Old Race 340 Teardown

Small Block Mopar Engine

  1. justinp61

    justinp61 Well-Known Member

    Messages:
    2,207
    Likes Received:
    1793
    Joined:
    May 15, 2009
    Local Time:
    8:03 AM
    That was a dandy build, it would fun to hear it sing with a four speed and a set of 5.13's.
     
    • Agree Agree x 3
    • qkcuda

      qkcuda Well-Known Member

      Messages:
      1,552
      Likes Received:
      1664
      Joined:
      Mar 6, 2013
      Location:
      Jarvis, Ontario
      Local Time:
      9:03 AM
      I looked up some info on X blocks and some of them were severely decked. That would explain the thin manifold flanges.
       
      • Like Like x 1
      • Thanks! Thanks! x 1
      • 70aarcuda

        70aarcuda Master Hoader of SBM FABO Gold Member

        Messages:
        16,559
        Likes Received:
        5357
        Joined:
        Jan 16, 2005
        Location:
        las vegas
        Local Time:
        6:03 AM
        I have a picture of it went it ran Pro Stock with Jim Meyer from the world finals at Ontario Motor speed way. Bob Harris was driving at the Super Gas
         
        • Thanks! Thanks! x 1
        • pishta

          pishta I know I'm right....

          Messages:
          21,388
          Likes Received:
          10777
          Joined:
          Oct 13, 2004
          Location:
          Tustin, CA
          Local Time:
          6:03 AM
        • pishta

          pishta I know I'm right....

          Messages:
          21,388
          Likes Received:
          10777
          Joined:
          Oct 13, 2004
          Location:
          Tustin, CA
          Local Time:
          6:03 AM
          Those BME rods can be run on the street just fine. I had a set from a 426 and read up on them. That W2 SD intake looks different from the one I had. My top was square, not clover shaped and the IIRC the bolt holes were double drilled on my example, just about 1/8 difference so they looked like 8's. Come to think of it, It must have been adapted to the LA when I got it as it bolted right up to my X heads with its port mismatch and all. Ran great! Traded it straight across for the proper LA SD intake at the Long Beach swap meet. That guy was selling a set of W2 heads for $300! That long ago.....
           
          • Like Like x 1
          • Thanks! Thanks! x 1
          • mbaird

            mbaird mbaird

            Messages:
            7,792
            Likes Received:
            4625
            Joined:
            Dec 10, 2005
            Location:
            boise, Id
            Local Time:
            7:03 AM
            image.jpg image.jpg image.jpg image.jpg
             
            • Like Like x 2
            • Thanks! Thanks! x 1
            • pishta

              pishta I know I'm right....

              Messages:
              21,388
              Likes Received:
              10777
              Joined:
              Oct 13, 2004
              Location:
              Tustin, CA
              Local Time:
              6:03 AM
              cool, I got to fashion one on my sheet metal intake. Thought about just running 2 Russel 45's out the flange, hosed to a remote stat housing.
               
              • Like Like x 1
              • Super Sleeper

                Super Sleeper Well-Known Member

                Messages:
                125
                Likes Received:
                223
                Joined:
                Aug 29, 2019
                Location:
                Sequim, WA
                Local Time:
                6:03 AM
                Cool, I'd love to see that picture if you care to post it. Here's one of the team. That's Bob, third from the left. I wish I knew more details.
                51565017758_eea4235489_z.jpg
                 
                Last edited: Oct 8, 2021
                • Like Like x 5
                • Thanks! Thanks! x 1
                • Super Sleeper

                  Super Sleeper Well-Known Member

                  Messages:
                  125
                  Likes Received:
                  223
                  Joined:
                  Aug 29, 2019
                  Location:
                  Sequim, WA
                  Local Time:
                  6:03 AM
                  Good to know, thanks. My knowledge of aluminum rods is very primitive. I assume they have a pretty limited life. If I decide to go with any replacement parts then these might be worth selling?

                  I really appreciate all of the help I'm getting on this thread. It will be another week before my friend can bring up his deck height micrometer. I'll have to try to cc a chamber also. All suggestions on how to assess this engine are certainly welcome.
                   
