Speedmaster Small block porting tips and results

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  1. 318willrun

    318willrun Roadkill '80 D150

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    not on the one I put together, but I didn't touch the seats and I put the valves back in the same ports. This morning I'm going to assemble the 2nd head, and I'm going to lap a couple of valves just to mark how much contact surface and if the ring is the same width all the way around. That will be the REAL story on this.
     
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    • j par

      j par Well-hung Member

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      That's why I was asking because of toolmanmike's paranoia video :)poke:) on post 495..
       
    • 318willrun

      318willrun Roadkill '80 D150

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      I can tell you this, the famed 340's with X heads didn't come from the factory with 5 angle valve jobs.
       
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      • j par

        j par Well-hung Member

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        that was weird I put the little poke in the eye guy's in between parentheses and that's how it came out...
         
      • j par

        j par Well-hung Member

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        We better take this conversation over to your thread about home inspection..
        This is pretty much a gurus only thread and anything or I should say anybody else their comments will be erased... Ask me how I know...
         
      • 318willrun

        318willrun Roadkill '80 D150

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        I will post pictures of the lapping ring on my home inspection thread when I get enough of the sleepies out of my eyes. I am slow in the morning waking up....
         
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        • j par

          j par Well-hung Member

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          What the heck! It must be noon there by now... what are you running banker's hours?!.. 6: 30 in the morning and I'm on my second cup of coffee... Just joking I got to go get some coffee...
           
        • 318willrun

          318willrun Roadkill '80 D150

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          when you sign off for bed, I'm still up hold'n the fort down.
           
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          • yellow rose

            yellow rose Doctor of Thinkology.

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            That would be near impossible to happen and even have the valve seal at all.

            They are just slamming a quickie valve job on there and sending them out the door.

            I'd rather they not even do a valve job at all. It should reduce the cost of the head some, and I can count on one hand the number of times I've used an out of the box valve job on anything.

            If my name is on the work, it has to be all my work. It just isn't worth the hassles if there is an issue later on. And for the most part, I'm not big on a 3 angle valve job.

            Most ports need at least 4 if you can fit the angles in there and the exhaust should always be a radius.
             
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            • pittsburghracer

              pittsburghracer Well-Known Member

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              Well I’ll say one thing, this head just isn’t responding like it should and I’m to the point last night where I started rounding up my old stone grinding equipment. My stone dresser is in need of some pieces so I guess I will be placing an order today or tomorrow. I’m thinking about trying a 75 degree bottom cut. I know a 2.05 or 2.08 valve would help this seat issue but I’m not ready to give up on the 2.02 valve yet.
               
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              • MOPAROFFICIAL

                MOPAROFFICIAL Well-Known Member

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                Yep, the most I do is add some hyper cool green crap in a bottle.
                 
              • yellow rose

                yellow rose Doctor of Thinkology.

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                I agree that a 75 might help. From the pictures the bowl looks like it can take that steep of a bottom cut.
                 
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                • pittsburghracer

                  pittsburghracer Well-Known Member

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                  That seat wall just looks to long (to straight) to me. Mid lift numbers aren’t responding right in my eyes
                   
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                  • Cudafever

                    Cudafever Well-Known Member

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                    I don’t know about other. But I’m excited to here about the latest investigation...........
                     
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                    • j par

                      j par Well-hung Member

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                      Well I hit the agree button but I'm more interested than excited LOL..
                       
                    • MOPAROFFICIAL

                      MOPAROFFICIAL Well-Known Member

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                      No way. Nothing keeps its shape when interference fit, if it did...I still say nope.
                       
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                      • yellow rose

                        yellow rose Doctor of Thinkology.

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                        I'd have to make a phone call but IIRC I had a 45 degree seat that had an 82 degree bottom cut for bowls like that. I know I had one with a 75 but that bowl may want even more than a 75.
                         
                      • MOPAROFFICIAL

                        MOPAROFFICIAL Well-Known Member

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                        I'm all about the 75 bottom/lower cut, do it.
                        What port volume is this one at to this point?
                        That's how you get a x,j,Etc to flow

                        Go right off the hard seat under the valve job.
                        Deeper the bowl helps if the rest complements such too. If only words could paint a clear picture. You know what you're doing,... we're all just excited is all. Lol
                         
                        Last edited: Jan 9, 2020
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                        • pittsburghracer

                          pittsburghracer Well-Known Member

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                          Again going back to the class I went to we were told to never exceed 15 degrees between our seat angles as air has a hard time navigating it. A bigger valve would lower that straight area but for right now I’m trying to help guys out with 2.02 valve info as that’s what 90% of them will be running. If I wanted to hit the easy button I could drop them off at the machine shop, hand over 64.00, and grab a different set of valves off the shelf. If it hits the 282-285 cfm I’m at now and I’m satisfied with the mid lift numbers it’s a win win.
                           
                          Last edited: Jan 9, 2020
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                          • toolmanmike

                            toolmanmike FABO Staff Staff Member FABO Gold Member

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                            Just asking questions guys. I was thinking something like in this photo. After watching the video I posted above and there's .010 seat runout it makes you wonder if they ground the seats and used the guide as a pilot like they should have.


                            valve_seat__43980.1456448358.500.290.png
                             
                            Last edited: Jan 9, 2020
                          • j par

                            j par Well-hung Member

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                            Thanks for looking out for us tightwads! Next year a valve job maybe in order and knowing the best route would be nice...
                             
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                            • pittsburghracer

                              pittsburghracer Well-Known Member

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                              I rarely even bother checking that but I know I’m under the 191 cc runner on my best set of heads.
                               
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                              • j par

                                j par Well-hung Member

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                                It would have been nice to see what your best valve job would have done with a unported head as I would say 90% of us aren't going to do more than smoothing off the rough spots and a little Port match...
                                 
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                                • toolmanmike

                                  toolmanmike FABO Staff Staff Member FABO Gold Member

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                                  Doing a little back reading. No convincing here. I'll take mine to Radar and have him correct the seats which will include machining them. If they seal they will work but I don't like the transition into the bowl. What ever it costs I know they will be done right and it's something I can't do at home.
                                   
                                  Last edited: Jan 9, 2020
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                                  • pittsburghracer

                                    pittsburghracer Well-Known Member

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                                    I can probably do that but remember the airspeed was a lot slower on a stock port. But I can check it out.
                                     
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