Intro into engines unit 3

Ball bearings are typically used in applications such as air conditioning compressors.

True

Needle bearings can be found in applications such as piston pins and camshaft bearings.

True

Ball bearings can handle both radial and thrust loads.

True

Roller bearings spread the load over a large area allowing the application to hold more weight.

True

Ball bearings are typically found in applications Where the load is extreme.

False

Plain bearings are typically made from a hardened steel alloy.

False

The oil hole allows oil to flow from the block into the clearance between the bearing and the journal.

True

Split bearings are slightly narrower at their opening than the cap or block bore that they fit.

False

Split bearings come in two halves and form around a shaft.

True

In-block camshaft bearings are full round bearings.

True

A bearing's capacity to absorb contaminants is _______

embeddability

Sometimes bearings in an engine are held in place with _______

bearing locators

A bearing's ability to stand up to high stress loads is _______

fatigue strength

A bearing's ability to adapt to slight variation and misalignment between the shaft and the bearing is _______

conformability

A bearing's ability to adapt to variation

Conformability

Technician A states that plain bearings are constructed of one material or layers of many different materials. Technician B states that plain bearings made of one material are aluminum bearings. Which technician is correct?

Both technician A and B

bearings in the engine block that support the crankshaft

Main Bearings

a bearing that is assembled around a shaft

Split Bearing

one-piece plain bearing that allows the shaft to be inserted into the bearing

Full Round Bearing

has a series of steel balls housed between two races

Ball Bearing

bearings found in roller lifters and roller rocker arms

Neelde Bearing

Allows the bearing to adapt to misalignment between the bearing and shaft

Conformability

Prevents particles from damaging the surface of the journals

Embedability

Allows bearing to withstand heavy loads

Fatigue Strength

Rubber bushings have an advantage over other bushings because they _______

allow a lot of movement

Metal bushings typically _______

add strength and durability to the application

Threaded insert bushings _______

do not require a nut and washer to fix two components together

Plastic bushings _______

are used in places that do not have high torque or load

Fleure bushings reduce excessive movement?

True

Metal bushings are used in low load applications?

False

The purpose of bushings is to reduce friction between moving parts?

True

allows one assembly to attach to another without a nut

Threaded Insert Bushing

isolates noise and reduces unwanted vibrations

Rubber Bushing

found in places that require durability and strength

Metal Bushing

are often found between cable ends and levers

Plastic Bushing

accommodate the flex between two components

Flexure Bushing

Threaded insert bushings press into components.

True

Plastic bushings are typically found on both ends of the engine strut mounts.

False

Rubber bushings require lubrication to function properly.

False

Unlike the two-stroke and four-stroke engines, the rotary engine does not have a reciprocating piston design.

True

Like the two-stroke and four stroke engines, the rotary engine contains a piston that rotates in a clockwise motion.

False

The main component of the rotary engine is the triangular rotor in the center of the engine.

True

The large internal gear rotates around a smaller fixed gear in the housing, determining the orbit of the rotor.

True

Instead of using intake and exhaust valves, the rotary engine uses intake and exhaust ports.

True

Technician A states that vibration control in a rotary engine is much better than the vibration control in a four-stroke engine. Technician B states that oil from the lubrication system is completely responsible for cooling the housing. Which technician is correct?

Technician A

Renesis rotary engine

Redesigns intake and exhaust ports to eliminate the port timing overlap.

Traditional rotary engine

Contains intake and exhaust ports that function like valves.

Why are rotary engines not used in many applications today?

Poor emissions

Why are rotary engines used in race cars today?

Power-to-weight ratio

Rotary engines are very fuel-efficient.

False

Rotary engines use seven main components.

False

A complicated emissions control system would be the only way to lower a rotary engine's poor emissions.

True

Rotary engines put out only a small amount of power.

False

The rotary engine has a high power to-weight ratio.

True

Technician A says that the Renesis rotary engine is more efficient than the traditional rotary engine. Technician B says that the rotary engine does not work well with turbochargers. Which technician is correct?

Technician A

_______ continues to manufacture rotary engine-powered vehicles today.

Mazda

The ______ run(s) the length of the engine with rotors riding on the offset journals.

output shaft

A rotary engine uses four _______ in the front and rear chambers.

spark plugs

The _______ consists) of five parts and is/are made of lightweight aluminum.

housing

Rotary engines contain three individual chambers.

True

The rotor pocket creates additional displacement for the air and fuel mixture in the rotary housing.

True

Match each component of the rotary engine to its correct location:

1. Housing

2. Spark Plugs

3. Intake Port

4. Rotor

5. Exhaust Port

Rotary engines contain one spark plug in each port.

False

The exhaust port compresses the air and fuel mixture.

False

The spark plugs, housing, and rotor are the only main components of a rotary engine.

False

The apex seals help seal the three chambers in the rotary engine.

True

Which of the following statements are true about the rotary engine?

1. The housing is the basis of this engine

2. Uses an output shaft with lobes

3. Uses three working chambers at the same time

Which of the following statements is true about the four-stroke engine?

Uses a piston to rotate the crankshaft

Technician A states that at the beginning of the compression step the working chamber is at its smallest size. Technician B states that the combustion step starts when the rear seal of the rotor passes the intake port. Which technician is correct?

Neither Technician A nor B

One of the reasons why rotary engines are not used in many cars on the road today is because of their _______

poor emissions

If the rotary engine pocket is damaged, you will experience _______

loss of compression

When one of the spark plugs fails to ignite, your rotary engine will experience _______

loss of power

Common causes of connecting rod bearing failure:

• oil starvation

• overheating

• overloading

• contamination

Key points:

• Use a hot tank or a spray washer if available.

• Use soap and water if a hot tank is not available.

• Clean oil passages with a rifle brush.

Key points:

• Refer to service information.

• Mark the main caps.

• You may have to tap main caps with a soft hammer to remove them.

Key points:

• Crankshafts above the minimum allowable diameter can typically be reconditioned or reused.

• Replace any crankshafts below the minimum allowable diameter.

Tech Tip:

To avoid a false reading, clean the deck surface before you begin to measure.

Key points:

• Main bores can distort if main bearings become overheated.

• A dial bore gauge set up with a micrometer is critical to obtaining correct measurements.

Key points:

• Take the block to a machine shop for reboring and sleeving.

• Pistons are available as 0.010 in., 0.020 in.,0.030 in., 0.040 in., and 0.060 in. oversizes.

• The 0.030 in. oversize is commonly used on older engines while new engines use 0.010 in. or more.

Key points:

• Honing removes minor imperfections in the cylinder wall and applies a crosshatch finish to it.

• Honing is performed after a cylinder has been rebored.

• Clean the crankcase to remove metal particles.

• Apply a thin coat of oil to block surfaces to prevent rusting.

Key points:

• Remove loose debris that may have lodged in the oil galleries with a rifle brush.

• Thoroughly dry the cylinder block with a compressor before lightly coating it with oil