Solved some of my tappet noise

[mjheathcote]

My tappet noise has always recently seemed louder when driving than when stationary.

Well this evening before taking her out for a run I was checking fluids etc when I noticed that my nearside rear engine lifting eye was at a funny angle. I quickly discovered that the lower exhaust manifold bolt was missing, and the top one was loose!

I have tubular manifolds and when I fitted them I secured them using stainless steel setscrews instead of studs, with spring washers and plenty of copper slip.

Well it appears that after over 15 years the stainless steel spring washers are no longer springy enough!

Fortunately I had some spare UNC setscrews of the correct size so I tightened up the loose one, and replaced the missing one. The threads being good and strong having all been helicoiled when I rebuilt the engine.

Its now much quieter, the manifold must have been loose enough to allow valve noise, but not to 'blow'. It does not help that I have a missing bulkhead grommet only a few inches away from the rear of the manifold allowing any noise to come straight into the cabin.

[staggering]

imported post

Had a frustrating similar situation some years ago (Iam RV8) when I thought I had worn tappets (due to click click noise at all revs etc). Stripped the heads, spent loads on complete set of new hydraulic tappets, spent time doing the job, started up and no difference :X:X.

Cut a long story short, found a hairline crack in hidden away part of the left hand tubular manifold - the click click noise was the gas pressure escaping the hairline crack. Had the manifold repaired (more cost) and noise disappeared

Ian