VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: NintendoKD on July 23, 2012, 09:08:20 am
-
I have a question, since the idea is to make the fuel and air mix more completely, then wouldn't it be a better idea to have fuel at or near the same temperature of the compressed air in the cyl? this way heat doesn't have to exchange before proper vaporization occurs. I mean this seems like a no brainer but can I get some engineer input here?
-
I have a question, since the idea is to make the fuel and air mix more completely, then wouldn't it be a better idea to have fuel at or near the same temperature of the compressed air in the cyl? this way heat doesn't have to exchange before proper vaporization occurs. I mean this seems like a no brainer but can I get some engineer input here?
intake air temp is a variable.. how are you going to heat/cool the fuel fast enough for any of this to matter?
-
Cool air is generally better for engines as it is more dense than hot air. Thus you have more oxygen in it. Similar to sea level compared to mountain air.
But all compression heats air so how will you match it in the cylinder, and the temp there is different at least at start up.
Heating fuel can be tricky, veg oil needs heat to flow and burn like diesel, diesel heats at the injectors and cools the IP. Gas, we all have gas but remember the days of gas heating on a summer day in a carb? Youngsters won't but vapor lock sucks in downtown traffic jams. Running down to the local McDs for a cup of ice to pack on the engine to start up again was a pain then and doesn't happen now with FI.
Best to not fool with the way things work. And what works is leave fuel alone and cool the air coming in, IC for you?
-
not to mention the safety aspect either, i wouldn't want to drive around with a tank of fuel close to the flash point!! after all the return will heat the fuel in the tank over a longish journey.
As for carb icing i had a mk1 ford escort with twin weber 40's, more than 20 mins on the motorway on a cold night then they were weber 6's with all the ice build up ;D happy days!!
-
modern tdis and such,have this fuel intercooler device,dont know if the same theory applys to idi
-
I can tell you a sufficiently worn injection pump is QUITE sensitive to both fuel and ambient air temp. :)
As was said over a longish journey the fuel is going to end up being about the temp of the IP near as I've ever been able to tell
with an IR thermometer. And that pump in the winter can be quite chilly when cruising on the highway with good airflow.
-
The object is to properly mix the diesel and air to create a more complete combustion right? I was thinking along the lines of vaporizing the diesel pre-injection, or getting close to it. This way the diesel doesn't have to absorb the energy from the compressed air to properly mix, and the compressed air doesn't have to shed heat/energy to give to the fuel to make a proper mix. this process takes time, and makes the diesel want to re-condense, as opposed to vaporize, "think, how does a de-humidifier work?" like the extreme difference in potential energy. I have an idea to do this, and I do realize that having tepid diesel/fuel go through the IP is a bad idea I want to heat the injector lines after the pump. the pump gains better pressures from increased viscosity=cooler fuel right? so returning fuel is not a lot here, I was thinking cool the fuel post filter pre pump, the heated fuel can't go back while heating expanding because the pump acts as a one way valve. The heating is a two step process to prevent the heat from coming back to the pump, but essentially there isn't anything special about my setup save the fuel cooler. I picked up a few from LAV upgrades when they threw the old ones away. The fuel expands after the pump, creating even more pressure the only drawback I see is there would be some kind of warm up valve adjustment to retard the timing to prevent the injectors from popping too soon. You would have to retard it anyway the fuel would burn...... well....... too well you would make more power and better fuel economy, plus lower emissions. just spitballin here.
