I know ! Another cam selection post

Discussion in 'Small Block Mopar Engine' started by dropshot1, Nov 14, 2017.

  1. dropshot1

    dropshot1 Well-Known Member

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    Im looking for help choosing a cam, my goal "high 12s", what i have, 70 dart ,391gears,14"wheels,245 bf goodrich,4spd,340 30over,performer rpm intake,electronic ignition conversion kit, 650 edelbrock carb,internals and heads stock, plan on headers and some port and polishing, i have 10.5 to 1 pistons and j heads, i appreciate any suggestions
     
  2. 1966DDart

    1966DDart Well-Known Member

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    Depends on a few other things too. How lopey or smooth do you want the idle? What are you wanting as far as the type of cam...a solid, hydraulic, or roller (hydraulic or solid)? Also, do you have power brakes?
     
  3. MOPAROFFICIAL

    MOPAROFFICIAL Well-Known Member

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    Last edited: Nov 14, 2017
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    • dropshot1

      dropshot1 Well-Known Member

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      Would like something lopey, no power brakes, as far as hydraulic or roller, i have no idea?
       
    • toolmanmike

      toolmanmike FABO Staff Staff Member FABO Gold Member

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      You have a pretty decent gear so a good cam and converter. These cam threads are always interesting. Have a seat and buckle in.
       
    • roccodart440

      roccodart440 Well-Known Member

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      Comp 20-629-5

      Lunati 30200912

      Rough idle and should put you in the 12's.
       
    • yellow rose

      yellow rose Doctor of Thinkology.

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      Call someone not named comp or lunati and let them pick it.

      Racer Brown
      Cam Motion
      Mike Jones
      Bullet

      That's just a few of the cam grinders who will grind a cam for you. I just can't grasp why guys spend all the money to build an engine and then use an off the shelf cam.
       
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      • roccodart440

        roccodart440 Well-Known Member

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        I'd mostly agree with you. If you're spending the money and looking for a specific engine performance or max performance, more than likely the answer is a custom grind. For mild builds or on occasion when an off the shelf cam will meet your specific needs they are ok.

        I'm not sure why you dislike comp cams. My new engine has a custom comp cam. Nothing wrong with it and if IQ trusts them, so do I. If you've had bad experiences I understand. I stay clear of Crane stuff now after having major issues with their gold race rockers on an engine.
         
        Last edited: Nov 14, 2017
      • yellow rose

        yellow rose Doctor of Thinkology.

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        I don't care for Comp mostly because of the hit or miss tech you get when you call them. I can call on the exact same combo on two different days and get two totally different grinds. The other thing is for me, it's hard to not have them pull a grind off the shelf.
         
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        • rumblefish360

          rumblefish360 so close yet so far away

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          A Hyd. Cam is the most inexpensive.
          A Mech. Cam is a little more costly, minor maintenance
          A roller is most expensive. Only consider a Hyd. roller if you already have a Hyd. roller set up like a. Agnum engine and will only use the engine in modest venues. Otherwise, the expense isn’t worth it. Use the mech. roller for serious drag racing.

          IMO, use a cam in the 236-240 intake duration area (max) with as much lift as you can get.
          Your BR Goodrich tires will hurt any performance increase chances. They are a OK street tire. That’s it. Use a stickier tire.
          Check your finish line rpm and adjust the new tire size accordingly. If your not sure, a 26 inch is a good diameter to start with. Drag racing with a 4spd can be a little difficult so practice up and get the car consistent before reselecting a tire. Finish line rpm (and speed) should be what your looking at to adjust the tire size for more or less rpm at the stripe.

          Good luck and have fun!

          Sounds about right for every place I have ever called due to;

          1: A different tech each time for a recommendation
          2: Perameters not fully / properly explained or understood

          3: Comp on line sales men/tech folk are suggested that sell what they have on the shelf first rather than create something new because of “Its on the shelf already, stock sitting doesn’t make money but takes up room preventing money to be made. Also, most people calling have less than a honest 15% understanding of what there doing with a cam on a custom order even though they think they have a 90% understanding.

          Then they get a fucked up cam for there combo and blame Comp Cams as a chit grinder.

          Smaller cam grinder houses are more than happy to custom grind you a cam because there. Not a big house with product by the thousands on the shelf ready the move.
           
          Last edited: Nov 14, 2017
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          • dropshot1

            dropshot1 Well-Known Member

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            Thanks to everyone for the input, roccodart would any of those cams you mentioned require any machinework?
             
          • dropshot1

            dropshot1 Well-Known Member

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            Would they be okay with stock bottom end and heads
             
          • yellow rose

            yellow rose Doctor of Thinkology.

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            The Lunati is a much faster ramp than the comp and has a tighter LSA.

            The Lunati grind is pretty damn close to what I run. You'll need the springs they want, you have to machine the spring pockets and trim the guides down.

            For either of those cams you will need an actual, measured 10.5:1 which means the piston should be out of the hole .040 or a bit more. You can't have a zero deck and get the compression where you need it.

            A minimum of 1.75 headers. The 650 is a bit small, especially on a dual plane intake. A 4K converter will be your best friend.

            If you get it right, you'll have a hard time making it slower than low 12's if you get it to hook.
             
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            • roccodart440

              roccodart440 Well-Known Member

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              Makes total sense. Now I'm not sure and I'd bet if I had called Vs. Jim calling the cam may very well have looked different.

