Why Diesel?
It's simple really. I just wanted to do something different and learn something else. I cant think of any advantages to making a diesel sports car over a gas version, except for the fact that the diesel will get slightly better mileage. In fact most people will look at you sideways for building a diesel sports car. I want to do something different and have some fun for a change. Diesel sports cars exist and are raced regularly and its becoming more appearent to most people that this is occuring. In fact rescently I watch an episode of Top Gear a Brittish car show on the BBC network. In this episode the hosts were challenged to build a BMW 3 series Diesel and race a 24hour endurance race. The car did quite well despite multiple problems and a major crash.
My Goal!
I'm setting out to build a Performance Diesel sports car! The end product will hopefully be turbo charged, intercooled, and propane injected! I hope to get my 1974 260z into the low 12 sec 1/4 mile times. I should be able to obtain decent mileage out of the car as well. Oh did I mention I will NOT be running Diesel?! I am going to make an attempt to do this completely on bio fuel. I have established a suply of waste oil.
Game Plan
I bought the drivetrain from a 82 Maxima. I was also given an extra LD28 block, rods, and pistons. I have a few extra heads, intake manifolds, and exhaust manifolds. I have both industrial top ends and the top ends from Maximas (they have the same cam stamp BTW). I will have to have a custom turbo header built at some point. Several people have tried to use the L28et exhaust manifold but as you can see form the pictures below neither the ports nor the bolt patterns line up. I want to use an Isuzu NPR intercooler. I plan on using a T28 turbo to start off with. I am going to try 10PSI of boost with this turbo. I've been talking with a local Nissan diesel freak and he has ran 20psi of boost on the stock LD20 4 cylinder versions. He has been playing with those motors for years and is very reputable. I will probably top it out at 16-18psi of boost. I then would like to plan on using a Bully Dog propane injection kit on the engine but at this point that is doubtful. This will be the topping on the cake. The idea is to cool the EGT (exhaust gas temp) EVEN more while adding torque to the motor. Kind of like NOS, doing it right is important! If I don't blow the engine first....
The first picture is of the Maxima engine I aquired. It had a hidden hole where #1 punched threw the block. This was way lame. I paid good money for that engine. I had to buy a second engine now... At least I could get one with a mid sump.
When I installed my mid sump engine I used a zxt flywheel and clutch. This is the biggest stock flywheel and clutch for a gas L series engine. It turns out the LD starter and flex plate use a different gear size than the gas flywheel. So I had to rob a ZX gear reduction starter of its output gear and the pictures show the two output gears. After installing the gas gear in the gear reduction starter for the Diesel everything worked fine.
I have an ongoing thread HERE
I HIGHLY recomend this site to anyone with a LD series diesel powered anything Click here for NissanDiesel
After I had identified the electronic components they were very easy to hook up to the 260Z's wire harnes. I built a manual glow plug circuit using the secondary relay from the original circuit. I hooked the power wire that runs the stock 260Z ignition coil to the fuel cut solenoid. I left the advance solenoid unconnected.. I do not have an EGR system. All the EGR stuff was subsiquently dumped. The alternator required a diagram but I was able to find the signal wire, guage wire, and the output wire easily. Ground is there to. The wire harness had to be extended to the other side of the car as the LD alternator is on the opposite side of the engine compared to the L series. I added in a fuse buss from an Infiniti Q45 with new fuses for the glow plug system and the alternator. I installed it just above the primer/fuel filter as seen in the pictures above if you look closely.
Being that I started my build with a mid-sump LD28 things became much easier to install. I still had to modify things. One noteable change was the passenger side engine mount. To put this engine in a S30 car you will need to use the entire mount system from this car. The IP or Injection Pump is very close to the mounting area. After installing the fuel lines to the injectors you will find that you have to notch the passenger side mount to fit the lines. I recomend that you either build a new mount that clears the pump for adjustability or notch the mount and build it up. The notch will weaken the mount sigificantly.
