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I have an early 74 260Z (L26) with duel '72 model SU's.

The engine makes excessive valve train noise, especially under load. I have listed to it at idle with a stethoscope and I am sure the noise I am talking about is comming from the valve train, although it doesn't seem to be isolated at one valve. I adjusted the valve lash to .008 intake, .010 exhaust cold, with no different in the amount of noise. Have not had time to adjust the valves hot.

Is there something else other than valve lash adjustment that can be causing this kind of noise (it's not knocking).

Could it be that the springs/clips (not the valve springs, but I'm not sure what their proper name is) that hold the rocker arm against the pivots be weak after 25 years? Would it help to get new ones? Any advice would help.
 

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Re: What's causing excessive valve train "cla

Those values you gave .008 and .010, are for hot which means your valves are too tight. They should be about .010 and .012 cold. Too tight can cause overheating of the valve itself and warpage as it tries to slam shut. I would not expect them to clatter however. Is it better when its cold? Mine are a bit loose and they are fine when cold but clatter when warm.

> I have an early 74 260Z (L26) with duel '72
> model SU's.

> The engine makes excessive valve train
> noise, especially under load. I have listed
> to it at idle with a stethoscope and I am
> sure the noise I am talking about is comming
> from the valve train, although it doesn't
> seem to be isolated at one valve. I adjusted
> the valve lash to .008 intake, .010 exhaust
> cold, with no different in the amount of
> noise. Have not had time to adjust the
> valves hot.

> Is there something else other than valve
> lash adjustment that can be causing this
> kind of noise (it's not
> knocking).

> Could it be that the springs/clips (not the
> valve springs, but I'm not sure what their
> proper name is) that hold the rocker arm
> against the pivots be weak after 25 years?
> Would it help to get new ones? Any advice
> would help.
 

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Registered
Joined
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107,597 Posts
Re: What's causing excessive valve train "cla

> I have an early 74 260Z (L26) with duel '72
> model SU's.

> The engine makes excessive valve train
> noise, especially under load. I have listed
> to it at idle with a stethoscope and I am
> sure the noise I am talking about is comming
> from the valve train, although it doesn't
> seem to be isolated at one valve. I adjusted
> the valve lash to .008 intake, .010 exhaust
> cold, with no different in the amount of
> noise. Have not had time to adjust the
> valves hot.

> Is there something else other than valve
> lash adjustment that can be causing this
> kind of noise (it's not
> knocking).

> Could it be that the springs/clips (not the
> valve springs, but I'm not sure what their
> proper name is) that hold the rocker arm
> against the pivots be weak after 25 years?
> Would it help to get new ones? Any advice
> would help.
take a good look at the cam, next time the valve cover is off. they can make a ton of noise if they are worn out. joe
 
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