Taking the Mystery Out Of Drag Racing With Alcohol

Posted by Race-Mart Tech on 5/28/2012 to Tech Articles

I have run across more racers than I can count who have said to me, "I don't know anything about racing with alcohol so I race with gas." I wanted to write this article to take a lot of the mystery out of the subject as racing with alcohol is really not that difficult. I started racing with methanol back in 1985 after Danny Bastianelli, a good friend of mine, talked me into it. At that time we made tons of mistakes and learned a lot the hard way, but we also ran pretty quick.

So, what is it? Methanol, racing alcohol, is comprised of one carbon atom, one oxygen atom and four hydrogen atoms (CH3OH), a clear, very toxic liquid fuel formed by catalytically combining CO with hydrogen in a 1:2 ratio under high temperature and pressure. It melts at -97.8°C (-144.04° F) and boils at 67°C (152.6° F). The boiling point is important so remember it for later in the article. Methanol mixes and absorbs water very easily.

These are all important considerations that you must take into account before beginning to race with Methanol"

1.) Methanol makes approximately 15% more horsepower than racing gas. You will go quicker immediately. It is also a very forgiving fuel and much more consistent as it is much less vulnerable to weather changes than gas.

2.) Slightly rich methanol engines typically run with much lower exhaust gas temperatures than with a gasoline engine, while the exhaust gas volume is higher. On the top end with methanol, a 1250° EGT is expected vs.1400° to 1500° for gas. The result is much lower coolant temperatures. On a typical run, pull out of staging at 160°, stage at 165°, go through the lights at 180° and cruise down the return road at 160°. Overheating is an issue of the past.

3.) Methanol evaporates very quickly when directly exposed to the atmosphere. As a result, fuel jugs and fuel caps must be kept closed when not transferring fuel.

4.) Methanol is corrosive so keep your fuel system full with fuel or it will evaporate, oxidizing certain types of metal such as pot metal, aluminum or steel (not stainless steel) and will dry or harden rubber seals and hoses. Corrosion can be kept to a minimum by mixing 2 oz. of top oil to each 5 gallon jug of methanol. This amount of top oil will not effect performance but will adequately lubricate the fuel system and the cylinder bores. After you are finished racing for the day, liberally spray your induction system with WD-40, turn the motor over for 5 seconds then repeat the process 2 more times. This will protect your carburetor or throttle body and keep any rust from forming on the cylinder walls.

5.) You will use almost twice as much methanol as you would racing gas. The optimum air/fuel ratio for methanol is 6.4: 1 while gasoline is 13.2:1. As a result, you need to be able to flow enough fuel so as not to starve the motor. If racing with a carburetor use a high flow electric fuel pump such as a Magna Fuel or Aeromotive or even better yet a mechanical belt driven pump with a 10-AN supply line.. If you use an electric pump, you need a good quality bypass regulator (I recommend only the Magna Fuel or Aeromotive) set @ 8 lbs. adjusted with the motor running on idle. A bypass is extremely important because methanol boils at 152.6° F and it doesn't take very long for methanol under a lot of pressure to reach that point. A 750 cfm Demon for my 370 cubic inch small block would use 94 jets on gas or my 775 cfm Demon on methanol would use 180 jets.

I learned the hard way that the ultimate fuel system for methanol is a Ron's Flying Toilet. It's worth .2 in ET. My 385 small block uses #35 injector nozzles and a .070 bypass pill.

6.) Seeing that you are pumping twice as much fuel through the motor as with gas, if you aren't careful, the oil will easily get polluted with fuel and water. To cure this, if you race with a carburetor, use a 2" spacer between the intake and the carburetor with a 1/2" NPT hole in the front of it with a 8-AN fitting. Run a 8-AN hose to the driver's compartment with a ball valve at the end that is easily accessed by the driver. Install a pyrometer in the car with an EGT sensor in a header 1" from the exhaust flange of a front cylinder. Whenever you are idling, open the ball valve just enough to lean the engine so that your EGT is 500°. The only time the ball valve should be closed is between the time when you pull out of staging until you enter the return road

EGT When racing with a mechanical fuel injection system, such as a toilet, you simply close the fuel shut off enough so that your idling EGT is 500°.

According to both Valvoline and Lucas, do not use fully synthetic oil if you race with methanol. They both recommend 20W-50 petroleum based racing oil and they both also recommend for the oil to be changed every 30 runs as a maximum. We have since switched to Joe Gibbs Driven XP-5 semi-synthetic which is specially formulated for methanol burning motors. We have been very satisfied with how this oil has performed.

Click the images for full size

7.) Methanol burns a little slower than gasoline which means that a little more advance timing is needed for optimum performance. Start out on the rich side with less advance. Sneak up on it until the car slows down, then back up slightly. Each motor is different. Some smaller cubic inch small blocks can run 36-38°, bigger cubic inch small blocks and big blocks 32-36° and blown or turbo charged cars in the 28-32° range. There are a lot of variables such as compression, heads etc.

8.) Methanol as a fuel, responds very well to compression. 14.0:1 - 17.0:1 vs 12.5 - 13.0 on gas.

9) Methanol requires colder plugs. Typically two steps colder than what you would run on gas. My small block did use a NGK R5671A-9 plug. After doing some spark plug testing at Atlanta Dragway, we have switched to the Pulstar BE-1I Iridium pulse plug with very, very good results. They were slightly quicker.

10.) To read spark plugs when using methanol, a proper tune up will show heat discoloration three threads down from the top of the electrode end of the plug. You should also see the heat mark on the ground strap just past the top of the bend and a slight coloring of the porcelain on the electrode side near the tip.

11.) A dead cold motor will not start on Methanol. Don't even try it as you will kill a starter in the process. You must prime the motor with gasoline. Ron's Fuel Systems makes a primer kit that contains a 1 quart fuel bottle, a small Purolator fuel pump, hose with fittings and a push button for your dash. The kit also includes a jet to install in your intake but for my car I opted to use an Edlebrock # 70063 nitrous spray bar so that when you prime the motor the fuel is atomized. You just need to cap one end of the spay bar. Once the motor starts and runs, the latent heat from the block will sometimes allow the motor to then restart without having to re-prime it.

12.) Caution...prolonged breathing of methanol fumes or prolonged exposure to the skin can cause blindness. Methanol burns with a clear ever so slightly blue flame that is very hard to see. Handle methanol with caution and common sense just like you would with gasoline. Happy racing.............