Leaded gas
Fri, Dec 02, 2011 - 5:52am
Hey Matthes or any other gear head I have a couple of questions. In the recent point/counterpoint it was stated that "the switch to unleaded gas in pro racing further killed the two-stroke advantage".
You'll have to excuse my ignorance but why did they ban leaded fuel in racing? I know it's poisonous but hey so is gas right? I know in cars it wil screw up the catalytic converter but why ban it from racing?
Also how does running leaded fuel give a two stroke an advantage that it doesn't give in a thumper?
Thanks
The amount of lead in gas is very low, but lead is a bad word politically. It was banned for possible future political issues. A two stroke desperately needs lead for octane and cooling to run right. When you are running high compression and tight squish bands, a leaded high octane fuel is needed. Europe had lower octane limits than the states and the power difference was pretty big as I understand it.
I think that the 4-stroke would benefit from the lead too. It lubricates and cushions the beatings that the valves and seats take. They get around that by using beryllium copper seats and putting coatings on the titanium valves that wear extremely well and have increased lubricity. Octane isn't as much of an issue for the 4-strokes it would seem. We were running 14+:1 with VP MR 9 and MRX01 which has octane numbers in the low 90's. Octane allows you to run more compression which is good, but then then flame travels rates generally go down. The smelly fuels like VP MRX01 seem to get the flame travel and increased energy release without detonation issues.
Working too much now, but normally race with the OTHG in the south 30+ Expert. I used to manage Curtis Sparks Racing, I have a real job now. I believe I lost the spot on the PulpMX.com show because of a bikini model!