CnC Porting

Discussion in 'Race 400/430/455' started by Briz, Sep 4, 2019.

  1. slimfromnz

    slimfromnz Kiwi Abroad

    They are my stg2TEs CNC port job by TA flowing 387cfm @ 650
    Julian likes this.
  2. Bens99gtp

    Bens99gtp Well-Known Member

    Great numbers, can you share the rest of the flow sheet. Curious on how mine cnc ones stack up. Youra are about 12 cm more than my are.

    What does TA get for that level of port work.

    I know finishline can get over 400, but they get pricey
    Last edited: Sep 9, 2019
  3. Briz

    Briz Platinum Level Contributor

    He had done that and there was no leaks but is going to redo the test

    Finish line is who did these heads. Like said above due to saftey reasons they backed off the port by 10%
    Old numbers
    Int 100. 71.o 200. 134 300. 196 400. 238 500. 286 600. 318 700. 320
    Ex. 100. 62 200. 111 300. 145 400. 185 500. 220 600. 243 700. 255

    New numbers
    Int. 100. 74 200. 143 300. 208 400 261 500. 310 600. 348 700. 366 800. 360
    Ex. 100. 61 200. 111 300. 152 400. 197 500. 231 600. 256 700. 274 800. 283

  4. hugger

    hugger Well-Known Member

    I think water is back there I'm not positive but I'd be leary of it even if it passed psi test cold I'd be worried what will it will do at operating temp. Would hate to hydra lock it or something,..don't trust anyone when it comes to this stuff. It may not be deep and just cosmetic but,...
    65Larkin and TORQUED455 like this.
  5. TORQUED455

    TORQUED455 Well-Known Member

    Briz, were those untouched castings before the port work?

    JESUPERCAT No Slow Boat

    Spray a light solvent like brake cleaner on the back side of the crack like area. It will wick through if there is an issue generally.
    Here is my new intake valve after the CNC. 20181027_153356.jpg
    See you soon Briz
  7. Bens99gtp

    Bens99gtp Well-Known Member

    Pretty pretty.

    Mine had that same stepped cut look and thought it would had been smoother, but seems to flow ok
  8. Bens99gtp

    Bens99gtp Well-Known Member

    Thought I had more pics of port work but can only find this 1

    Attached Files:

  9. Briz

    Briz Platinum Level Contributor

    Bob sealed the water ports inside the heads under pressure. He's 100% sure there is no crack its only a flaw in the casting that had some carbon in it. Just to be sure he has cut open the boxes, disassembled the heads again and will have them retested.
    The heads had a light clean up prior to running them for the last 18 months. I know there was power left on the table. The CNC was the best way to get out all there was to be had.

    Bob had mentioned the same thing. I'd asked him for his input here but says he is not / will not be a part of this page.
  10. Bens99gtp

    Bens99gtp Well-Known Member

    If BM says they pressure tested them and they dont leak, then I would fully believe they are good to go. My experience with Finishline has far beyond exceed anything I could had dreamed of. They are the best ppl. Beyond willing to help. They will have my business for many years to come.

    My heads had some casting irregularities, several ports you could see bare castings right in the middle of the cnc cut.........just a lower spot in the casting that was so low the program couldn't touch it.

    As nice as the TA heads are they seem the have a little profile discrepancy in the runners when cast. These come to light when the original casting gets changed when porting.

    I can't imagine these heads would not have been check both b4 and after cnc work, for issues
    Briz likes this.
  11. Todd69GS

    Todd69GS Silver Level contributor

    Bobb will stand behind his work. If there is an issue he will go above and beyond. Been a customer of his for many years.
    GraySky likes this.
  12. TORQUED455

    TORQUED455 Well-Known Member

    IIRC, the old castings flowed 290-300 out of the box. So if a 42 cfm gain got you to 366, then they started at 324. Takes a fair effort (bowl-job+) to get from 290-300 to 324, much more than a clean-up. Something doesn’t seem right? If it was me, I would want to make sure about that suspicious looking crack/casting flaw. Much easier now to deal with than later picking up the pieces. If you are happy with everything, bolt them on!
  13. Briz

    Briz Platinum Level Contributor

    I say light clean up cause I really dont know how much was removed. They were not flowed before or after. I didnt do the work. My local race car shop did the port work and assembly in trade for a 21" center con fishing boat I was no longer using. Remember Kenny saying he wasnt sure on how much meat was in there so he didnt want go to deep and strike water. I know Bob wont ship those heads back until everything is right. Not worried.
  14. Julian

    Julian Well-Known Member

    What size bore? 4.5?

Share This Page