-
I understand that there is "more" oxygen in the air when it is cooler cool air on cold mornings with a cold start = peppier car, starting to notice the trend here??? The common factor here is not so much air volume "it does to a small degree" but air temp, the air and fuel are at a close approximate temp, therefore less energy is lost but engines are not designed to run like this because they are heat pumps and get hot so the air gets hot while the fuel stays "relatively" cold the bigger the difference the more inefficient it is. How much "more" oxygen are we talking??? the idea is to pack energy into the air, and to "allow" the release of the potential energy in the fuel by the use of infared/electromagnetic means. The carbon acts as a transducer to varying degrees. the less energy that has to be absorbed by the carbon the more energy it can release, but an equilibrium of kinds must be reached. example we tell our guys to drink warm water in hot weather because it absorbs into the body faster, why? because the temperature has to equalize first. the closer the value energy/temp is to one another the easier it is to release the stored potential energy, to a certain degree. I can't have an ice cold diesel start on ice cold diesel, but a 100f deg air temp + 100 deg fuel temp is much better for combustion, which I imagine increases as temperature goes up. I imagine that it keeps going up as temp of both increases to a certain degree. This is the very basis that rudolph had in mind for the diesel engine, as I understand it. The way our motors are designed will not immediately work with this concept in mind, there will need to be a mechanical control of some kind that increases and decreases pump control/timing with temperature of air and fuel, and I'm not talking about tdi here, I really believe that IDI is the way to go. key to understanding more of this is IONIZATION, not COMBUSTION, also understanding that the ICE is only two things, an air pump, and a heat pump.
-
Unfortunately it is not the fact that the temps of the fuel and air on a cold morning are approximately the same that increases the 'peppiness' of your car.
It is a simple thermodynamic law that density increases with cooler temperatures. It is the density of the air that increases the 'pep' of your car. Think of it simply as the cold (and dense) air has more calorific value.
Rather than heat the lines why dont you increase the pressure of the pump? Higher presssure= higher temperature.
-
So those guys running meth injection must be losing mad power?
-
important not to confuse 2 things here.
intake air temperature (say, in the manifold) is going to be anywhere between 10-110 deg C, depending on how hot the engine is, the weather, the boost, etc etc etc.
But, the temperature of the air in the combustion chamber before the fuel is injected is VERY HOT, regardless of how warm it is before it is compressed by the piston.
The OP's suggestion is to heat the fuel to closer to the temperature of the air in the cylinder, right before injection. This temperature is ~210 deg C (anywhere between say 180 and 300 more like).
If you could figure out a way to heat the fuel closer to this temperature, then i guess in theory, upon injection, it will absorb less energy from the air charge and the peak pressure will be higher.
But, if you consider the actual thermal mass of an injection charge - it is very small. Infact, it is much smaller than the thermal mass of the air charge.
The heat capacity of diesel is about 1750 J / kg·K. an injection charge for a VW diesel making about 75kW is about 6 mm^3. 6mm^3 of diesel weighs around about 5.1e-3g, or 5.1e-6kg From thermodynamics, we know that:
deltaH = m*c*deltaT, that is the change in heat energy is equal to the mass x heat capacity x temperature difference. So if we run the numbers to find out how much energy it takes to heat that much diesel fuel from say, 60C to 210C (deltaT will be 150K), we have
deltaH = 5.1e-6 x 1750 x 150
= 1.33875 Joules.
Now, if the engine is making 75kW, then the air mass if the AFR is pretty rich for power making and boost is around 25psi and the engine speed is say 3000rpm is about 1.065e-3kg.
The heat capacity of air at ~210C is about 1026 J/kg.K. So, the intake charge has, at 210C:
H = m.c.T
= 1.065e-3 x 1026 x (210+274)
= 528.86 J of heat energy.
Now, remember that this air mass is calculated with an AFR of 16:1, pretty rich for a diesel, which normally might run under full power 19 or 20:1 AFR, and at idle more like 200:1 - so even in this very rich condition, the amount of thermal energy needed from the air charge to bring the diesel fuel up to combustion temperature, is only
(1.33875/528.86)*100 = 0.25% of the thermal energy of the air charge. Not much really.
btw - I am not being a smart ass - I was actually curious about your idea so I have sat here in the cold for about 30minutes preparing this response for all to see, please take it kindly, in the spirit is has been given :-)
-
So those guys running meth injection must be losing mad power?
