VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: NintendoKD on September 07, 2009, 06:13:30 am
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Have an 80' rabbit diesel, the newer engines have commonrail systems on them. Rather than try to hunt down a salvaged one and possibly pay a small fortune for it is there anyway that it would work from a gasser? lots of gasoline engines have this system, is there a way to convert/install/mod this to work in my older car? Higher pressure fuel=better fuel economy=better performance right? I understand that the injectors are pezoelectric? what electronics would I have to take as well? Dimensions???
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gasoline injection takes place an under 100 psi. diesel injection takes place at over 2000 psi. diesels also dont breathe in the fuel with the air. they just suck in clean fresh air. the fuel is injected at the very top of the stroke, and the compressed air ignites it.
so, in other words, gas fuel injectors will not work on a diesel. EVER.
but if you took a common rail injection system like whats in the new TDI's or the duramax/cummins that use the CP3 pumps, you could adapt one of those to work probably. but this is definitely not for the light walleted person. its gonna cost a ton of money to make something like this work. to get a common rail system to work, you basically have to take the electronics system off one engine, and graft it to another engine.
how much money you looking to spend here? might be cheaper to just drop the whole duramax in your rabbit.
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uhh, the short answer is -no
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oh, its possible, ive seen a diesel V6 chevrolet engine. it started out life as a gasoline engine. some dude made some super high pressure piezo infectors for conversions, and he had some sort of home brew (but beautifully done) electronics system/ecu for the engine. and the worst part, it was HELLA EXPENSIVE!
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He's pulling your leg. GM had a 4.3 V-6 diesel as well, from the factory.
Brendan
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He's pulling your leg. GM had a 4.3 V-6 diesel as well, from the factory.
Brendan
im pulling someones leg? no, im really not. it was a GM 3.4 litre or something V6. a new one. i just read about it a few months back in the Diesel Power magazine. he takes gas engines, and puts these special injectors in them and retrofits them to diesels. and i didnt even know that they made 4.3 diesels. what did they come in? i dont care how ***ty they are, i want one.
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NAH! the beautiful thing about older diesels is no fancy schmancy electronics, Don't want to deal with em. I was just wondering if there was a way to retrofit a system from another vehicle to my car, I can manage some modification/fabrication so it wouldn't cost much except for the pick-and-pull parts to make it. Can a gasoline commonrail handle the pressures of a diesel commonrail? I guess that was my question, use a much cheaper much more common system from a gasser and add the correct diesel components, and voila everyone can use commonrail on their older car to achieve more power and efficiency. 8) I think it can be done, without staeling one from a new tdi "too new, too hard to find, too exspensive" no thanks. I must apologise, I am new to this forum but not to automotive tuning, I sometimes have ideas out of scope but not out of reach, I find the more radical the better.
Thanks,
Kevin
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A bit off topic, but for more info on the gm diesels look here:
http://en.wikipedia.org/wiki/List_of_GM_engines#Diesel_piston_engines
lots of information thats how I do a lot of research
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Gasoline injectors & fuel rails will not handle the pressures needed for diesel.. I think about the highest pressures I;ve seen a gas engine injection operate is about 120 psi versus the close to 1900psi that our diesels operate.. Seals would never hold, injectors would blow apart, or at best just leak..
The reason for the high pressure on a diesel is that diesel fuel does not atomize as easily as gasoline.. Heck gasoline turns to vapor just sitting in a bucket at room temp..
I'm not going to say that fabricating such a setup is imposible, but you're gonna need injectors and plumbing designed to handle alot more pressure...
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so the question remains, can you use the rail from a gasser and swap the injectors as opposed to the confuzing mazelike piping that is currently there?
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Guys, you have the right idea about CRD, but you are off by an order of magnitude. The current crop uses 1600 - 2000 BAR, not psi. That equates to 23,200 psi - 29,000 psi. The higher being the new bread for the latest electric piezo injectors. They use this high pressure because they do up to 5 injection events per combustion cycle per cylinder. I have first had experience with the CRD they put in the Liberty when I worked at their head quarters
http://www.vmmotori.it/en/01/00/01/dettaglio.jsp?id=56 (http://www.vmmotori.it/en/01/00/01/dettaglio.jsp?id=56) (the RA 428 DOHC )
Attaching a CP3 pump, common rail, and adapting the injectors is the easy part. I bet many of us could do this. The problem comes in the controls. There needs to be a precision crank angle sensor. (The source of many PowerStrokes dying along the freeway) And the computer needs to have a profile to the specific engine - valve timing, compression ratio, displacement, barometric pressure in the intake, temp, etc, etc. The difference can be dramatic if the profile does not match the engine.
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So then I guess my next question is How does the VE pump work? I am sure there is already a thread on this? thanks guys and sorry about all of the annoying questions, I have to start somewhere.
Thanks for all of the great input and knowledge,
Kevin
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the way i learned about VW pumps was, get a junk one, take it apart. CLEAR APART! well, i have still never taken out the vane pump, but i can guess as to what it looks like. i took a junk 1.6 pump and just sat down one day and started tearing into it. they are pretty friggen simple if you can look at something and determine how it works. but use a junk pump or one you dont care about, cause then if you break something its not a big deal.
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He's pulling your leg. GM had a 4.3 V-6 diesel as well, from the factory.
Brendan
im pulling someones leg? no, im really not. it was a GM 3.4 litre or something V6. a new one. i just read about it a few months back in the Diesel Power magazine. he takes gas engines, and puts these special injectors in them and retrofits them to diesels. and i didnt even know that they made 4.3 diesels. what did they come in? i dont care how ***ty they are, i want one.
Wonder if he upgrades the bottom end. Because if it isn't...well...
