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Anyone else make biodiesel?

1737 Views 26 Replies 13 Participants Last post by  kernelkrink
I have logged over 100K miles on my own fuel in 5 different vehicles. Right now I own an 02 F350, a 93 K3500, and an 86 K5 Blazer. My wife uses the F350 as a substitute for a minivan (she told me she would never, ever own a minivan, that's how I knew she was the girl for me). I drive the K3500 as my commuter car. They are cheaper for me to run than my Honda Accord! The only caveat is that when the temps drop below the 20's, I have to run diesel, as the bio turns to butter. It is a very satisfying hobby. It also fits well with my survivalist mentality. All of my neighbors just know that I'm crazy. One of them calls me Doc Brown.

Anyway, I was just wondering to myself how many other Gunco-ers were bio-brewers also.
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That is pretty cool you do that..
I watched a show on a guy who went around to restaurants and got there old frying grease.
The restaurants were glad to have someone haul the old fry grease away.
He had the equipment in his barn to make the fuel..
How much did the initial equipment cost to make the fuel if you dont mind my asking. I like the idea.
In Thailand a lot of little trucks had propane tanks in the back of their trucks.
I dont know anything about how it works. But my buddy told me they rigged their trucks to run on the stuff.
Guess they ran them on whichever was the cheapest.
My truck runs SVO (straight vegetable oil).

Cracking it into biodiesel is a waste of time.

If you want to run your concoction year-round, I'd suggest you buy a tank and fuel line heater (they're made for folks who run biodiesel or SVO)
Wont the french frys clog the injectors? Seriously though I was told that you have to get the jelly out of the fryer oil to keep it from gumming up the works. I work on fryers and that stuff is nasty. I found a plan to make a system out of a hot water heater looks easy.
I'm on my 3rd processor right now. The first one was made out of a water heater. It made 25 gallons at a time. The second one was made out of a 55 gallon barrel that I cut the bottom off, and welded a cone onto. It made 45 gallons per batch. Now I'm on to the 3rd itteration. It is made out of a 90 gallon pressure vessel. I can make about 70 gallons at a time.

I haven't kept track exactly how much they cost to build, but I'd say probably around $300. My fuel cost me about $1/gallon now, so my ROI is pretty quick with 3 big diesels in the fleet.

I know all about SVO. My first experiment into biofuels was an 85 Suburban with a 2-tank SVO system. I logged about 40K miles on that thing on veggie before I sold it. The only issue I have with it is that now that I have 3 vehicles, the initial investment to run them on SVO would be a lot higher than to run them on bio, since I would have to buy 3 of everything. It's a big chunk of change to drop right now, especially since I already have the bio equipment up and running. I'm planning on eventually installing veggie systems to my trucks, but it will have to wait for a while, as cash is tight around here right now.
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Wont the french frys clog the injectors? Seriously though I was told that you have to get the jelly out of the fryer oil to keep it from gumming up the works. I work on fryers and that stuff is nasty. I found a plan to make a system out of a hot water heater looks easy.
You have to strain the used vegetable oil before you put it in the tank.
You know I was going to and ended up not getting a diesel but got another Jeep instead. The wifey knows the local Asian restaraunt owner so getting WVO would have been a snap for me :)

Frige there's a process to make it from what you see in the bucket into something that won't gum up the works. Relatively easy if you don't mind the extra work! If you look up on Youtube there should be quite a few videos about the process. Actually Mythbusters did a segment on it as well, but they didn't make Biodiesel insomuch as they used WVO to run a car. Diesel was built around that premise.

