4.4 Engine components

• The main components of an internal combustion engine
• The function of each component
• Sketching engine components
• Measuring engine components

• identify the components of an engine
• sketch the components of an engine
• describe the functions of the components of an engine
• perform measurements on engine components
• appreciate the need for engine components

“What are the main parts of an engine, and what does each do?”

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1. The main components of an engine
   40 min · 1 practice tasks · quiz
   The names and positions of the main engine parts, grouped into stationary parts, moving parts and valve gear.
2. The cylinder block
   40 min · 1 practice tasks · quiz
   What the block does, the bores, water jackets, oil galleries and main bearing housings, and why its shape must never change.
3. The cylinder head
   40 min · 1 practice tasks · quiz
   What the head carries, why its face must be dead flat, and what happens when overheating warps it.
4. The piston
   40 min · 1 practice tasks · quiz
   The parts of a piston, why it is aluminium, and why a cold piston is deliberately not perfectly round.
5. Piston rings
   40 min · 1 practice tasks · quiz
   The two different jobs rings do, how gas pressure makes the top ring seal harder, and why ring faults show as oil use.
6. The connecting rod
   40 min · 1 practice tasks · quiz
   The small end, shank and big end, why the shank is an I-section, and why caps must never be swapped.
7. The crankshaft and flywheel
   40 min · 1 practice tasks · quiz
   Journals, crankpins, webs, counterweights and oil drillings, and the flywheel bolted to one end.
8. Bearings and the oil film
   40 min · 1 practice tasks · quiz
   How a journal floats on a film of oil, why shells are soft and journals hard, and what happens when the film fails.
9. Valves and the valve train
   40 min · 1 practice tasks · quiz
   The valve, its seat, guide, spring and collets, and why the spring being the only closing force explains most valve faults.
10. The camshaft and its drive
    40 min · 1 practice tasks · quiz
    How the camshaft opens each valve at the right moment, why it runs at half crankshaft speed, and what happens if the timing slips.
11. The sump, oil pump and gaskets
    40 min · 1 practice tasks · quiz
    The lubrication loop from sump to bearings and back, and the gaskets and seals that keep everything where it belongs.
12. Sketching engine components
    40 min · 1 practice tasks · quiz
    What makes a component sketch useful rather than decorative, and the five things every one needs.
13. Measuring tools
    40 min · 1 practice tasks · quiz
    The steel rule, vernier caliper and micrometer, what each can read, and choosing the right one for the job.
14. Reading a micrometer
    40 min · 1 practice tasks · quiz
    The three parts of a micrometer reading and how to add them, with practice until it is automatic.
15. Measuring a bore for wear
    40 min · 1 practice tasks · quiz
    Where to measure a cylinder bore, and how six readings give taper and ovality where one gives nothing.
16. From measurement to decision
    40 min · 1 practice tasks · quiz
    Turning a measured figure into a decision by comparing it with the manual, and the judgement in between.