Tuning methanol motor

[keeks]

Does anyone run an A/F gauge? Or a most getting their tuning done on the dyno, or just by reading plugs?

[stock car driver]

Chassis Dyno.

Af monitor illegal.

I don't think u can read plugs and tell anything. I have heard of guys going by water temp. Too rich will not build heat and run cold.

I prefer a chassis dyno, well worth the money.

[JustAddDirt]

It is harder to read a plug on Methanol:
I always ran a 180 thermostat in summer months and a 195 if it is colder racing season. It keeps alky out of oil better, and motors like to run better when they are warmer (to a point)

If motor is blubbering, and the plugs are clean white porcelain looking, exhaust temps are low, as well as water temps, it is rich.
If the plugs are black, exhaust temps hot, water temp hot, it is lean.

I generally look to see how deep the temperature ring goes down on the plug threads, you should see a slight discoloration down about 3 threads, and no further. if you see heat marks higher up the threads it is a bit lean. (former engine builder told me above, he was really good with Fuel Injection on big pulling truck and tractor engines)

Dyno is your best bet, because you can watch air fuels all threw RPM band.

When testing be sure to kill the motor after running WOT on track to give a true WOT reading. no idling around or driving back to pit.

JMO

[let-r-eat]

Tuning a methanol engine is much easier than one on race gas because alky has a larger tuning window due to BTU of the fuel. The hardest part is knowing your fuel system is up to the task because it takes 2X + the volume.Of course alky engines won't last lean so start rich. Pay no attention to your water temperatures because that doesn't tell you anything about how lean or rich the engine is. Alky engines have a different sound than gas engines. At idle you should be sharp sounding and not flat sounding. A wideband 02 sensor can be used but don't let it fool you into believing Lambda is the end all be all because it isn't. You have to give the engine what it wants. You know an alky engine is lean because it will feel like you threw out an anchor or a brake is dragging. It will melt pistons shortly afterward.A circle track engine should have 3 pound fuel pressure at idle and 11-12 pound at WOT. Heat on an alky plug can be seen the same as heat on any other plug or piece of metal. Tell us more about the combination, fuel system etc and perhaps we can give more targeted advice.An alky engine can run 10% rich with little to no effect on power.