biodiesel as fuel additive for gasoline
 

Anyone run biodiesel as a fuel additive in a gasoline vehicle?
I'm going to try it but wanted to know if theres anyone who's experimented with it already.
i was thinking id start with 250ml for a 40l tank, then increase until i find the ideal amount. Does anyone know what type of damage i could cause by putting too much in? Im expecting i'll need to change my fuel filter after i start using it.
I track my FE but because i have a carburetor theres no way to accuratley measure it. the best im able to do is run my tank down near empty and fill up again. i wish there was a scanguage device for carb'd cars.
i'll have to wait till my next tank to add it because this tank im testing a front air dam. should be later this month.

Check here:

https://www.gassavers.org/showthread....ight=biodiesel

ah sweet. thanks metrompg. i knew i remembered reading something about that before. guess i should have searched a bit.

There are other, better tested, 'top cylinder lubrication' fluids than biodiesel. Have you considered ashless two stroke oil as an additive? Biodiesel is almost non-flammable due to its high flash point and low volatility. I'd be concerned about running it in a spark ignited engine.
Typical diesel engine rpm maximum is 3500 to 4500. That is the limit created by the time needed to vaporize and burn the fuel (diesel or biodiesel). The engine can't run faster because the burn and expansion rate isn't faster. At those speeds the piston is being pulled down by the connecting rod as much as it is being pushed down by the combustion expansion on top.
Adding diesel or biodiesel to gasoline and then running the engine rpm above these levels may lead to not enough time for the diesel fuel portion to burn. The gasoline will be consumed but there may be some continued burn of the small proportion of fuel oils during the upstroke for exhaust.
I tried to 'use up' some bottom of the barrel biodiesel in a flathead lawnmower engine at a 20% rate to unleaded gasoline. Twenty percent wasn't a help. I don't expect that 10% would have been anything but 1/2 as un-helpful as 20% was. The exhaust smelled better than gasoline, but it didn't run as well. Would fresh biodiesel have had different results? Maybe, but why would I put good quality expensive biodiesel into a non-diesel engine?
I now have a diesel lawn tractor to use up the biodiesel dregs (and kerosene, and home heating oil, and neighbors turkey fryer oil, etcetera) that I won't ever put in my diesel car.

if you're driving for FE then i wouldn't think your rpm would be higher then that anyway. and although bioD may not be the best top cylinder lube it should be better then nothing. plus the cleaning effect could be beneficial on an old carb.
I've made a small one liter test batch already using the dr pepper technique so i'll dump it in with my next tank.

What are you trying to accomplish with BioDiesel? If it's to clean the fuel system just run some acetone and Torco GP7 for a few tanks or even a mixture of 20%-30% E85. I've had a slight increase in FE running a mixture of E15.

Diesel has octane numbers around 15-25. They tend to ignite easily from high compression.

Diesel fuel is rated by its cetane number. Instead of heptane and iso-octane they use napthalene (cetane rating = 0) and n-cetane (cetane rating = 100). In total opposite to octane ratings, the higher the cetane rating the higher the fuel's propensity to knock! Adding biodiesel to regular gas is liable to drop the octane rating that you currently have and thus decrease FE because the engine is designed for a specific octane rating.

How high is 'high'?
Don't minimize the importance of fine atomization possible from pushing fuel at 30,000 psi through .184 mm nozzles. A 60psi fuel injector for gasoline won't break the drops of fuel into a near vapor size needed to compression ignite. A carburetor venturi definitely won't. The drips of biodiesel will burn when lit by the gasoline, but not too well on their own.
Sawdust and a tree trunk are the same substance, but one ignites more easily than the other. Biodiesel liquid at 60 psi and 8:1 compression is more like a log than biodiesel atomized by 30,000 psi and 20:1 compression.

