And what country can preserve its liberties if their rulers are not warned from time to time that their people preserve the spirit of resistance? Let them take arms. The remedy is to set them right as to facts, pardon and pacify them. What signify a few lives lost in a century or two? The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.
Sleeve valve engine, probably WW2 vintage Centaurus. Very British, designed when the pathway between poppet valve and sleeve valve technology was unclear.
While I'm in awe of the magnificently beautiful design and machining, the sheer number of parts is scary. In most engineering, "the simpler the better" is practically a law. You don't make things more reliable by adding parts.
The advantage of sleeve valve engines is they breathe better. When a poppet valve is open it is still in the port and the valve head and stem obstruct flow. A hot exhaust valve will cause pre-ignition and burnt valves means the cylinder(s) have to be changed. A sleeve valve provides a huge unobstructed hole and it's impossible to have a burnt valve. The difficulty is the sleeve has to be perfect both in dimension and heat treatment. The fastest piston engine fighter of WWII below 20,000ft was the Hawker Tempest with it's 2,420hp Napier-Sabre sleeve valve engine. Later a new supercharger upped the horsepower of the Napier-Sabre to 3,500hp from 37 litres. The P&W 'corn cob' made more horsepower but was almost twice the size at 71 litres. Al_in_Ottawa
Sleeve valve engine, probably WW2 vintage Centaurus. Very British, designed when the pathway between poppet valve and sleeve valve technology was unclear.
ReplyDeleteI wonder what would happen if a single tooth on a single gear broke as the contraption was close to redlining?
ReplyDeleteIt would quickly "fail to proceed in spectacular fashion".
DeleteWhile I'm in awe of the magnificently beautiful design and machining, the sheer number of parts is scary. In most engineering, "the simpler the better" is practically a law. You don't make things more reliable by adding parts.
ReplyDeleteSame with government.
DeleteSomebody should mention that to the defense procurement agency.
DeleteI bet that thing makes a hell of a racket & I don't mean just the exhaust.
ReplyDelete14 cylinder?
ReplyDeleteThe advantage of sleeve valve engines is they breathe better. When a poppet valve is open it is still in the port and the valve head and stem obstruct flow. A hot exhaust valve will cause pre-ignition and burnt valves means the cylinder(s) have to be changed. A sleeve valve provides a huge unobstructed hole and it's impossible to have a burnt valve. The difficulty is the sleeve has to be perfect both in dimension and heat treatment.
ReplyDeleteThe fastest piston engine fighter of WWII below 20,000ft was the Hawker Tempest with it's 2,420hp Napier-Sabre sleeve valve engine. Later a new supercharger upped the horsepower of the Napier-Sabre to 3,500hp from 37 litres. The P&W 'corn cob' made more horsepower but was almost twice the size at 71 litres.
Al_in_Ottawa
The thing looks more like an art piece than an actual working engine.
ReplyDeleteLooks like it takes a lot of beer to work on one too.
ReplyDeleteI look at that and all I can think of is the incredible losses. Put the wrong oil in it and you probably couldn't start the engine.
ReplyDeleteSome Japanese and Swiss made automatic wrist watches rival that complexity, but in extremely smaller size. Love the engine and my Grand Seiko.
ReplyDeleteA Bristol Hercules radial engine.
ReplyDelete