400 Non Stroker Build

Big Block A body Tech

  1. Bronson77

    Bronson77 Active Member

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    Thanks for the help everyone! If I go aluminum heads I will definitely pick a cam to take advantage of them. That cam is from the build I linked so it’s not set in stone that’s what I will run.
     
  2. MOPARMAGA

    MOPARMAGA FABO Gold Member FABO Gold Member

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    There's definitely better cams. Comp23-227 is a very good choice
     
  3. Bronson77

    Bronson77 Active Member

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    Mine may goal is pump gas 93 octane is fine doesn’t have to be 87. And try to make this Cbody move a little with this 400 and be streetable. I will probably run at least 3:55 gears or lower. If I wanna go on a road trip will swap gears. I just wanna make sure the motor is not to radical where it can’t be driven etc.... So I think this will be a good build! Should have a lot more pep than the stock 383 2 barrel. Which for 71 only had 275 hp I think?
     
  4. IQ52

    IQ52 Well-Known Member

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    Nope. Not me. Never in my life have I run a Thumper cam. Not my style.
     
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    • Bronson77

      Bronson77 Active Member

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      Sorry bout that! I apologize
       
    • mygasser

      mygasser FABO Gold Member FABO Gold Member

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      big heavy car, not huge motor that looks to be leaning toward hp not torque? i'd still skip the aluminum heads for now at least along with the proposed basic rebuild and go straight to the stroker with your iron heads. way more torque for similar money and the heads can come later for even more power (with stroker torque from the get go).
      neil.
       
    • Edorion

      Edorion Active Member

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      That's the same build as the one I posted. Brian @ IMM Engines (The builder, IIRC he goes by OU812 here and on Moparts) was concerned about the stock rockers, the better heads definitely helped, if I were starting out now I'd wait for a set of the TF 240 heads and use the Mancini branded rockers. They are the best "stock" replacement heads right now, with plenty of room to grow. **Edited and updated**
       
      Last edited: May 6, 2021
    • EchoSixMike

      EchoSixMike Well-Known Member

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      I'm posting this as another option, and some data:
      I built a 400 using the stock crank, albeit forged, and had the rod journals ground to 2.200 (BBC) used 6.800 rods with the Icon IC828 piston with a compression height of 1.485. The block was decked to 9.965, so the pistons were .010 proud. With a Cometic .045 gasket, that's about as tight as you can get for piston/head clearance. 452 iron heads, with a good value job and some blending, flow as 240I/200E at .500, surfaced until they were flat, and average of 3 chambers was 89cc. Calculated compression is 9.0:1, runs fine on 91 octane, under all condition so far. Cam was an Erson hydraulic roller, 231/237 at 050, 112 LSA, used with solid roller lifters and .008 lash, per Erson. There were some issues with the hydraulic roller lifters and I needed to put it together. Made 435HP and 440ft-lbs of torque with an out of the box Holley 750 vacuum secondary card and basic Performer intake, minimal tuning. Has 20 inches of vacuum. I'm sure there's a lot left to be found, but time was short.

      Assuming the crank needs to be ground anyways, it may not be a big deal to get the rod journals to BBC dimensions instead. Something to consider. S/F...Ken M

      Addendum: If you get 6.76 rods with a .990 pin, that leaves you .030 in the bore, going to a .030 gasket, and the math says 8.6:1 compression, which will run on 87 all day long.
       
      Last edited: May 6, 2021
    • MOPARMAGA

      MOPARMAGA FABO Gold Member FABO Gold Member

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      I was going to mention that as well
       
    • fishmens67

      fishmens67 FABO Gold Member FABO Gold Member

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      A closed chamber aluminum head would be my addition to your nice short block.
      435 HP and 440ft torque is nothing to sneeze at, very nice.
       
    • Bronson77

      Bronson77 Active Member

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      I will have to see what the machine shop says etc.... about grinding and the $.

