Tappet noise - but coming from the case...

[fido]

Recently I have noticed I can hear the tappets much more loudly when driving along (windows open). I hear it from the left side when driving, but not the right side.

I have adjusted those damn valve gaps repeatedly (well, checked them -they are absolutely fine at 0.15mm)...

I also hear the same noise coming from the crankcase when idling with the engine hatch open.

I only started to hear these (or notice them) when I changed oil and filter (Champion brand - Federal Mogul made). Now, that filter doesnt hold oil pressure, so I can hear the main bearing rattle for a second or so when she starts from cold. Its a 20W50 oil I have in there.

What am I missing here? The engine has around 200k miles on it. W case 1700 from a 411 saloon, dished pistons (about 100k miles ago), Q heads (new valves 10k miles ago).

doesnt get louder on deceleration. just sounds like the valve train is loud. One reason I may hear it more on the left side is that side has a "new" rocker cover... its much thinner metal, so maybe it allows the sounds through more. I'll swap the covers over to check this sometime. Compressions are all in the 130 ± 5 psi. oil pressure is fine, she doesnt run hot (CHT or oil).

Maybe the cam is worn?

I do notice that my valve adjusting screws seem to flatten dramatically - the gaps tend to widen 0.1mm each time I adjust them (usually every 1500-2000 miles). I put this down to the poor quality metal they are made from. I'll install Porsche swivel-feet at some point.

Just an old engine do you think?

[72Hardtop]

Let me ask this. Why rebuild the heads with so many miles on the bottom end? Generally not a good idea and usually will result in issues with the lower end do to the new found power from the top end rebuild.

If the lash gaps keep opening then you have cam issue.

[fido]

why do work on the top end? All I did was replace the valves. Thought it sensible after so long... The barrels and pistons went in in 1984.

I am convinced that my valve gaps increasing is due to the tappet screws flattening. They are cheap and crap. I would happily pay 4 times as much for some decent ones. Eventually they flatten down and I dont need to adjust them, but then I inspect them and think - these look very flat, and they should be curved, so replace them, and try a different supplier. Maybe I should just let them be, and they were desigend to flatten somewhat?

[Oregon72]

why do work on the top end? All I did was replace the valves. Thought it sensible after so long... The barrels and pistons went in in 1984.

I am convinced that my valve gaps increasing is due to the tappet screws flattening. They are cheap and crap. I would happily pay 4 times as much for some decent ones. Eventually they flatten down and I dont need to adjust them, but then I inspect them and think - these look very flat, and they should be curved, so replace them, and try a different supplier. Maybe I should just let them be, and they were desigend to flatten somewhat?

You are SOOO RIGHT --- The valve adjustment screws out there are total crap. On my new engine I had to adjust my valves about every 400 miles because they wore down so fast. I finally got a good set which were about $3.00 each and they seem to be quite a bit better.

Have you checked your rocker assemblies to make sure they are at proper torque? Also, you might just for kicks remove one of your rocker assemblies pull out a pushrod tube and extract one of your lifters for examination? (Cant remember if you can see the cam lobe or not with a properly directed mini-flashlight and mirror from there, but seeing a lifter can give clues sometimes).

[fido]

where did you get the screws from? I'd pay $10 each if I knew they were good.... Guess I should just put in the swivel feet for that money though!

Yes, I should pull a lifter and take a look. The rockers are all torqued to 10 ftlbs. Maybe I'm being pernickety! The sound isnt that loud. Listening to Ratwells engine sounds, mine sounds the same. I used to have a thunderbird header and muffler, but now I have a stock exhaust (genuine original german one bought for £10!!) I can actually hear the engine its so quiet in comparison.

The original tappet screws were a bit pitted, but maybe I'll put them back on - they never needed adjusting....

[Amskeptic]

Yes, I should pull a lifter and take a look.

A) You prefer soft adjusting screws. Remember those overly hard screws that were being sold there for a while? They were drilling out people's valve stems.

B) You may have drilled out valve stems. Pull the rockers and look. Feeler blades will not give you an accurate reading, but a dial indicator will.

C) Porsche (real Porsche) swivelfoot adjusters . . .

[fido]

solved one problem... the oil filter had worked loose. astonishing - not seen that before. Anyway, bottom end doesnt rattle on startup now.

Some more clues to the second issue...

Changed rocker covers so they are both the same. On cold startup, there is no difference in tappet sounds on either side.

After a few minutes of idling, the right side of the engine quietens down, and is VERY quiet - just like a nicely adjusted engine should sound.
The left side, though, gets louder than it was at initial startup...??

So what have I done? I changed pushrod tube seals on that side just before I started to notice this. Could it be related? Must be.

I'll take the rocker gear off and have a look. However, I'm starting to wonder if it is a valve seat? Why would this sound get louder relatively quickly after startup? Its not horrendously loud. sort of metal on metal hammering. Probably only 1 rocker or valve seat.

[fido]

solved the problem. Bought some new feeler guages! The old 0.15mm was all twisted and curled through constant feeling.. new ones nice and flat, slipped through three of the gaps like butter... they are now nicely set. Lets hope they stay that way for a while...