Gonna write this stuff down and post it so I don't lose it. Had to wade through a lot of pages to find it. The 5th Generation Camry's
2AZ-FE engine (an advanced powerplant, by the way) is the same engine that was used in the '01 Highlander SUV. 5th Generation Camrys cover Model Years '02 - '06.The cylinder block is made of aluminum alloy. It uses aluminum pistons, high-strength steel connecting rods and caps, forged steel crankshaft, and, IIRC aluminum camshafts. The VVT-i only works on the intake camshaft, not the exhaust camshaft. It varies the timing of the intake valves. There are two intake valves per cylinder and two exhaust valves per cylinder. Having two of each increases the total port area, so more air can flow into and out of the combustion chamber. As the manual's authors write, "Intake and exhaust efficiency has been increased due to the larger total port areas."
The cylinder head cover (not to be confused with the cylinder head) is made of magnesium alloy for lighter weight. I think cylinder head cover is synonymous with "valve cover," but the Camry manual refers to it as the "cylinder head cover."
Since the manual doesn't mention what the cylinder head, itself, is made of, I will assume iron, but just an assumption.
The cylinder head gasket, used between the aluminum engine block and the (iron?) cylinder head is a steel-laminate type of material. Any concern about electrolysis taking place between the steel-laminate and aluminum?
When the service and repair manual says the dry weight of the engine is 267 pounds, does that include the crankcase, crank, cylinder head, and valve head with camshafts--or does the weight only include the engine block without crankcase and cyclinder head, etc.?
The crankshaft and camshafts are connected by a timing chain, not a belt.
The oil pump is located behind the timing chain cover at the front bottom of the engine, even lower than the crankshaft. The oil pump has its own short section of chain that's connected to the crankshaft. Couldn't tell from the picture if this is a second, dedicated chain, or just part of the larger chain that ascends to the camshafts. Double overhead cams, don't ya know (DOHC) :-)
If I had to guess, I'd say the oil pump has its own dedicated short chain that's separate from the timing chain, ie., camshaft chain..