I know right? But they do make more power, that is why I am asking all of the questions here, seems a bit confusing, and I'm sure I'm not the only one.
-
important not to confuse 2 things here.
intake air temperature (say, in the manifold) is going to be anywhere between 10-110 deg C, depending on how hot the engine is, the weather, the boost, etc etc etc.
But, the temperature of the air in the combustion chamber before the fuel is injected is VERY HOT, regardless of how warm it is before it is compressed by the piston.
The OP's suggestion is to heat the fuel to closer to the temperature of the air in the cylinder, right before injection. This temperature is ~210 deg C (anywhere between say 180 and 300 more like).
If you could figure out a way to heat the fuel closer to this temperature, then i guess in theory, upon injection, it will absorb less energy from the air charge and the peak pressure will be higher.
But, if you consider the actual thermal mass of an injection charge - it is very small. Infact, it is much smaller than the thermal mass of the air charge.
The heat capacity of diesel is about 1750 J / kg·K. an injection charge for a VW diesel making about 75kW is about 6 mm^3. 6mm^3 of diesel weighs around about 5.1e-3g, or 5.1e-6kg From thermodynamics, we know that:
deltaH = m*c*deltaT, that is the change in heat energy is equal to the mass x heat capacity x temperature difference. So if we run the numbers to find out how much energy it takes to heat that much diesel fuel from say, 60C to 210C (deltaT will be 150K), we have
deltaH = 5.1e-6 x 1750 x 150
= 1.33875 Joules.
Now, if the engine is making 75kW, then the air mass if the AFR is pretty rich for power making and boost is around 25psi and the engine speed is say 3000rpm is about 1.065e-3kg.
The heat capacity of air at ~210C is about 1026 J/kg.K. So, the intake charge has, at 210C:
H = m.c.T
= 1.065e-3 x 1026 x (210+274)
= 528.86 J of heat energy.
Now, remember that this air mass is calculated with an AFR of 16:1, pretty rich for a diesel, which normally might run under full power 19 or 20:1 AFR, and at idle more like 200:1 - so even in this very rich condition, the amount of thermal energy needed from the air charge to bring the diesel fuel up to combustion temperature, is only
(1.33875/528.86)*100 = 0.25% of the thermal energy of the air charge. Not much really.
btw - I am not being a smart ass - I was actually curious about your idea so I have sat here in the cold for about 30minutes preparing this response for all to see, please take it kindly, in the spirit is has been given :-)
An engineer answered my question, thanks, just made my day. Where did you glean this information?
-
He's an engineer. He went to school or is in school and learned the principles and the formulas and he is now calcualting a resulant answer based on your hypothetical potsualtions.
It is what they do. How do I know? 1 gd, 1 dad, and three brothers just like him. Needless to say family gatherings are generally not spent discussing such stuff but given enough fuel aka alcohol, the conversation can drift in this direction. Until one of the wife's pokes her head in and cusses us out.
-
Where did you glean this information?
the calcs are mine, but I did cheat some:
I used the not2fast website turbo calculator to get my "amount of air" starting figures.
And, I searched around for a guideline figure for the injection quantity. Found that 6mm^3 on tdiclub. I would say its about in the right order of magnitude.
Yes, engineers and family gatherings.... my sister hates it, she says all I do is talk about "science". She did a BA in "film and stage" ::)
-
good stuff, question how much oxygen we talkin? by that I mean temperature wise, ex. @ 60 deg f, oxygen content is X% whereas @ 100 deg f oxygen content is X% how much more compressed is the air, I know that it does. AKA high pressure system=coldfront, ususally accompanies claimant weather, low pressure system=warmfront when the two collide tornadoes and other natural vortices form. which brings me to my next point, at what temperature is to warm for fuel, because for a natural "swirl" to occur, inevitably mixing the air and fuel, you need some clash of air and fuel at differing temperatures. can someone please expound, not only with quantitative but qualitative, in other words, a real world example as well as an engineering/arithmetical explanation. I work better with visuals, and understand things better this way. Essentially I want to get the most bang for the buck here, what should we be attempting to achieve pre and post IP? pre temp optimal, and post temp optimal for the best fuel economy/efficiency the performance comes later.
