7. Answer the questions.

1. What kind of base does the D12 have?

2. What features of the engine help to cope with out-of-balance forces?

3. How many take-offs are possible?

4. What kind of cooling system is used? What are its advantages?

5. What kind of water filter is used by the cooling system?

6. Where and how has the engine been tested?

7. What are the results of the tests?

8. Give the summary of the text, using the answers to the questions. Unit 9

High-Powered Medium-Speed Engines. A550 Engine

1. Read and translate the words. Mind the pronunciation.

   ratio	–	соотношение
   large-end bearings	–	подшипники нижней головки шатуна
   to mount	–	устанавливать
   composite	–	составной
   crown	–	днище поршня
   skirt	–	юбка
   cage	–	коробка
   welded	–	сварной
   thermal efficiency	–	термический КПД
   mechanical efficiency	–	механический КПД
   b.m.e.p. (brake mean effective pressure)	–	среднее тормозное эффективное давление
   m.c.r. (maximum con­tinuous rating)	–	максимальная длительная мощность

2. Read and translate the text.

The A550 engine develops 1200 bhp/cylinder at 430 rev/min and has a low stroke/bore ratio resulting in a very compact machine of moderate length and overall height.

A deep bedplate is made of cast iron held in compression with the cylinder block while large-end bearings are mounted side-by-side on the vee-form ma­chines. Composite oil-cooled pistons have a steel crown bolted to an aluminium skirt while the cylinder cover mounts the inlet valves and two exhaust valves in cages. Heavy fuel is burnt in the A 550 engine.

The engine is built in both in-line in six, eight and nine cylinders, and vee-form in 12 to 20 cylinders and while a heavy cast iron frame construction is used for in-line engines; an alternative design of welded steel frame is devel­oped for vee-form machines.

Principal particulars of the A 550 engine:

Cylinder bore 550 mm

Piston stroke 590 mm

Operating cycle 4-stroke

Cylinder configuration in-line and vee-form

Maximum continuous 1200 bhp/cyl

Corresponding engine speed 420 rev/min

B.m.e.p. at m.c.r. 17.92 kg/cm²

Maximum pressure 114 kg/cm²

Corresponding pressure 75 kg/cm²

Thermal efficiency 41 per cent

Mechanical efficiency 89 per cent

3. Arrange the following words

   	to mount		to incinerate
   	compact		an intake (valve)
   	a cover		a machine
   	to burn		small
   	an engine		to install
   	an inlet (valve)		a cap

4. Give the whole names of the abbreviations:

bhp/cyl; rev/min; b.m.e.p.; m.c.r.; kg/cm²

5. Answer the questions.

1. What does a low stroke/bore ratio result in?

2. What is the bedplate of the engine made of?

3. How are composite pistons cooled?

4. What fuel is burnt in this engine?

5. What cylinder configurations are used in this type of the engine?

6. How are large-end bearings mounted on the vee-form machines?

7. What frame construction is used for in-line engines and for vee-form machines?

6. Translate the sentences from Russian into English.

1. Двигатель A550 развивает мощность в 1200 л.с. при 430 об/мин.

2. Подшипники нижней головки шатуна устанавливаются рядом на V- образных двигателях.

3. Фундаментная рама сделана из чугуна.

4. В двигателях этого типа сжигается тяжелое топливо.

5. Составные поршни с масляным охлаждением имеют стальные дни­ща, прикрепленные болтами к алюминиевым юбкам.

6. Чугунные станины используются в рядных двигателях, в то время как сварные стальные станины разработаны для V-образных двигателей.

7. Translate the sentences paying attention to the infinitives and in­finitive constructions.