Challenger Posted September 17, 2008 Share Posted September 17, 2008 For all the motor builders, could it be done? I understand youd need a standalone that can run the fuel injectors at different timing for different rpms, loads, throttle position, etc. and then lots of fuel pressure. Heres a version of BMW's direct injection. Would be hard to do on a L series with the cam in the way. Here would be a more practical way, with the injector from the side. Ive got a spare head that is complete (really nice, kind of rebuilt) that I may experiment with since I cant seem to give it away ($75). Anyone have thoughts. I figure its impossible and would be extremely difficult but hey its a cool idea, and you could have a cool intake manifold. Quote Link to comment Share on other sites More sharing options...
PalmettoZ Posted September 17, 2008 Share Posted September 17, 2008 Hey Derek- I work for a company that will start producing the direct injection injectors at my plant beginning of 2009. They run at 1500 psi, and I would assume that they have an external pump that will be driven by the engine. It really bumps up the power since it atomizes the fuel much better as well as controlling the injection more effeciently. I think that VW has a 1.8 liter now with this out that produces a ton of power for the displacement. The idea is not new ( WWII aircraft had this mechanically ) but to control it electronically is much more effecient. I can try to find some photos of the pump and injector set up and post it for you- Quote Link to comment Share on other sites More sharing options...
PalmettoZ Posted September 17, 2008 Share Posted September 17, 2008 Here is a photo of the Bosch pressure regulator and one of the injector itself. I would suggest to use the current manifold injector position and set this up as a regular style injector. The better atomization of the injector and the deeper nozzle depth would create much more power than a standard set-up. It appears to be a magnet valve style injector which could be controlled by a mega-squirt style of computer. Quote Link to comment Share on other sites More sharing options...
Kennysgreen280zt Posted September 17, 2008 Share Posted September 17, 2008 the 1.8t motor is standard style..... the new 2.0t is FSI (direct injection) You could just run the diesel head, with some custom pistons. They already are setup to do it too bad its cast iron. Quote Link to comment Share on other sites More sharing options...
Challenger Posted September 17, 2008 Author Share Posted September 17, 2008 Oh yeah forgot about the diesel head. Id like to see one of those... Quote Link to comment Share on other sites More sharing options...
Kennysgreen280zt Posted September 17, 2008 Share Posted September 17, 2008 I forgot you wouldnt have a place for the spark plug.... So you would still be stuck with having to bore a hole. I have a spare diesel head here. If I have time ill snap some pics. Quote Link to comment Share on other sites More sharing options...
Challenger Posted September 17, 2008 Author Share Posted September 17, 2008 Sweet, thanks. So either head youd still need to drill a hole. So the diesels dont have a glow plug? Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted September 17, 2008 Share Posted September 17, 2008 Here is a photo of the Bosch pressure regulator and one of the injector itself. I would suggest to use the current manifold injector position and set this up as a regular style injector. The better atomization of the injector and the deeper nozzle depth would create much more power than a standard set-up. It appears to be a magnet valve style injector which could be controlled by a mega-squirt style of computer. They may run at a higher voltage than what normal solenoid injector drivers are meant to run, and the code would need to be written specifically for direct injection. I know with diesel versions they often use multiple injection events for each combustion cycle. The timing requirements are pretty complicated. Right now you'd probably be looking more at the Motec end of the ECU spectrum to control this. Quote Link to comment Share on other sites More sharing options...
PalmettoZ Posted September 18, 2008 Share Posted September 18, 2008 They may run at a higher voltage than what normal solenoid injector drivers are meant to run, and the code would need to be written specifically for direct injection. I know with diesel versions they often use multiple injection events for each combustion cycle. The timing requirements are pretty complicated. Right now you'd probably be looking more at the Motec end of the ECU spectrum to control this. Hey Matt- For heavy duty Common Rail diesel injectors it is 12 volts at the magnet valve. These injectors are running 1600 bar with as you said multiple injection points. The magnet valve can open and close fairly rapidly due to somewhat of a balance with the high pressure and low pressure in the injector. The high pressure is only at a very small point at the needle. Atomization on these injectors is incredible, you can barely see the holes at the nozzle they are so small. The Piezo injectors use a long crystal which grows slightly when energized to open and close the valve at an even faster rate. As far a trying to use a diesel head on a gas engine goes, the compression ratio is around 22:1 on them with little to no combustion chamber in the head. I don't think it would be possible to use this head for a gasoline set-up. Quote Link to comment Share on other sites More sharing options...
Kennysgreen280zt Posted September 19, 2008 Share Posted September 19, 2008 ^^^^ that is why I said custom pistons. Well aware of the high compression ratio. Im not positive how the glow plug is setup on the LD, I dont believe the glow plug is directly in the chamber like a spark plug would be. Quote Link to comment Share on other sites More sharing options...
