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BioD24TI Project (greenblock pics)

Yes, biodiesel will eat the engine bay fuel lines, and the injector pump seals. I don't know if it will dissolve any parts associated with the fuel tank yet, as I haven't had problems with that.

Viton seals and fuel lines will fix this problem permanently, and I recommend going with them anyways (even if you keep using regular diesel). Any old diesel engine you find for a good price will almost inevitably have old fuel lines that should be replaced, and upgrading the seals on the IP to viton is good insurance anyways....

I do not recommend the 50/50 mix waste vegetable oil and petroleum diesel as an alternative to biodiesel or correctly heated vegetable oil unless you live in death valley. Even at 50/50 it will be way too thick to be pumped or injected properly, and it will coke up your injectors and rings causing engine problems later on. I think that vegetable oil is okay in an engine if you design or install a system that meets this criteria:
-The fuel temperature is nearly at the boiling point of water (100C) at ANY time vegetable oil is being injected into the engine (this means you cannot start cold on WVO or any mixture of WVO). This means coolant heat, and high current electric heating.
-The oil has been filtered to a particle size of no larger than 1 micron before putting in the tank.
-The oil is either new (not used waste oil) or has been verified to be free from contaminants.
-The oil has had any/all water removed, by heating the oil to boil off any water.

Even if you do all of the above, there is not much data out there about how WVO affects long term engine wear. This doesn't mean that it will cause problems, just that nobody knows for sure. Elsbett AG in germany has been modifying VW diesels to run on WVO since about 1980, and they have a reliable system that uses extensive heating, different injectors, and different glow plugs:
http://www.elsbett.com/us/elsbett-conversion-technology/cars-and-vans.html


Biodiesel has been tested extensively and shown not to cause long term problems.

Mercedes diesels injection systems are a lot tougher than Volvo diesels, but if you look at the Mercedes forums you will see tons of people who have ruined their engines and injection systems by running waste oil, and Mercedes enthusiasts are upset about how many good classic mercedes are being damaged with poorly thought out cheap fuel experiments.

Ruben said:
Isn't biodiesel a lot more aggressive on the fuel-lines?
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Thanks for your answers on the intake manifolds. I am glad to hear I can send the intake in where ever I want. When pondering it previously, I never really thought that only one or two valves would be open at once, but know that you mention it, it makes perfect sense. This is what I am talking about as far as intake runner length:

http://auto.howstuffworks.com/question517.htm

Are they saying that this "wave" of pressure does not enter the manifold itself, and just stays in the runners? Or should we be calculating the entire length all the way to the back of the intake manifold? I am kind of leery to do the math myself. Anyone want to run some numbers? :oogle: I think you'd want to time the runners to 2400RPMs. That would probably be the most beneficial seeing as its where peek torque occurs already and its a pretty good cursing speed in fifth. What do you guys think?

I also want to weld up an exhaust header with equal length runners. First of all because they are awesome. And, well, I think thats just about covers it. You all know why they are awesome. I am kind of suspicious of the efficiently of the stock turbo exhaust manifold. I finished welding my side exit exhaust today. Made it out of some used 2 1/4" exhaust pipes I had lying around. It was some good pipe angling and welding practice.

Where might one find some of these Viton pump seals? and how much must the pump be dissembled to replace them all? Is it a job someone with decent mechanical experience but who hasn't cracked one of these pumps open yet, can handle?

Thanks everyone,

-E
 
Tom Bryant said:
Regarding the length of the runners: I have no educated knowledge. But personal opinion is that the length of the runners does not make any significant difference. I really don't know why the NA manifolds have such long runners; I can see no advantage, but I've read somewhere that the length of the runner can have some effect on "ramming" more air into the cylinder.
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And you call yourself a fluid dynamics injurnear.

As for the allegation that the NA and non-TIC manifolds might starve the furthest cylinders for air, I say: "Total Crap." That idea could only have been generated by someone with total lack of understanding of how fluids flow and of how intake valves open and close.
Click to expand...


Your statement immediately above this gem here seems to be written by a person with a total lack of understanding of how fluids flow
Click to expand...
 
Eli said:
Thanks for your answers on the intake manifolds. I am glad to hear I can send the intake in where ever I want. When pondering it previously, I never really thought that only one or two valves would be open at once, but know that you mention it, it makes perfect sense. This is what I am talking about as far as intake runner length:

http://auto.howstuffworks.com/question517.htm

Are they saying that this "wave" of pressure does not enter the manifold itself, and just stays in the runners? Or should we be calculating the entire length all the way to the back of the intake manifold? I am kind of leery to do the math myself. Anyone want to run some numbers? :oogle: I think you'd want to time the runners to 2400RPMs. That would probably be the most beneficial seeing as its where peek torque occurs already and its a pretty good cursing speed in fifth. What do you guys think?

