Need Help- Porting Heads for beginners

Discussion in 'Street/strip 400/430/455' started by Christopher Spouse Drew, Jul 25, 2018.

  1. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    I want to learn how to port heads for my 455. I have been reading on here and watching videos on how to tackle this. I want to also say im leaning towards edelbrock aluminum heads so if i screw up, no big deal, if i get it right then awesome, money saved. My goal is to replicate the stage 1 heads with my 74 heads.

    So here's what I learned and you guys can correct me or give me your way of doing it.
    Supplies needed: Some type of rotatory tool, die grinder(I have a dremel) and a set of carbide tips and sand paper tips.
    Intake/Exhaust Porting Method: So online I saw a lot of people put the gasket on to see how much material to take off by tracing the outline of the header or intake manifold gasket with a sharpie for the intake and exhaust ports.(process applies to the intake manifold as well)
    Controversy: I've read a few opinions of porting the intake/exhaust ports, such as Do Not take any material off the bottom of the port of either the intake/exhaust port. The top of the port should be the main point of material removal. Another one I read was not to take too much material off like I explained in the Method above, but to smooth the port and clean up imperfections from the factory.

    Combustion Chamber Porting Method: This is where I need help the most, I didn't find that much detail out there. So I saw people take the valve guide all the way down almost flush with the rest of the surface for better flow. Its crucial to smooth the short turn radius of both intake and exhaust ports.The 3 angle valve job ill leave obviously to the machine shop to do.
    Controversy: I didn't find different opinions but that's probably from the lack of info I found/understood. People said don't take any material off or near the valve seats(which makes sense to me) right?

    So guys, i'm committed to doing this, anyone with success with this please help me out. Pictures, videos, articles, experience, and tips would be appreciated. Im going for the best flow possible. So the thing i need more clarification on is what I need to do exactly to replicate the stage 1 heads or whatever setup for best flow. Thanks guys!
     
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  2. flynbuick

    flynbuick Guest

    Stage 1 heads were machined for bigger valves. I cannot imagine that any porting was performed by Buick. There was no time for that. The stock heads do not flow well.

    People that really know what they are doing generally use a flow bench to measure the results of their work. The best advice someone could give you is to farm this task out.
     
  3. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    I appreciate the advice but im already committed to doing it myself, if i screw up, no big deal. I'll have it tested on the flow bench when i take it to the machine shop after im done with it.
     
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  4. hugger

    hugger Well-Known Member

    Dremel isn't going to work, you will need a good compressor and I mean a good compressor to run a air powered in line grinder or an electric inline grinder these are what most pros use but they are big and expensive for a good one. Harbour freight has theirs and it's OK but will burn up but get the warranty and who cares up to you.

    Good bits are EXPENSIVE, you'll need 3in and 6in

    Porting iron heads SUCKS yea it's fun the first 30min but when the metal slivers get in your socks, shoes and buried in your skin it becomes unfun real quick.

    Stuff is bad for you wear a mask,....and I'm that guy that never wears a mask and even I'm saying do it ha

    Sandpaper rolls is a waste of time the the bit puts a very nice finish on the metal. A smooth finish is only there to make the customer feel fuzzy inside.

    If converting heads to big valve, you will have a good bit of work to do after they are cut, so you need to have them cut and roughed in then pick them up and clean up the ridge that's going to be left then take them back. To do it rite it's a lot of work, is it worth it,.. no it's not,...I'm not saying you shouldn't try it,..it's hot rodding 101, every car guy should try it once
     
    Last edited: Jul 25, 2018
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  5. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    Okay, ill look into different grinders, i think i might have one gotta check. I have bits already at my job I can use. I don't care about having fun, i care about getting the job done. and yeah i always take safety precaution when doing something like this. Yeah i just want to do it, im kinda young, 27, im trying to do as much as I can when it comes to working on my car. Thanks for the tips.
     
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  6. hugger

    hugger Well-Known Member

    Here's a few pics of a set I'm piddling with now, taking pics of Port work is about impossible, and I'm certainly no head Porter,.. just do what I think will work.
    rps20180725_183048.jpg
    Stockish exhaust guide, I say stockish because these heads had actually been worked a little previously. rps20180725_183021.jpg For the most part finished , guide was dropped a good 1/4in rps20180725_182810.jpg
    Pretty much finished intake side
    rps20180725_182949.jpg
    What it was originally, like I mentioned these had been worked moreso on the intake side so the above pic isn't what you find in an untouched head but even still I removed quite a bit of material
     
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  7. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    This a great reference hugger, thank you! Whats your method on taking the material off? do you go in a circular motion with the die grinder around the port to get even material off? I wonder if you could take more material off that finished intake valve guide. Ive seen people take it down a bit more than that, but i dont know if thats the right thing to do.
     