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He's pulling your leg. GM had a 4.3 V-6 diesel as well, from the factory.
Brendan
im pulling someones leg? no, im really not. it was a GM 3.4 litre or something V6. a new one. i just read about it a few months back in the Diesel Power magazine. he takes gas engines, and puts these special injectors in them and retrofits them to diesels. and i didnt even know that they made 4.3 diesels. what did they come in? i dont care how ***ty they are, i want one.
Wonder if he upgrades the bottom end. Because if it isn't...well...
Probably would not matter as long as he is not trying to make huge amounts of power with the diesel conversion - reason, today's engines are designed to have around 2x the power of 25 years ago. So, the lower ends today are much stronger than in the past.
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what years did they satrt using the commonrail system in production diesel engines, more importanly the small ones, maybe I can get lucky and retrofit a system to my car from the boneyard. 8)
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2009. ;)
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NOT soooo lucky :( I'll stil try
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NOT soooo lucky :( I'll stil try
You're going to have a whole lot of fun coming up with how to attach or otherwise affix all the sensors necessary for that system to function onto a IDI block.
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No, I think that the fun part comes when I have to use my programming knowhow to flash an 09' ecu to accept given values for an idi engine, unless of course it is a learning ecu then it would be a breeze. ;D
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mitsubishi GDI gasser injectors work at 2000 psi pressure - they are direct injection gasoline engines, pain the butt to fix once they start faltering
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mitsubishi GDI gasser injectors work at 2000 psi pressure - they are direct injection gasoline engines, pain the butt to fix once they start faltering
That is still an order of magnatude less than is required for a diesel.
On the years here in the US, 2005 saw the Jeep Liberty 2.8L CRD, but please don't use one of these - I want to bolt it into my Jeep Rubicon !! :-D
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No, I think that the fun part comes when I have to use my programming knowhow to flash an 09' ecu to accept given values for an idi engine, unless of course it is a learning ecu then it would be a breeze. ;D
Incorporating the rail and the injectors without also making use of the sensors to give it inputs is hobbling the entire setup. It's not going to perform very well, and you'll probably end up with dead spots, stutters and skips if it somehow manages to run at all.
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you are taking a great engine with no problems, and complicating the hell out of it. whats up with wanting to put a new complicated expensive injection on an ancient engine? its gonna be so god damn hard dude...
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No, I think that the fun part comes when I have to use my programming knowhow to flash an 09' ecu to accept given values for an idi engine, unless of course it is a learning ecu then it would be a breeze. ;D
Incorporating the rail and the injectors without also making use of the sensors to give it inputs is hobbling the entire setup. It's not going to perform very well, and you'll probably end up with dead spots, stutters and skips if it somehow manages to run at all.
a CRD absolutely will not start nor run w/o at the very least the crank angle sensor.
We have not even discussed an equally important aspect - the combustion chamber size and shape, including the crown of the pistons. A gasser head simply will not get you 20:1 compression. If you could come close, then you have the problem of the injector spraying on a flat crown. The flat topped piston likely would not take too kindly to this.
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you are taking a great engine with no problems, and complicating the hell out of it. whats up with wanting to put a new complicated expensive injection on an ancient engine? its gonna be so god damn hard dude...
I am a MARINE, the more you say it's going to be hard the more I want to do it ;D Not so much that I want to do it, just exploring the options of being able to do something unique, something new that no one has ever done, my 78' tube framed rabbit with 24v vr6 mid engine mounted with all wheel drive is definately that.... err, will be, when it is finished. Something like that I gotta push the limits, It's all I know.
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Sounds very cool and very unique. I'd put a 1.9 TDI in that AWD ride if I wanted unique diesel power :-)
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how are you going to find a injector suited to work with an IDI but also work on a common rail system? to my knowledge, there is no such thing as an IDI common rail injected diesel. a direct injection fuel injector will not even work right with the pre combustion chamber..
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Learn to balance your body solely on your left pinky. You would certainly be the only person I had ever heard of having that ability. I'm sure that would be a very unique accomplishment, very hard to do and similarly productive. The benefit is that it would cost far less money.
but I would have to be HUGE for that to work... ;) we arent all brawn and no brains out here, this could possibly be a worthwhile venture opening up a unique door to tuning these long lost engines, the honda/rice fanboys had to start somewhere before the aftermarket parts were made available, we have something similar except some don't like change. I agree with you all not all change is good but to be open to new and radical ideas is how progress is made. :-*
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lol, im with andrew. peace out.
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you would probably see more of a return if you spent that money having nearly every part of the engine ceramic coated. This is a fools errand. The VE pump is beautifully simple and capable of a lot, just look at what guys like Giles do with it. If you want a CDI swap the whole thing in, I'd subscribe to that thread. Why wouldn't you start this project with a direct injection engine if efficiency and the elimination of fuel pulse is what you are interested in. At least those are set up with sensors to run ECU's, I just don't think any of us understand why you want to do this. In any design project I think it is best to start with the problem you want to address and then determine the best (cheapest, easiest, most reliable) means to achieve that goal. You have put the cart before the horse. You have started with common-rail injection and are trying to come up with a reason as to why you should use it. Start with fuel efficiency, or reliability, or torque, and then research that. It is an old VW there will be plenty of time for thinking outside the box and rigging up junkyard solutions. I know we seem like naysayers here, but you asked if it can be done and the answer is a resounding not worth it, sorry if that is not what you wanted to hear.
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Hey! thanks for all of the input guys 8) you have been really insightful and helpful in this. It wasn't meant to hurt anyone or their feelings. If there is anything that I can take away from this it's perspective. Thaks for all of the valuable input.
Kevin 8)