IMHO the peanut farmers of today could be the oil barons of tomorrow if Biodiesel were to take off - keep the money here :)
i had been running it. but murphy oil started going around collecting all the used cooking oil from the fast food joints and cut off my supply of used oil.
I have been running diesels for many years but have never tried cooking oil. In the Middle East they don't use diesel to run drilling rigs. They burn filtered crude oil; of course, it is better that West-Texas oil.
You should read up on using cooking oil / waste oil etc. before trying it because it can cause some issues if you aren't careful. As I recall the two "issues" are a clogged filter since the oils and/or biodiesel actually have a solvent action (read: runs cleaner) and causes crud in the system to dislodge and clog the filter. Also you need to use non-rubber feed lines since the biodiesel will degrade it. So upgrade the lines and filter and you'll be all set. In theory you could walk into the grocery store and pour cooking oil right into the tank, so long as it is warm enough to prevent hardening of the oils... of course that won't save any money vs. using waste oil :) A tank heater is required for a full conversion.
i had been running it. but murphy oil started going around collecting all the used cooking oil from the fast food joints and cut off my supply of used oil.
Same thing here, with big stickers on the tanks telling how it belongs to the waste company and they'll prosecute you for theft.

I've run up to 20% vegetable oil mixed with regular gasoline in my 1980 Malibu. Smelled a bit odd at idle, but started and ran fine, mileage went up about 1.5mpg, probably because the factory smog calibration in the carburetor is very lean, so it was closer to stoichiometric with the SVO.

I'd still be using it if it was still available for free.

I used to run about the same proportion of Diesel to gasoline, back when Diesel was cheaper than gas. Been a long time now.

Diesel mixes fine with gasoline, but you have to premix vegetable oil, which is a pain in the ass. Once it's stirred and mixed, it stays that way - I let test burets sit for a week in the freezer, and a month out in the shop, with no separation. But if you just pour it into the tank it'll run to the bottom and get sucked up by the pickup tube, the carburetor will fill with straight oil, and you'll find that gasoline engines *really really* don't like that. Fortunately the engine was fully warmed up and I was on a long straight road after dumping some oil in after refuelling. I moved along wide open at about 25mph for twenty miles or so before it cleared, limped back home, and had to put new plugs in. On old G-bodies like that you have to either have prehensile hands or you jack the car up, take off the front wheels, and access the plugs through the fenderwells. <sigh>

I also tried 25% nitromethane/alcohol (model air plane fuel) injection through a spraybar in the air cleaner lid. The nitro dissolved the plastic on a couple of windshield-washer pumps I tried. I thought the nitromethane would work like a poor man's nitrous oxide setup, but the car actually lost power when I hit the switch. I figure the 75% alcohol part cost me more power than I gained from the nitro, and I was probably airflow-limited by the ~200CFM Rochester DualJet carburetor anyway.

"Diesel-Kleene" or other Diesel fuel additives work great in gasoline engines. To simplify things considerably (for detail, get Glassman's "Combustion, Third Edition" from the library) the additives make fuel easier to light. In Diesels, it increases the cetane number. In gasoline engines, it makes the fuel easier to light and faster to burn, without making it more sensitive to detonation. Running is noticeably smoother and gas mileage goes up. However, after checking mileage through several tanks, I came to the reluctant conclusion that, price-wise, it was a wash. Plus the additive stinks to high Heaven, and even the empty funnel will stink up a station wagon.

Uh... I've played with fuels a bit.
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Do you recall the vapor-only gasoline engine designs? Remember that guy down in Daytona Beach that had the 2-cylinder that had as much power as a 4-banger? Smitty or something? I was going to build up a vapor feed system, started buying parts even, then went off to college out of state and lost access to dad's shop :) To this day I still am not sure if the vapor feed system was a gimmick or really did work.
I love the versatility diesel engines offer. You can run on just about any oil. I have fueled my suburban with all kinds of oil. Trans fluid, used engine oil, hydraulic fluid, veggie oil.

