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fluegel

Clacking

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I started up the 260 Z today and noticed at idle I can hear a clacking noise intermittently it mostly goes away when I rev the engine. I took the cover off and and went through the messy process of running the engine to check the oil bar jets were all working. I noticed that two were partially blocked so I took the oil bar off and squirted it out with carby cleaner and compressed air. When I put things back I went through the messy process again and noticed that the rear jet was a bit sluggish compared to the rest which were all working, I didn't rev the engine again.

 

Some time back I had had the head properly reconditioned  with new rockers fitted and the valve stems equalized for height do that the cam lobes are centered on the rocker pads. Because the head had had 3mm shaved off  I fitted a Kamiari twin sprocket chain tensioner set which I have now removed and refitted the standard tensioning system with suitable modifications as described in previous posts, so that works well.

 

I have never heard how the reconditioned head should sound on this engine because originally a couple of the cams were coming off the rocker pads and hitting the steel giving a regular tappet type sound. I fitted the kamiari tensioner straightaway so I couldn't hear what the  camshaft should sound like because the noise of the sprockets and chain drowned everything out. I haven't readjusted the vale clearance.

 

I need to know if everything is normal with this engine , is there anyone in Adelaide I could take the car to to reasure me the engine is OK or not.

 

Richard

Edited by fluegel

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A member not that long ago was complaining about a similar noise, turned out it was an exhaust gasket leaking.

http://www.viczcar.com/forum/topic/14197-engine-noise/

The noise I am getting sounds just like the video. I'll do a compression test to check if it may be valves if that shows OK I'll replace the manifold gasket which I got quite fast at doing as it always was a problem. Any suggestions as to the best way to stop further leaking.

 

Thanks, Richard

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Is the timing chain oil plunger/tensioner working correctly?

If t comes out too far, it can cock in the bore and jam.

With the 3mm off the head, you did slot the mount holes for the curved chain guide?

And, slotted the mount holes for the chain tensioner block, to "push" it over?

You need a positive stop in those slotted holes to stop it moving back.

Also the oil supply groove may need the slot milling further.

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Is the timing chain oil plunger/tensioner working correctly?

If t comes out too far, it can cock in the bore and jam.

With the 3mm off the head, you did slot the mount holes for the curved chain guide?

And, slotted the mount holes for the chain tensioner block, to "push" it over?

You need a positive stop in those slotted holes to stop it moving back.

Also the oil supply groove may need the slot milling further.

I moved the holes in the tensioner casting i.e. they enable the tensioner to be closer to the chain by about 2mm  the holes have positive stops so it can't slide back to the old position I slotted the top hole for the curved guide and the oil slot groove still covers the supply hole in theengine block .

 

I am confident oil is getting to the plunger, moving the curved tensioner closer in at the top slot took up most of the slack and the plunger projects no more than2-3mm. I was wondering if I should have fitted a soft washer behind the plungers rubber block so that it was in contact with the casting as the manual says 0mm clearance but they are probably have a relatively new engine in mind. Looking down into the front space everything looks good and there are no funny noises coming from there as well.

 

I have set the ignition timing to 16deg advances with 98 fuel which is great for extra power but I would prefer the original head specs i.e close to original thickness and therefor original compression ratio. I have a couple of heads which I will eventually get recond with this in mind.

 

Richard

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