thanks
-
Your weather analogy is ok on a macro scale, but I dont think it really applies in the precombustion chamber.
regarding oxygen - the oxygen content of the air remains the same. The mass of the air changes, and the oxygen is part of the air, so relatively it is the same. (Basically, hot air has the same concentration of oxygen as cold air).
I don't think you will have much luck getting any real results by heating the fuel pre-injection, unless the fuel is for some reason so cold that the injector system components arent working properly.
The best thing you can do is to have all the injectors working at their best (good atomisation). The design of the prechamber itself is already very well thought out. It is a wonder of engineering in of itself... took decades of development to get the design right.
There well may be an optimal temperature for fuel atomisation as it is sprayed from the injectors, but I dont know what that would be. To find it, you would need to do an experiment. But, since modern TDI's regulate their fuel temperature, then aiming for that temperature is probably not a bad way to cheat, if you are keen.
-
I want a neighbor like you. :)
-
To add to gldgti I would think that heating the fuel would change its flow properties. So everytime you change the temp the timing, break pressure, and fuel quantity would need adjustment. Also, at what point do the seals fail? In basic terms you are doing the same thing the VO, WVO, WMO, etc. are doing. In these engines what are you hoping to gain? 10% is 5hp. It is almost like a lesbian on birth control or separating fly poop from pepper...too much over redundantcy reoccuring again.
The compression part of the ignition of these diesel engines does just what you are wanting, just a bit later than you are wanting.
-
The modern stuff mostly runs fuel coolers to protect expensive pump modules IMO.
-
In basic terms you are doing the same thing the VO, WVO, WMO, etc. are doing.
That is what I was thinking all along theman53, We greasers note that the fuel has to be hot to flow like diesel and we note that even when hot it doesn't perform quite the same. I know I run a few pounds different on hot WVO compared to even warm diesel. So I do note the timing change and that might be the reason it runs different. I think it has more to do with the fuel character actually.
I am not sure we can figure out the extra amount of O 2 in the cylinder compared to native intake. If boost equals 15 psi how much extra air is that? 15?
Where is that engineer when you need em.
They do make wires that you can wrap the delivery lines with that can be heated so if you really wanted to have hotter fuel after the pump and not disturb the other normal settings then there is a possibility for that. But knowing the fuel sits on those hot injectors long enough to get to engine temp seems like it would do the trick. How much hotter do you really need to get? Combustion temps? Talk about vaporization. The injectors are designed to deliver a fluid not a vapor. So best not get it too hot.
-
15psi would be over a little twice the air that an na engine would be getting. But I agree the only difference heated fuel may make would be in how it flows in the pump and injectors which probably effects timing and such and perhaps would help it mix a bit better when it first enters the swirl chamber since it will be slightly thinner from being hotter so I would image the molecules are a bit more excited. But to gain some huge mpg or power increase I am doubtful. It's always possible tho. It's just that diesels don't work like fuel injected or carbed gassers the adiabetic ideas don't really apply when the fuel is I jected at the time of combustion
-
15psi would be over a little twice the air that an na engine would be getting. But I agree the only difference heated fuel may make would be in how it flows in the pump and injectors which probably effects timing and such and perhaps would help it mix a bit better when it first enters the swirl chamber since it will be slightly thinner from being hotter so I would image the molecules are a bit more excited. But to gain some huge mpg or power increase I am doubtful. It's always possible tho. It's just that diesels don't work like fuel injected or carbed gassers the adiabetic ideas don't really apply when the fuel is Injected at the time of combustion
the fuel being injected CREATES combustion...