  8. hugger

    hugger Well-Known Member

    Just move it around where it needs it let the bit do the work and keep varying the rpm as needed, you can but imo, you jeopardize the support of the valve, Ive seen some Gessler heads that had no guide boss, but I'm just not convinced it's a good idea for longevity, ..flow yes.
     
  9. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    Exactly what i was thinking about the support of the valve. I'm in the same boat i want my motor to stay together and not apart all the time haha longevity is key. So what new valves would you be putting in?
     
  10. hugger

    hugger Well-Known Member

    TA undercuts
     
  11. Stevem

    Stevem Well-Known Member

    You need a set of these inside snap gauges and a cheap plastic dial caliper to get even sizes and shapes as you go from port to port!
     

    Attached Files:

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  12. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    Yeah I have those and will use them. Thanks!
     
  13. matt68gs400

    matt68gs400 Well-Known Member

    C1D27CC3-81D1-46EA-86E1-6FEE98E45DBF.jpeg D02D2949-5276-41A9-AFA2-6F4D4A21D0E0.jpeg An electric grinder from Harbor freight and reostat from eBay worked very well on my intake manifold.
     
  14. matt68gs400

    matt68gs400 Well-Known Member

    Also, a ton of good advice from board members here. Hugger, Stevem and Derek were very helpful. I haven’t fisnished my heads as I ran into a bunch of electrical FUBARS to work on this summer. Ugh!

    I’m also of the understanding that stage 1 intake valves are a waste of time. Have big exhaust valves and save some money.

    751C8FC4-5A89-42FB-B67C-5E84FC3C602A.jpeg
     
  15. RG67BEAST

    RG67BEAST Platinum Level Contributor

    Any time you use bigger valves with proper bowl porting and shortside radius low, mid and high flow# go up. That makes power. That's a fact. Combine proper unshrouding of the chamber then things get even more efficient.
    It's all about air flow.
    Ray
     
  16. Stevem

    Stevem Well-Known Member

    You will get far better gains from bowl porting work if you step up to the bigger valve sizes, as just the valve job provides greater numbers!

    Note that on the Exh side if you boat tail the valve guide top you will drop off much needed low lift cfm, this is due on heads like this to the very shallow Exh bowl .

    A bigger Exh valve with a 3 angle valve job will get that lost low lift flow back and more.

    With keeping the stock size Intake valve a novist porter will get some 215 to 220 cfm way up at 600" lift, the bigger valve will allow you to attain those flow numbers at a more useable lift when combined with bowl porting and cutting / grinding back the valve guide support web on the Exh valve side on the Intake bowl!
     
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  17. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    Guys this is some great advice and I appreciate it. As for the intake and exhaust ports I'm going to gasket match and grind off the access.

    The thing I need clarification on is the bowl porting, I'm going to shave down the valve guide( I've researched and people have shaved the guide flush down to the bottom or kept some of the valve guide for structure and stability(like hugger in his above pictures), I want to hear from you guys and what you've done and the outcome it made, my goal is an increase in flow but longevity is important) and I'll lightly clean up the entire bowl, is there more I should do to make better flow? And yes I'm getting the bigger stg 1 valves and a 3 angle valve job from the machinist.
     
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  18. Stevem

    Stevem Well-Known Member

    Here's what a stock 1237661 head flows , then with some bowl work and the with larger valves and a tad more work, but not even a gasket match.
    Stock Intake Flow@28"
    Intake
    .050"--100"--200"---300"---400"---450"---500"---550"---.600"
    30.4---60.9--122.6---177.6---209.3--216.2--218.5--229.6
    Stock Exh flow@28"
    21-----47.3----97.4----126----142.6---147.6---149.5--151.5
    With the stock head the overall Exh to Intake ratio = 72%, target on a less then 10 to 1 street motor should be 75%.
    Intake flow with very quick bowl blend and bullet nosed guide, nothing earth shattering here but a gain none the less for 15 minutes of work!
    31.7---62.7---128.7---181----212.7----221.9----same---224.9

    I will post up Exh flow numbers and the results of bigger valves tomorrow.
     
  19. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    Very informative Steve! Do you have any pics of your head porting?

    Can you explain the numbers a bit to me. Is 50"-600" representing the lift of the cam? So basically your flow numbers are from idle to high rpm?

    I'm getting them flow tested and I was gonna wait for the machinist to explain it.
     
  20. Stevem

    Stevem Well-Known Member

    The .050" to .600" Numbers are the lift at the valve not the Cam lobe lift, the Cam lobe lift for example of a Cam that provides let's say .450" lift at the valve by means of a 1.5 ratio rocker would be .300"
    Sorry I have no pictures , but they do not help much anyway as they are a 2 dimensional copy of something that many times need to be viewed in person in 3 dimensions!
    At lunch time I will post the Intake flow numbers with the bigger valve.
     

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