The Bad
I was able to get the car fired off and drove it down the street. 50/50 peanut-soy / diesel mix. Ran okay. Needed to time the IP. Little bit of white smoke. There is also the chance that excess water is in my fuel system and remnants of gas. I had a dead battery so starting the car became an issue immeadiatly. I parked the car and bought a large battery. I started the car with the new battery and was warming up the engine when I started to hear a knock. I ran for the ignition switch but it was to late. The engine came to a stop. Dropped #2 threw the bottom draining 5L of oil into the feild. Dammit! It was idling so Im hoping minimal damage accured. I have a spare set of rods and good pistons. I dont have a spare crank. I can fix the pan. The rod came straight out the bottom and didnt try to swing around so the force was small. My fingures are crossed. I have sourced the gaskets and bearings. I need to get the bottom end out and pull it apart.
Here are a few links to related topics!
How to make Bio Fuel "HOME MIXING OF USED VEGETABLE OIL INTO FUEL FOR DIESEL ENGINES
Vegetable oil will react very similarly to diesel fuel under the conditions inside a diesel engine; i.e. when it is highly compressed, it will heat up and ignite, causing the air in the cylinder to expand, and to push the pistons, in time. If you burned straight unprocessed vegetable oil, however, the fatty acids in the oil would start to congeal and harden (coke up) on the inside of your engine as well as in your fuel injectors, eventually leading to big, expensive engine problems.
Therefore, it is necessary to process your oil to remove the fatty acids-- making the oil more similar to diesel compositionally, or to otherwise devise a system to keep your engine clean of residues from unprocessed oil.
Following is our procedure for edible waste oil transesterification, which we used on our cross country trip. Please always use extreme caution when working with these ingredients.
WARNINGS AND DISCLAIMERS!!!!!!!!!!!
-We are not automotive engineers, chemists nor scientists of any type so this information is still in a crude, explorative stage. Experiment to find what works for you.
-This information was collected from various individuals and has been used by us BUT by no means do we hold any responsibility for anyone attempting to do this process. Essentially this is public information to be used at your own discretion and risk. There is information available regarding transesterification and biodiesel. It is highly recommended to cross-reference and /or to contact someone in the organic chemistry department at a local university.
-This information shall not be resold to any individual but given freely to all who may inquire about this procedure.
-Methanol is toxic. It can be absorbed by the skin and cause nerve deterioration with prolonged usage. If splashed in eyes it can cause blindness and could be fatal if swallowed. Take necessary precautions when using methanol! A good respirator and decent rubber gloves are recommended.
-Lye is also very toxic and burns the skin upon touch. It is also extremely damaging if ingested. It is possible, however to set up a safe means of being able to mix fuel. An outdoor area is preferable or a space with plenty of ventilation. Access to electricity and water are both necessary. Have lots of newspapers and detergent on hand.
-Always mix a small batch first in an old blender to test your ratios. If successful the amounts can be multiplied directly.
NEVER EVER USE ANY OF THE UTENSILS, POTS NOR BLENDER FOR LIQUID NOR FOOD CONSUMPTION AGAIN!!!
Production of Biodiesel for Diesel fuel use
You will need:
- Used or fresh vegetable oil (strained with a coffee filter or cloth)
- Red Devil Lye
- Methanol (dry gas methanol-- we found it at automotive racing stores)
- Isopropyl Alcohol (for tests-- use 99% IPA)
- eyedropper- or other type of 1 milliliter dropper
- PH paper-- available at drug stores-- to test for acidity
- an old blender
- plastic or glass measuring cups or beakers, with metric measures-- and/or a gram scale
- plastic, glass or stainless stirrers and spoons,
- plastic buckets
- rubber gloves, safety glasses, plastic apron
Titration Process to determine how much Lye to use
Free fatty acids will increase with the amount of time vegetable oil has been heated-- oil which has been used for cooking will require more of the reactive agents-- lye and methanol-- than fresh oil. The presence of too many free fatty acids will retard or stop the reaction which produces biodiesel, so it is necessary to detect the exact amount of LYE (Sodium Hydroxide-- or NaOH) needed to neutralize the acids. Adding too much or too little NaOH will just make excessive amounts of bi-product (soap).
- Dissolve 1 gram NaOH (Sodium Hydroxide- Red Devil Lye) in 1000 ml. of water. This is your NaOH solution.
- Dissolve 1ml. of Wasted Vegetable Oil (WVO) in 10 ml. Isopropyl Alcohol(IPA). This is your WVO solution.