-
I was just reading in my Bently and it states that (At maximum compression pressure, the air tempature is forced up to 900 C/1650 F).
I would bet diesel would cook in the lines/injectors at anywhere near that temp, plus your return lines would melt.
-
Aside from the actual engineering caluclations regarding the energy required to heat the quantity of fuel to combustion temperatures, and the fact that you could realistically probably only heat the diesel to 200 degrees which is still a long way from it's flash point, there is the question of whether it's even beneficial to do this...
From my understanding, in a diesel engine, fine droplets of liquid fuel are injected into the cylinder combustion area. These droplets first vaporize (because you can't ignite a liquid) and then ignite under the heat and pressure. In doing so, the droplets travel towards the piston due to expanding gasses as they ignite, and create a flame path with a specific geometry which pushes the piston down in some specific way, part of the function of the prechamber is to direct the combustion accordingly. I think if you were to heat the diesel up to near it's flash point before injecting it, you would have problems because the diesel would basically be igniting too soon, and the combustion would have the wrong "geometry."
-
In basic terms you are doing the same thing the VO, WVO, WMO, etc. are doing.
That is what I was thinking all along theman53, We greasers note that the fuel has to be hot to flow like diesel and we note that even when hot it doesn't perform quite the same. I know I run a few pounds different on hot WVO compared to even warm diesel. So I do note the timing change and that might be the reason it runs different. I think it has more to do with the fuel character actually.
I am not sure we can figure out the extra amount of O 2 in the cylinder compared to native intake. If boost equals 15 psi how much extra air is that? 15?
Where is that engineer when you need em.
They do make wires that you can wrap the delivery lines with that can be heated so if you really wanted to have hotter fuel after the pump and not disturb the other normal settings then there is a possibility for that. But knowing the fuel sits on those hot injectors long enough to get to engine temp seems like it would do the trick. How much hotter do you really need to get? Combustion temps? Talk about vaporization. The injectors are designed to deliver a fluid not a vapor. So best not get it too hot.
pre combustion, and I mean just before, I want to achieve near vapo temps. The concept is simple, viscosity pre pump is the same, cool the returning fuel and you have something, but the trick is getting just the right temp, and maintaining it. As well as having dual settings for fuel and timing, could easily be mechanically controlled when desired heat is reached.
-
They say 6.2 injectors don't last as long because of the heat introduced to them by their proximity to exhaust port.
bajacalal ha s a point, if you have instant ignition as opposed to gradual burn, peak cyinder pressures go up, and you'll have similar results to running gasoline.
-
Aside from the actual engineering caluclations regarding the energy required to heat the quantity of fuel to combustion temperatures, and the fact that you could realistically probably only heat the diesel to 200 degrees which is still a long way from it's flash point, there is the question of whether it's even beneficial to do this...
From my understanding, in a diesel engine, fine droplets of liquid fuel are injected into the cylinder combustion area. These droplets first vaporize (because you can't ignite a liquid) and then ignite under the heat and pressure. In doing so, the droplets travel towards the piston due to expanding gasses as they ignite, and create a flame path with a specific geometry which pushes the piston down in some specific way, part of the function of the prechamber is to direct the combustion accordingly. I think if you were to heat the diesel up to near it's flash point before injecting it, you would have problems because the diesel would basically be igniting too soon, and the combustion would have the wrong "geometry."
I don't see how, just advance/retard the timing accordingly the fuel will still vaporize, and still burn would it not? how would this effect eh flame front? you could be correct though, I have been wrong before, this is exactly why I brought this up, and I believe that this is a VERY important subject and nothing like giving birth control to lesbians. I think that this is exactly the thing that no one has focused/put enough focus into. I truly believe that unlocking the secrets of the diesel process impinges upon just this, I mean the principle of operation even says so right???
