The engine on RA3910 is currently sick. I first noticed the plugs sooting up, which I put down to the fuel I was using. Then I came across oiling on number 6 cylinder.
So the car was moved to the workshop of one of the few engineers familiar with sleeve valve Daimlers - Darren Christian in Banks, near Southport. Eventually (he's a busy man), he got round to taking the lid off my engine.


The news was not good. The inner sleeve for number 5 cylinder actually has a hole burned through it.

The outer sleeve shows a hotspot at the problem area:

The inner sleeve has been burned through from its outside:

The inside of the outer sleeve shows where the white metalling has been burned away, allowing exhaust gases to attack the inner sleeve.

So, there has been a worldwide hunt for spares. The grapevine eventually revealed that someone in the London area had some genuine factory-made sleeves, which had been sitting on a shelf since the 1920s. So I paid what was asked for a pair. After all, where would I find another one?
There are other problems which need to be addressed whilst the engine is disassembled. A couple of big ends need sorting, and the odd main bearing. These are "ordinary" engineering jobs, familiar to many restorers. The oil system will also need to be investigated.