Chapter 34 Engine Blocks

Engine blocks are made of:

- Gray cast iron - Cast aluminum - Die-cast aluminum alloy

Cast iron is used to make engine blocks and cylinder heads for the following reasons:

- The carbon in the cast iron allows for easy machining, often without coolant. - The graphite in the cast iron also has lubricating properties. - Cast iron is strong for its weight and usually is magnetic.

Monoblock

- the cylinder, water jacket, main bearing supports (saddles), and oil passages are all cast as one structure for strength and quietness.

Engine Block Service

-Main Bearing Housing Bore Alignment -Arbor Check Method -Machining the Deck Surface of the Block -Deck Surfacing Finish -Cylinder Bore -Sleeving the Cylinder -Cylinder Honing -Cylinder Surface Finish -Chamfering the Cylinder Bores

Cast iron has about how much carbon content?

3%

An engine block should be machined in which order?

Align honing, block decking, cylinder boring

A bedplate is located between the _____________ and the ______________ .

Bottom of the block; oil pan

Ultrasonic testing is used to test ______________.

Cylinder wall thickness

cooling jacket

Cylinders are surrounded by cooling passages. These coolant passages around the cylinders are often called

Siamese cylinder bores are ______________.

Cylinders where the walls are casted together without a water jacket.

wet cylinder sleeve

Some engines have die-cast aluminum blocks with replaceable cast-iron cylinder sleeves. The sleeves are sealed at the block deck and at their base. Coolant flows around the cylinder sleeve, so this type of sleeve is called

decking the block

The block deck must be resurfaced in a surfacing machine that can control the amount of metal removed when it is necessary to match the size of the combustion chambers.

dry cylinder sleeves

The cast-iron cylinder sleeves are either cast into the aluminum block during manufacturing or pressed into the aluminum block. These sleeves are not in contact with the coolant passages and are called...

oil gallery

all the oil holes in an engine block

main bearing caps

are cast or manufactured from sintered or billeted materials, separately from the block.

A sizing hone

can be used to straighten the cylinder and to provide a suitable surface for the piston rings.

Bores

cylinder holes

Bedplate

is a structural member that attaches to the bottom of the block and supports the crankshaft

Styrofoam

is often used as a core when casting an aluminum block.

The best way to clean the honed cylinders

is to scrub the cylinder wall with a brush using a mixture of soap or detergent and water.

What should be installed and torqued to factory specification before machining a block?

main bearing caps

core plugs (e.g. freeze plugs)

openings in the block are plugged with...

A deglazing hone

removes the hard surface glaze remaining in the cylinder.

Engine blocks can be manufactured using which method(s)?

sand cast or die-cast

After the engine block has been machined, it should be cleaned using ________________.

soap and water

The surface finish for the cylinder walls usually depends on _______________.

the type of piston rings to be used

oil gallery plugs

the unneeded open ends (oil holes) may be capped by pipe plugs, steel balls, or cup-type soft plugs, often called...

girdle

ties all of the main bearing caps together to add strength to the lower part of the block.

The block deck is the ______________.

top surface of the block

block deck

top surface of the block

Aluminum

used for some cylinder blocks and is nonmagnetic and lightweight.

Siamese cylinder bores

where the cylinder walls are cast together without a water jacket (passage) between the cylinders.