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Discussion Starter · #1 ·
Hi All,

Hoping to get some feedback on a concern I have come across during my cylinder head rebuild. After removing the right cylinder head and rebuilding (cleaning/checking valves, checking valve to guide clearances, lapping seats, new guide seals etc) I installed a new head gasket, reinstalled pushrods and upper rocker arm and torqued to required specs. The piston was TDC on the compression stroke as require for proper install. However, after that I went to adjust valve clearance and all was good on the intake side (.003) but on the exhaust side there was a large gap between the adjustment screw and the top of the valve (twice as large as the intake side). In order to get proper clearance i had to turn the adjustment screw way down, so far that the top sits half way down the threaded hole. This does not seem right to have to sink the screws on exhaust side down so low. I had recently finished the rebuild on the other side and the valve clearances were "normal" after install and needed very little adjustment. Any ideas? Would appreciate any feedback. Thanks guys!
 

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Are you sure that the push rod is properly in place?

You wrote "on the exhaust side there was a large gap between the adjustment screw and the top of the valve". Was this true for both of the exhaust valves?

Do the exhaust valves on the right seem to be sitting as high as those on the left (height of the top of the valve steam above the cylinder head surface) ?
 

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A photo would be helpful. There's a possibility the collets haven't seated, slid up the stem and jammed in place further down the stem.

Are the stems protruding the same amount as the other valves?
 

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Can you get compression in that cylinder with the valves supposedly closed?
 

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Discussion Starter · #5 · (Edited)
Thanks for the feedback. Here are some more details. The stems are the same height from the seats to the top as all the other valves right and left side. The collets are properly seated and the push rods are properly seated and functioning. However, upon further inspection I realized that the rocker for the exhaust valves sits approx 2.1mm lower than the arm of the intake side (The pictures are of TDC on compression stroke). Its minimal but would explain why i have to screw the adjustment screw down to get proper clearance. I know for sure that the push rods were the same length and in perfect condition so this leads me to believe that maybe the lobe on the cam shaft is worn? Or maybe there is an issue with the lower rocker for exhaust side? Here are a few pics...
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Pretty weird. You dont mention removing the back cover so this may be a poor suggestion...but Could timing positions be out?
 

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Discussion Starter · #9 ·
The camshaft was not removed so my inspection was only from top with cylinder head removed and from front with camshaft holder removed. The lobes did not show signs of uneven wear but the face of the lower rockers were obviously hard to see. Im starting to think its a combination of two things. 1) as seen in the picture the push rod for the exhaust valves sits a little lower than intake (TDC on compression) this could be from a slightly worn lower rocker arm face or cam lobe. 2) the top of the exhaust valves on the right cylinder seem to sit about 1mm lower than the exhaust valve height on the left cylinder. Possible the combination adds up the the gap? There is no side to side play on the push rods so I know they are seated properly. And i also know they are not bent. Im starting to wonder if it even matters that much if i can still get proper valve clearance?
 

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Have you installed the front cam support???
 
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Discussion Starter · #12 ·
Not yet. Are you thinking that once installed the support/centering of the shaft will fix gap?
 

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Doh!

if the cam droops it wont be on center so less lift you cant adjust the valves unless the cam is supported

loosen them all off put the cam support back then do this

dont got get the oring and dowel AND gasket when you put it back
 

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I should have mentioned this sooner....sometimes the cam support does not just slip into place.
Do not forse it,DAMHIK. Loosen the tappets, rotate the engine while pressing the support into position.
I did pull one into place by tightening the bolts but I know better now. No harm was done but that is not the
correct way.
 
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