I have yet to play around too much with alternate fuels on gas engines. I did install an HHO (one of those hydrogen/oxygen scams) on a friends vehicle. I want to try my hand at making ethanol. My uncle in Montana built a great big still setup in his shop for making his own alky for his jeep, 4-wheeler and lawn mower, but he never tried it in his other vehicles.
with the big price difference on E85 here in Colorado (currently $2.65 for 85 octane gas, $1.89 for E85), I converted my car (a '99 Neon) to run on E85.. all I did was swap in injectors that are 30Lb/hr to replace the factory 19Lb/hr

I get 27-28mpg on E85, compared to 34-35 on gas, and the E85 is also about 106 octane.. car gets more power.. and when it's time to rebuild the engine (has over 193k miles now), it'll get a compression bump to 12:1 or 13:1 or more..

interesting on the SVO/Diesel in the gasoline, never heard of that before.. would think that would drop the octane- I doubt it would mix with E85, but that would be a good combination- E85 has octane to spare, but doesn't like to ignite below 50 degrees (I've used a propane feed to start in the winter before, works well, E85 runs fine after the engine is started)

I've only got 1 Diesel in the fleet (Cummins Dodge), and don't drive it enough to go through the effort for biodiesel/SVO right now..
Smokey Yunick. He had some of the OEMs looking at it for a while, blamed failure to sell his invention to them for Big Bucks on the "Not Invented Here" mentality, then got sour over the whole thing.

I acquired both the original and revised patents, which are beautiful examples of the patent application lawyer's art. They lay out the various claims while giving a minimum of useful information. Still, it wasn't *that* difficult to figure out.

Basically, I think Yunick's method would have been unable to pass the EPA's cold start emissions cycle. It would also have been a dog to drive until fully warmed up. Also, I think throttle response would have been... strange, at least to people used to carbureted cars with direct throttle linkage (as opposed to many modern cars, where the pedal and engine RPM are only related by software). Finally, the whole "Hot Vapor Engine" thing went away about the same time the EPA cranked down hard on NOx emissions. Oxides of nitrogen are generated primarily as a factor of temperature, and though some new catalyst technology can *partially* deal with them, it wasn't available back then.

Combustion of gasoline is fairly complex. The fuel-air mixture starts off stable, like a rock at the top of a hill. The spark kicks the rock downhill. The fuel-air combustion creates a dozen-plus-odd intermediate compounds. The first several-odd ("gasoline" is a complex and variable product, so you can't nail things down precisely) reactions take more energy to complete than they release; that is, they're self-extinguishing. So you need a big spark to provide energy to kick the rock out of the hummocky area and down the slope.

During this time the piston is moving down the cylinder. As this happens, temperature and pressure start to drop more rapidly than combustion proceeds. Combustion depends on temperature and pressure; at some point, the combustion process basically stops. On most engines, this happens somewhere around 2/3 of the piston's way down the bore.

There are still flammable compounds in the cylinder, it's just that it's too cold for them to burn. What Yunick did was to raise the starting temperature - make the hill higher - so that more of the fuel would react before the charge hit the freezing point. Yunick used an "interheater" between the intake and exhaust to raise the charge temperature.

Yunick's patents went over this in detail; it's basic engine design stuff you can get from many textbooks.

Generally, when you raise the starting temperature you increase the chance of detonation or "knock." That's bad for the mechanical bits of the engine. At the temperatures Yunick was describing, his engines should be been like Diesels, if not just hammering themselves to bits in short order.

What was cleverly mentioned but not explained in the patents was the method by which he controlled knock. EGR. The nasty smog-control method that made so many '70s and '80s cars run like crap. Particularly bad examples would keep on running even after you turned them off and removed the key, like the Family Truckster on "National Lampoon's Family Vacation."

What Yunick did was to use a *lot* more EGR than Detroit was using; enough to reduce the tendency for the engine to knock. Yunick used so much EGR that the engine needed a turbocharger to make the same power it did before.

What Yunick did *not* disclose was the method by which he controlled the EGR in relation to engine load, etc. Nowadays you'd do it all with the engine computer. Yunick kept his method a secret. It was probably quite a trick - he would have to do it with mechanical linkages and vacuum doodads, electronic engine controls not being around when he did his first demo cars.

