Hey guys. My first project in fuel economy is gong to be with my 2003 Harley Sportster. It already gets 3.5l/100km, but I have the Edelbrock 1200cc conversion kit. So I'll be increasing the displacement from 883cc to 1200cc and also increasing compression from 9:1 to 10.5:1. Now this kit as delivered is pretty detonation resistant... For a Harley anyway.:) . I already have the pistons coated with a thermal barrier and I will be doing the same to combustion chamber, valve faces and exhaust runner/port. Soon I will be ripping the cylinders off to be rebored for the new pistons, so the heads have to be ready to go. Basically what I need to know is what the optimal quench is for the singh grooves. By removing the base gasket I'm told I should come into a squish band somewhere in between 0.030" and 0.040", which comes out to about 11.2:1 compression ratio. Will the be too small of a gap for them to work? I really don't want to shave down my new heads to increase compression. Any ideas or suggestions would be greatly appreciated.