Where might one find some of these Viton pump seals? and how much must the pump be dissembled to replace them all? Is it a job someone with decent mechanical experience but who hasn't cracked one of these pumps open yet, can handle?

Thanks everyone,

-E
Click to expand...

Sorry, I don't know exactly how to calculate the optimum runner length. I also don't know exactly how the wave reacts when it reaches the intake manifold; whether it bounces off the lower velocity air right at the runner inlet, or if it bounces off the wall of the intake manifold. That's all just sooo complex. And whatever you calculate it for, it's only going to work over a very narrow RPM range. It's the sort of thing that gives injurneers headaches and is very empirical. But, it's also something that can be tested and rules developed, and those rules applied to subsequent cases. I personally would *not* want to tune the runners to 2400 rpm, however. That's really low on the power band; max HP is at 4800 rpm, and if you want to get high horsepower, I think you should tune those runners for the peak HP range.

As for the Viton pump seals, you can't buy them as a kit. And, I'm not convinced that they would provide significant benefit for the money spent. According to the local Bosch dealer, the OEM Bosch seals work satisfactorily with Biodiesel. That's also what I've heard from many people who use Biodiesel.

But, I have been making myself a list of pump seal sizes and have been intending to order some Viton seals. Not because they're really necessary, but because I figured I could buy them in bulk and save a few dollars on rebuild kits. I hadn't figured on buying *all* the seals in Viton, however. There are some that are just so oddball that I intended to just continue buying them from Bosch. But, if you really wanted *all* your seals to be Viton, I might be able to oblige. But, I'm rather skeptical that I could get the input shaft lip seal in Viton, and the pump cover seal would probably be impossible. There might be others that would be difficult also.

To replace all the seals, and do it right, the entire pump must be disassembled, right down to parade rest. And that is not a job for a novice nor for the timid. You can also figure that you're almost certainly going to break (read "totally destroy") a pump or two before you get the hang of it. And, special tools (sockets) are required for disassembly and for re-assembly. The cost of the tools and the learning curve is probably prohibitive, unless you plan on doing a lot of them.

Quite frankly, you're probably better off having someone else do the job for you. If you'd like a quote on how much I would charge for the job, send me a PM.
 
John V said:
Tom Bryant said:
And you call yourself a fluid dynamics injurnear.




Your statement immediately above this gem here seems to be written by a person with a total lack of understanding of how fluids flow
Click to expand...

It's outside my area of expertise, and I said so. I have not spent my career designing automotive intake systems. I'm always careful to indicate when I know what I'm talking about, and when I don't. 'Nuff said.
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small hijack...

Tivo the upcomming "Some Assembly Required" on Discovery channel...episode 6 they build a new BMW Diesel engine, not sure if they build engines in Spartanburg, South Carolina...seems all the shows have been US based so far and not Canadian like How its Made.
 
Tom Bryant said:
I stand corrected. I just checked with my Bosch distributor, and the seals are now made of Viton, or so he believes. I *assumed* they were not Viton because Viton seals are usually a dark brown, almost black, whereas these seals are either black or green. The green ones especially didn't appear to be Viton to me.
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Viton is really just a brand name of DuPont, that covers several different compounds, all of which are synthetic rubbers containing fluorine (fluorocarbon elastomers). I have seen green, black, white, and brown viton seals in valves and hoses used for making biodiesel. I think the color coding has some significance indicating different properties and usage, for example black viton contains carbon black.

I think that materials compatability is the single biggest obstacle when making biodiesel, or using it. Biodiesel dissolves almost everything which makes it very good at cleaning carbon out of engines and injectors, but also makes it very difficult to find any kind of flexible tube or seal that won't dissolve in it. Even certain Viton compounds will dissolve eventually if used in a biodiesel reactor (but not in an engine running on biodiesel meeting the ASTM D6751 standards).
 
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Tom Bryant said:
I also don't know exactly how the wave reacts when it reaches the intake manifold; whether it bounces off the lower velocity air right at the runner inlet, or if it bounces off the wall of the intake manifold. That's all just sooo complex.
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I don't know much about intake manifolds either, but I do know a bit about waves (in general). I would imagine (pure speculation) that the boundary conditions at the valves, and between the intake runners and the main manifold reflect a portion of the pressure waves, creating harmonics and standing waves at various RPMs. This constructive/destructive interference would create high and low pressure regions in the intake manifold, which could change the a/f ratio slightly between cylinders, and may be important in a high compression or boost gasoline engine. If effort is taken to make the intake as symmetric as possible (such as the stock manifold on the B230FT), one can be confident that the interference patterns will affect all cylinders equally, even if you don't know/understand exactly what those patterns are, or when they occur. I don't see how this could be an issue at all in these old diesel engines where we are just concerned with keeping the a/f as lean as possible, and not maintaining an exact air fuel ratio.

