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v-tec vs port and polish

Discussion in 'General Tech and Maintenance' started by Delsolcrazy, Nov 21, 2004.

  1. Delsolcrazy

    Delsolcrazy Junior Member

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    So would it be worth it for me to get the head on my b20b ported and polished or should i just save my money and get a v-tec head.
     
  2. Delsolcrazy

    Delsolcrazy Junior Member

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    Boost...Turbo project I have a t3 that will be going on at some point after the swap. Some would say vtec isn't good for boost, but vtec heads have better flow. I was just wondering if a port n polish on the b20 head would be as affective if not better than just getting a vtec head.
     
  3. civicious

    civicious FüK-VTEC VIP

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    Who would say that vtec isn't good for boost?
     
  4. driver1

    driver1 Senior Member

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    vtec is fine for boost and will make mopre power under boost but just requires some finer tuning...and as far as porting and polishing theb20 head....i dont believe u will find it to be as good than going vtec
     
  5. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    You can't really compare a port/polish and a VTEC head swap. The VTEC head basically allows you to have two different flow options depending on engine speed, and the port/polish job lets your head breathe better at one specific range of engine speed.

    You can port your stock B20B head to flow better than a stock VTEC head up top, but then you'll lose some streetability at low rpm because of the size of your ports. If you're want maximum streetability on a boosted setup, just swap to a VTEC head and drop in some turbo grind cams. If you want a crazy turbo setup that makes tons of power without VTEC, port the head. If you want the best of both worlds, do both.
     
  6. sohcslammer

    sohcslammer Senior Member

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    Road racers. Try road racing a VTEC turbo and having the VTEC engage around a turn.... :p
     
  7. UDT

    UDT Senior Member

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    Yeah i thought about that, i mean in a sence it would seem to me that Vtec would have almost the same effect a turbo has when it kicks in, just not quite as strong, though im willing to bet on even the strongest N/A Vtec engines they dont find it to be to big a problem when it enguages, im sure the power increase isint so much that the tires cant over come it.

    though lower the enguagement some and im sure you will never find yourself out of Vtec very often if at all.
     
  8. sohcslammer

    sohcslammer Senior Member

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    Quite true, but I know a few guys that race hondas professionally and they all run turbo or supercharged LS motors. They all say that they like the more linear power delivery... :shrug:
     
  9. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    If you're good at tuning, you can smooth out the VTEC transition so much that you don't feel it at all. That's how I prefer my VTEC engines- I can only hear the VTEC crossover- I never feel it.

    Also, on a road race only car, you're not using the low range of your engine's power band at all, so running a non-VTEC head lets you have a much simpler engine setup. It's easier to tune because you only have one cam profile, you have fewer items bumping against each other (lower friction), you have fewer lobes (less mass) on the cams... there are lots of advantages to running a non-VTEC setup on the track. That's why they make VTEC killer cams. ;) I wouldn't want to run a setup like that on the street though.
     
  10. sohcslammer

    sohcslammer Senior Member

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    :) Is there anything you DON'T know?
     
  11. UDT

    UDT Senior Member

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    How to suck a noodle in his nose and out his ass?
     
  12. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Teach me, of guru of anal noodle explosion! :lol:

    Seriously though- it's just common sense once you really understand what VTEC and a port job do for you.
     
  13. sohcslammer

    sohcslammer Senior Member

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    How important is porting the head really? I just found out that the machine shop I was going to go to, can do everything but port the head. Valve job, milling, and I assume polish? Should I take the head somewhere else and get it ported? My setup is in my sig...
     
  14. Arachnid

    Arachnid Senior Member

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    don't bother with porting until you get some pimp cams. and most if not all the bolt-ons to allow for that free flow.

    unlike calesta there's a reason i go vtec and that's to feel it so imo i'd set vtec higher just cause IT'S VTACC YO!!!

    sohcslammer you're running a sohc? if y8 should do some porting if z6 should do some porting then you'll have all the flow you'll want. if turbo'd d then porting will make good power. a good porting job will/should always make more power.

    porting a turbo set-up is for efficiency. porting n/a is for breathing at higher rpms. but if done correctly then powerband will rise on both. imo
     
  15. sohcslammer

    sohcslammer Senior Member

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    Uhhhhh... thanx. But it CLEARLY states in my sig that I drive a 99 SI now. I haven't had a single cam for like 4 cars now... :lol:

    I'm running @ 11:1 compression.
    I'm running zex/comp stage 2 cams (check the specs, they are pretty aggressive)
    I'm running dual valvesprings with ti retainers
    I plan on revving to 9k at least.
    I am more than likely going to replace the rods with some scat H beams as well

    How much will I benefit from porting the head? And what's the difference between port and polish and just polish?
     
  16. xj0hnx

    xj0hnx I wanna be sedated VIP

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    Porting is altering the combustion chambers shape, polishing is smoothing out the existing surface.
     
  17. sohcslammer

    sohcslammer Senior Member

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    That's what I figured. Polishing will smoth out my power curve? And porting will add more power in the higher rpms?
     
  18. Arachnid

    Arachnid Senior Member

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    porting will hit you up on the power curve. polishing will make your head look kool.
     
  19. MikeBergy

    MikeBergy Blah blah blah....

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    Porting alters the path the air follows up to and following the combustion chambers. Unless you are planning on doing chamber work as well, then porting doesn't do much of anything in the way of changing the combustion chamber. Polishing smoothes out the surfaces to get rid of the abnormalities in the factory casting. Polishing usually goes hand in hand with porting, and I've never heard of porting without then polishing. Oh yeah. Porting will basically move your power curve to the left or right on a dynoplot, depending on how you set your motor up. Most hondas tune for power at peak rpm, because the torque is weak at the bottom end, unless you have turbo, or mike's motor :) . Vtec is good for the streetability of the car, but adds a lot of junk when building a race motor. Basically ditto to what mike said earlier. And he doesn't know anything about CALIFORNIA. :p .
     
  20. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Nope, sure don't. Except that Houston and DFW are starting to look like California when it comes to emissions testing and modification laws. :p
     
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