Jus wanted to share some ancient desmoquattro tuning stuff, for those who are interested. Took me a while, but my 'tuning in progress' project finally got to the stage that I could dyno tune her. The bike: 851SP3 with 95 mm bore (so 907cc) 748R heads, cams and valves (36/30 valves), inlet and exhaust ports optimized by Biggelaar Machined 95mm JE High Compression pistons - enlarged valve pockets, shimmed 1.3mm of the top of the piston deck to reduce the pocket depth Machined 1.2 mm of the cylinders to get 0.85 mm squish. CR measured at 12.25:1 S4 crankcases Carrillo conrods IW31 injectors (4) Raised fuel pressure 3.7 bar Cam timing 748R advanced 3 degrees both inlet and exhaust (so 107 centerline inlet, 105 centerline exhaust) 50 mm tangential sil moto exhaust with termignoni cans OEM airbox (no lid) with K&N airfilter See the attached graph. The numbers are nice, but those are just numbers and differ between dyno benches. To me what's interesting is the broad fat powerband that I didn't expect to see. I was expecting a rev happy engine because of the 748R cams, with less torque down low and a bump at higher revs. Pleasantly surprised! Regards, Jacco
