For all you meth burners, spark plug tips
- Thread starter Carl H
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johnm
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These examples appear to be from drag racing with supercharging? He talks about boost. Is that supercharging or turbocharging. I assume those plugs are removed and inspected after each run. So a few seconds under full power plus however long the motor spends starting and on the grid?
The reason I ask this is that my experience with methanol is with road racing over say 20 minutes or so of running as a minimum and my plugs don't look much like these examples when they come out. I do agree with the section on timing on the strap and that often people use too much advance and drown the motor with fuel to try and cool it down. I have definitely seen that.
Interesting but I'd think hard about the cross over from 10 seconds of running in a drag motor to 20 mins plus of running in a road racer. I certainly tuned a lot more toward " to finish first , first you have to finish". Those motors are a lot more on the ragged edge than mine.
I went from petrol to methanol tuning after a few years of reliable running on petrol. I did use Lambda meters to fine tune the petrol fueled bike.
When I went from petrol to methanol I did the volume calculation for the stociometric rate from petrol to methanol and jetted appropriately. 15 to 20 years ago now but I think it is about 2.3 times ????? Don't quote me. Check it if your doing it yourself.
For timing I experimented over the standard 3 to 6 degrees range more advance for methanol to account for slower burn and checked the plugs. Went from 28 degree advance with petrol on a Dommie 500 to 34 degrees on methanol. The new plugs showed the very light pepper spots on the white ceramic that Gordon Jennings says comes from very early pre-ignition causing oil to come past the rings. Backed off to 31.5 degrees. Pepper spots disappeared and the bike ran perfectly thereafter on methanol.
I don't know what the hp increase was but lap times were consistently improved.
Run under New Zealand Classic Racing Register rules between 2000 and 2011
The reason I ask this is that my experience with methanol is with road racing over say 20 minutes or so of running as a minimum and my plugs don't look much like these examples when they come out. I do agree with the section on timing on the strap and that often people use too much advance and drown the motor with fuel to try and cool it down. I have definitely seen that.
Interesting but I'd think hard about the cross over from 10 seconds of running in a drag motor to 20 mins plus of running in a road racer. I certainly tuned a lot more toward " to finish first , first you have to finish". Those motors are a lot more on the ragged edge than mine.
I went from petrol to methanol tuning after a few years of reliable running on petrol. I did use Lambda meters to fine tune the petrol fueled bike.
When I went from petrol to methanol I did the volume calculation for the stociometric rate from petrol to methanol and jetted appropriately. 15 to 20 years ago now but I think it is about 2.3 times ????? Don't quote me. Check it if your doing it yourself.
For timing I experimented over the standard 3 to 6 degrees range more advance for methanol to account for slower burn and checked the plugs. Went from 28 degree advance with petrol on a Dommie 500 to 34 degrees on methanol. The new plugs showed the very light pepper spots on the white ceramic that Gordon Jennings says comes from very early pre-ignition causing oil to come past the rings. Backed off to 31.5 degrees. Pepper spots disappeared and the bike ran perfectly thereafter on methanol.
I don't know what the hp increase was but lap times were consistently improved.
Run under New Zealand Classic Racing Register rules between 2000 and 2011
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Normally a plug chop is done by "killing the engine" at the RPM you are testing with new spark plugs. Drag racing gives you a good chop as you are wide open at the end and you just "shut her down." Some road racing courses are excellent as you have the pit road mid-way down the long straightaway and can pull off and coast in. But the thing that impressed me with the video is how clearly he explained and showed the "burn marks" and what they tell you. But he said many times this is the way," I do it and others might have their own ways." I didn't know how tricky Methanol is to use.
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