Well we had our test and tune today for the '08 season. The 28 on my boys tractor runs extremly well. No problems, and has a whole lot more power. His engine is a stock bore 28 with an ohv rod, light piston, billet dog bone and a lmt with a bottom adjuster and a air cleaner setup from Don G. I also put an 11hp head on it with some very mild port work on the block. You guys know about my big opposed twin. I have stock rods with bearing inserts, Don G cam, billet steel flywheel, crank trigger ignition and alot of port work and block prep. I am very impressed with the twin. I pulled it 6 times and it only pushed out 4 oz. of oil into the catch can. Pulling in the same class as last year at 800lbs I ran a 25 tooth third wich is 2mph faster than last years 23 tooth gear. about 16% faster. The engine ran up into the rpm and stayed there. The tractor is alot faster and the engine ran a higher rpm even with the faster gear. I can't tell how high it revs because i don't have a tach yet. I do know when checking the rpm with the hand held laser tach we use in our club with a quick run of the throttle it will run 6000-6100. That is 1200 rpm more than it would turn last year. I can say an opposed a 6000 is insane.
Dennis