Hi Patrick, I had a similar problem happen on my BJ8. It turned out to be the
front couple of tappets were not getting enough oil and eventually started
sticking in the bore until the cam lobe came around again and knocked it back
the other way. Very loud knocking at idle that sounded very serious, but
quite easy to fix.
The best way to isolate the problem now matter what it is is to get a
mechanics stethescope and listen with it to see if you can isolate where in
the engine the sound is coming from. A large screwdriver works well also; put
the blade end of the screwdriver against the engine and the end of the handle
against your ear. Just be careful where you put the screwdriver with the
engine running...
On my engine, the cause was a stripped and leaking oil fitting at the rear of
the valve train with the result that the rear of the valve train was getting
lots of oil, but the further towards the front of the engine they got less
oil, so the front of the valve train on the first two cylinders weren't
getting much oil. The tappets on the first two cylinders were completed
concave and badly pitted from lack of oil. In fact they were difficult to get
out, whereas the tappets towards the rear easily came out. On the BJ8 engine,
you can access the tappets through several access plates on the side of the
engine, so they are easy to remove. A weekend job and no more. I just
replaced the tappets with a new set from Healey Surgeons, well lubed with
assembly lube and thats it. I should have checked the cam lobes for wear and
perhaps replaced the cam as well, but chose not to. It runs fine; it maybe
isn't making all the power it should if the cam lobes are worn, but
qualitatively, it seems to have as much power as before. I also changed the
oil with a good quality 20W-50 oil with an additive. That was two or three
years ago and haven't had a problem since. I will rebuild the engine one of
these days and check the cam out at that time.
Hope this helps,
Frank Magnusson
Wichita, KS
'65 BJ8
Yesterday morning we were 560 kilometres from home in the BN3 having
> just
> crossed some many kilometres of featureless plains and semi dessert.
> We
> arrive in a large town looking for fuel and then suddenly an audible
> clanging sound emanates from the engine. We immediately pull over to
> investigate and despite much head scratching nothing significant can
> be
> found. I disconnect the fan belt and also eliminate a rocker hitting
> the
> rocker cover.
>
>
>
> Six and a half hours of sitting in the back seats of a tilt tray
> truck we
> arrive back home.
>
>
>
> Today I removed the rocker cover and all valves are opening
> correctly, plus
> the noise is still there. So what do we think the noise is? Oil
> pressure is
> still good, so it probably isn't a slipped big end. It is definitely
> not
> coming from the gearbox.
>
>
>
> Without taking the engine out, my guess is a broken crankshaft. What's
> yours?
>
>
>
> Hoo Roo
>
>
>
> Patrick Quinn
>
> Sydney, Australia
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