Challenger Posted September 19, 2008 Author Share Posted September 19, 2008 Well alot of the new direct injected engines are really high compression, but not that high. Heres a few things about the fuel system. Ultra lean burn mode is used for light-load running conditions, when little or no acceleration is required. The fuel is not injected at the intake stroke but rather at the latter stages of the compression stroke, so that the small amount of air-fuel mixture is optimally placed near the spark plug. This stratified charge is surrounded by mostly air which keeps the fuel away from the cylinder walls for lowest emissions. The combustion takes place in a toroidal (donut shaped) cavity on the piston's surface. This technique enables the use of ultra-lean mixtures impossible with carburetors or conventional fuel injection. Stoichiometric mode is used for moderate load conditions. Fuel is injected during the intake stroke, creating a homogeneous fuel-air mixture in the cylinder. From the stoichiometric ratio, an optimum burn results in clean exhaust readily further cleaned by the catalytic converter. Full power mode is used for rapid acceleration and heavy loads (as when climbing a hill). The air-fuel mixture is homogeneous and the ratio is slightly richer than stoichiometric, which helps prevent knock (pinging). The fuel is injected during the intake stroke. The stoichiometric air-fuel ratio for petrol (gasoline) is 14.7 to 1 by weight, but ultra lean mode can involve ratios as high as 65:1. These leaner mixtures, much leaner than in a conventional engine, reduce fuel consumption. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 19, 2008 Share Posted September 19, 2008 These injectors are running 1600 bar with as you said multiple injection points. I just double checked and that's not a typo. For those of you keeping score at home that's ~23000 psi. I don't think you'll be able to get that with a Walbro 255. Also remember that you are now forced to get the entire injection completed essentially on the intake stroke instead of having the entire 720deg of rotation that we are used to. Also controlling the injector at a 65:1afr will require the use of extremely short pulsewidths - don't think a Motec will be up to the task ether. I'd love to try this too and it's not impossible but it would require some new aftermarket products to be developed - sounds like maybe a job for the MegaSquirt guys... Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted September 19, 2008 Share Posted September 19, 2008 The first time I saw the pressures these things ran at, I really did a double take. That pressure is higher than the breaking strength of most aluminum alloys. The first version of the Megasquirt-III will be sequential but not coded for direct injection. It's possible that a future code release may give it that capability. Quote Link to comment Share on other sites More sharing options...
woldson Posted September 19, 2008 Share Posted September 19, 2008 Man I would hate to see a leak on that system! In the future I will be checking for direct injection before working on particular car! That is enough pressure to sever fingers at close range. Quote Link to comment Share on other sites More sharing options...
PalmettoZ Posted September 19, 2008 Share Posted September 19, 2008 Man I would hate to see a leak on that system! In the future I will be checking for direct injection before working on particular car! That is enough pressure to sever fingers at close range. The 1600 bar is for the Bosch Common Rail diesel systems first generation. 3rd generation is now running 1800 bar ! As far as leaks go, the rail has a pressure sensor on it, and the second there is a low pressure sensed it stops the pump pressure. But these high pressures are diesel only. The direct injection gas is running around 300 bar and has a mechanical pump on top of the engines with the rail right on top of the injectors: Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 19, 2008 Share Posted September 19, 2008 But these high pressures are diesel only. The direct injection gas is running around 300 bar and has a mechanical pump on top of the engines with the rail right on top of the injectors: ...So that's just 4350psi, just two orders of magnitude more than currently used instead of three. Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 21, 2008 Share Posted September 21, 2008 If it 's controlled by an OEM computer, I posit the Motec can drive it. This is nothing difficult, this technology has been around as stated for the diesel world for years. I doubt the OEM's are using processor speeds faster than aftermarket offerings. And if they are, people would be ramping up to drop their aftermarket systems and hack the stock ECUs. So this is where Diesel Technologies landed. South Carolina. PCM Bosch bought em, shut em down, and moved south. Good to see they are making good use of the technology they acquired. Quote Link to comment Share on other sites More sharing options...
PalmettoZ Posted September 22, 2008 Share Posted September 22, 2008 If it 's controlled by an OEM computer, I posit the Motec can drive it. This is nothing difficult, this technology has been around as stated for the diesel world for years. I doubt the OEM's are using processor speeds faster than aftermarket offerings. And if they are, people would be ramping up to drop their aftermarket systems and hack the stock ECUs. So this is where Diesel Technologies landed. South Carolina. PCM Bosch bought em, shut em down, and moved south. Good to see they are making good use of the technology they acquired. Hey Tony- Bosch has had a manufacturing plant in Charleston since 1975 producing mainly EV injectors, ABS components and Diesel injectors and pumps. The Common Rail technology is Bosch technology though, I am not sure who Diesel Technologies is. Where were they located ? Scott Quote Link to comment Share on other sites More sharing options...
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