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Thread: Xflow rocker noise

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    Spanner Monkey

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    Xflow rocker noise

    Hi all any help appreciated.1700 xflow.1300 pistons.stage 4 race head. Twin 40 dellortos 244 cam twin chain double valve springs steel rocker posts.theres hell of a racket coming from i believe rocker area.there adjusted as kent spec for cam.what would cause this noise ie wrong post size. Not useing steel shaft.push rod legnth.other than noise engine pulls v well and set up on rollers making 141bhp@6400 revs 124ft torque.any ideas as the noise is unbearable its that bad.plus you cant hear noise when on rollers or from outside.and i can soften noise over certain revs in diff gears.cheers
    Last edited by Painter an; 17-07-2018 at 20:24.

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    Re: Xflow rocker noise

    check valve to piston clearance!

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    Re: Xflow rocker noise

    Quote Originally Posted by Graham View Post
    check valve to piston clearance!
    Pistons pocketed! But how can i check?
    Cheers

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    Re: Xflow rocker noise

    on an x/f its easy, pick a cylinder, get it at tdc with valves on overlap, ie slightly open. loop a ring spanner over the tappet adjuster and check to see how much further you can open the valve by lifting the end of the spanner

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    Re: Xflow rocker noise

    Tin rocker cover hitting the rockers? Tin rocker cover letting noise through?

    Thick aluminium rocker covers can mask some of the noise.

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    Re: Xflow rocker noise

    Worn rockers?
    Hexham and District Motorclub

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    Re: Xflow rocker noise

    rockers quite often hit the inside of alloy rocker covers

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    Re: Xflow rocker noise

    Thanks for all the help/ideas guys i origionly thought about rockers hitting cover i had alloy vulcan one swaped to tin no diff and no marks on cover.thanks graham il try what you surgest. Any ideas why noise would only be under load not even at full throttle and like i said does not make this noise on rollers just on road
    Cam comes on around 2800 revs and noise can ease off then???

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    Re: Xflow rocker noise

    pockets in the pistons need to be wide enough for big valves, not only deep enough … I would take the head off to be sure (if all other Obvious things are checked, 244 needs a lot of play between valve and rocker also, I have given more play then stated by KC)

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    Re: Xflow rocker noise

    Quote Originally Posted by Painter an View Post
    Thanks for all the help/ideas guys i origionly thought about rockers hitting cover i had alloy vulcan one swaped to tin no diff and no marks on cover.thanks graham il try what you surgest. Any ideas why noise would only be under load not even at full throttle and like i said does not make this noise on rollers just on road
    Cam comes on around 2800 revs and noise can ease off then???
    If it doesn't do it under load or on the rollers could it not be a vibration from something else and not the engine atall?

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    Re: Xflow rocker noise

    Quote Originally Posted by racing escort View Post
    pockets in the pistons need to be wide enough for big valves, not only deep enough … I would take the head off to be sure (if all other Obvious things are checked, 244 needs a lot of play between valve and rocker also, I have given more play then stated by KC)
    Rockers set at 22 and 24 what would you surgest?

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    Re: Xflow rocker noise

    Quote Originally Posted by davemk1 View Post
    If it doesn't do it under load or on the rollers could it not be a vibration from something else and not the engine atall?
    Iv thought that as well as changed exhaust manifold thinking might be blowing.any ideas what could be? I cant understand if i sit in and rev it its not there but as soon as pull off it is.its really loud and anoying not to mention worrying.cheers

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    Re: Xflow rocker noise

    22 and 24, what does KC suggest ? inlet seems big clearance, outlet sounds right to me ?

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    Re: Xflow rocker noise

    Quote Originally Posted by racing escort View Post
    22 and 24, what does KC suggest ? inlet seems big clearance, outlet sounds right to me ?
    Those are kc figures for 244
    Cheers

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    Re: Xflow rocker noise

    If it's only doing it moving and on the road it would tend to move the diagnosis to transmission / axle / suspension!

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    Re: Xflow rocker noise

    Quote Originally Posted by katana View Post
    If it's only doing it moving and on the road it would tend to move the diagnosis to transmission / axle / suspension!
    I know noise travels etc but def under bonnet area
    I read some where about flywheel bolts loose but not sure what would sound like or if you could feel it.
    Thanks for all the ideas tho guys

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    Re: Xflow rocker noise

    Just a thought i had a noise when I rebuilt mine which was a bolt and dropped between the bulkhead and bell housing only made the noise at 2000rpm
    Hexham and District Motorclub

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    Re: Xflow rocker noise

    harmonics and resonance. i had a similar spec motor that rattled at a certain rev range in a certain gear. wouldn't be too worried about it too much if all seems ok. if your that bothered take the head off for a look

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    Re: Xflow rocker noise

    Quote Originally Posted by fatboy slim View Post
    harmonics and resonance. i had a similar spec motor that rattled at a certain rev range in a certain gear. wouldn't be too worried about it too much if all seems ok. if your that bothered take the head off for a look
    Yer i know what you meen.funny tho as before this engine the one i had before was 1700 with 1300 pistons but only 224 cam gt head twin 40s which made a similar sound which is why im leaning towards it not being engine. Going to see if i can upload sounds on youtube thanks again

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