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Thread: Duplex Valve Springs 2.8/3.5 Cologne

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    Duplex Valve Springs 2.8/3.5 Cologne

    Hi All,
    I'm new the the forum and there seems to have some knowledgeable characters lurking here.
    So my question is, do the 2.8 V6 Colognes require double valve springs with BV heads to rev to 6000-6250rpm?
    I have been running the BurtonPower TV416 HD single valve springs in my N/A 2.8/3.5L engine but am experiencing a dramatic drop off of power at about 5700rpm.
    Sort of thinking it could be valve bounce? The engine has been revved to 6500rpm on a few occasions but doesn't sound like any valve bounce is happening.
    My next round of planned mods to the engine will require the heads to come off anyway. So would like to hear from the brainz trust here on their thoughts in regards to duplex valve springs or is this dramatic power loss at 5700rpm normal for the N/A 5 port heads? I'm sort of leaning towards putting duplex in anyway.

    The TV416 springs spec sheet says as a guide they are good to 6500rpm.
    Camshaft spec is Isky F6-66 228 degree duration@0.050" 2000-6300rpm power band.
    Click image for larger version Name:	dyno1crop.jpg Views:	54 Size:	45.7 KB ID:	81048
    Last edited by 3.5cologne; 23-06-2017 at 02:16.

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    Re: Duplex Valve Springs 2.8/3.5 Cologne

    i have experienced valve bounce in a couple of different engines, it doesnt tend to show up as a dip in power, more like a rev limiter, the engine hits a brick wall and wont rev further, that snot what yours is doing

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    Tyre Kicker 3.5cologne's Avatar

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    Re: Duplex Valve Springs 2.8/3.5 Cologne

    Quote Originally Posted by Graham View Post
    i have experienced valve bounce in a couple of different engines, it doesnt tend to show up as a dip in power, more like a rev limiter, the engine hits a brick wall and wont rev further, that snot what yours is doing
    Thanks Graham for your reply. Yes that does make sense. I'm hoping the plans for the new mods will help in this area, it's just that I had a bit of doubt with the valve springs as I haven't really experience valve float before. Good to rule it out before I take the heads off.
    Thanks I'll keep the single valve springs then.

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