Because the mixture can only be admitted to the cylinders from the crankcase through ports in the cylinder itself. Most two strokes use the suction from the descending piston to admit the mixture into the combustion chamber. This can be controlled by reed or disc valves in the case of a normally aspirated two stroke engine. For forced induction (supercharging for the ignorant)two strokes, the admission of mixture into the cylinder must be more positively controlled. Thats where the sleeve valve comed into play. Voila.

Not really relevant but it’s quite possible to make a two stroke with no valves as such. Many British motorcycles (and the majority of modern 2-stroke model aircraft engines) had engines where the induction and exhaust were controlled simply by the piston uncovering holes in the cylinder wall.

The BSA Bantam springs to mind, a single cylinder engine with 3 moving parts.

Most of an Orpheus 700 I believe.
Having looked at the website earlier today (for far too long) it appears to have sufferd more than the boat from 34 years underwater.

There were I think two huge estates of prefabs in Welwyn Garden City when I lived there throughout the sixties. I believe they’re all gone now.

There are still a fair number in Chesterfield that are still lived in.

I don’t know if I’ll get the chance to go again, but for me, my trip last year is right up there with a day at ‘Legends’.

Geoff.

but a LOT colder.

A Google says it was G-AGYD. Shame, would have been a nice claim to fame.

two pic’s of some boxy looking tank engine (highly polished) which he finished his career on, as a pilot (he said) showing less experienced drivers the layout & points/lines in & out of Liverpool St Stn.

The station pilot was an engine permanently on station for pulling stock/trains in and out of the platforms, not for teaching drivers. I suspect it’s possible that may have happened too but that’s not why it was there. Liverpool St had two I believe.

I’m sure one of the more fanatical spotters on here can be even more accurate but that’s my understanding.

I also have no interest in diesels but I do make an exception for Deltics. There’s something about the sound that really gets to me. I had a cab ride in one recently when the six remaining production locos were all together at the Deltic Preservation Society’s open day at Barrow Hill. Seriously overpowered train – two coaches and a Deltic at each end.

No – timber preservatives are oil based – you wont get paint, fabric, or anything else to stick to them. Someone tried that on our Sea Venom – and then had to try and get it out again….

Bruce

Just bumping this back to the top again after confirming what I thought I read on a tin of wood preservative in my shed.

Cuprinol Wood Preserver – Clear. Can be glued, stained, varnished or painted after the wood has dried, usually 3 – 5 days, longer if cold etc.

I know it works, painting wise that is – not preserving, I only did it a few weeks ago on a door frame.

Likely to be of interest?