• 14 parts
  • Checked October 2026

Parts of an Engine Valve

An engine valve with its spring parts in a row, then the same valve closed in a cylinder head.

Parts of an Engine Valve

Name Date

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1 2 3 4 5 6 7 8 9 10 11 12 13 14
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Write the name of each numbered part.Answer key

  1. Valve head
  2. Valve face
  3. Valve stem
  4. Valve tip
  5. Stem seal
  6. Valve spring
  7. Retainer
  8. Keepers
  9. Cylinder head
  10. Valve seat
  11. Valve guide
  12. Port
  13. Combustion chamber
  14. Rocker arm

Drawn for this site on 2026-10-01 from plain geometry. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a part is answered.

Next step Next: the whole engine round the valves

All 14 parts on the diagram

Show the list

Valve and spring 8

  1. Valve head The disc that closes the port. Its sloped edge seals on the valve seat.
  2. Valve face The ground band that seals on the seat. It is cut at 30 or 45 degrees.
  3. Valve stem The shaft that slides in the valve guide. The spring and retainer fit over it.
  4. Valve tip The hardened end of the stem. The rocker arm presses on it to open the valve.
  5. Stem seal It works like an umbrella over the guide. It keeps oil from running down the stem.
  6. Valve spring It holds the valve closed. It also shuts the valve again after each opening.
  7. Retainer The cap on top of the spring. The keepers lock it to the stem.
  8. Keepers Two wedges that fit a groove near the tip. They lock the retainer to the stem.

In the head 6

  1. Cylinder head The casting that closes the top of the cylinder. It holds the valves, seats, guides and ports.
  2. Valve seat The ring the valve face closes on. It is part of the head or a pressed-in insert.
  3. Valve guide The sleeve that keeps the stem straight. It lines the face up with the seat.
  4. Port The passage the valve opens and closes. An intake port lets the fuel and air in.
  5. Combustion chamber The space where the fuel burns. The closed valves seal it.
  6. Rocker arm A lever that pushes the valve open. One end presses down on the valve tip.

How this list was compiled: Every name checked on 2026-10-01 and kept only where two independent sources use it. (1) US Army TM 9-8000, Principles of Automotive Vehicles (1985), chapters 2 and 3, https://archive.org/details/tm-9-8000-principles-of-automotive-vehicles-1985 . (2) The Federal Aviation Administration's Aviation Maintenance Technician Handbook: Powerplant, volume 1, chapter 1, https://archive.org/details/faa-h-8083-32-amt-powerplant-vol-1_202601 . (3) Wikipedia, text only: Poppet valve, https://en.wikipedia.org/wiki/Poppet_valve ; Valve seat; Valve guide; Valvetrain; Rocker arm. Valve tip, retainer and combustion chamber rest on sources 1 and 2; every other name is in all three. Licence: own work

The drawing: Drawn for this site on 2026-10-01 from plain geometry; no maker's product, nothing traced. Licence: own work

How it works

An engine valve is a disc on a long stem. It opens and closes a port in the cylinder head. The first view sets the valve and its small parts in a row. The second shows it at work.

Read the full guide

The valve and the four parts that hold it shut

The wide end is the head, and the sloped band round its edge is the face, the only part that seals. The stem ends in a hardened tip. A stem seal, the spring and the retainer slide over the stem. Two keepers wedge into a groove near the tip and lock the retainer on.

In the head, the valve meets three more

The stem slides in the valve guide. The face closes on the valve seat at the mouth of the port. A rocker arm presses on the tip to open the valve, and the spring shuts it again.

  • Keepers are also called collets, valve locks or split locks.
  • Intake and exhaust valves have the same parts, so learn one.

Questions and answers

What are the parts of a valve engine?

This usually means the engine's valves. Each valve has a head, a face, a stem and a tip. A spring, a retainer, two keepers and a stem seal hold it, and it works in a guide and against a seat in the cylinder head.

What is the difference between a valve seat and a valve face?

The face is on the valve: the sloped band round the edge of the head. The seat is in the cylinder head: the ring the face closes on. Both are ground to the same angle, usually 30 or 45 degrees, so they seal.

What holds an engine valve in place?

The valve spring pulls it shut. The spring pushes up on the retainer, and two wedge-shaped keepers lock the retainer to a groove near the tip of the stem. The valve guide keeps the stem straight.

What is the difference between intake and exhaust valves?

They have the same parts. The exhaust valve runs hotter, so it is made of more heat-resistant steel. Some exhaust valves are hollow and part filled with sodium, which carries heat from the head to the stem.

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