How much power can unported 430 heads produce?

Discussion in 'Street/strip 400/430/455' started by johnriv67, Jul 18, 2018.

  1. johnriv67

    johnriv67 Well-Known Member

    I am on the fence between porting my stock heads, or just running them as is with just gasket matching. What have people run with stock setups to get good power? I'm reaching for about 400hp with a TA290-94h cam. Does that seem possible? Compression at 10:1 with the GM steel shim gaskets.
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Porting them yourself? Or having someone else do it? Out of the box aluminum heads will out flow the best iron ported heads. 400 HP is possible with un ported heads.
     
    britt'sStage 1 and Briz like this.
  3. Briz

    Briz Founders Club Member

    I put about 3 K into my iron heads and would be money and power ahead if Id bought S1 aluminum heads. You can make 400 HP with your stock heads
     
  4. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Gasket matching is a waist of time/money. Gasket matching won't gain you anything and could actually slow the air flow down, don't do it.

    Gasket matching puts a "bulge" in the intake tract that the air goes from unported to ported back to unported, sometimes creating reversion.

    Also removing material from the floor of the port does nothing but slow down air flow, most of the air is flowing at the top of the port. Although removing material from the floor of the port will make the heads slightly lighter.:rolleyes:


    On the higher end cast iron port work they will some times epoxy the floor of the port and raise the roof as high as they can to straighten out the flow of air to try and get more flow.

    If you want to get some more flow doing the work yourself without ruining your heads, just open up the bowl area(the area under the head of the valve), open it to the end of where the valve angle is ground and "V"(vee) the guide so the air hits the point of the "V" directing it to the widest area entering the bowl.

    After opening the bowl, just blend the sharp edge left from opening the bowl up into the short turn radius trying not to alter it, just blend it so there aren't any sharp turns. If you lay the short turn down to far you can do more harm than good so in this area, less is more.(short turn radius = the transition of the floor of the port into the bowl of the port)

    Bowl blending will add way more power for $$ than "gasket matching" would ever think about doing.(mainly because G/M usually hurts flow)GL
     
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  5. johnriv67

    johnriv67 Well-Known Member

    So with a mild 220-230 duration cam, 10:1 compression in a 430 with stock intake, stock heads with TA stage 1 springs, does 400hp seem possible? 450hp? That's really what this all comes down to. I'm grateful for the bowl work information, and I hope I could use it at some point.

    And Briz if those heads are on the selling block, I'd very much like to see pictures and more. Of course, all up to you
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    400 HP is attainable. 450 HP? No, you'll need better head flow. Unless you can do the work yourself, save your money and buy aluminum heads.
     
    johnriv67 likes this.
  7. johnriv67

    johnriv67 Well-Known Member

    I have two sets of 430 983 big port heads. Should I try and port a set as my first porting challenge? Very quick learner and solid performer when it comes to cars. I've been reading a stupid amount of information about porting. Just read cover to cover David Vizards How to Port Cylinder Heads, and I'm feeling quite confident.
     
    Last edited: Jul 18, 2018
  8. hugger

    hugger Well-Known Member

    Don't waste your time, those heads are prone to crack and probably are now,...if your going to port some do 70 or 71's,...or as stated buy aluminum and be a head of the game, if your just really wanting to learn and do it yourself then by all means go for it, I just would on early heads
     
    matt68gs400 likes this.
  9. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Yeah, the 430 heads are prone to cracking on top underneath the valve springs.

    If you have 430 heads that aren't cracked that you want to try to use, try to choose a cam that doesn't need a whole lot of spring pressure to not press your luck with them.
     
    john.schaefer77 likes this.
  10. 455stude

    455stude Well-Known Member

    Went 11.70's with my 430 with home ported heads done by my buddy George Pollakis. Headers, sp-1, 850 demon, hemi killer cam, t-400, 3800 stall, 3.73 rear 3460 lbs with me on board. We're all the 430 heads prone to cracking? Or just certain years?
     
  11. johnriv67

    johnriv67 Well-Known Member

    Thank you, and I've heard just certain castings.
     
  12. Briz

    Briz Founders Club Member

    They may be one day. I'll have completely forgotten about this thread by then. Keep your eyes open. I'll post em here first.
     
  13. patwhac

    patwhac Well-Known Member

    Nice one :D
     
  14. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Port them by all means. Back cut all your valves 30 degrees . have whoever does your valven seat cutting un shroud the comb chamber slightly around the outside of the valve area. Carefully smooth out the combustion chamber to a polish
    Taking off as little material as possible. This will reflect heat back into the cylnder and a bigger benifit is carbon wont build up near as much .if you have vizzard port and flow, and how to build horsepower in Big block then youve read this.
     
  15. Stevem

    Stevem Well-Known Member

    With stock valves sizes on these Heads there is NO need to drop compression by doing unnessary unshrouding work !
     
    matt68gs400 likes this.

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