Gen IV BBC Valve Adjustment
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Gen IV BBC Valve Adjustment

  1. #1
    Custom User Title 4runnin's Avatar
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    Default Gen IV BBC Valve Adjustment

    First time looking at these valves. End of last season seemed to have a good bit of valve noise that wasn't there before. I'm assuming these are all stock with hydraulic lifters.

    My question is, does anything lock the nuts down once set to 0 lash + 1/2 turn? Or just set the lash and move on?


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    Senior Member ol guy's Avatar
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    first question would be how many seasons on factory lock nuts? Second would be have you checked the rest of the valve train, springs,push rods and rocker studs. 3rd would be did you change or has the cam been changed to a higher spec without upgrading the rest of the valve train? If all checks good then go with a set of poly-locks and readjust. if you are running a stock set-up from factory and twisting the engine higher than stock expectations then upgrades need to done. M

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    Or Seth, either one Budweiser's Avatar
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    To add to ol guy's post... if it's all stock, typically the valves are a set it and forget it deal. The adjustment shouldn't change, even with the stock lock nuts.

    If it is stock, and it's a little noisy... is it all the time, all day? When it's at running temp? Only cold and clears up once it's warmed up? Only at idle? Sound like all of them or just one/a couple?

    My personal opinion... if it's all stock and getting noisy, it's not likely an adjustment issue. More likely it's an indication of another issue. Could be that it's not a serious issue at all, depending on what the circumstances are when it occurs.

    If it's only on the first cold startup of a trip, could be that the lifters are bleeding off... which I personally wouldn't worry about... and adjustment wont solve.

    If you just want to reset the lash, I wouldn't worry about poly locks the first time through. I have no issue with the stock lock nuts. However, that's just me, poly's are certainly not a bad idea.
    Last edited by Budweiser; 03-04-2017 at 09:28 AM.

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    Senior Member ol guy's Avatar
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    After a closer look at the picture I would say springs are shot. Without any feed-back from the O.P as to when it gets to clicking I am going by the fact that if you look at the rocker studs it appears that the rockers are bottoming out on the studs and wearing on the stud all the way down and on the boss at the bottom---valve float!!!! MLAOP. Mark

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    Or Seth, either one Budweiser's Avatar
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    Quote Originally Posted by ol guy View Post
    After a closer look at the picture I would say springs are shot. Without any feed-back from the O.P as to when it gets to clicking I am going by the fact that if you look at the rocker studs it appears that the rockers are bottoming out on the studs and wearing on the stud all the way down and on the boss at the bottom---valve float!!!! MLAOP. Mark
    Are you looking at the stud without a rocker on it? I see, what looks like a little divot right above the tool hex as it tapers down to the stud diameter. But there's also some shmoo right there at the base. Could just be lighting, angle, and focus. Also, looking at the rockers that are still mounted, none of them are that low on the stud. They wouldn't make contact that low.

    Maybe you're seeing something I'm not?

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    Senior Member ol guy's Avatar
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    Quote Originally Posted by Budweiser View Post
    Are you looking at the stud without a rocker on it? I see, what looks like a little divot right above the tool hex as it tapers down to the stud diameter. But there's also some shmoo right there at the base. Could just be lighting, angle, and focus. Also, looking at the rockers that are still mounted, none of them are that low on the stud. They wouldn't make contact that low.

    Maybe you're seeing something I'm not?
    I guess I am, look farther down the rack you only get 5 studs to see but all are showing wear to low. To see a rocker flipped over would seal the deal. Also I would bet his valve noise is heard at higher RPM but he has gone into the dark hole and has not responded to our comments so ?????? Mark

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    Or Seth, either one Budweiser's Avatar
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    Given the simplistic nature of the inquiry, I'm gonna guess he googled and found the answer he was looking for 5 minutes after he posted the thread. Based on his average, I'd guess he'll post back up in June.

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    Senior Member ol guy's Avatar
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    Quote Originally Posted by Budweiser View Post
    Given the simplistic nature of the inquiry, I'm gonna guess he googled and found the answer he was looking for 5 minutes after he posted the thread. Based on his average, I'd guess he'll post back up in June.
    With that being said I think I'll take june off!!! Sounds like use and abuse. 3k later he will wish he stayed here. I have the valve train in my garage to fix the problem. Mark

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    Custom User Title 4runnin's Avatar
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    Wasn't near a computer this weekend, but thanks for the replies. That's a picture I borrowed from an earlier thread, so not the ones on my actual boat, just an identical setup.


    Yes, all stock 1978 as far as I know, but that's just hearsay.


    Cold start and warm up it sounds fine. When coming to an idle after a long run it has a very loud, noticeable tick that is rhythmic with rpms. Seems to go away once back on plane or above 2-3k rpm, but also could me masked by the other engine sounds.


    Thank you guys for the help.

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    Senior Member ol guy's Avatar
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    Quote Originally Posted by 4runnin View Post
    Wasn't near a computer this weekend, but thanks for the replies. That's a picture I borrowed from an earlier thread, so not the ones on my actual boat, just an identical setup.


    Yes, all stock 1978 as far as I know, but that's just hearsay.


    Cold start and warm up it sounds fine. When coming to an idle after a long run it has a very loud, noticeable tick that is rhythmic with rpms. Seems to go away once back on plane or above 2-3k rpm, but also could me masked by the other engine sounds.


    Thank you guys for the help.
    With that being said, I would run the valves and check it on the water. Second question would be what engine oil are you running? M

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    Custom User Title 4runnin's Avatar
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    Quote Originally Posted by ol guy View Post
    With that being said, I would run the valves and check it on the water. Second question would be what engine oil are you running? M
    Valvoline vr1 racing oil straight 40 weight and 20w50. Same result.

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    Senior Member ol guy's Avatar
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    Quote Originally Posted by 4runnin View Post
    Valvoline vr1 racing oil straight 40 weight and 20w50. Same result.
    Stick with the straight weight 40 and run the valves. If it is an original 1978 build things wear in and adjustment loosens up, I would do that first. Mark
    Last edited by ol guy; 03-06-2017 at 01:51 PM. Reason: add on

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