              He gave me my choice between 2 very similar cams, one from comp and one from another grinder who is escaping my mind right now. The final decision was based on the duration at .020, which differed between cam grinders. We both agreed the comp grind was preferable for my combo.
               
            • crackedback

              crackedback FABO Gold Member FABO Gold Member

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              12's is going to be all about the HOOK! 4 spd and BFG's aren't going to play well. If tuned well, It will make enough power with a comp XE268H camshaft or similar grind. Headers are a plus... everything else sans tires/suspension is OK.

              It would take about 320ish hp to run 12's in a good hooking car. I know my dart with a 215/224 hyd cam ran 13.30 at 103 mph. 60's were a bit soft...
               
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              • ir3333

                ir3333 Well-Known Member

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                i'm not a racer so can't point you to a hi 12 second combo but stock heads will limit your lift to about .480. As suggested spend an extra $100 for a custom ground cam for your combination.
                 
              • RustyRatRod

                RustyRatRod Just another dumbass. FABO Gold Member Technical Editor

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                When I read stuff like "10.5:1 pistons", I see inexperience. No offense meant, this post is meant to help you. You want a measured compression ratio. Just because you have pistons someone said, or you read were 10.5:1, that means absolutely nothing, zero, zilch. All that means is those pistons can acheive 10.5:1 if everything else "measures up". So, you "could have" 8.5:1 if things do not match up with where everything needs to be. Chamber volume, deck height, etc.
                 
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                • yellow rose

                  yellow rose Doctor of Thinkology.

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                  I've been 12.4X's on an MP .480 lift cam, so it's doable.
                   
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                  • mopar74

                    mopar74 Well-Known Member

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                    The below combo is close to what you are wanting and it ran in the high 12's with the MPH of a mid 12 car


                    Here's what I had in the early 90's. Won many a street race with this combo in Escondido Ca. back in the day.
                    1972 340 Duster 3 speed manual brakes, manual steering car. pulled tired 340 out and sold it for $500 dollars which is what I paid for the car. Built the following engine for it:
                    74 360 .030 over
                    Badger 9 to 1 pistons
                    stock 360 crank .010 mains and .010 rods
                    MP 274-474 lift cam
                    home ported J heads with 2.02 and 1.60 valves
                    MP dual plane intake and Holley 3310-1 780 vacuum secondary carb.
                    hooker 1 3/4 super comp headers and 2 1/2 dual exhaust to 40 series mufflers turned down before the axle
                    833 4 speed, Hayes center force clutch and pressure plate.
                    original 340 flywheel drilled for balance as per the MP bible performance book
                    8 3/4 with 3.91 gears and sure grip.
                    26 x 10 slicks
                    This combo was good for 12.80's at 107-108 mph spinning the slicks at the world famous Carlsbad drag strip back in the early 90's. They did not have 60 foot timing lights back in the day and you were lucky to get reaction time on your time slip. Sadly this drag strip closed in the late 90's or early 2000's to make room for a business park. Those were the days had a lot of fun with that car. It was known in Escondido as Al Bundy's car from "Married with Children" As a side note the short block is still together and in my 74 Challenger slightly detuned, but it is very tired and will be coming out when I get the car back from paint and body hopefully the first part of the new year.

                    Kevin
                     
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                    • Krooser

                      Krooser Reform School Graduate

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                    • MOPAROFFICIAL

                      MOPAROFFICIAL Well-Known Member

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                      I think he is fine with 1 5/8 headers and 2 1/2" to 3"pipes.
                      Hooking is the trick, as already said.

                      If it pumps 155 ish with those "10.5" pistons, it's more like 9.5
                       
                    • dropshot1

                      dropshot1 Well-Known Member

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                      Thanks to everybody! Im learning slowly, put the motor together myself about 20years ago following a book called " how to rebuild your smallblock chrysler" its still running well, just want more. I had the machine work done, crank polished and heads put together, bought the oversize bearings and followed the tourque specs for everything.i just never learned the finer things like proper tuning and stuff!thats why i love this site!
                       
                    • IQ52

                      IQ52 Well-Known Member

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                      I don't by shelf cams anymore, I design my own. I worked with a tech at Comp Cams before he went to another cam company. It had taken him a while to get me to use Comp Cams as I was with another competitor. At a Contest at Comp Cams, when we had beaten everybody our engine size by 135 HP (using a cam I designed), he had asked me which cam I was using, and I had to tell him "brand XXX". He called a NHRA Stock Eliminator we both know and ask him what he had to do to get me to use Comp Cams.

                      His replacement at Comp took a little convincing that I didn't want him to suggest a grind, I wanted him to grind what I asked for. I said, "I don't want your shelf grind. I want you to grind me a cam like this! Will you do it?" "Yes", was the answer and we have gotten along well.

                      I just really enjoy designing my own cams and they seem to work reasonably well.
                       
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                      • nm9stheham

                        nm9stheham Well-Known Member

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                        If the pistons are truly 10.5:1 types, then the engine is likely in the low to mid 9's for real static CR. Not too bad if the main goal is just drag racing. Put in a cam in the 284 duration range with as much lift as the heads will take, and go to town. Learn to rev it a but and feed out the clutch right; I would not be surprised if the clutch needs an upgrade with some regular track use.

                        BTW, the Lunati cam that Roccodart listed looks like .570 valve lift... no way it will go into a stock head's valvetrain .

                        OP, are you in Stoney Creek TN by any chance?