Engine noises

[JoeRowing]

Some testing yesterday suggested sticking valves and a bit of redex in the carb didn't fix it so I popped the head off to find this:
   

   

   

Looks like the bores are good with no discernable wear. The clean, stamped pistons speak to a rebuild I assume so I'm hoping to clean up this carboration and the valves and run it.

Comments welcome, as are cleaning tips!

I've absorbed a bit through osmosis over the years but I'm still very much a rank beginner.

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Both inlet and outlet valves seriously grubby.

You'd not believe it has a new tank, new fuel, cleaner additive and I cleaned the fuel lines thoroughly...

   

[Charles P]

Bores look ok but JP pistons have been known to be troublesome by a number of people. One failed on me and broke a chunk out of the top land. They were sold around 10-15 years ago so the good news is that it means someone has been inside your engine. That may also be the bad news.
I reckon that you have to go deeper.

Sorry about that

Charles

[JoeRowing]

Thanks Charles. Looks like it's sump next then. No space at the moment to pull the engine out and work on the bench.
What's the go-to piston at the moment?

[Hedd_Jones]

I have to say I've listened to the video 3 times now, and fail to 'hear' any problem.

Its a bit tappety, which is pretty standard for a cold 7 engine. If as you say the tops of the adjusters are a little worn, then with them set at 6 and 7 you will have a smidge more no matter what you do.

The engine I've thrown in my daughters saloon temporarily is exactly like that, a little tappety, which improves as it warms up. Pulls like a train though.

[Malcolm Parker]

It's good that the head and manifold have come off without breaking any studs or other woes.   It will be easy to check whether the valves are sticking now that the head is off.   Assuming they are all free I would replace the head and manifold and try the engine again.   When replacing the head I would use a new gasket and give each side a very thin smear of Loctite 5920 copper silicone.  Torque the head nuts down to 18 lb ft and then to 20 lb ft if the engine is okay.

[Parazine]

What's the go-to piston at the moment?

I'm using the Tony Betts slipper pistons in the Chummy and they're very good with negligible oil consumption. I've also used Seven Workshop pistons recently and they're also good, however I think Jamie has supplier issues at present and can't get hold of new stock.

[Charles P]

Tony Bett's pistons are great but come in metric over sizes, so would mean a rebore. Seven Workshop are imperial.
I'd be tempted to clean it up and regrind the valves, reassemble, check compressions and see how it runs. If it still has an uncomfortable noise you can loosen the tappets and remove the block, head and exhaust manifold off as one, so you don't disturb the new gaskets

Charles

[JoeRowing]

I think this is exactly it. It seems so clean inside, even to the point of no corrosion in the head, that I'm going to try cleaning it and going again. Of course I need to fetch a valve spring tool from Essex....

And order some more gaskets...

I found that the manifold gasket had seen better days round the rear intake, which are the worst fouled. I suspect the culprit is gummy old petrol before we took it on.

[Andy Bennett]

I have to say I've listened to the video 3 times now, and fail to 'hear' any problem.

Its a bit tappety, which is pretty standard for a cold 7 engine. If as you say the tops of the adjusters are a little worn, then with them set at 6 and 7 you will have a smidge more no matter what you do.

The engine I've thrown in my daughters saloon temporarily is exactly like that, a little tappety, which improves as it warms up. Pulls like a train though.

I thought the same at first but under the light tappety noise is a deeper clinking. You might need speakers rather than just laptop to hear but there is something below the frequency of tappets rattling gently to itself.

["Slack Alice" Simon]

It's a 3 bearing, isn't it?

I don't know what noises one should listen for on a 3 bearing.