Injector size - what's the solution?

Discussion in 'The Garage' started by DestinWahoo, Mar 1, 2007.

  1. DestinWahoo

    DestinWahoo New Member

    Messages:
    15
    Likes Received:
    0
    Joined:
    Jan 3, 2007
    I contacted Aeromotive and Anderson Ford Motorsports for Injector size.
    I got two very different answers. Aero says 50lb injectors, where as, AFM says 38lb injectors will work fine.
    My calculations show the 38lb in range, but I want to get right the first time and not rebuy.
    The engine arrives next week and I need to get my tail in gear.

    Here is the specs on my engine for reference;

    LONGBLOCK: 347 SB2002 PRO BULLET FT/TW:
    347 cid short block Balanced to racing tolerances and blueprinted.

    RODS: 4340 forged steel ultra-lite 5.400" I-beams w/ ARP bolts & full floating pins

    CRANK: nodular iron 3.40" stroke,

    PISTONS: forged Pro-X # 4320 (FT/TW -3cc),

    RINGS: moly E-458K,

    ROD BEARINGS: tri-metal CB-634P,

    MAIN BEARINGS: tri-metal BC240J,

    CAM BEARINGS: tri-metal CC440

    MAIN SUPPORT SYSTEM: 6061-T6 X 3/4" ALUMINUM

    CYLINDER HEADS: Trick Flow Twisted Wedge 185CNC ported heads, 2.02/1.60 valves, #51400004-C01

    INTAKE: Trick Flow Track Heat (TFS-51511002)

    ADAPTER: Trick Flow (TFS-5150SN95-11)

    PHENOLIC SPACER: 1†(TFS-51520008)

    TIMING CHAIN: Pro Gear 3 Position

    430HDSTK LIFTERS: Ford Racing

    RETAINING HARDWARE: Hydraulic

    PUSHRODS: 4130 .080" Wall Seamless

    HEAD BOLTS: ARP 8740 Hex Head Bolts

    HEAD GASKETS: Fel Pro Graphite 8548 PT2

    ROCKER ARMS: DSS Aluminum Roller Rockers

    T-WASHERS: 1/2" to 7/16" reducer bushings for cylinder heads

    CAMSHAFT: Comp Cams XE274HR Roller (.555"/.565" 224°/232°@.050"
    112°LSA 2200-6200RPM) (35-518-8)

    BALANCER: 28oz SFI Steel/Aluminum balancer 1 (208SA)

    FLYWHEEL: Fidanza SBF 157T/late model SFI aluminum flywheel
    (28oz balance,replaceable friction surface) (186501)

    WINDAGE TRAY: 5.0 Stroker Pro Tray 1 (7005)

    ARP flywheel bolts: 7/16" x 1.00" 6pcs (manual trans) (100-2801)

    ARP balancer bolts: 289-460 except 351C (150-2501)

    OIL PAN: OP7050 DSS low profile 7qt oil pan with pickup and
    passenger side 3/8" NPT baffled oil return hole (for supercharger/turbo).

    OIL PUMP: OP1000 DSS 302 std volume oil pump kit Includes pump
    w/ adjustable pressure, heavy duty oil pump and pickup
    fasteners, and an ARP heavy duty oil pump driveshaft.

    DISTRIBUTOR: MSD #8455

    THROTTLE BODY: PP 75mm (69212)


    http://www.fishingdestinflorida.com/cobra/MyFavoriteToy/index.html
     
  2. Adam

    Adam Member

    Messages:
    231
    Likes Received:
    0
    Joined:
    Mar 28, 2006
    38lb injectors will support 675 crank hp. If this is an NA motor, (looks to be) 38's shold be plenty.
     
  3. DestinWahoo

    DestinWahoo New Member

    Messages:
    15
    Likes Received:
    0
    Joined:
    Jan 3, 2007
    Yes it's NA. Thanks for the help! DSS thinks it will be around 450 FWHP.
    I am using electric water pump and anything else I can think to squeeze out extra HP.
     
  4. 94twinscrew

    94twinscrew Active Member

    Messages:
    465
    Likes Received:
    0
    Joined:
    Apr 5, 2006
    50's?! that's way overkill for the new NA combo.lol 38's would leave you PLEANTY of room to grow in NA form. Hell,for that matter,it could be done with 36's.
     
  5. IceMan

    IceMan Active Member

    Messages:
    654
    Likes Received:
    0
    Joined:
    Nov 10, 2006
    if you are staying N/A 36-38 lb should be fine... even 42's might be an overkill...
     
  6. Adam

    Adam Member

    Messages:
    231
    Likes Received:
    0
    Joined:
    Mar 28, 2006
    Good injector calculation is:

    (number of injectors X size of injectors=total lbs of fuel per hour)
    ____________________________________________________
    divided by BSFC(.45 on NA or .60 on Blower cars)


    8 X 38lb= 304lbs of fuel per hour/ .45 =675hp at 100% duty cycle.
    You can figure out any injector with this calculation :)
     
  7. DestinWahoo

    DestinWahoo New Member

    Messages:
    15
    Likes Received:
    0
    Joined:
    Jan 3, 2007
    Thanks Adam, I was looking to run at an 80% duty cycle to prevent abusing my injectors.
    But, I find everybody has a different opinion as to the right size.
     
  8. DestinWahoo

    DestinWahoo New Member

    Messages:
    15
    Likes Received:
    0
    Joined:
    Jan 3, 2007
    Decided to go with the 38 pounders, but now It occured to me that I need to ignite the fuel.
    Looking for suggestions on the best plugs for this build.
    I will post pictures of the tear down and rebuild as soon as I can.
     
  9. Adam

    Adam Member

    Messages:
    231
    Likes Received:
    0
    Joined:
    Mar 28, 2006
    Thats a good plan. Even at 80%, thats still 540hp, I think you will be fine.
     
  10. ripper

    ripper Well-Known Member

    Messages:
    3,323
    Likes Received:
    0
    Joined:
    Jan 2, 2007
    Crap with that motor i see a blower in the near future. Get 42's. Plug wires? Taylor Thundervolts 10.5.
     
  11. blown98gt

    blown98gt Well-Known Member

    Messages:
    1,117
    Likes Received:
    0
    Joined:
    Mar 11, 2009
  12. BigTang

    BigTang Active Member

    Messages:
    893
    Likes Received:
    0
    Joined:
    Oct 9, 2008
    just curious but why that cam? its robbing at least 30 hp from you.
     
  13. Javi

    Javi Legend

    Messages:
    27,385
    Likes Received:
    44
    Joined:
    Sep 8, 2007
    Location:
    Th3 405
    Back from dead.
     
  14. BigTang

    BigTang Active Member

    Messages:
    893
    Likes Received:
    0
    Joined:
    Oct 9, 2008
    crap, i didn't even notice that. At least it wasn't me that dug up the corpse.