I only put around 200 miles on my Honda CB125 motorcyle with a 10:1 mix of bio-diesel in it befor putting it away for the winter, but I never had a problem with how it ran, I even put an o2 sensor in it to make sure that it wasn't going to foul up o2 sensors, and as far as I can tell it's not causeing any problems.
I didn't notice any jumps or drops in gas mileage with bio-diesel, it seemed to burn just like gasoline when mixed at 10:1, sure one part bio-diesel to ten parts gasoline is not alot, but it's as high of a mix as I could get without making any adjustments to the engine, I also found that my motorcycle was able to keep the exact same top speed (almost exactly 60mph), and the o2 sensor readings seem to stay pretty close to the same with the mixed, and unmixed fuels.

so I say go for it, from what I've been able to tell, it's not going to harm anything, altho I haven't seen any magical results either.

mainly i just want to see what it does as a fuel additive.

on a car with a fuel injection and a knock sensor i could see a lower octane rating hurting FE but because i have a carb i don't think it would hurt my FE unless the octane rating dropped enough to cause pinging.

Back in the Rambler days I ran a little home heating oil in the gas - well I don't recommend using it in a Fuel Injected car. In a carburated engine it made a lot of white smoke when cold and kept running with the ignition off when the concentration was a little too high after it warmed up. Now with the Synlube in the engine I don't have to worry about top cylinder lube but I do have to worry about any additional lubricant getting into the Synlube and fouling it up.

diesel in a carb car
 

Ok, i have to admit that as a teenager I rarely had enough money to keep my 73 Pontiac grand ville (455 no less) in gas. but i lived on a farm and my dad had a diesel tractor and we had diesel fuel around. so i ran a few "experiments" myself. Fact is it rarely minded having a little diesel in the gas (couple of gallons in a tank) and it even would run on 100% diesel but just barely (no power, but it would move around the yard, oh and it would continue to run after you turned off the key sometimes) my guess is that it was not really good for the engine, but then again at 16 i did worse things to the car anyway

so it looks like i should start with more then originally planned. maybe start with a 1:40 ratio and go up from there.
i better start making some more.

Well i added one liter of biodiesel today, I've gone about 8km since i added it so i cant be sure if i'm burning it yet. I would think that all the gas in the lines would be out by now but i cant say i notice any difference at all. I guess it will take more then a liter to find out.
Anyway, guess we'll have to wait a couple weeks to see.

it should take less then a minute for the fuel to cycle thru the fuel lines in any vehicle that has a fuel pump, so you should be burning biodeisle already, I didn't notice any change in proformance, so I'm not sure what kind of changes you might be looking for.

this last weekend I went to a short talk on growing your own bio-diesle, it was pretty amazing, and not the kind of thing I would want to start doing on a small scale, as the equipment is a large investment (tens of thousands of dollars), and you only get about 110 gallons per acer.

That's odd. I was under the impression it was pretty simple, but labor intensive, for the DIY'er. What crop was used for BD production?

my car doesn't have a return fuel line so it might take a bit longer then most. I drove more today though so i know i'm burning it now, no difference at all though. I was thinking with the added lubrication it might be quieter. I guess not.

the costly part of growing your own was the equipment to harvest it, and press it, if you are going to grow more then an acer, I would think you would want some kind of mecanical harvester, altho I supose spending a few days out there with a trailer or a pickup truck, and a big knife loping off the heads of sunflowers (that was there recomended crop) I think they said it was about 2000 pounds of sun flower seeds would make round 70 gallons, then you have to press the seeds, for that a screw press was being recomended, $5,000 to $10,000 for a screw press, the more exspensive german made one was being recomended, chinese made ones had many complants ranging from low oil production, to sloppy workmanship, to short life.

WOW! I had no idea it was so difficult to obtain biodiesel (please note the spelling of the word). Your home production of your gasoline is a good idea. Why not share with us the costs of the equipment you use for that?

My B100 biodiesel comes from a fuel pump at a full service (gasoline, diesel, biodiesel, home heating oil, kerosene) fuel station. I have yet to make my own biodiesel, not even a test batch, just as I have never made my own gasoline.

Sunflower has a relatively low oil yield per acre (again, note the spelling) and is not a crop usually selected primarily for oil production. Sunflower, soy, rape, cocoanut, Jatropha, corn, mustard and any other oil producing seed grain have other uses that are their primary reason for being harvested, the oil frequently is a byproduct of that prime use. About the only oil crop for biodiesel for which I know of no other prime purpose is algae. Although algae has the highest oil yield per acre it is not yet commercialized due to no high profit primary market value as with the other, more traditional crops.
Even when the vegetable oil IS the primary product, biodiesel can be made from the oil at the end of its use for it's primary purpose.
And the byproduct of biodiesel production can be used as a food ingredient.