-
They say 6.2 injectors don't last as long because of the heat introduced to them by their proximity to exhaust port.
bajacalal ha s a point, if you have instant ignition as opposed to gradual burn, peak cyinder pressures go up, and you'll have similar results to running gasoline.
called heat management, I have some ideas on this exact subject. In fact, I am building a 6.5 right now. I get it, no one here can think of a way to do it, but I am asking "IF" you could what would be the result, good? bad? better? why? I have a plan, and some very unique designs that I want to try, but before I put all of the effort into it, I would like some real world engineering advice. Win or lose, you guys are the best. you want it to be hot enough to not burn/vaporize prematurely, not hot enough to screw the return lines "easy solution there, use different lines" have to adjust timing, and fuel rates, cant have hot fuel prior to IP got it, anything else I can't do? fuel temperature is very important, from everything everyone is telling me, but what temp gives the best performance? someone said tdi fuel temp is a good place to start.
thanks bunches, hopefully this will be a sticky one day to help the new guys coming into this, I have learned a ton here so far.
-
In basic terms you are doing the same thing the VO, WVO, WMO, etc. are doing.
That is what I was thinking all along theman53, We greasers note that the fuel has to be hot to flow like diesel and we note that even when hot it doesn't perform quite the same. I know I run a few pounds different on hot WVO compared to even warm diesel. So I do note the timing change and that might be the reason it runs different. I think it has more to do with the fuel character actually.
I am not sure we can figure out the extra amount of O 2 in the cylinder compared to native intake. If boost equals 15 psi how much extra air is that? 15?
Where is that engineer when you need em.
They do make wires that you can wrap the delivery lines with that can be heated so if you really wanted to have hotter fuel after the pump and not disturb the other normal settings then there is a possibility for that. But knowing the fuel sits on those hot injectors long enough to get to engine temp seems like it would do the trick. How much hotter do you really need to get? Combustion temps? Talk about vaporization. The injectors are designed to deliver a fluid not a vapor. So best not get it too hot.
pre combustion, and I mean just before, I want to achieve near vapo temps. The concept is simple, viscosity pre pump is the same, cool the returning fuel and you have something, but the trick is getting just the right temp, and maintaining it. As well as having dual settings for fuel and timing, could easily be mechanically controlled when desired heat is reached.
If you just try to heat the injector nozzle the heat will radiate into the body, which will heat the fuel in the return lines, tank, filter, pump...hence the comment of "same thing the alternative fuel guys are doing" If you are only heating it to 200F or so then I can see no benefit coming out of this. One could play with the breaking pressure of injectors and the timing of the pump to get better gains. How do you propose to have dual timing settings easily mechanically controlled?
While I appriciate your wanting to think outside the box but this is pointless. This will be as your steel head thread or newly designed precups both of which never got off the ground. It is good to offer a what if, but you seem to be defending something you don't even know is possible. Plus you are looking at .1% of the injection time with tunnel vision and there is a ton more that could be looked at. Port Velocity is easier to achieve by porting the head and precups and with a flow bench you could get your optimum atomization without adding a heater that would probably take more energy to run than any gain you will ever see from it. Instead of not building an engine to show us and going for the home run of fusion or something, why not take some baby steps and get into one of these engines. Tackle some port work or your steel head or newly designed precups? It is just a suggestion, but I think you are on step 6,053 in you head, but haven't started the project yet.
-
15psi would be over a little twice the air that an na engine would be getting. But I agree the only difference heated fuel may make would be in how it flows in the pump and injectors which probably effects timing and such and perhaps would help it mix a bit better when it first enters the swirl chamber since it will be slightly thinner from being hotter so I would image the molecules are a bit more excited. But to gain some huge mpg or power increase I am doubtful. It's always possible tho. It's just that diesels don't work like fuel injected or carbed gassers the adiabetic ideas don't really apply when the fuel is Injected at the time of combustion
the fuel being injected CREATES combustion...
+1 post count
-
Aside from the actual engineering caluclations regarding the energy required to heat the quantity of fuel to combustion temperatures, and the fact that you could realistically probably only heat the diesel to 200 degrees which is still a long way from it's flash point, there is the question of whether it's even beneficial to do this...
