Engine still knocking....

[Denis Sweeney]

The attached a video link was taken today, have been putting the engine back together having had the block re-honed and new rings fitted.
As noted in other posts I have not touched the bottom end, however the sump and filter were removed along with the clutch and flywheel.
The rear main bearing seal plate was cracked and replaced along with new lip seal.
The front and rear main bearings have not been disturbed.
At no time had I noticed this particular knocking at any time when rotating the flywheel.
The engine had been sitting on its rear end supported on wooden blocks whilst the oil filter screen was refitted along with the sump.
Once the engine was sat back level again on its stand I decided to pack up for the day but when rotating the flywheel the noise was pretty evident and is far more noticeable from the front end.  
Any ideas, will obviously be taking off the sump and filter again to investigate but that's for another day

https://youtube.com/shorts/rHV1oeqZfiA

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Just checked back over previous posts on this subject which included an earlier video in which the same noise was present. Colin Wilks suggested then that it may be the spring on the starting handle catching.
I had not removed the front cone at that time but I noted that once it was removed along with the spring the noise appeared to disappear. As can be seen from the latest video the cone and spring have not yet been fitted but the noise has returned.

[Stuart Giles]

Have you tried turning the motor over with your ear close to the timing gears? Difficult to see in the video, but it looks like there's some backlash there.

[Howard Wright]

Hi Dennis

To my “untrained” ear it does sound as though it’s cam / timing gear related. I believe noises like this can arise as the follower is pushed down by the valve spring?

Cheers

Howard

[Reckless Rat]

I tend to agree it sounds like eiither a sticking cam follower or a valve.

[Peter Naulls]

My Ruby engine does something similar but much more quietly. I always assumed it was clearance in the timing gear mesh. If you rock the cam gear backwards and forwards with the crankshaft stationary do you get a similar noise?

[robert regan]

does it make te same noise if you spin the fly wheel back the other way regards rob.

[Steve Bryant]

May I suggest removal of one of the timing gears so that you can isolate the noise to either crank / rod related or cam / lifters/ valves when you turn either separately ?
Stephen

[Ruairidh Dunford]

This is perfectly normally noise on an engine that has backlash in the timing gears.

As the cam rotates, the followers (aided by the valve spring), push down on the camshaft and takes (snaps) up the slack. This manifests in the clunk you hear in your film, the cam gear is slamming against the crankshaft gear. If you hold the camshaft gear with your hand as you rotate the noise will be reduced, adding thick oil will have the same outcome.

[Tiger]

Dennis
I have reread all your posts.
From your recent information are you saying with the engine vertical no noise was present ?
But when you placed it horizontal it was heard again ?
Am I correct in this assumption?
Regards
Tim

[Ruairidh Dunford]

I needed to put the block on this engine at some point, so on it went, today.

The backlash on this engine is spot on and everything is newly machined etc. but you can hopefully you can still hear the clunk as the springs push the cam followers down and the cam lobe over. This noise will get more pronounced as the gears wear.

My hand reduces the impact and therefore the noise.

I hope this helps.

https://youtu.be/94gVi24e-bQ