Ouch $$... I suppose with sunflowers the press that gets the most oil out is preferred. I bet sunflowers are the only decent oil crop that could grow up there, so even if the kwh/ha is on the low end (~6,000kwh/ha) and upkeep is on the high end, it's the best that can be done. All the really good oil producers like oil palm (~35,000kwh/ha) and jatropha (~23,000kwh/ha) grow in the tropics, don't require much in the way of upkeep, and provide for other crops, which is why China is going to use it. But, it's a perennial, and can't take frost, so outside of a greenhouse it can't be used up north. At 100mpg I'd need a little less than half an acre per year of Jatropha to drive 10,000 miles... Which isn't too bad imo, but using sunflower I'd need almost two acres... Not as doable.

Hemp is about 12,000 kWh/ha, but is much easier on the soil and less finicky about climate. You're almost always garunteed a harvest with hemp.

After I convert the GT6, I'm considering building a biodiesel dune buggy, modelled after that custom aero Model T metrompg posted on. It would be nice to have a V8 turbodiesel and a large 50 gallon tank on a small, aerodynamic(at least relative to open wheeled vehicles) vehicle like that. Imagine the cruising range, performance, and fuel economy all rolled into one.

Is industrial hemp legal nationally, or on a state by state basis? As long as you gear it right, you could see at least 80mpg@60mph in that vehicle, just make sure your biodiesel doesn't oxidize and whatnot, since you'll only be filling up twice a year! :D

If you grow industrial hemp in the U.S., you will be arrested. You can thank William Randolph Hearst of the timber industry and his yellow journalism campaign, DuPont who had a nylon patent to protect, the cotton and textile industries who didn't want a fabric that could make clothing that lasted decades and was much softer than cotton to take hold, the oil companies, and a slew of other businesses for it being nigh impossible to legally cultivate hemp in the U.S. You can also thank them for starting the war on drugs. All to protect their bottom line, of course, at the expense of our civil liberties, the expense of our environment, and today at the expense of our chances of getting off of foreign oil.

Hemp yields roughly 300 gallons per hectare per harvest, can be grown in virtualy any climate, needs no pesticides, needs very little fertilizer relative to most other crops, can be used to make clothing, plastics, car bodies, biodiesel, medicines, and many other things that high profit margin oil is used for.

If I ever build such a vehicle as that buggy and put in the 4.2L, 324 HP V8 turbodiesel found in the Audi A8, I expect roughly 50 mpg and 0-60 mph < 4 seconds. This is with high rolling resistance studded tires for traction and offroad capability(Cr ~.015-.020). Imagine being able to drive coast to coast on one tank, go offroad, and have enough acceleration to get away from anything that might share the road. Then to have the low maintenance of a diesel to boot. Might become very handy in a post peak oil America.

Too bad it's of a variety that is almost useless for the applications I described above. The low THC variety that the governments in various states are pushing also has very low seed oil yields and its fiber tends not to be near as strong.

What is really annoying is that virtually all hemp by its nature is of low THC content, so low that you couldn't get stoned from normal industrial hemp(let alone the specially bred kind). But this still doesn't satisfy the various state governments or the Feds.

You might want to look for a mechanical IDI if concerned about maintaining that beast after TEOTWAWKI. Course, I don't think we'll see any significant destabilization from a peak in oil production. There's plenty on the shelf that can be rolled out in short order. If we can build an A-bomb in a few years, we can roll out fuel efficient cars pretty quick. We're just being led along so a certain group can make as much cash as they can. Shame about hemp in our enlightened western world... :rolleyes:

I've thought about that, but do you know of any with decent horsepower(say, 200+ HP) that weigh under 800 lbs? I couldn't find one, but do very well love the idea. Low maintenance is crucial, but parameters such as performance and weight still take precidence. It has to be able to perform and have a suitable weight distribution(~35-40%/60-65% FR with mid or rear engine)

I think so too, but the greater the crisis is, the higher the price of oil, the more money is made for the industry. A post peak oil dieoff is a very real possibility, even if it is entirely preventable with today's technology. Our current power elite will no doubt use such a crisis as a way to expand their control. They just don't care how this will effect the majority, as addressing this issue properly will hurt the bottom line of many industries and turn our tax structure around. Our government and corporations just won't have that...