- With an eyedropper, drop the diluted NaOH into WVO mixture a milliliter at a time. Count the drops. After each ml drop check the ph level of the WVO solution with standard ph paper-- you will see an eventual rise in the ph level. Continue to add the NaOH solution into the WVO solution, a drop at a time, until it reaches a ph of 8-9.
To determine your proportions, figure:
The number of drops of NaOH needed for the WVO solution to reach a ph of 8-9 1 ml. plus 3.5 g. NaOH to catalyze the oil
An example formula used with one particular batch of WVO-wasted vegetable oil.
1 ml of oil was titrated with a 1g NaOH/1000 ml H2O solution. It required 6.0 ml to raise the ph level to 8 = .006g so 6.0g/1000ml to neutralize the free fatty acids plus 3.5 g NaOH as catalyst = 9.5 g per 1000ml oil or 9.5g/915g oil=103% by wt.Transesterification For Wasted Vegetable Oil (WVO)
Vegetable Oil: Diesel has a chain of 11-13 carbons, and new vegetable oil has a chain of about 18--but wasted vegetable oil-- which has been heated--has chains of up to 32 carbons. To burn in an engine, the chain needs to be broken down to be similar in length to diesel
Lye: (Sodium Hydroxide ((NaOH)-- or potassium hydroxide also works) is the catalyst for transesterification. It works by "cracking" the vegetable oil molecules, splitting the triglycerides from the hydrocarbons and shortening the carbon chain. (3.5g or .35% is the standard amount of lye necessary to create a reaction, when using fresh vegetable oil, so you can figure that used vegetable oil will always use more.)
Methanol: The amount of methanol needed will also vary, but the ideal is to use the least amount of methanol necessary in order to get the highest yield. The yield is related to completion; so if you get a 90% yield that means that 90% of the fatty acids have been eliminated from the vegetable oil. We have found that the best is to use 15% to 20% methanol, based upon the total weight of your batch of oil.
*it is best to use dry gas methanol (we found methanol at an automotive racing store)A hydrometer can also be used to check the amount of completion according to density
- Vegetable Oil has a specific density of .910
- Biodiesel has a specific density of .850-.870
Recipe for Colorado Gold example test
-- using WVO we got in Colorado
- Weigh 4kg of WVO heated in a stock pot on a hot plate up to 120F degrees
- In separate container mix-15%of 4Kg=600g Methanol (MeOH)* (or 17.2% by volume=750ml) with-
- 40g (1%) of NaOH until the NaOH dissolves. Add the NaOH slowly! It will become extremely hot, and on a larger scale potentially dangerous.
This combined mixture makes Sodium Methoxide. Add this to the WVO and mix for 40-60 minutes. We used a dry wall mixer bit attached to a 1/2 foot drill to do the mixing
NOW---Draw out samples every 5-10 minutes to check the rate of separation. The cloudy looking free fatty acids, called glycerine, will sink to the bottom and the methyl esters--a translucent liquid, will remain on top. When the separation appears not to be advancing any more, stop mixing. Let the mixture settle for at least 8 hours.
The liquid you have on top now is methyl ester, but before using it you have to remove any remaining soaps or salts which could cause engine damage . The glycerin which has sunk to the bottom should be disposed at your local toxic waste disposal site.
RINSING METHYL ESTER: Pour off the methyl ester into a separate clean container, so it can be washed free of any remaining soaps, salts or free fatty acids.
Add water to the methyl ester. Stir slightly and then allow mix to settle. When the water has cleanly separated from the methyl esters, drain or pump the water out from the bottom. Repeat until the discarded rinse water reaches ph level of 6-7 -- and no soap bubbles appear.
If the liquid is cloudy, there is water being retained in the fuel, and it will need to be reheated slowly to evaporate out the water. Any white substances forming at the bottom or any bubbles forming at the surface is a sign of soaps and should be removed or the liquid should be re-washed. The cleaned methyl esters are now a homemade version of biodiesel and are ready to go into your diesel tank.
ONE MORE WARNING: To use 100% Biodiesel for longer than 4 weeks straight will cause complications to any rubber components of the engine that the fuel might come into contact with-fuel pump, hoses, o-rings, etc. These can either be replaced with steel or heavy duty rubber or.. it is recommended to use a percentage of diesel with your homemade fuel- at least 20%.
HAPPY MOTORING! "
Some pictures of interest!
My Diesel Engines!
Administrator -Ray
