APTuning have tested methanol fuel extensively over the last five years and have learned how to set up engines and carburetors for most engine applications. The following is a list of tips that every methanol fuel user should be aware of.
Preliminary Facts Regarding Methanol
Methanol fuel is generally harder to set up for than gasoline, therefore APT recommend its use for experienced tuners only. If you are not proficient in Fuel Injection System and evaluating engine performance then it is best to gain these experiences with gasoline first. Methanol fuel is recommended for short duration racing only such as drag racing or short sprint racing, you will consume twice the amount of alcohol fuel for any given horsepower output when compared to gasoline, so the range of your fuel tank is basically cut in half. Because methanol is "hygroscopic" meaning it absorbs water, it requires special handling procedures. The number one piece of advise is to buy only as much fuel as you will use in a week, and buy the fuel from a reputable vendor who stores the fuel in sealed metal drums. It is preferable to store methanol in a sealed metal container. Plastic is OK for short term storage only, but put the container on wood, not on the ground. Be sure to keep your container sealed at all times. In addition to attracting water, methanol is corrosive to metals, gaskets and seals. In four stroke engines it is recommended that you use a "top lube" or methanol fuel treatment in order to VP Racing Methanol must be drained from the fuel system at the end of the day every day. This is especially important in the coastal climates. Because fuel tanks and carburetors are ventilated to the atmosphere the methanol inside will absorb water and corrode costly fuel system components. Once the methanol has been drained from the entire fuel system you will have to put gasoline into the carburetors and run the engine. Start the engine and run it for two or three minutes, leave the gasoline in the fuel system until the next ride.
Engine and Fuel System Set Up
Because alcohol fuels burn so much cooler and slower than gasoline APT recommend that you increase the compression of the engine to maximize performance, there will be little or no advantage to running methanol on a stock compression ratio. We suggest first checking your cranking compression and then consulting your engine builder before running methanol, some engines will tolerate less compression than others. Advance the ignition timing. Your results may vary depending upon compression ratio and the sophistication of the ignition system. Proceed carefully and document the timing change by measurement, either by degrees of crank rotation or by millimeters before top dead center. Minimize flow restrictions between the fuel tank and the carburetors. Remove the petcock from the fuel tank and cut off the filter screen and the reserve stand pipe. Remove any in-line fuel filters or petcocks, use as large a fuel line as you can fit over the fittings on the carbs and petcock. Check the operation of the slide, make sure that it opens all the way to clear the bore of the carburetor or injectors, this is particularly important with modified or bored carbs. In our experience a methanol equipped Mechanical Fuel Pump
Procedures For Tuning Methanol
Even if you are an experienced tuner, you will want to read up on your particular engine design before you proceed with methanol testing. Methanol fuels are less tolerant of a lean air/fuel ratio than gasoline and will detonate violently. Fortunately methanol detonation or pinging is quite audible, so if you hear any "rattle" you must stop immediately and richen the fuel settings. Some words about the power jet. The power jet is essentially another fuel circuit in addition to the slow and main circuits, the power jet is throttle position sensitive and generally only comes in from 3/4 throttle and up. Many power jets have a screw type adjuster on them so you can vary the amount of fuel they deliver, turn the screw out from seated in order to increase the fuel fuel flow. The power jet will allow you to keep the slow and mid throttle settings clean/ correct and still allow enough fuel flow for wide open high rpm power. If you are running into a lean condition at wide open throttle (WOT) and you are getting no results and make the engine breaks, you have reached the fuel flow limit of the big size injectors.Better for 4cyliders 8 injectors 1600cc each.New Siemens injector 2000cc are there. Now, for methanol, the ratio for stoichiometric combustion is somewhere in the neighborhood of 6.5:1. So if we were running an engine on pure methanol, we'd have calibrated our wideband controller such that produces a display of 6.5. Hypothetically, if we were to take that same engine and run it on gasoline, then a stoichiometric mixture of gasoline and air, despite being 14.7:1 in reality, would still produce a display of 6.5.
Normally aspirated
Engines often need a LOT of advance as either the compression is to low or the piston domes to get really high compression interferes with flame travel. With wedge heads some tuners use a slot cut through the dome between the spark plug electrode and the far side of the chamber. Methanol really only starts working OK at over 12:1 and gains all the way to 16:1 or higher, depending on chamber shape and plug location. When effectiv compression rato gets up around 18 or 2:1 is when you need the 4.5 or 5:1 A:F ratio.
A lot to rich (not just a bit rich for safety) creates problems with bore wear due to wash down and oil dilution resulting in the oil turning into a custard like consistency. Heavily diluted oil if left in the engine can corrode things, especially in the ring lands and the bearing shells.
Timing starting from 33-36deg on full boost,but can go 40deg looking your engine design
Part For Metahnol Fuel System
1.Engine Management Haltech,Microtech,Motec or Vi-PEC
2.Mechanical Fuel Pump and Gear(belt)
3.Injectors 1600cc 8 injectors
4.Methanol Regulator x 2pc
5.Bigger fuel line
6.Aluminium Fuel Tank
