AJS & Matchless Owners Club

Hi, I would be grateful for some advice concerning a bit of an unexpected noise coming from an engine currently being re-built

Its a '59, and we have replaced both the cams with new, and new pushrods. As the engine is turned over by hand, there is a clicking sound as both inlet cam lobes go over top (fully open). There is no sound coming from the exhaust side of things. The tappet clearances have been set correctly and checked, and the springs are not getting bound.

I'd be grateful for any help/suggestions what might be causing the noise, thank you.

Do you mean clicking as in a 'click click click' sound, or a single click? Can you identify whether it is coming from the valve or the cam end? Putting your ear against the handle of a long screwdriver with pressing the blade against various points on the engine while it is turned over can sometimes help to locate sounds.

Malc

MalcW, going by the OP's description this has to be a single click.

Q, this is a long shot but I'd inspect cam follower bushes and valve guides for wear. Some parts appear to be moving laterally while under load ...

-Knut

You are aware that '59 push-rods are a different length to '60 onwards rods and not that easily come-by Just a long shot!

Possibly excessive endfloat on the camshafts if you have not already checked it, not much to strip down to check just see how much play you can feel on the timing gear.

1608 wrote:You are aware that '59 push-rods are a different length to '60 onwards rods and not that easily come-by Just a long shot!

Now in stock at Kettering.

Hi everyone, thank you for taking the time to reply to my query.

In answer to the posts..

Malc, its a single click coming from the cam end, as it goes over the lobe, inlet cam only, but on both lobes. There is no noise from the exhaust cams.

Knut- cam followers were replaced less than 1000 miles ago, and were not showing any signs of wear. We'll double check value guides- I think they were checked for wear, but will make sure

1068- Yes, I was, thank you. I ordered a new set of pushrods "59 only" from Kettering.

Duncan, we will double check end float as well.

Thanks all!

Different animal admittedly but it was excessive cam end float causing the ‘clack' on my G3. The lobe contacts the tappet off center, turning it slightly to even out wear, thus pushing the camshaft axially sideways.

Apologies if I'm preaching to the converted.

Steve

That fine Steve, thank you. Its been suggested cam end float could be the issue, which we are going to check.

Hi. I'd be interested to learn [*]what your findings were.

-Knut