Chapter 56 PowerPoint

Define these Technical Terms using the textbook:

1. casting numbers

2. engine hoist

3. engine overhaul

4. engine rebuild

5. engine stands

6. thread chaser

7. vehicle identification number (VIN)

Answer these discussion questions using the textbook:

1. What does the 10th digit of the VIN represent?

Read the chapter summary below:

■ The vehicle identification number (VIN) is a unique number identifying the vehicle and some of the equipment installed on the vehicle. Contained within the VIN may be codes for the engine type and size, transmission type, differential type, body style, and optional equipment.

■ Many engine repairs can be done with the engine block still bolted to the chassis. These repairs include valve jobs, valve spring replacements, oil pump replacements, main bearing replacements, piston service, and external engine part service.

■ Engine repairs that normally require engine removal include cylinder block service, crankshaft service, and cylinder repair.

■ An engine overhaul involves complete disassembly of the engine assembly cleaning, inspection, and measurement of critical parts replacement of worn bottom end parts and top engine parts in cylinder heads replacement or repair of worn camshaft drive assembly parts machining of worn or warped engine casting and forgings and reassembly of the engine.

■ An in vehicle engine overhaul can only be done when cylinder and crankshaft wear are within specifications and the oil pan and heads can be easily removed with the engine installed in the vehicle.

■ To prepare for engine removal, most technicians disconnect everything under the engine first. The parts under the engine are disconnected first so that oil, fuel, and coolant are not leaking out from the disassembled top end while working under the engine.

■ Position the lifting fixture or chain at the manufacturer’s recommended lifting points on the engine. Make sure the attaching bolts are the correct diameter for the hole in which they are installed. Also, the bolts must be fully seated and a proper length. They must thread into the hole a distance equal to at least 1 1/2 times the diameter of the bolt.

■ Make sure the crane boom or engine hoist is centered over the engine. Then, attach the crane or hoist to the lifting fixture or chain. Place a floor jack under the transmission if needed.

■ If you pulled the engine and transmission/transaxle together, you will need to separate the transmission from the engine.

■ Most engine stands have a removable, rotating plate to which the engine is bolted. It is usually easier to bolt the engine to this plate first while the plate is not attached to the stand.

■ Tear down is the basic disassembly of the engine.

■ The engine top end generally includes the valvetrain, cylinder head, and related components. The top end is normally disassembled second, after the front end.

■ The engine front end should be disassembled first, especially with OHC engines.

■ After top end and front end disassembly, you are ready to take the bottom end apart. The bottom end includes the pistons, connecting rods, crankshaft, and related bearings.

■ After you have removed all of the parts from the engine block and cylinder head(s), everything should be cleaned. Different cleaning techniques are needed depending on part construction and type of material.

■ Always wear eye protection when cleaning parts with power tools.

■ Never use gasoline as a cleaning solvent. The slightest spark or flame could ignite the fumes, causing a deadly fire!

■ A hot tank is used to aggressively remove mineral deposits, hard carbon deposits, oil, grease, and even paint.

■ Automotive machine shops may use a heat cleaning oven in place of a hot tank to clean engine parts.

■ Media blasting can remove paint, carbon, and other dry deposits from parts. Cylinder heads, intake manifolds, valve covers, etc., can be cleaned and readied for painting with media blasting.