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VTEC v. NonVTEC Valves

Discussion in 'General Tech and Maintenance' started by brian11to1, Feb 15, 2006.

  1. brian11to1

    brian11to1 Senior Member

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    [​IMG]
    Side-by-side View of Valves
    Comparing the valves side byside, you can see the difference. As you can see from my shitty pictures the Intake Valves are different. Not only are they shorter, but the stems are not as wide. Reason one why VTEC valves will not work in a nonVTEC b series head.

    [​IMG]
    [​IMG]
    Valve Differences
    Intake valves are 33mm wide (v. 31mm for LS/B20) and are about 3mm shorter than the Intake valves from nonvtec b motors. As mentioned earlier, the stems are smaller in diameter as well. Theres also a difference in the exhuast valves, the two being pretty much the same as the intake. Shorter and smaller diameter stems. Thus, VTEC valves will not work in nonVTEC b series heads.
    Reason 2, why they wont work.

    [​IMG]
    [​IMG]
    [​IMG]
    Springs/Retainers
    The springs and retainers are different as well. Since ITR and GSR's have inner valve springs, the retainers are designed to retain both springs inner/outer. Also, the nonVTEC retainers are wider and a tad thicker since they dont have the second plane for the inner valve springs. Also, not to leave out the fact that the LS springs are taller, since the valve stems are longer. I estimate 3mm, not sure exactly what it is.

    [​IMG]
    Retainer Keepers
    lastly, im sure there are a lot more differences than I was able to point out. The last difference is obvious. the valve stems are smaller in diameter on vtec valves (intake and exhuast), well so are the keepers. a keeper essentially has a rib type thing on it that slids into a groove on the valve steem and thus, locks or KEEPS the retainers in place. These are different. The nonvtec keepers are bigger (just like the springs and valves themselves) than the VTEC keepers.

    i suck at taking pictures.
     
  2. HatchSpeeD

    HatchSpeeD ...Hi...

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    :thumbsup:
     
  3. MikeBergy

    MikeBergy Blah blah blah....

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    True, true. Nice pictorial. I came across this last year about this time. vtec valves are way better for the revs. But I have some awesome valvesprings for my ls. Next to add the Ti retainers.
     
  4. D See 2

    D See 2 Senior Member

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    Way to clear things up. :thumbsup: We need more write-ups like this.
     
  5. brian11to1

    brian11to1 Senior Member

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    Im going to open a can of worms with saying this...

    Looking at the valves (VTEC v. nonVTEC) the VTEC stems are smaller in diameter, where as the LS' are wider. Wider = stronger, correct? If so, then why are the VTEC valves so much smaller in diameter? Wouldnt a wider stem result in less chance of it breaking? Would it be for higher rev's, less weight, less stress???

    Im sure there's a reason, maybe the VTEC valves are made different, I dont know. But, when I was looking at everything, this is only question that came up multiple times.

    Oh, and I get bored at home.
     
  6. MikeBergy

    MikeBergy Blah blah blah....

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    Who needs a strong valve? All you need is for the valve faces to be able to take the heat. If my engine is going to have a catastrophic failure in which my valves are in danger of being broken, the last thing on my mind is my valves. I'm most likely going to have to replace the head at that point anyway.

    Vtec valves are smaller physically, but have a larger valve area. They are lighter weight for easier revving, and are capable of flowing a larger amount of air in comparison to the ls valves. As an added bonus, the reduced surface area of the valvestem in contact with the valveguides reduces the amount of overall friction in the system.
     
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