And fuel efficient cars will only take hold if people have the money to buy them. If they're spending all their disposable income on fuel and on price increases from other products due to increased energy costs, they'll have no money left to put towards reducing their dependence on oil. Once the crisis is well underway to the point where all disposable income has been sapped, there isn't much one can do to get out of it. If we stick with oil, most people be trapped with using it. If gas gets $10/gallon, Joe Average now doesn't have the money to put into an EV conversion, even though he may be desperately considering it by that time. Hell, I was in this situation last year at $3/gallon gas. Needed to get to school somehow, and by car is the only practical means with a lack of decent mass transit(nevermind the cost of mass transit where I live and the time/travel distance needed to use it). There went a good chunk of EV money.

Um.... I'm pretty sure a VW I6 IDI can make ~150hp@5k rpm, maybe more, and weighs ~500lbs. Maybe one of the I5 TDIs with the mechanical pump from the VW I5 IDI (found in industrial equipment and Volvos iirc)? The TDI with a mechanical pump off of a VW 1.9L IDI a nice swap since the engine stays 100&#37; mechanical, but ~130-150hp is possible. I'm guessing a tweaked mechanical I5 TDI could make ~200hp/350ftlbs and weigh ~450lbs wet, but it'd run you ~$5-6k to put together right now, probably less later.

Joe Average can't really afford a V8(unless it's used). The problem seems to me to be more endemic to your upper middle class and wealthier. Joe Average can't really give a hoot about peak oil if he is unaware of it. While that responsibility does ultimately rest on Joe Average, much of the blame goes to our corporate media for not even giving lip service to the problem or explaining how it's caused and giving an honest overview of possible solutions.

5k RPM for a diesel? That sounds a bit high! 150 hp would be enough if I kept the curb weight down to about 1,500 pounds. That would theoretically yield 0-60 mph ~5 seconds, not spectacular, but good enough. 200 HP and such a weight would be much better. Maybe a duel engine setup with a 2,000-2,500 pound curb weight is doable. Price to build is not a concern if the build cost is kept under $20k. I'll have an electrical engineering degree in a few months, probably a job, and I'm single. I'll have more than enough money to play with.

Maybe if the electric GT6 works out good, try out that Battletruck idea as well. :p

If I were to get a motorcycle, I'd like a 70s era Kawasaki KZ1000, like Toecutter had in Mad Max. Maybe add a slightly modified mini-bullet fairing to complete the look of Toecutter's bike, but with some regard to aero efficiency as well. It would definately be converted to diesel. I don't like the idea of using petroleum at all.

Personally, I'm more a fan of cars.

IDIs make peak torque at really high speed for a diesel. The TDIs make it lower, and each one has it's pros/cons... Just make sure you don't go over 7k rpm, I've read the valves can float. ;) Good luck in the job market, my buddy is EE (I used to be until I was bored to death) and all he could find was a job fixing buses for $18 an hour iirc, but technical jobs are pretty region dependent and he didn't want to move so I suppose you can do way better if you have something local or don't mind moving. I'm waiting for a really nice gig, but if that doesn't pan out I'll probably end up teaching. Not something I want to do, but it'll get me enough for the many projects I have in my head! :D

I don't see why with a 1,500 pound car you would need anything more then 70hp, and for that the early 1980's vw diesel engine with a turbo would work fine, a new TDI in it and you would have loads of power.

the Biodiesel workshop that I was at was for Organic Farmers, and the presenter was pointing out that if you have the land to grow 10 acers of oil crop that you can grow more of your own fuel then if you used that ten acers to grow soy (less oil then sunflowers) and sell that soy to buy petrol diesel, and you then have controle over your fuel suply and can ignor the fuel prices everyone else pays, he was saying that after property taxes, and paying his time, and equipent deprciation (already owning equipent for other farming practices) and seed, and all the stuff to prosess it from raw oil, in to the thiner biodiesel, it came out to about $1.55 a gallon.
The reason for sunflowers as the crop was that they grow well in northern wisconsin, and he did point out that with research, and an investment in better seed that he could get higher yeld sunflower seed.

