Some details of the 2AZ-FE engine
in [Toyota]
|
From: N8N on 16 Jul 2008 09:04 On Jul 16, 2:34 am, Built_Well <Built_Well_Toy...(a)hotmail.com> wrote: > 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_r... > > 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.- Hide quoted text - > > - Show quoted text - Your original post said "direct INJECTION" not "direct IGNITION." I've never heard of a distributorless ignition called a "direct ignition" although I guess it kind of makes sense for a coil-on-plug type setup. Now direct INJECTION refers to something completely different, as I described in my post. Generally used on Diesel engines although I have heard that some mfgrs. have or will introduce it on gas engines as well. nate
From: EdV on 16 Jul 2008 12:38 On Jul 15, 10:58 pm, Nate Nagel <njna...(a)roosters.net> 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. > So its like a turbo charger? how is the pressure of the fuel increased? and the pressure is increased when the liquid fuel is already in vapor stage right? Isn't it necessary to cool down the temperature of the high pressure vapor fuel before directly injecting them into the combustion chamber.. like the purpose of an intercooler for a turbo system. thanks!
From: EdV on 16 Jul 2008 12:43 On Jul 15, 11:57 pm, johngd...(a)hotmail.com wrote: > 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. > IIRC, The flat torque is because of the CVT transmission design and not the engine. I could be wrong. ..
From: N8N on 16 Jul 2008 14:35 On Jul 16, 12:43 pm, EdV <systme...(a)hotmail.com> wrote: > On Jul 15, 11:57 pm, johngd...(a)hotmail.com wrote:> 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. > > IIRC, The flat torque is because of the CVT transmission design and > not the engine. I could be wrong. > . The old 1.8T had an essentially flat torque curve over the same rev range and was only available with conventional transmissions. I wasn't aware that Audi had a CVT yet, although I have missed stuff before. I thought their new high end transmission was the dual-clutch deal? nate
From: N8N on 16 Jul 2008 14:37
On Jul 16, 12:38 pm, EdV <systme...(a)hotmail.com> wrote: > On Jul 15, 10:58 pm, Nate Nagel <njna...(a)roosters.net> 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. > > So its like a turbo charger? how is the pressure of the fuel > increased? and the pressure is increased when the liquid fuel is > already in vapor stage right? Isn't it necessary to cool down the > temperature of the high pressure vapor fuel before directly injecting > them into the combustion chamber.. like the purpose of an intercooler > for a turbo system. thanks!- Hide quoted text - Think Diesel engine. Bigass mechanical pump driven by the engine. No, it doesn't pressurize the intake air, but the fuel has to be pressurized to significantly more than the normal 50-100 PSI because it's being sprayed into the compressed air in the chamber rather than into the intake, where it's spraying into air that's at atmospheric (or less, under part throttle - or slightly more, in a turbo/ supercharged engine on boost) pressure. nate |