                  • Like Like x 3
                  • rumblefish360

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

                    Messages:
                    41,707
                    Likes Received:
                    13954
                    Joined:
                    Jun 21, 2005
                    Location:
                    Florida
                    Local Time:
                    9:03 AM
                    As far as a “How to” refine it for the street, I would just simple order a set of custom thickness (& diameter) head gaskets from Cometic. Swap the cam to meet the need and run everything else it came with.
                     
                    Last edited: Oct 9, 2021
                    • Agree Agree x 3
                    • Like Like x 1
                    • Thanks! Thanks! x 1
                    • TT5.9mag

                      TT5.9mag Two atmospheres are better than one

                      Messages:
                      1,916
                      Likes Received:
                      1880
                      Joined:
                      May 5, 2016
                      Location:
                      So cal
                      Local Time:
                      6:03 AM
                      The rods are eye candy for sure. If you can meet your compression requirements with that piston I’d not hesitate to use it. As well as the rods. The rods do have a life cycle in a drag race environment but in a de tuned street engine they’ll last a good long while. If you are going to road race it you should consider moving to a forged steel rod for constant high rpm durability.
                       
                      • Like Like x 2
                      • Thanks! Thanks! x 1
                      • Agree Agree x 1
                      • dustertogo

                        dustertogo Well-Known Member

                        Messages:
                        773
                        Likes Received:
                        86
                        Joined:
                        Mar 7, 2006
                        Location:
                        Brandon, MS
                        Local Time:
                        8:03 AM
                        I knew the class wasn't right. Way too many pieces on that motor that are/were not Super Stock legal.
                         
                      • Mean416

                        Mean416 Well-Known Member

                        Messages:
                        208
                        Likes Received:
                        137
                        Joined:
                        May 10, 2021
                        Location:
                        Georgia
                        Local Time:
                        9:03 AM
                        I would think this engine would be pretty valuable to the right person. You could sell this for quite a chunk and us the proceeds to build a proper street ripper. Replicating an engine like you have would be super expensive. Not to mention the development and tuning that would have gone into it. It's probably nicely sorted out as a race engine. You may find out the expensive way why that intake is so cut up. I bet you spend way more making that a street engine than you imagine.
                         
                        • Agree Agree x 1
                        • 70aarcuda

                          70aarcuda Master Hoader of SBM FABO Gold Member

                          Messages:
                          16,559
                          Likes Received:
                          5357
                          Joined:
                          Jan 16, 2005
                          Location:
                          las vegas
                          Local Time:
                          6:03 AM
                          It is on another computer that has not run in a couple of years......give me a couple days to fire it back up.....
                           
                          • Like Like x 1
                          • Thanks! Thanks! x 1
                          • Super Sleeper

                            Super Sleeper Well-Known Member

                            Messages:
                            125
                            Likes Received:
                            223
                            Joined:
                            Aug 29, 2019
                            Location:
                            Sequim, WA
                            Local Time:
                            6:03 AM
                            I know the feeling with old PCs! I have several old hard drives spinning in newer PCs just to stay connected with older stuff. Thanks for taking the time!
                             
                          • Super Sleeper

                            Super Sleeper Well-Known Member

                            Messages:
                            125
                            Likes Received:
                            223
                            Joined:
                            Aug 29, 2019
                            Location:
                            Sequim, WA
                            Local Time:
                            6:03 AM
                            Thanks! Certainly I understand that this purpose-built combo is worth keeping together. At this point I just wanted to assess its internal condition. Never really considered making it a street engine, just "de-tuned" as a possible road race engine. All the input I have got in this thread, including yours, goes a long way towards helping me understand what I have here.
                             
                            • Like Like x 2
                            • A56

                              A56 MoPar Affliction

                              Messages:
                              5,373
                              Likes Received:
                              14165
                              Joined:
                              Jun 24, 2014
                              Location:
                              South of the Mason-Dixon Line
                              Local Time:
                              8:03 AM
                              Not to mention the extreme sentimental value
                               
                              • Agree Agree x 2
                              • SSG_Karg

                                SSG_Karg Heeeeeres Johnny!

                                Messages:
                                1,510
                                Likes Received:
                                1489
                                Joined:
                                Feb 24, 2010
                                Location:
                                In the pits
                                Local Time:
                                9:03 AM
                                Yellowrose would be creaming his pants over this thread…..
                                 