Hell, I really wouldn't 'need' more than 20 horsepower in a 1500 pound vehicle with good aero, but there's that aspect of performance that I'm also aiming for. I want something that nothing on the road would be able to keep up with.

The closest comparisons I can make is the VW AAZ and 1Z diesel engines. Both have the same 79.5 mm bore and 95.5 mm stroke (1.9 liter displacement). Both are turbocharged, came with catalytic converters and EGR systems. The big differences are the AAZ has pre-chamber heads, the 1Z is direct injected. The AAZ has a nominal 22.5:1 compression ratio, the 1Z has a 19.5:1 ratio.
The AAZ makes a peak of 55 Kw (75 hp) at 4200 rpm and has a flat torque output of 150 Nm (110 lb*ft) from 2400 to 3400 rpm.
The 1Z makes a peak of 66 Kw (90 hp) at 4000 rpm and a peak torque output of 202 Nm (149 lb*ft) at 1900 rpm.
If the claim is that the IDI peak occurs at a higher rpm than the DI, then yes, that is true. However, the peak is significantly lower.
The 1Z TDI makes 75 hp or more from 2250 to 4400 rpm. The 1Z makes 110 lb*ft of torque or more from 1200 to 4200 rpm.

Seven thousand rpm from a diesel? Not from looking at my dyno charts. I can't get over 5000 rpm. I believe the piston is being pulled down by the con rod faster than the flame front can push.

Yup, pretty much.

You need to get around the fuel cut to make power past ~4500 rpm with an IDI. Although, as the post states, going past ~5500 is kinda pointless because of the limited amount of air the head can flow. Supposedly, any diesel is ultimately limited by the fuel/air mixing rates.
Probably because the prechamber affords some sort of cushion for combustion, but that's just a guess. This is also probably why the torque curve is so flat. The passageway between the prechamber and the cylinder limits the flow of energy, unlike in a TDI, where the combustion process can transfer all the energy in a much smaller time frame. Power wise, an IDI should make more per liter than a TDI, but isn't as efficient due to more area in the head for heat to soak out of. Advances in electronics led to pilot injection to quiet the engines down, which finally allowed higher efficiency DIs in passenger cars. Intercooled VNTs also helped out in the efficiency ballpark... :thumbup:

so i filled up today, 26.93MPG. last two tanks were 22.6 mpg and 21.48.
nearly 5mpg higher then the last two tanks, in case you're wondering i was getting around 21mpg same time last year.

changes were:
one liter biodiesel.
i drove about 60km highway where i normally don't have any.
outside temps are starting to rise.

i usually struggle to get 27 even in summer. my highway FE isn't great either, last trip was around 30 and it was in summer iirc.
so anyway, I'm not saying biodiesel was good for 5mpg but it may have helped.
I'll run this tank without any mods and see where it ends up.

did you add that liter of biodiesel to the numbers when you figured out your mileage to make sure your numbers were counting it as fuel used?

sure did, that would have effected my last tank anyway, not this one.

So now that I'm back to normal gas I've noticed a couple differences. One is the car seems to have more power, this could be(quite likely) caused by the warmer temps outside now. The second thing I've noticed is the exhaust smell, its stronger then with the bio. At times reminding me of a chainsaw exhaust, kinda burns the eyes a little. My cars not in a great shape of tune though.
Misses and stalls quite frequently at idle. Maybe a weak ignition system? or maybe I need a set of better spark plugs.

Gassed up again, no bioD this time and i got 26.73, last tank with the bioD it was 26.93 under similar conditions.
So it appears to make no difference, although i would like to revisit this later, maybe with some way of better tracking FE. and try different ratios.

So you had 2 tanks with bio-diesel around 27 mpg and one tank without at the same? Why not run another tank without and see what it does before you give up on it. Did you check the plugs?

If your car is not in good running condition your not going to get any kind of consistent results when adding different things in to your gas.
Your first consideration should be tuning your engine.