Tappet adjuster screw wear?

[Shinnster]

Hi all,

My engine has started to make a rattly noise, which i thought was tappets so i adjusted them today (still noisy though)
but i noticed when doing so, the screw seemed different lengths on some of them. for example, i had to adjust one where there was hardly any thread left on the screw to hold the nut on, yet on others there is still a fair amount of threads sticking out after the nut.

do the screws wear down? or does it sound like i've adjusted them wrong? I hand cranked the engine round till the relevant one was in the correct position to be adjusted. (seems pretty straight forward , watched videos and followed the haynes manual)

added the worst pic ever, but just to give you an idea of what i mean. the arrow points to the screw with not a lot of thread after the nut.

[sarran1955]

Hello,

Not the best picture...

If one adjuster is way down, it can be for several reasons.. the most common being the valve seat working its way out of the head,
also the hardened tips of the adjuster screws do wear down..

Cordialement,

[R0B]

Are you certain the rattly noise was not tappet bleed down?

[Rosie n' Jim]

Looking closely at the adjuster screw, they all,  appear to be much the same length (minimal wear), but with much more or less thread showing through the rocker. So either the valve seat is working itself out of the head, or you are not adjusting them from the true contact point.
I'm assuming your engine has the same hydraulic lifters that my CU engine has. The adjusters need to be wound fully clear of the valve stem, leave uncompressed for a few seconds before gently screwing in to the contact point.  Then turn in 1.5 turns (correct for CU engine, maybe not yours), and lock down. 
Sorry if this isn't relevant to your engine, but I've made the assumptions stated above. This would be a whole lot less trouble than dropped valve seats!
​​​

[Shinnster]

Are you certain the rattly noise was not tappet bleed down?

i did take it for a blast for a few miles and the noise didnt go away, as thats what i assumed it was first of all.

[Shinnster]

Looking closely at the adjuster screw, they all,  appear to be much the same length (minimal wear), but with much more or less thread showing through the rocker. So either the valve seat is working itself out of the head, or you are not adjusting them from the true contact point.
I'm assuming your engine has the same hydraulic lifters that my CU engine has. The adjusters need to be wound fully clear of the valve stem, leave uncompressed for a few seconds before gently screwing in to the contact point.  Then turn in 1.5 turns (correct for CU engine, maybe not yours), and lock down. 
Sorry if this isn't relevant to your engine, but I've made the assumptions stated above. This would be a whole lot less trouble than dropped valve seats!
​​​

i followed the process for adjustment , it says a similar thing in the manual.
a
 

[Shinnster]

i think ive done a noob mistake for this, are there 2 tdc's for each cylinder? so i may not have been on compression stroke tdc for cylinder 1 for initial set up?
i just hand cranked the engine until the rotor arm was pointing towards the lead going to cylinder number 1

[Rosie n' Jim]

There are two TDC's, exhaust and compression, but the rotor arm rotates at half the crank speed, so if the arm points to a lead then it the compression for that cylinder. However, it's not likely to be TDC. You can use the position of the arm to select a cylinder, but then determine true TDC by checking the piston via the spark plug hole. I use a screwdriver to feel the piston move up and down, rocking the crank back and forth till I fine the high point. You will also notice a lack of rotational friction at this point. WARNING. Use a screwdriver with a handle that is too big to fall into the cylinder!

[Shinnster]

There are two TDC's, exhaust and compression, but the rotor arm rotates at half the crank speed, so if the arm points to a lead then it the compression for that cylinder. However, it's not likely to be TDC. You can use the position of the arm to select a cylinder, but then determine true TDC by checking the piston via the spark plug hole. I use a screwdriver to feel the piston move up and down, rocking the crank back and forth till I fine the high point. You will also notice a lack of rotational friction at this point. WARNING. Use a screwdriver with a handle that is too big to fall into the cylinder!

thanks for the reply, I have seen a few ways to find tdc now, I was going to go with the screw driver method to determine it was actually there.
will try again tomorrow on my day off and hopefully do it properly!
 

[ajsimmo]

Unnecessary. If dizzy rotor arm is pointing at number 1, and pulley is on tdc mark, that's correct and accurate enough for your needs.

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