what i do to it. i can't get the same specs as you. not even close. the head file i have is a untouched 882 also.

    when you adjust the timing, are you putting a "-" infront of the number, if you don't the power goes down, if you do it goes up. "-10" is 10*BTDC and "10" is 10* ATDC. it makes a big difference.

    with hydraulic lifters i get 350hp at 5500rpm and 388tq at 4000 rpm
     
  12. Stoopalini

    Stoopalini 1/2 ton status

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    Thanks for the input everyone.

    When I ran the numbers with 0' timing and low performance large valve heads, I got these results:

    [​IMG]

    Thomas.
     
  13. stevewix

    stevewix Registered Member

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    i've got a similar program that costs about 500 bucks that involves much more than DD, i used to use DD until i discovered the better software, i'll run the numbers when i get home.


    i need to know your thermostat temp, water pump design and fan setup.

    what size are the primaries on the headers, and what specific intake manifold is on it? also, give me the size of the air filter, it will give me back hordes of information.

    it will tell me where to set the timing, likelihood of knock, holley jet sizes, BSFC etc. i've had VERY good luck with this program. extremely realistic.

    PS, are they vortec heads?
     
  14. sled_dog

    sled_dog 1 ton status

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    /me bows to steve. Ok where do I get this program?
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

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    No idea how much it cost, but sounds like "engine analyzer".

    I haven't used it much, there is a ton more info to enter than DD2K though.
     
  16. Stoopalini

    Stoopalini 1/2 ton status

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    Thanks Steve.

    Thermostat, waterpump and fans are all stock setup. Fan is a clutch fan assy.
    Not sure on the header pri size? They are Hooker Super Comp Shorties though...
    The intake manifold is the Edlebrock Performer Dual Plane manifold.
    Air filter is a 4" open element.

    The heads are not vortec, they are stock GM 305 heads that are being modified by installing 1.94i and 1.50e valves and a 3-angle valve job.

    Thanks again for running it through, I appreciate it! :waytogo:

    Thomas.
     
  17. sled_dog

    sled_dog 1 ton status

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    305s? Ok then whatever I told you, cut 20hp off that. 305s flow like a brick wall. Did you get dished pistons so you won't be running gobs of compression or are they not the usual 58cc heads?
     
  18. Stoopalini

    Stoopalini 1/2 ton status

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    Ya, 305 heads with large 350 valves installed. Using flattop pistons and opening up the chamber a bit to get the compression down to 9.5:1

    Considered having them ported or getting some nice 350 heads, but after spending as much $$ as I am on this build, I just can't afford it.

    Thomas.
     

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