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  • Big valve head install questions...

    So I've got this big valve ported head sitting in my garage and a race car that could use some more ponies. Never having done something like this before, am I better off taking it to someone who know what the hell they are doing or can I give it a try myself? I've changed clutches and flywheels, turbos, and manifolds...never the head.

    Thanks!
    Hoping to get on the track soon

  • #2
    Got Guinness?

    It makes a good gasket sealer for the mechanics!

    While you're at it, if you find a deal on 42 or 46# injectors, that may be the next step to swap in at the same time, depending on whether a wilder cam is in that head.

    Comment


    • #3
      pat works for beer

      Vince If you have already changed out the turbo and the manifolds you are already done the PTA. After that the head is a cake walk. plus you have pat and eyelawdoc in your back yard.
      Confucius says" a closed mouth gathers no foot"

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      • #4
        best quick directions (imo) for a head swap/head gasket replacement written up by SVO1:

        Drain the radiator ( no need to remove it), pull the fan out of the way, pull the cover and drop the timing belt.. unbolt the exhaust manifold ( leave it bolted to the turbo/downpipe and wire it up for a little support). Yank the throttle body/upper intake. Pull the Valve cover, Head bolts, Unhook the Sensors under the intake/fuel lines, and the oil feed line to turbo..
        Pop the head loose with a couple small taps from a deadblow, then being able to use the intake for a bit of leverage hoist it up & out carefully. Clean head gasket surfaces carefully. Put it back together that way you took it apart. Take care finding TDC etc, when you re-install the timing belt. You can re-use the headbolts if they are 12 point heads and in good shape.
        -James Price- '84 SVO 9W leather, SVO #124

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        • #5
          With the fan out of the way, you can actually stand in the engine compartment and do most of the unbolting and lifting of the head off the engine. Get someone to stand outside of the engine compartment to hand the head off to. :-)

          Many suggested getting replacement headbolts, which I did, but the torque-to-yield bit kind of scared me. I just reused the old bolts. 3 years later and not problems so far (finds wood, knock, knock).

          And if you have never taken the cam gear off, you need to know that you need to seal the snot out of the cam gear bolt, or you will be in for a big mess. I have read NOWHERE except here, and only after I had the big mess, that you have to seal the cam bolt to the cam. The cam is hollow, and is full of pressurized oil when the engine is running.

          Gene Beaird
          86 2R SVO, G Stock,
          Pearland, Texas
          Gene Beaird,
          86 2R SVO, G Stock,
          Pearland, Texas

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          • #6
            Cam Question

            Heres a picture of the cam that was in my car. I think it's a motorsport a237 cam. My next post will be the cam thats in the big valve head.

            Question...is the A237 cam good for road racing or more top end? Can I use the stock cam with the roller rockers (I think thats what they are called)?
            Attached Files
            Hoping to get on the track soon

            Comment


            • #7
              Cam in the big valve head

              Here is the cam in the big valve head.
              Attached Files
              Hoping to get on the track soon

              Comment


              • #8
                the 237 is a roller cam --
                I believe it may be the 234, but there is no way to tell --

                the A237 is suposed to be a good top-end cam
                Eric C
                SVOCA Webmaster

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                • #9
                  on my 237 cam the numbers are on the back of the cam.
                  HTH -RICH-
                  < - - - Brothers From Different Mothers

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                  • #10
                    M6250-A237 is the cam that is currently on the old head...I just looked at some old paperwork.

                    So the question is...is it better than a stock cam for road racing where I need a wider power band?

                    Can I use the rollers on the stock cam or do they need to work together with the cam?

                    Thank!
                    Hoping to get on the track soon

                    Comment


                    • #11
                      Originally posted by MikeFleming
                      [B
                      What RPM range do you need the power?
                      /***/ [/B]
                      Well as wide as possible

                      Depending on the track. At the big tracks like Willow where I never get into second gear, 4500 on up would be good.

                      For the more technical tracks like Laguna, Buttonwillow, LV and Cal Speedway, I'd like the power to come in around 3500.

                      With the head that's in the car now (stock), power would really come in around 4500. On those turns where third was too low and second just too high, I would keep it in third, hammer the gas, and wait for the RPM's to come up.

                      Now I dont know what a ported, polished, big valve head will do with a stock cam, but I'd rather just do this once.
                      Hoping to get on the track soon

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