Announcement

Collapse
No announcement yet.

The Pontiac OHC Six

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Re: The Pontiac OHC Six

    dang - it's getting hard to be "unique" with Megasquirt anymore.


    I remember back in the day - I did the first LS, the first Mod motor, the first DSM 4G63. Nowadays, you better be megasquirting the Space Shuttle if you expect to be the "first" at anything noteworthy. haha.
    www.realtuners.com - catch the RealTuners Radio Podcast on Youtube, Facebook, iTunes, and anywhere else podcasts are distributed!

    Comment


    • #17
      Re: The Pontiac OHC Six

      No kidding :P That cam sensor was just there for testing, eventually he moved it to the backside of the cam sprocket so he could maintain the covers over the belt.
      Escaped on a technicality.

      Comment


      • #18
        Re: The Pontiac OHC Six

        So, Randal, what are the plans? It's great to see something different ;D Too bad Detroit didn't spend more attention on the inliners.
        Tom
        Overdrive is overrated


        Comment


        • #19
          Re: The Pontiac OHC Six

          I still remember seeing this engine for the first time.......it
          was the four barrel version and was pretty damn cool.

          They also had a unique sound when cruising.

          Good pick Randal
          Thom

          "The object is to keep your balls on the table and knock everybody else's off..."

          Comment


          • #20
            Re: The Pontiac OHC Six

            Cool thread, Randall. The interesting thing to me is how similar it is to my 250s. I could be wrong but I think my manifolds would fit.

            I'll be watching this!
            Dan

            Comment


            • #21
              Re: The Pontiac OHC Six

              One noticeable difference is the lack of side access plates on the block. I'm surprised they went that far in converting this to OHC. It shows the engineers were starting from scratch at that point. I'd like to see a 250 Chevy and this engine side by side and just do some studying.

              Randal, are you interested in going up to the 215 hp cam, intake and such to start your efi turbo setup?
              BS'er formally known as Rebeldryver

              Resident Instigator

              sigpic

              Comment


              • #22
                Re: The Pontiac OHC Six







                1967 Chevelle 300 2 Door Post. No factory options. 250 ci inline six with lump-ported head, big valves, Offy intake and 500cfm Edelbrock carb.

                Comment


                • #23
                  Re: The Pontiac OHC Six

                  PS: somebody mentioned a turbo...if the manifolds in fact interchange with the Chevy 230/250/292 I know of a guy who makes a turbo manifold.
                  1967 Chevelle 300 2 Door Post. No factory options. 250 ci inline six with lump-ported head, big valves, Offy intake and 500cfm Edelbrock carb.

                  Comment


                  • #24
                    Re: The Pontiac OHC Six

                    Thanks for the pictures Pete. I had a curiousity about the motor mounts on the Chevy I6, I heard they mounted up different, and yeah they sure do.

                    Turbo exhaust manifold?
                    Escaped on a technicality.

                    Comment


                    • #25
                      Re: The Pontiac OHC Six

                      Originally posted by Rebeldryver
                      One noticeable difference is the lack of side access plates on the block. I'm surprised they went that far in converting this to OHC. It shows the engineers were starting from scratch at that point. I'd like to see a 250 Chevy and this engine side by side and just do some studying.

                      Randal, are you interested in going up to the 215 hp cam, intake and such to start your efi turbo setup?
                      They eliminated the side covers and iirc right the block has a deeper skirt around the mains than the Chevy 230/250 too.

                      I'm not sure what I'm doing for cam's just yet. I'm not sure getting the 215Hp cam is the right track yet, particularly when I'm running lower compression than the 215Hp set up. Pontiac used the same pistons in the high compression engines and the low compression engines, different heads were how compression changes were made. Another downside to this engine design, is milling the head and block results in retarding the cam timing. If available still, for ~$250 a guy makes a cam sprocket that's adjustable so you can fix the timing or even advance/retard the cam to your liking.
                      Escaped on a technicality.

                      Comment


                      • #26
                        Re: The Pontiac OHC Six

                        Awesome, I've always wanted to mess with one of these.

                        Are you doing a TBI?
                        Cheap, slow, half-assed: Pick three

                        Comment


                        • #27
                          Re: The Pontiac OHC Six

                          Goal is MPI, a Turbo and as many RPM as I can cram into it.

                          A few stock engine specs:
                          250cid or 4.1L
                          3.875" Bore
                          3.53" Stroke
                          Rods 5.7" long
                          1.92" Intake valves
                          1.60" Exhaust valves
                          ~8.5:1 Compression
                          Forged Rods (to be verified!)
                          Cast Crank
                          Escaped on a technicality.

                          Comment


                          • #28
                            Re: The Pontiac OHC Six

                            Originally posted by TheSilverBuick
                            Turbo exhaust manifold?
                            This isn't the guy I was thinking of, but here is one for sale on ebay:
                            http://cgi.ebay.com/ebaymotors/194-2...Q5fAccessories

                            I'm not sure it will work on the Pontiac. It's hard to tell from your pictures. The manifolds have a very similar shape but the exhaust port furthest aft looks different.
                            1967 Chevelle 300 2 Door Post. No factory options. 250 ci inline six with lump-ported head, big valves, Offy intake and 500cfm Edelbrock carb.

                            Comment


                            • #29
                              Re: The Pontiac OHC Six

                              Here's a video of the guy I mentioned. He is using the same type manifold as the ebay one:

                              http://www.youtube.com/watch?v=PLmUO...watch_response

                              330 Hp from a 250 on this run:
                              http://www.youtube.com/watch?v=jCT8s...eature=related
                              1967 Chevelle 300 2 Door Post. No factory options. 250 ci inline six with lump-ported head, big valves, Offy intake and 500cfm Edelbrock carb.

                              Comment


                              • #30
                                Re: The Pontiac OHC Six

                                Originally posted by TheSilverBuick
                                Goal is MPI, a Turbo and as many RPM as I can cram into it.
                                Awesome, I wonder how hard it would be to make a cap girdle.

                                What kind of intake manifold are you thinking?
                                Cheap, slow, half-assed: Pick three

                                Comment

                                Working...
                                X