It's no different. Did you try the stick trick? Or a length of garden hose to listen for exhaust leaks?
Sounds like my engine when one of my hydraulic lifters fails to pump up (like every time I start it!)
Not yet, Going to be my next step tomorrow now though When I was underneath the exhaust did look very tired, although I couldn’t see/hear anything from it ... Sent from my iPhone using Tapatalk
To me it sounds like there is an exhaust leak – like a light tap that can be confused with tappets, but that’s not the deeper knock that is the same as before the adjustment. The idle speed seems to be lower now but maybe that’s just my ears slowing down. As I said before, cam thrust bearing wear sounds similar – it reduces as revs increase and there is no loss of power, but that would be from the centre of the engine if you think the knock is from one side remove a plug lead with the engine idling, if the noise stops, or is significantly less, it could a small end bearing failure. The low oil pressure warning light goes off very quickly from a cold start so it’s unlikely to be a problem with main or big ends.
Not sure I’m confident driving up until I have grounded the know Ray... Sent from my iPhone using Tapatalk
I'm wondering what my phone would record if I pressed a corner against the case or a rocker cover and put my thumb over the mic.
You mentioned no valve clearances on number 3&4. I might be wrong but is sunken valve seats a possibility? Sorry i might be looking at worse case scenario
I know that I’m a bit of a muppet in my Bay Knowledge so I’m wondering where to put the hose on the engine due to all the tinware? By the manifolds? Sent from my iPhone using Tapatalk
Point the hose at anywhere there is a join in the exhaust system. Heads to heat exchangers - you won't access them very accurately with the lower tins in place but you'll be able to locate a loud noise like you have by poking the hose in from the rear. Heat exchangers to silencer and immediately HX side of that join (rust hole favourite location). Generally holes in the silencer if it's that far gone.
The stick is more fun but that's for mechanical noises. A stick and some garden hose. Diagnostic tools for the discerning.
I was atempting to make it easy, most people have s stick and a garden hose that can spare 2ft from the end?
Sounds cammy. It sounded just as bad when first started. Improved when warm. I’m terrible at engine sounds though. Half the time I listen to those videos and can’t hear a thing. Yours I can hear.
I would imagine that you have looked for anything fouling the tin roof or fan shroud. Or even loose tin. These engines make a racket when anything is loose. My maintenance regimen always involved wiping the engine bay completely clean from time to time and tightening all the tin, carbs, manifolds and linkages. These old crates seem to shake themselves apart every x miles. On a newly installed engine that needs to happen even more often. You can check your cam end play by pulling your oil pump and trying to push it forward/aft as you turn the engine with the cooling fan. I was able to measure my cam end play as quite a bit out this way (with a vernier depth gauge). I had no knock but I suspected end play issues because of build mistakes I became aware of. When I got the engine apart, it turned out I was right. I would check the simple stuff first.
It can be the oil pump COG locater pin on the oil pump walking back into the cam wheel, the 5 cam wheel rivets as the engine runs knocks the pin. As has been advised use a piece of tube or something to listen to the engine while its running...start at the oil pump