From my understanding, in a diesel engine, fine droplets of liquid fuel are injected into the cylinder combustion area. These droplets first vaporize (because you can't ignite a liquid) and then ignite under the heat and pressure. In doing so, the droplets travel towards the piston due to expanding gasses as they ignite, and create a flame path with a specific geometry which pushes the piston down in some specific way, part of the function of the prechamber is to direct the combustion accordingly. I think if you were to heat the diesel up to near it's flash point before injecting it, you would have problems because the diesel would basically be igniting too soon, and the combustion would have the wrong "geometry."
6.2/6.5 engines already have weak heads and gaskets, dont make it so that there is more peak cylinder pressure, that will make it LESS reliable..
you need something direct injected if you wanna play around with injecting fuel already heated to its flash point..
IDI will not easily lend its self to anything you want to do with it. IDI already burns VERY clean and efficient..
-
Agreed, which is why I believe that there is indeed merit to the IDI tech yet.
found an interesting article on something along these lines, to keep the mystery out of it I will briefly explain my idea afterwards.
http://www.dieselbombers.com/general-diesel-related/2404-fuel-coolers.html
The idea is to use a heat exchanger just before the injection in the form of a tube with coolant or oil in it, may even do both. The injector lines will run right through this and pick up heat just prior to injection, not enough to flash the fuel but enough to aid in atomization and help efficiency some, in the 180~ range at maximum. Now hot fuel will inevitably return to the tank right? so I will cleverly protect the fuel lines from as much heat pre injection pump, and run the lines to a cooler built into the airbox with air flowing right over it to keep it nice and cool no loss in flow is expected, simply based on the fact that the engine is forced induction and will flow enough air at any engine speed to keep the cooler "cool". The 70~ degree fuel will then go to the injection pump, which will also be cleverly shielded from as much heat as possible "have some unique ideas. the higher viscosity will lead to higher initial pressure and lubriccation of the pump will aid in extended life, since the fuel pump acts as a one way valve, the fuel cannot simply expand and go the other way as it is pressurized and forced down it's path so fueling will need to be adjusted for this, which is fine, running slightly lean initially "and I mean slightly" will help the engine warm up and the process will start. I just need some dual spring injectors like the AAZ ones and I'll be in buisness. The concept is simple enough, I got the idea pondering about why engine heat up when they run lean?, why EGR's rise what does it take to do that? all questions led me to the same conclusion, apparently no one has really loooked at heating or cooling the fuel and what the optimum fuel temperature should be. I started this thread to explore an aspect of my plan to build a better IDI. the heads are in final production phase, I will likely have to tell tran to hold off for a few more months because I am in a transitional phase and will be at my end of active service as of this month and need to find an alternat form of employment to continue my research. If I stay in, "BIG IF" I plan to take leave and travel to the plant and survey all that my meager funds have afforded my efforts. I read the comment that folks on here believe I am bat S**T crazy, well believe what you like, they called Tesla crazy until here recently for some of the things he said and talked about. I am not holding a sign that says Jesus Freak, or the end is near, or end world hunger, or perpetual motion, I have an idea, and a dream and am pursuing it to the fullest extent possible by my very meager assets. You are all very likely much more intelligent than I, and I applaud you, let this retard explore, and learn for myself. I may not have much more time to do so. In terms of the 6.5 reliability, it is similar in fashion to the vw IDI needs head studs to hold the heads on right, see:
http://heathdiesel.com/welcome-to-our-new-site/
smart guy, running "mostly" stock at 45psi twin turbo setup. Bill is a little hard headed though "aren't we all" he probably got ridiculed a lot too poor fellah. The engines are not bullet proofed except bottom end studs, has no stock oil squirters like the vw's do, I think that with the right combination of effort, this can certainly be a viable engine technology again, not just for the 6.5 but for all IDI's. A good friend of mine builds Stanley Steamers, up in Maine. Good friend of mine, I used to think that he was bat crap crazy till I swallowed my pride and listened up. There used to be this young snot nosed kid that would hang around learning tool turning from him, by the name of Jay Leno. I soon learned more than I ever wanted to know about all things steam car related. It was soon afterwards that I had an epiphany, without going into too much detail basically it meant doubling the efficiency of the diesel engine without sacrificing power. I have been chasing that dragon ever since. I told ol Ben and he encouraged me to pursue it, said there was merit in anything that had any passion behind it. I have since asked him many a question, and some he had answers for and many more he didn't. That said, I don't plan to leave the forum community, but a little less ridicule and a little more support would be professionaly appreciated.
