CnC Porting

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

  1. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Is there a running motor with the wildcat heads yet?

    JESUPERCAT No Slow Boat

    Yes it should be at the Nationals next month
    Briz, Julian and 300sbb_overkill like this.
  3. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    So ounce you get the wild cat headed motor goin. Did you have to update the rest of the car to handle the motor? Ware as before the issue was mostly keeping a motor together. Now you may be keeping your drive train and tires together.
    Last edited: Sep 27, 2019
  4. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    I hope you are able to record it running and maby a pass or two.
  5. buicksstage1

    buicksstage1 Well-Known Member

    No, not anymore. The % between the Int and Ex is just a custom cam grind away from happiness. Just about anyone you talk to now doesn't care about the Ex side keeping up, its about size of throat and exit size and Blow down.
    Kingfish and GS Kubisch like this.
  6. 65Larkin

    65Larkin Well-Known Member

    Back to regular scheduled programming.
    Any updates Briz?
  7. Briz

    Briz Platinum Level Contributor

    Got the heads back. Happy as a clam. Cleaned up the shop and put all my tools away to make a nice clean well organized space to reassemble. Set aside time that weekend to set the completed engine back in the car. Once the heads were on and lash set I posted pictures on FB. Couple of well respected guys saw them and commented that the valve / rocker geometry looked like it was messed up. They were right. upon closer inspection the valves were now way to high. .75 or more. seems that during the porting the seats were re-cut as part of the procedure which allowed the valves to sit higher in the head. New valves on order. Due to the holiday it will probably be after the first of the year before I get them back on the engine. This also pushes back my plans on pulling the engine out of the Riv to clean and refresh it. By the time it all comes together the Tomahawk might be close to ready.
    Last edited: Jan 2, 2020
  8. hugger

    hugger Well-Known Member

    200?? The seats aren't even that thick,.no way they let them leave that far in hole
  9. Bens99gtp

    Bens99gtp Well-Known Member

    Are these the same valve the heads went up with?????? Same springs etc.

    How did you figure the valve are now .200+ too high?

    Are you still using a shaft rocker
  10. Briz

    Briz Platinum Level Contributor

    Intakes are 5.275 and the exhausts were 5.340. Going by memory, and thats not been to good lately . My notes say I need 5.200 w/.200 tip intake and 5.175 on the ex. Yes same valves / springs and using TA's 1.7-1 roller rockers. After reading my notes, edited the last post. Got a pretty bad headache this morning. Sneezed awhile ago, vision got blurry and head started hurting.
  11. Bens99gtp

    Bens99gtp Well-Known Member

    I have never measured mine, I know bobb had to get me different pushrod. But I never ran the heads b4 having them ported.
    Briz likes this.
  12. lemmy-67

    lemmy-67 Gold Level Contributor

    Get well soon, Briz. Cold & flu season is no fun.

    Wonder if the combustion chamber volume/compression ratio is affected with the valves now sitting deeper in the head?
  13. Briz

    Briz Platinum Level Contributor

    I would think it would be minimal and any change will be offset with the increased flow.
    I dont have the cold or flu. I think I popped a blood vessel in my brain.Its happened before when I felt an actual pop in my head then dizziness and a massive headache for awhile. When I laid down to rest afterwards thought to myself that I might not wake back up. Then figured oh well its been a good ride. Today Im fine.
    slimfromnz and 300sbb_overkill like this.
  14. offbrand Racing

    offbrand Racing Platinum Level Contributor

    Briz I would suggest a visit to your primary care might wanna get a mri/ct scan to make sure you don’t have a cranial aneurysm....

    Doug Hoyle, HotRodRivi and Briz like this.
  15. Bens99gtp

    Bens99gtp Well-Known Member

    X2, that's nothing to mess with at all
    HotRodRivi and Briz like this.
  16. Briz

    Briz Platinum Level Contributor

    With the help of my local race car shop I ordered new valves today Went with Victory Titanium valves. Manley was 5 weeks out and Victory est was 7 - 10 days and its a better product. At the rate this is going i'll have more into these heads than the Tomahawk block cost. Hoping its all worth it when I finally get back into the seat.
  17. Jim Rodgers

    Jim Rodgers Well-Known Member

    Make sure you dont need lash caps with those valves!!! Or you will knock the tips of the stems off.
  18. Briz

    Briz Platinum Level Contributor

    indeed! They are the same valves the guys run on their Mountain Motors Pro Stock and 632 cars. IM sure Kenny Voss will know whats needed. I keep his house and shop cool, He'll do it right for me

Share This Page