Some details of the 2AZ-FE engine
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From: Built_Well on 14 Jul 2008 23:08 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..
From: Ed White on 14 Jul 2008 23:34 "Built_Well" <Built_Well_Toyota(a)hotmail.com> wrote in message news:97101848-da38-42b3-88d7-6dcb0def23b9(a)s50g2000hsb.googlegroups.com... > > 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) Advanced, in what way? Lots of comparable engines from many manufacturers. I have a hard time thinking of any engine that requires routine valve adjustment as "advanced." But I guess that is also a trend these days. And since most people ignore the routine valve clearance checks, I guess it is irrelevant. I was shocked when I found out my Nissan Frontier requires valve adjustment. You have to love the chutzpa of the Nissan engineers. The engine in my Frontier requires valve adjustment only when the valve noise is objectionable. It is going to be damn loud before I'll spend hundreds (maybe thousands) to have the valves adjusted. I assume the engineers at Nissan (and Toyota) have designed the valve system so that the valve clearance increases with wear - else you run the risk of burning valves if the clearance goes too low (learned from sad experience on older engines). > is the same engine that was used in the '01 Highlander SUV. > 5th Generation Camrys cover Model Years '02 - '06. It is still used today in Camrys, RAV4s, and ? > 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. Nope, it is aluminum. > 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? Nope, but be sure to use the recommended coolant. > 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.? Everything that makes up the main engine assembly (block, pistons, heads, cams, etc.) but no oil or water. Probably does not include accesorries (alternator, starter). May or may not include intake system. Probably includes intake to the throttle body. > The crankshaft and camshafts are connected by a timing chain, > not a belt. Common practice these days. Cam belts are mostly on the way out for modern engines. > 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. Completely separate chain (referred to as the No. 2 Chain Sub-assembly). > 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.. Correct. Ed
From: Hachiroku ハチロク on 15 Jul 2008 10:41 On Mon, 14 Jul 2008 20:08:50 -0700, Built_Well wrote: > 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." Yeah, that's the valve cover... > > Since the manual doesn't mention what the cylinder head, itself, > is made of, I will assume iron, but just an assumption. Toyotas have been using aluminum heads for as long as I can remember. My first Corolla, a '74, had an iron block and aluminum heads, which worked well for them, but was a fatal combination for certain Chevy (VEGA) models...
From: Built_Well on 15 Jul 2008 00:23 Ed White wrote: > Advanced, in what way? Lots of comparable engines from many manufacturers. ========== Well, the manual, or something I read, said it was "advanced." I don't think it was a case of self-promotion by the manual ;-) You wrote, "I have a hard time thinking of any engine that requires routine valve adjustment as advanced." Well, it's not exactly routine. The scheduled maintenance guide says to inspect the valve clearance after 120,000 miles or 12 years. 12 years is a long time. When they say valve clearance, I guess they mean the gap between the top of the valve stem and the bottom of the lifter and/or tappet? Anyone know if "lifter" and "tappet" are the same thing? By the way, it's a shimless system. Yes, the 2AZ-FE is still used today. I saw an '07 or or '08 Solara with the 2AZ-FE, and the '08 Camry owner's manual I bought off Ebay says the '08 Camry also uses the 2AZ-FE. It's a very good engine. Toyota's not gonna junk it anytime soon, I would guess. By the way, that '08 Camry manual I got off Ebay says the engine's drain-and-fill oil capacity with filter is 4.5 quarts. That's a whole 0.5 quarts more than my '06 Camry manual says to use (4 quarts). I thought maybe the new Camry might be using a bigger filter, but without the filter the '08 Camry manual says to use 4.3 quarts, again a half-quart more than the 3.8 quarts called for in my '06 manual without filter. Does anyone know why the two Toyota manuals recommend different oil amounts for the same 2AZ-FE engine? That's a big half-quart difference. I have always put in 4.25 quarts, instead of the 4.0 quarts recommended in my manual, but do you think I should increase it to 4.5 quarts, which would equal the amount recommended in the new '08 manual? Frothing probably wouldn't be a problem with that small amount extra, but you never know.
From: Nate Nagel on 15 Jul 2008 00:32
Ed White wrote: > "Built_Well" <Built_Well_Toyota(a)hotmail.com> wrote in message > news:97101848-da38-42b3-88d7-6dcb0def23b9(a)s50g2000hsb.googlegroups.com... > >>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) > > > Advanced, in what way? Lots of comparable engines from many manufacturers. I > have a hard time thinking of any engine that requires routine valve > adjustment as "advanced." Solid lifters = less reciprocating mass, and higher RPM potential because the lifters won't pump up. The reduction in reciprocating mass allows the use of lighter valve springs for less friction. Doing away with the need for oil feed to the lifters reduces the required capacity of the oil pump and therefore pumping losses. With careful design and material selection, the required valve adjustment intervals can be quite long. I don't think I ever adjusted the valves on my old Scirocco; by the time I'd collected the required tools and shims I realized that the darn thing would just keep running indefinitely whether I adjusted them or not. (for some inexplicable reason, VW went to hydraulics anyway.) I did have the valve cover gasket replaced once while it was in my care but I can't even remember if I asked the mechanic to check the valve clearances or not. (don't remember why I didn't do it myself.) nate -- replace "roosters" with "cox" to reply. http://members.cox.net/njnagel |