Semper Fidelis,
Sgt Kevin A. Davies, USMC
-
The injector lines will run right through this and pick up heat just prior to injection, not enough to flash the fuel but enough to aid in atomization and help efficiency some, in the 180~ range at maximum
Heat transfer from the head to the injectors does that for you already. There is a reason for the heat shield between the injector and combustion chamber.
Adding heat to the air charge is a bad thing, return through a finned tranny cooler pipe wold be more to the point.
-
Ok, to clarify a bit more. I want to keep heat in the exhaust manifold, use heat wrap. Keep heat out/in of the intake manifold "I have my reasons" also with heat wrap. Keep heat in/out of injector and fuel lines also with heat wrap. keep heat from leaking out of coolant hoses, and "radiant" heat from building inside the bay. Basically the ICE is a heat pump, operated by principle of an air pump. I want to "control" this heat as much as possible, the diesel takes advantage of the heat side much better using thermal energy to aid in combustion. The heat shield removal will only really do so much and amount of saturation will vary on multiple values, however a physical heat exchanger will work much better at cooling the coolant, and heating the fuel. I was thinking of using oil because coolant oil coolers are common on vw's and are interchangeable, pretty easy, cheap to come by. The matter of pressure threshold and whether or not I can make this kind of exchanger work with the type of setup I have in mind is yet to be seen. I will run a line into the heat exchanger with pressure fittings on the in, and out tubes it will likely be a simple tube running parallel to the engine where all lines traverse through and exchange heat, no pressure is lost, in fact as the viscosity changes, pressure will increase to a degree which will have an effect on timing depending on fuel temperature. Thick "er", viscous fuel will enter the IP relatively cool, and exit slightly warmer, then get heated again before injection. Heat control is very important, if not then many variables will have to change, necessitating the re-design of the engine or it's individual components. This is relatively easy to do in comparison with some methods I have devised. So....... pipe for inlet outlet of coolant, drilled with four holes, injector line long enough to go through and fittings for re-connecting it on either side then weld them to prevent leaks. the other side to this is cooler intake air box air will be used to cool the fuel via heat exchanger which leads to the IP. pretty simple setup, the coolant will come post thermostat, for heat regulation, as long as the heat has reached a certain point the system will work beautifully, a solenoid can be used to mechanically regulate timing prior to a given temperature.
-
The injector lines will run right through this and pick up heat just prior to injection, not enough to flash the fuel but enough to aid in atomization and help efficiency some, in the 180~ range at maximum
Heat transfer from the head to the injectors does that for you already. There is a reason for the heat shield between the injector and combustion chamber.
Adding heat to the air charge is a bad thing, return through a finned tranny cooler pipe wold be more to the point.
you would indeed be correct in an N/A setup, but with a turbo the hotter charge cannot expand outward as the turbo acts as a one-way valve.
-
If you are exchanging downstream of the turbo, under load, you will have a fuel heater, not a cooler.
NA or not, I say adding heat is bad because heat in = increased EGT = less engine life & power potential, and we have plenty of more productive ways to raise EGTs.
-
he he, plenty of other ways to raise egt's ;D we will see. I have some work to do to get that far yet.