It's an interesting system.
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I did install an HHO (one of those hydrogen/oxygen scams) on a friends vehicle.
Hydrogen works as a combustion accelerant, like throwing gasoline onto a barbecue grill. A little bit goes a long way. Unfortunately, its effectiveness falls off rapidly.

Spare hydrogen atoms move throughout the combustion process like dancers at a square dance. Swing your partner, do-si-do, swap those electrons around all the carbon bits. Once there's enough hydrogen to match all the available slots, more hydrogen doesn't do much.

Providing a snort of hydrogen can really perk up performance, particularly at low RPM or part throttle, where combustion can be weak or unstable anyway. It's much less effective at WOT.

Despite the massive propaganda, hydrogen is a piss-poor motor fuel (knock sensitive, among other things), and its combustion byproduct is not "just water" as the enviro-dweebs like to claim. It would be just water if you were dragging along your own oxygen supply, but if you burn ordinary air, you output lots of nasty oxides of nitrogen and come other byproducts, all regulated by the EPA.

Like the man said, "There Ain't No Such Thing As A Free Lunch."
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would think that would drop the octane
Octane and cetane are different things, not opposites.

Any kind of knock rating is very slippery to define, which is one reason the gas companies opposed mandatory octane ratings for decades before the Fed ordered a standardized test and pump labeling.

Octane is determined as a fuel's resistance to knock, as compared to a chemical called iso-octane, as tested in a standard variable-compression test engine. It's made by Waukesha, operates at low RPM, and has a hockey-puck shaped chamber.

What the Feds didn't know, or didn't want to hear, was that their "octane rating" only applies to engines of similar geometry. Quench, swirl, and tumble, among other things, greatly affect an engine's knock tendencies, along with spark plug placement, bore size, and exhaust valve cooling. If you've ever owned a vehicle that ran just fine on regular or mid-grade but pinged on premium, that's what can happen.

My Bandit 1200 has slightly over 13:1 CR, runs fine on most regular gas, and pings on some "premium." This isn't because the fuel is bad or the gas company is ripping people off, it's that it's compounded to pass the octane test in a very different engine. In most cases, though it's close enough, particularly with modern closed-loop engine management systems.

There are fuels like methanol or propane that have high octane ratings, but don't always perform well in unmodified gasoline engines. That's because those fuels have a much narrower range of acceptable temperature and spark advance before they start to knock. Back in the old days keeping the engine tuned to propane's sweet spot was often quite a trick - people like Ak Miller and Rite Autotronics made a living doing that sort of thing.
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I wonder if the revenuers will come after you for not paying your fuel tax.
Octane and Cetane are different things, not opposites.
They're measured different ways, but it's impossible to have a fuel that's high in both.. Diesel has an research octane number of 15-25.. I found this at my favorite diesel site:
Mixing Gasoline And Diesel
this is from the perspective of putting gasoline into Diesel in a Diesel engine- not in a gasoline engine.. I would think Diesel wouldn't be as much of a problem in a gasoline car, but would absolutely lower the octane, while at the same time increasing the amount of energy (BTUs per gallon, Diesel is significantly higher, while alcohols are lower) This has me wondering if putting a bit of diesel into a tank of E85 would help the cold start ability, and increase the mileage..

Pump octane rating is an average of research and motor octane..(RON+MON/2) Both are measured by the variable-compression engines as you describe, but the motor octane test involves pre-heating and more ignition advance..

They don't normally publish octane numbers for E85, but those that run turbocharged engines into ever-increasing boost levels love the fuel.. main problem is getting big enough injectors, and still being able to idle (banks of injectors?) the latent heat of evaporation of ethanol really cools the intake charge well, making it denser & decreasing the knock sensitivity..
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They're measured different ways, but it's impossible to have a fuel that's high in both..
Not in the least, though you could debate the value of "high." Combustion enhancers and accelerants play a big part in racing fuels, for example.

You can take net.lore and, or you can go to Glassman, or the first volume of Taylor's "The Internal Combustion in Theory and Practice", or just hit for many of the papers from the original researchers.
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