After text activity

I. Reading Exercises:

Exercise 1. Read and memorize using a dictionary:

camshaft; dependent variable; efficiency; in the opposite direction; in the opposite order; independent variable; inertia; intake; on the opposite side; OverHead pushrod; random variable; rocker arm; variable.

Exercise 2. Answer the questions:

1) What does OHV engine design mean?

2) Where is the camshaft installed in SOHC engine?

3) What is the disadvantage of an OHC engine?

Exercise 3. Match the left part with the right:

1. OHV means OverHead Valve - an engine design where	a) is installed in the cylinder head.
2. In the SOHC engine the camshaft	b) "breath" better meaning that it can produce more horsepowers with smaller engine volume.
3. OHC engine requires	c) the camshaft is installed inside the engine block and valves are operated through lifters.
4. Double OverHead Cam engine can	d) has been successfully used for decades.
5. Although an OHV design is a bit outdated, it	e) a timing belt or chain with related components.

Exercise 4. Open brackets choosing the right words:

DOHC or Double OverHead Cam - the setup (got/used) in many today's cars. Since it's possible to install multiple valves per cylinder and (feel/place) intake valves on the opposite side from exhaust vales.

II. Speaking Exercises:

Exercise 1. Describe intake valve; camshaft; rpm; cylinder; horsepower using the suggested words and expressionsas in example:

intake valve metal; a rod; a flat disc; intake passage; cylinder head example:Intake valveisa metal valve that looks like a rod connected to a flat disc that opens/closes the intake passage in the cylinder head.

camshaft inside an engine; lobes; engine's valves; "pushrod" engines; cam lobes; the up and down motion; rocker arms; to actuate the valves

rpm abbreviation; revolutions; per; minute; engine speed; expressed as;

cylinder a chamber; within; piston; to move

Horsepower a unit of measure; power output; James Watt; a horse; the amount of effort; in one minute; after internal friction

Exercise 2. Ask questions to the given answers:

1) Question: ___________________________________________?

Answer: OHV means OverHead Valve - an engine design where the camshaft is installed inside the engine block.

2) Question: ___________________________________________?

Answer: OHV engine is also known as "Pushrod" engine.

3) Question: ___________________________________________?

Answer: OHC in general means OverHead Cam while SOHC means Single OverHead Cam.

4) Question: ___________________________________________?

Answer: Double OverHead Cam engine can "breath" better meaning that it can produce more horsepowers with smaller engine volume.

III. Writing exercises:

Exercise 1. Complete the sentences with the suggested words: per; at; with; to; in; by;

In the SOHC engine the camshaft is installed ____the cylinder head and valves are operated either _____ the rocker arms or directly through the lifters (as in the picture). The advantage is that valves are operated almost directly by the camshaft - easy to achieve the perfect timing ____ high rpm. Also it's possible ____ install three or four valves ____ cylinder. The disadvantage - an OHC engine requires a timing belt or chain ____ related components - more complex and more expensive design.

Exercise 2. Fill in the table with words and expressions from the text:

	parts	ability	place
Example: OHV means	OverHead Valve	-	-
the camshaft is installed
OHC in general means
DOHC engine can
it's possible to install multiple valves

Exercise 3. Compose a story on one of the topics (up to 100 words):

“Engine block and valves”

“The valve timing”

“The 3.5-liter V6 DOHC engine of 2003 Nissan Pathfinder”.

Lesson 3

Дата добавления: 2015-11-16