Narrowed Down to 2 Cams

Small Block Mopar Engine

  1. thedartsport

    thedartsport Well-Known Member

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    So I've narrowed my choices down to two cams and was hoping some of you could help me decide.
    The car is a 1972 Dart Swinger
    Full interior
    Stock 360 w/ 4 barrel and eventually headers
    Will do mild port work to the factory heads
    904 with stock stall and rebuilt lockup converter (was told it was around 2000)
    Will have an 8.75 with 3.23 SG (maybe 3.55)
    245/60/15 rear tires
    This car will mainly be street driven, but I'd like to run the 1/8th mile at the local track if I ever felt like it every now and then. Hopefully either of these will spin the tires.
    Which cam fits? I'll get valve springs that either cam calls for.

    Summit 1789
    Summit RacingĀ® Cam Kits SUM-K50052

    Comp XE-262H
    COMP Cams Xtreme Energy Cam and Lifter Kits CL20-222-3
     
  2. aaronk785

    aaronk785 Well-Known Member

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    Use the comp cam. I cant remember what mag it was, but they made that exact build minus the head porting and made 300 hp. Should be a great street engine and run on 87 fuel.
     
  3. Krooser

    Krooser Building Chinese Free Engines since 1959...

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    Neither... both of those cams are ground for a Chevy diameter lifter.

    Find a cam that's ground for a .904 lifter. I go to www.jonescams.com or try Howards. Jones will cost you more but give you more smiles per mile. You may have to have a custom grind... yes it makes a difference.
     
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    • yellow rose

      yellow rose Overnight Sensation

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      Or call Jim at Racer Brown.
      Or Cam Motion.

      Both do .904 lifter specific grinds.

      If you don't correct geometry you lose most of what you gain with the .904 lobe.
       
    • Krooser

      Krooser Building Chinese Free Engines since 1959...

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    • BoogieMan67

      BoogieMan67 FABO Gold Member FABO Gold Member

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      Put you a 68 340 four speed cam in it.
       
    • nm9stheham

      nm9stheham Well-Known Member

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      Mixed reaction..... Maybe a bit more torque with the Comp.... a modest improvement for tire spinning with the Sure Grip and general street driving. The Summit's slower ramps will be easier on the valve train.
       
    • Krooser

      Krooser Building Chinese Free Engines since 1959...

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      I visited my buddy last night who has a fresh BB and SB in stock each waiting for a home.

      The 340 has a cam ground by Erson that was a custom grind set-up by his engine guy. About 487 lift/228 duration on a 106 lsa.... damn near the specs of my kids dirt b-mod motor. The HP program he uses says it will be around 480 HP at 6500 rpm's... should be a real neck snapper as it comes in around 4000... it's also a .904 grind.
       
    • mod5v

      mod5v Well-Known Member

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      If your looking for a low cost bigger than stock cam go with the Summit. BUT like the others said neither cam is really optimum for what you are doing. I would wait until you have the short block done so you can measure how far in the hole the pistons are and them have a grinder pick you out a cam after you fill out their on line questionnaire. Howards and bullet both come to mind but there are a few others that do a great job also.
       
    • toolmanmike

      toolmanmike Moderator Staff Member FABO Gold Member

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      Another vote for calling the cam company.
       
    • scatpackbee

      scatpackbee Well-Known Member

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      Where do you get one of those?
       
    • toolmanmike

      toolmanmike Moderator Staff Member FABO Gold Member

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      A couple guys on here were working on the grind. No one has replicated the 340-4 speed cam.
       
    • rumblefish360

      rumblefish360 I have escaped the evil Empire State! FABO Gold Member

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      Between the 2 choices, the Comp cam.
      IMO, your not going to see a lot with a custom ground cam for the diameter of the larger tappet. It will be there and measurable on the dyno, but not with the butt dyno.

      Your call.
       
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      • dogbreath

        dogbreath Well-Known Member

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        The 262 is to small , step up to the 268 you will be happy.
         
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        • toolmanmike

          toolmanmike Moderator Staff Member FABO Gold Member

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          That's not one of the choices though. (although a better choice for a 360) :poke::poke:
           
        • thedartsport

          thedartsport Well-Known Member

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          I've just read of people on here having trouble bogging off the line with the 268 and a stock stall. That's why I chose the 262.
           
        • Lelo Dart

          Lelo Dart * FABO Gold Member

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          I vote comp 262. I don't know about bogging with the XE268, sounds like a tuning problem.
           
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          • RustyRatRod

            RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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            Either is fine for what you plan to do. Flip a coin.
             
          • aaronk785

            aaronk785 Well-Known Member

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            If its a stock 360 compression is about 8 to 1. I would guess the 262 would be better for that compression.
             
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            • 273

              273 Well-Known Member

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              I'd go 262 cause thr factory heads need a little help on the exhaust.
               
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              • AJ/FormS

                AJ/FormS 68 B'cuda fb, Form S clone ... 367/A833/3.55s

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                The Summit will steal your low-rpm torque, and throw it right out the tailpipes.
                With a low-compression engine, you can't afford those Summit ramps.

                Here's your Summit,272/110,216@.050
                Static compression ratio of 8:1.
                ICA of 62*
                Effective stroke is 2.84 inches.
                Your dynamic compression ratio is 6.55:1 .
                Your dynamic cranking pressure is 122.91 PSI.
                V/P (Volume to Pressure Index) is 105..........................................................105

                Heres the Comp,262/270/110,218/224@.050
                Static compression ratio of 8.0:1.
                ICA of 57*
                Effective stroke is 2.95 inches.
                Your dynamic compression ratio is 6.77:1 .
                Your dynamic cranking pressure is 128.43 PSI.
                V/P (Volume to Pressure Index) is 114.........................................................114

                The comp is 114/105=8.6% stronger from idle to somewhere around 3500. That's a lot! The com is also more flexible in the installed centerline, and to top it off it has more .050 duration and a tad more lift, which on the exhaust side will help those stock iron heads breath. With a2000 TC and 3.23s, only the Comp stands a chance of spinning both tires. 114VP is the same as a stock 318LA. A VP of 105 is pretty sucked out, that's about where a stock slanty is at
                For comparison, here's the factory stock 360, with the 252/112 cam
                Static compression ratio of 8.0:1.
                ICA of 54*
                Effective stroke is 3.02 inches.
                Your dynamic compression ratio is 6.91:1 .
                Your dynamic cranking pressure is 131.95 PSI.
                V/P (Volume to Pressure Index) is 120........................................................120

                Read about VP here;
                V/P Index Calculation

                The .050 numbers give you a pretty good idea of how to compare cams hence it was said "flip a coin".
                The advertised numbers give an idea of what the idle will sound like,lol, and maybe how hard the cam might be on the valve-train, as was also mentioned.
                The difference between the two gives a idea of how much compression will be lost in the initial take up of the acceleration ramps.And that's the point I'm trying to make.
                To bring the Summit cam up to speed, you would have to raise the compression to
                Static compression ratio of 8.5:1.
                ICA of 62*
                Effective stroke is 2.84 inches.
                Your dynamic compression ratio is 6.95:1 .
                Your dynamic cranking pressure is 132.97 PSI.
                V/P (Volume to Pressure Index) is 114........................................................114
                Now you can enjoy the same114VP, with a tad less duration at .050 and a tad less lift, but with a bit of a lope in the idle, that the Comp won't have.
                 
                Last edited: Nov 2, 2017
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