Of the mass produced turbo diesel engines I have seen, none seem to have intake manifolds designed with a high degree of symmetry. Most appear to be designed mostly to save space, flow adequate air, and maintain a high ratio between the size of the main body, and the individual intake runners. Of course, they are probably focused on reducing cost and saving engine bay space, while we are concerned with performance and efficiency. Does anyone have a photo of the intake manifolds on a purpose built race diesel, such as the VW turbo diesel Le Mans engine?

Again, I am not claiming to know anything about intake manifold design either, just about the physics of waves. Can anyone with some experience or knowledge in this area confirm or deny my wild speculation, and help improve my understanding?
 
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I found a photo of the VW V12 TDI race engine:
3060000000058099.JPG


It's a little hard to see, but it looks to me like the inlet is on the front, and the runners are very short.
 
casioqv said:
Again, I am not claiming to know anything about intake manifold design either, just about the physics of waves. Can anyone with some experience or knowledge in this area confirm or deny my wild speculation, and help improve my understanding?
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I think the 4 cylinder diesel engines may be a useful analogy. There's a bunch of people with the 4 bangers who have experimented with longer-runner intake manifolds, modifying the gasser intake manifold to fit.

Dave Cross has been experimenting with building intake & exhaust manifolds for the 4 cylinder diesels. Maybe I can prod him to join TBricks and post in this thread. The 4 banger diesels are not crossflow heads, so both the manifolds are jammed up against each other on the same side of the head. I assume the D24T is not crossflow, either, but I haven't got a photo of of a D24 head handy to double check.

Here's some photos of what Dave is doing for the 4 banger oil burners. You can see where Dave cut the top off the stock intake manifold, and then welded the big plenum into it's place. The stock manifold just has a little L-shaped 90 degree snorkle in the middle of the log. I'm no engineer, but my eyeball tells me that's not the most efficient way to flow air into the engine.

http://vwdiesel.net/phpBB/viewtopic.php?t=7676

prototypeintake3.jpg


lightmanifold.jpg


3rdmanifold.jpg
 
Otis said:
Here's some photos of what Dave is doing for the 4 banger oil burners.
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The exhaust manifold looks great, but I don't see how that intake could possibly be any better than a D24 N/A intake. BTW, the D24 head is not cross flow. If I were him, I would just take a D24 N/A intake, cut off the last 2 cylinders, and weld on a plate.....
 
casioqv said:
The exhaust manifold looks great, but I don't see how that intake could possibly be any better than a D24 N/A intake. BTW, the D24 head is not cross flow. If I were him, I would just take a D24 N/A intake, cut off the last 2 cylinders, and weld on a plate.....
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How big is the supply of D24 intakes vs. VW intakes and some aluminum stock?
 
Perhaps we don't have the same space constraints that the VW has.

Personally, I would try to run the exhaust lower, and open up that bend on the intake.
 
Kevin Hawkinson said:
Perhaps we don't have the same space constraints that the VW has.
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I think you're absolutely right. An N/A D24 intake manifold would probably stick out the hood of a VW Golf/Rabbit like the intake on a top fuel dragster :rofl:

244tiCanuck said:
How big is the supply of D24 intakes vs. VW intakes and some aluminum stock?
Click to expand...

D24 intakes are pretty rare, I had been looking for one for a while before Tom kindly offered to give me one for free.
 
casioqv said:
D24 intakes are pretty rare, I had been looking for one for a while before Tom kindly offered to give me one for free.
Click to expand...

Can you post a picture of it? I'm curious why they appear better than the plenum design in the photos I posted.
 
casioqv said:
I think you're absolutely right. An N/A D24 intake manifold would probably stick out the hood of a VW Golf/Rabbit like the intake on a top fuel dragster :rofl:



D24 intakes are pretty rare, I had been looking for one for a while before Tom kindly offered to give me one for free.
Click to expand...

Actually, when you get that D24 Intake Manifold, I think you'll have to agree that it's smaller than that "marvy" home-made job. It doesn't stick up as high as the one in the photos you posted.

D24 intakes aren't all that rare in my shop; I've sent one to Tyler, two are going to a guy in Canada tomorrow, and I still have a dozen or so in my garage. But, if I'd known they were such gold, I'd have put a price on them. :-)

BTW, the VW crowd likes to take the D24 intake manifold, cut one cylinder off each end, and bolt it up to their 4-bangers.

That homemade intake looks impressive, but I have serious doubts if it'll have any measurable effect on performance. For starters, the intakes are longer than those of the D24s, and assuming that the factory "injurnears" got the length "right", then (I think) the homemade job has to be "wrong", especially since it appears that they're turbocharging it, and that makes the temperature higher, and the speed of sound varies with the square root of temperature, so if anything, a turbocharged inlet should be shorter, not longer.

If anyone ever sees any dyno tests of the OEM manifold and the fancy one, please post the results.
 
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