      I’m gonna have to set down and figure out how much more a stroker kit would be.
      I’m leaning toward just boring this out .030 with KB240 pistons and getting a decent cam and for heads run a set of these heads just 2.08 and 1.74 valves and hardened seats and maybe the 78cc combustion chamber to raise compression more. And running the stock valve train will get pushrods for right length. And putting 3.91 gears and a converter and letting it rip!!!!!l

      B and RB, 2.08 x 1.74 Stainless Valves (2.14x1.81 Valves Add $100.00) 86-88cc Open Chamber Design, .509” Lift Springs, 185cc Intake Port Volume ................. Same Features as Above 383-400-440 But Utilizes Select #452 or #906 Castings with a Larger Intake Port Volume, 200cc Intake Port Volume ............................... Chrysler Big Block Assembled Head-Same Features as Above 383-400-440 But Has a 78cc Combustion Chamber to Increase Compression

      May have the heads ported. As mentioned the intake is the DP4B.
       
    • 69conv

      69conv error 401 FABO Gold Member

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    • rumblefish360

      rumblefish360 Getting closer FABO Gold Member

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      • Thanks! Thanks! x 1
      • mygasser

        mygasser FABO Gold Member FABO Gold Member

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        bear in mind also when looking at stroker kits, the cast crank in the kits is almost always cast steel not cast iron so a good step up in strength/quality without the expense of going to a forged crank kit. the cast crank kits are a fair bit cheaper than the forged crank ones.
        neil.
         
      • Bronson77

        Bronson77 Active Member

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        If I run stock heads should I upgrade the valves to 2.14x1.81?
         
      • rumblefish360

        rumblefish360 Getting closer FABO Gold Member

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        It would probably be a plus but I also possibly see it as an expenditure not worth much power vs cost spent. In other words, I’d do it if it fit the build.

        Meep in mind that a valve upgrade by itself is t all the head should receive. The area right under the valve would need work to make the most of the increased valve size. Otherwise, the flow gain is small. When you port the pocket accordingly, the gains will be significantly better.
         
      • aaronk785

        aaronk785 Well-Known Member

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        Why not eddy E-streets with a 75cc chamber.
         
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        • rumblefish360

          rumblefish360 Getting closer FABO Gold Member

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          Well that’s the whole thing now and for a while. The balance of cost of working old iron vs new aluminum vs each other’s flow rates. At least to the point of the valve lift being used.
           
        • Bighead440

          Bighead440 Well-Known Member

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          I had a '70 Challenger R/T factory 383 car with a non-matching '68 383 in it with Stage 4 DC heads and TRW domed pistons. It was tired and leaking everywhere, so I yanked the motor and parted it out for other builds. I needed a big block for it, and I had a good running '77 Newport 400 that I saved from the crusher that I used for a donor. Took the 400 out and had it decked to 9.98" and ball-honed it myself. Had the crank polished and cleaned the pistons/rods myself, the motor was well maintained and mint inside really. The heads I had milled .060" on the decks and .072" on the intake face, so the intake would line back up. The machine shop did a valve job and I put a Crane retainer/spring kit in, and used .018" steel head gaskets. For a camshaft I used a 275DEH Comp Cams DUAL ENERGY cam, perfect for HP exhaust manifolds and 2.5" exhaust with H-pipe. The Chally came with a DP4B intake, so I used that with a 750 Carter Comp Series AFB (think Edelbrock). With a 2500rpm factory hi-stall converter and 3.23 gears, the thing was a BEAST, at basically all speeds, from dead starts to top end. People thought it was a 440 or 451 stroker, I mean it ran extra good. That camshaft (219/235*@.050". .462/.482" lift 110LSA) is still my go-to cam for a lopey daily driver B engine. I have a bigger go-to for 440s but I think I may try the 275DEH in a RB one day, it runs so good! You could duplicate this proven build really affordably, of you can reuse the factory pistons, but if you buy the KB's, you can do less milling and spend on the pistons themselves and the bore job. Either way, you'll have the cylinder pressure that was always the culprit with making a 400 run as well as a similar 383, when it can run as well or better with the extra bore/CID.
           
        • PRH

          PRH Well-Known Member

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          If there are budgetary concerns.......I’d probably look for one of those low buck “400 stroker kits”, complete with a block.
          Also known as a rebuildable 440.
          Reuse block, crank, rods, & there are more choices for pistons.

          Sell the 400 block to someone who wants to build a low deck 470 or 511.
           
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          • mygasser

            mygasser FABO Gold Member FABO Gold Member

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            not a bad idea :thumbsup:
             
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