( E ) exhaust camshaft, ( I ) intake camshaft, ( S ) spark plug, ( V ) poppet valve | valve s, ( P ) piston, ( R ) connecting rod, ( C ) crankshaft, ( W ) water jacket for coolant flow.

Another heat transfer application is in high-performance internal combustion engines with poppet valves, where valve stems partially filled with sodium are used as a heat pipe to cool the valves.

A pipe leads from the tank to a poppet valve, and then to the decomposition chamber of the rocket motor.

The rocket is fired when the computer sends direct current through a small electromagnet that opens the poppet valve.

* Tappet, part of an internal combustion engine that actuates a poppet valve through rocker arms and pushrods

A uniflow diesel engine takes in air via scavenge ports, and exhaust gases exit through an overhead poppet valve.

( E ) Exhaust camshaft, ( I ) Intake camshaft, ( S ) Spark plug, ( V ) poppet valve | Valves, ( P ) Piston, ( R ) Connecting rod, ( C ) Crankshaft, ( W ) Water jacket for coolant flow.

The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve.

A small number of designs used a " cuff " sleeve in the cylinder head instead of the cylinder proper, providing a more " classic " layout compared to traditional poppet valve engines.

In other words, at higher RPM the engine typically requires larger ports that remain open for a greater proportion of the cycle, which is fairly easy to achieve with sleeve valves, but difficult in a poppet valve system.

This helps scavenging when exhaust / inlet timing overlap is used and a wide speed range required, whereas poor poppet valve exhaust scavenging can dilute the fresh air / fuel mixture intake to a greater degree, being more speed dependent ( relying principally on exhaust / inlet system resonant tuning to separate the two streams ).

Greater freedom of combustion chamber design ( few constraints other than the spark plug positioning ) means that fuel / air mixture swirl at TDC can also be more controlled allowing improved ignition and flame travel which as demonstrated by Ricardo, at least one extra unit of compression ratio before detonation compared with the poppet valve engine.

A problem with high-speed engines that use poppet valves is that as engine speed increases, the speed at which the valve moves also has to increase.

Sleeve valves did not suffer from the wear and recession caused by the repetitive impact of the poppet valve against its seat.

In the Knight engine, carbon build-up actually helped to improve the sealing of the sleeves, the engines said to " improve with use ", in contrast to poppet valve engines, which lose compression and power as valves and valve stems and guides wear.

In a poppet valve engine, the piston possesses piston rings ( at least three and sometimes as many as eight ) which form a seal with the cylinder bore.

In the 1940s this was not a major concern because the poppet valve stems of the time typically leaked appreciably more than they do today, so that oil consumption was significant in either case.

This paper outlined the advantages of the sleeve valve and suggested that poppet valve engines would not be able to offer power outputs much beyond 1500 hp ( 1, 100 kW ).

Following World War II, the sleeve valve disappeared from use, as the previous problems with sealing and wear on poppet valves had been remedied by the use of better materials and the inertia problems with the use of large valves were reduced by using several smaller valves instead, giving increased flow area and reduced mass.

Up to that point, the single sleeve valve had won every contest against the poppet valve in comparison of power to displacement.

Her poppet, her Sergius, was no chicken, with a dud arm that prompted hope of early retirement.

Upon Knight's return to America he was able to get some firms to use his design ; here his brand name was " Silent Knight " ( 1905 – 1907 ) — the selling point was that his engines were quieter than those with standard poppet valves.

In the past, " puppet valve " was a synonym for poppet valve ; however, this usage of " puppet " is now obsolete.

In the early days of engine building, the poppet valve was a major problem.

James Watt was using poppet valves to control the flow of steam into the cylinders of his beam engines in the 1770s.

Criticism was reported in the journal Science in 1889 of equilibrium poppet valves ( called by the article the ' double or balanced or American puppet valve ') in use for paddle steamer engines, that by its nature it must leak 15 percent.

One of the designers in the engine department was Samuel Heron, who later went on to invent the sodium-filled poppet valve, instrumental in achieving greater powers from piston engines.

Although the engine was cylinder-ported and required no poppet valves, each bank had a camshaft, driven at crankshaft speed.

Stellite was a major improvement in the production of poppet valves and valve seats for the valves, particularly exhaust valves, of internal combustion engines.

The engine was a vertical one with horizontal, opposed poppet valves for inlet and exhaust.

The 68 Special was an inline poppet valve design very similar to the SMG-60 in layout and design.

While the Pro-am was like the 68 Special in layout, being an inline poppet valve design, it was a major change in design, with a different body, valve, breech, hammer, hammer to bolt linkage, and sear arrangements.

When the mainstage signal was received, pneumatic pressure was applied against the gas generator control valve actuator assembly which moved the piston and opened the fuel poppet.

The valve gear that was settled upon was a modified form of Caprotti valve gear, the novel rotary cam-driven British Caprotti valve gear with poppet valves.

However, there was a drawback of the metallurgy used, meaning that the poppet valve could not take the stress of sustained high speed operation ( meaning over.

The locomotive was a 4-cylinder compound fitted with Lentz-Dabeg poppet valves.

He also testified that Bishop asked him to dye lace, which apparently was too small to be used on anything but a poppet ( doll used in spell-casting ).

Sleeve valves were also subjected to less intense heat buildup than poppet valves, owing to their greater area of contact with other metal surfaces.

However, their aircraft engines soon equaled the single-sleeve-valve engines ' performance by introducing improvements such as sodium-cooled poppet valves, and it seems also that the costs of this research, along with the October 1929 crisis, lead to the Continental single-sleeve-valve engines not entering mass production.

A poppet valve ( also called mushroom valve ) is a valve typically used to control the timing and quantity of gas or vapour flow into an engine.

When used in high-pressure applications, for example, as admission valves on steam engines, the same pressure that helps seal poppet valves also contributes significantly to the force required to open them.

Schrader valves ( also called American valves ) consist of a valve stem into which a poppet valve is threaded with a spring attached.

He also found that the album's music and the distinctive pronunciation of Ellis-Bextor's vocal delivery did not work to complimentary effect ; " This former indie poppet explained away her leap into clubbing's sweaty embrace through Number 1 hit Groovejet's use of guitars.

Use of poppet valves also increased the speed each set of drivers could achieve because they gave very accurate steam delivery to the cylinders.

Further technical improvements also followed, including the introduction of poppet valves and the hot-tube ignitor in 1888 and the introduction of the carburettor, allowing volatile liquid fuels to be used.

Wedges can also be used to hold objects in place, such as engine parts ( poppet valves ), bicycle parts ( stems and eccentric bottom brackets ), and doors.

Superalloys ( such as Nimonic 80A ) are also used in the poppet valves of piston engines, both for diesel and gasoline engines.

The electronic control unit may also control electronic throttle control ( drive-by-wire ), poppet valve timing, boost control ( in turbocharged engines ), Anti-lock braking system, the automatic transmission, speed governor ( if equipped ), and the Electronic Stability Control system.

The majority of mechanical markers employ a simple blowback design utilizing a poppet valve ( also known as a “ pin valve ”), which is opened when struck by a compression force, provided in the form of a hammer propelled by a spring.

However, they are also more gas efficient than spool-valve models because the poppet valve only releases the precise amount of air needed to fire the marker.