Forum

[John R]

I ride an '89 350, which is in good nick. I adjust the tappets just a little on the tight side, and when I start up, nothing competes with the rhythmic thump of the Goldie exhaust. Then, after about a mile, the valve train loosens up and there is a staccato clatter. Now, I know, that's normal, they all do that sir, it's because the cylinder expands more than the pushrods. But does it have to be so? If you fit an alloy barrel, does the same thing happen? Could you devise pushrods that expanded a bit more? Or adapt hydraulic valve lifters somehow?

[Alan R]

Hi guys,--------- JOHN R, try setting your tappets at zero when up to running temperature. After all that's how they're supposed to be anyway, allowing for running clearances that is...( Also, convert the stud within the tappet access panel to a bolt---then you can use normal spanners for the push-rod lock-nuts etc)...Where's that "staccato clatter" coming from ?? Is it a light, "clicking" from the R/H side of the engine,(Cam followers wearing out ??) or a noisy CLATTERING from the front end... Try using the "Long screwdriver stethoscope" idea to pin-point the actual source....I recently had exactly the same scenario which turned out to be a poorly fitted exhaust valve seat in the cylinder head.........

[Frank]

I certainly know what you mean regarding the noise but i don't think fitting an alloy barrel will be of any help. I would have thought it may even make things worse as the alloy will expand more. Admittedly I speak only from experience with the Electra X, but as far as this goes the theory would be the same. I've tried various things like setting the clearances to 0 when hot but this only leads to burnt fingers and lack of compression when cold. The specified 0 clearance when cold is presumably to compensate for the expansion when hot allowing a little clearance over all, but I guess it's difficult to judge an exact figure and so it is a bit of a compromise. What I have found is that merely kicking it over until compression is felt, and then adjusting both valves is not good enough, as the pushrods have a little way to relax afterwards. I prefer to turn the engine over whilst looking at each individual pushrod and the adjust it when I'm sure it's fallen to the lowest position. Not perfect as far as the noise when hot is concerned, but probably the best you are going to get.

[Dennis C]

What we all need to remember here is that these engines where designed over 60 years ago and the noise from the tappets ETC is a part of them, accept them for what they are, there are some things you can do to improve them and some things you can't improve, if you want a silent engine then you need to buy a more modern design

[Alan R]

Hi guys-------- DENNIS C, agree with you re}--- old design, but there is a distinct difference between the "rustle" of a properly adjusted, normally operating OHV system--- and the CLATTER of something not quite right..The problem for an untrained "ear" is knowing when the former is changing to the latter, I would say....I think FRANK has the best approach overall for actually setting the rods.....Ideally the cam follower should be at the very lowest point on the cam itself (sometimes known as the base circle),..This requires each rod to be done individually as valve overlap means both base positions will NOT be exactly in the same place simultaneously...For our "cooking" engines the TDC Compression stroke is good enough....The unusual gear wheel drive train ( crankshaft--exhaust(directly driven)---inlet(indirectly driven)--two idlers,---distributor) can also give rise to some "odd" noises as the inlet valve spring can "unload" onto the exhaust cam wheel at the same time as the exhaust valve spring is "loading" up and one tends to fight the other momentarily....Hence the two different pushrod lengths as well ( other makes use a direct drive for both inlet and exhaust, giving just one length of rod to manufacture !!!)...My mate Tim's 1938 model C has exactly the same set up...Enfields, Don't you just LUV 'em ??--------Incidentally I changed from a Iron barrel to an Aluminium one this year and can't say I've noticed any real differences re}--- settings..

[Winkie]

I had a great ride out to Ironbridge today but on the way back there was a dreadful clattering noise which sounded like the pushrods had come loose. Got home, undid the inspection cover and then noticed that the rear petrol tank mounting stud had almost vibrated itself out! The noise was just the tank rattling! Nothing to do with this thread, really, but interesting. Remarkably the nut on the right hand side had fallen off, leaving the stud free to start exiting to the left, but the nut had obligingly fallen to rest on top of the gearbox and had miraculously stayed there on the journey home. Saved the need to hunt in the spares box for a new nut..

[Peter 53]

I had that too, the nut falling off thing... small tip: it's the exact same as the one that holds the exhaust bracket by the footpeg.

[Alan R]

Hi guys----------WINKIE, you should have given me a shout I'm only at the other end of the Eastern Primary !!...........that loose nut sounds like a job for}---- ta-da!! LEAPING LOCTITE MAN !!