                                • Agree Agree x 5
                                • Super Sleeper

                                  Super Sleeper Well-Known Member

                                  Messages:
                                  125
                                  Likes Received:
                                  223
                                  Joined:
                                  Aug 29, 2019
                                  Location:
                                  Sequim, WA
                                  Local Time:
                                  6:03 AM
                                  Yes
                                   
                                • Super Sleeper

                                  Super Sleeper Well-Known Member

                                  Messages:
                                  125
                                  Likes Received:
                                  223
                                  Joined:
                                  Aug 29, 2019
                                  Location:
                                  Sequim, WA
                                  Local Time:
                                  6:03 AM
                                  Just a little update. I had a good look around the crankshaft, looks like a 2532457 forging with an 8-bolt flange. The piston travel I measured with my caliper was 3.454. So it's a stroker? The rod journal measured 2.1245, with a Clevite 0.001 undersize shell (in very good shape). So does that mean this crank was welded to build up the journal size? Or were there 2532457 forgings in 3.454 stroke?
                                  51557837208_1f3bea5451.jpg
                                  51574996170_0b369ab7e6.jpg
                                  51573263827_ec5b8e86cd.jpg

                                  BTW, one bolt head broke off when I removed the flex plate. All 8 holes are threaded. - Jim
                                   
                                  Last edited: Oct 11, 2021
                                  • Thanks! Thanks! x 2
                                  • 79410aspenrt

                                    79410aspenrt Well-Known Member

                                    Messages:
                                    300
                                    Likes Received:
                                    270
                                    Joined:
                                    Nov 23, 2010
                                    Location:
                                    Saskatchewan
                                    Local Time:
                                    8:03 AM
                                    I have the same crank, it’s 3.46 stroke. not welded up, the crank is a forged piece. I also have BME aluminum rods.
                                    cubic inch is 362

                                    C818F20C-9F6A-4B87-B322-9B8B6D05B4E5.png
                                     
                                    • Like Like x 3
                                    • Thanks! Thanks! x 1
                                    • rumblefish360

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

                                      Messages:
                                      41,707
                                      Likes Received:
                                      13954
                                      Joined:
                                      Jun 21, 2005
                                      Location:
                                      Florida
                                      Local Time:
                                      9:03 AM
                                      MoPar had a few (*3 I think*) small journal forged cranks in that stroke range to compete in the 355 cid rule. I also have one that makes 352 cubes with a 4.03 bore.
                                       
                                    • Super Sleeper

                                      Super Sleeper Well-Known Member

                                      Messages:
                                      125
                                      Likes Received:
                                      223
                                      Joined:
                                      Aug 29, 2019
                                      Location:
                                      Sequim, WA
                                      Local Time:
                                      6:03 AM
                                      Great, thanks for the info.
                                       
                                    • Rocket

                                      Rocket FABO Gold Member FABO Gold Member

                                      Messages:
                                      2,288
                                      Likes Received:
                                      381
                                      Joined:
                                      Apr 22, 2005
                                      Location:
                                      U.S.A.
                                      Local Time:
                                      2:03 PM
                                      Here is a shot of a 1993 Mopar Performance catalogue showing the forged crankshafts available at the time. Yours should be the P4120312 or equivalent. The last 3 digits were often punched into the front counterweight face.

                                      911B5211-B868-4DE6-B6D2-22C525082BC5.jpeg
                                       
                                      • Like Like x 2
                                      • Thanks! Thanks! x 1
                                      • Ironracer

                                        Ironracer Gearhead

                                        Messages:
                                        2,561
                                        Likes Received:
                                        1782
                                        Joined:
                                        May 8, 2020
                                        Location:
                                        Tampa Bay Florida
                                        Local Time:
                                        9:03 AM
                                        Not sure, but food for thought. I have an old strip Dom on my 340. I friend of my ( ol.school Mopar drag racer) stopped by when I was buttoning up the top end. He said " lemme see that, before you put that on there" I handed it over, he flipped it over and closely inspected it. Said the areas around the bolt.holes were prone to hairline cracking on that intake, causing hard to find vacuum leaks....maybe they were preventive in your case?
                                         
                                        • Thanks! Thanks! x 1
                                        1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
                                          By continuing to use this site, you are consenting to our use of cookies.