Some details of the 2AZ-FE engine
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From: Nate Nagel on 15 Jul 2008 22:58 Built_Well wrote: > C. E. White wrote: > >> EdV wrote: >> >>> Is the 2AZ-FE considered a direct injectin engine? >> >>No > > ============= > > The 2AZ-FE is a direct injection engine. It does not > use a mechanical distributor, and the engine does > use a crankshaft sensor and a camshaft sensor, among > other things. "direct injection" typically refers to a very high pressure fuel injection system that injects fuel directly into the combustion chamber rather than into the intake runner or a throttle body. What you are describing is a "distributorless ignition." nate -- replace "roosters" with "cox" to reply. http://members.cox.net/njnagel
From: johngdole on 15 Jul 2008 23:57 Hee hee hee. 2AZFE "an advanced powerplant?" that's a good one. Checkout the Audi FSI 2.0T for an advanced design with a flat torque curve from 2000-5000 RPMs. On Jul 14, 8:08 pm, Built_Well <Built_Well_Toy...(a)hotmail.com> wrote: > 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.
From: Steve W. on 16 Jul 2008 00:14 Hachiroku $B%O%A%m%/ wrote: > On Tue, 15 Jul 2008 06:16:02 -0700, N8N wrote: > >> On Jul 15, 7:47 am, "C. E. White" <cewhi...(a)removemindspring.com> >> wrote: >>> "Hachiroku ハチロク" <Tru...(a)e86.GTS> wrote in message >>> >>> news:pan.2008.07.15.14.41.47.208604(a)e86.GTS... >>> >>> >>> >>> >>> >>>> 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... >>> Actually Vegas had aluminum blocks and cast iron heads! One of the >>> stangest combinations ever. The original Vega block was the linerless >>> aluminum type and was die case with an open top deck. > > <SNIP!> > >>> Ed >> Thanks for confirming that my memory isn't completely shot :) >> >> FWIW the all-aluminum engine in my 944 leaks more oil than it burns >> AFAICT. I seem to have a penchant for attracting vehicles that aren't >> known for gasket integrity :( >> >> Rust seems to be a common theme with cars from the mid-70s and older. >> The same neighbors that had the Vega also had a Volare wagon, the >> front fenders were rusted through in only a couple of years. My dad's >> Oldsmobile fared a little better, but it still had rusty fenders, >> possibly because of some collision repair early in its life (was >> sideswiped in a snowstorm on a windy country road by another driver >> who lost control of her car) Once the Germans started using >> galvanized body panels and that waxy undercoating the problems pretty >> much went away (my mom's Golf lasted almost 20 years in semi-rural PA >> before any significant corrosion showed up) I don't know about newer >> American cars but I would assume that they've taken similar measures. >> >> nate > > > And, thanks to both of you for correcting me! I knew an iron > block/aluminum head works, since Toyota did it for so long, but I had > forgotten the reversal on the Vega. Like nate said, nice little car, but > what an abortion! If chevy had gotten it right it would have been an > import fighter for sure. Looks, OK handling, etc. > > The few who got the Cosworth version were the lucky ones! > > Considering that the Vega was an imported design (Opel) It wasn't a bad car. Between my uncles and closer family we owned about 8 of them (and more than a couple Monzas as well). The later Durabilt engines with the steel liners held up pretty well. The front subframe to body plates is the place to look for real rot on them. If it's gone walk away unless the rest of the body is mint. -- Steve W. Near Cooperstown, New York
From: johngdole on 16 Jul 2008 01:13 Using only half a set of variable valve timing (VVT) saves money. Some manufacturers use it on the intake side, some on the exhaust side. If VVT is used on the exhaust side then the engine should have NO EGR valve. The timing will allow the exhaust gas to be sucked back into the cylinder. So that's one advantage for exhaust side VVT. Of course, real luxury car engines would have VVT on both intake and exhaust. Not only that, for instance, accelerator pedals on some newer BMWs use CONTINUOUSLY VARIABLE VALVE LIFT to control acceleration! (What throttle valve?) That's another reason why I say Toyota Lexus isn't worth the money unless you like the dolled-up look, which really is fine. On Jul 14, 8:08 pm, Built_Well <Built_Well_Toy...(a)hotmail.com> wrote: > 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."
From: Built_Well on 16 Jul 2008 02:34
Nate Nagel wrote: > Built_Well wrote: > > C. E. White wrote: > > > >> EdV wrote: > >> > >>> Is the 2AZ-FE considered a direct injectin engine? > >> > >>No > > > > ============= > > > > The 2AZ-FE is a direct injection engine. It does not > > use a mechanical distributor, and the engine does > > use a crankshaft sensor and a camshaft sensor, among > > other things. > > "direct injection" typically refers to a very high pressure fuel > injection system that injects fuel directly into the combustion chamber > rather than into the intake runner or a throttle body. > > What you are describing is a "distributorless ignition." > > nate ============================================ Very good information. I enjoyed reading it, and you're right that the Camry does not inject fuel into the combustion chamber but into the "antechamber" in the cylinder head that comes just before the valve. That's what the manual's diagram seems to show anyway. But the 2AZ-FE /is/ a Direct Injection System. Here's a quote from the Camry's service and repair manual on Page EG-57: "A DIS (Direct Ignition System) has been adopted. The DIS improves the ignition timing accuracy, reduces high-voltage loss, and enhances the overall reliability of the ignition system by eliminating the distributor. The DIS in this engine is an independent ignition system which has one ignition coil (with igniter) for each cylinder." Also, the book "Auto Upkeep" says, "Some manufacturers call the distributor-less ignition system a direct ignition system." Maybe there are two sides with an honest difference of opinion? Sorta like how API Group III oils are considered synthetic in the U.S.A., but not in Europe. However, the book says there are 3 types of ignition systems: Conventional, Electronic, and Distributor-less. The web site ProCarCare.com doesn't mention firing into the combustion chamber as a pre-requisite for D.I.S. Here's a quote: The Direct Ignition System (DIS) uses either a magnetic crankshaft sensor, camshaft position sensor, or both, to determine crankshaft position and engine speed. This signal is sent to the ignition control module or engine control module which then energizes the appropriate coil. You obviously know a whole lot more about cars than I do, but the 2AZ-FE does seem to be a Direct Ignition System. Here's a link to the ProCarCare site with the info: http://www.procarcare.com/icarumba/resourcecenter/encyclopedia/icar_resourcecenter_encyclopedia_ignition.asp Britannica Online seems to agree: direct-ignition system, or distributor-less ignition system (engineering): description and use: Many automobile engines now use a distributor-less ignition system, or direct-ignition system, in which a high-voltage pulse is directly applied to coils that sit on top of the spark plugs (known as coil-on-plug). The major components of these systems are a coil pack, an ignition module, a crankshaft reluctor ring, a magnetic sensor, and an electronic control module. From Wikipedia's entry on Ignition System: Other systems dispense with the distributor and coil and use special spark plugs which each contain their own coil (Direct Ignition). This means high voltages are not routed all over the engine, but are instead created at the point at which they are needed. Such designs offer potentially much greater reliability than conventional arrangements. A site devoted to the Honda Insight says this: The Insight engine employs a direct ignition system similar to those used on the Honda S2000 and the 1999 Odyssey. Separate ignition coils for each cylinder are located directly above the spark plugs. |