Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

beatr911 · 04-01-2014, 07:20 PM

Doing research, the cams from the Suzuki GR650 bolt into the GS500. (theGSResources.com) They have a little more lift and less duration than the 500 cams. So they are designed for more torque and lower RPM hp peak.

As the GR650 has 8.7:1 compression and the 500 has 9.0:1 and they are of the same engine family. I suppose one can infer that the increase in dynamic compression with the GR650 cams is equal to about .3 over the 500 cams. Overlap is presumably less as duration on both intake and exhaust is less which is good for fuel efficiency.

I'm considering a GS500f for my future high speed commute. Considering taller gearing and these torquey GR650 cams to make the engine run more optimally at 70-75mph. The engine should handle it okay because the 500 motors seem to do best with an additional 4-6 degrees of ignition advance. The extra .3 compression should make the stock ignition advance about right or at least closer to it.

Anyway, just thought I'd post in case anyone was interested in these dated but rock solid bikes.

04-01-2014, 07:20 PM	#24 (permalink)
beatr911 Master EcoModder Join Date: Feb 2008 Location: West Coast, USA Posts: 516 B2300 - '96 Mazda B2300 SE Focus - '05 Ford Focus ST The red car - '00 Honda Insight Thanks: 6 Thanked 77 Times in 56 Posts	Doing research, the cams from the Suzuki GR650 bolt into the GS500. (theGSResources.com) They have a little more lift and less duration than the 500 cams. So they are designed for more torque and lower RPM hp peak. As the GR650 has 8.7:1 compression and the 500 has 9.0:1 and they are of the same engine family. I suppose one can infer that the increase in dynamic compression with the GR650 cams is equal to about .3 over the 500 cams. Overlap is presumably less as duration on both intake and exhaust is less which is good for fuel efficiency. I'm considering a GS500f for my future high speed commute. Considering taller gearing and these torquey GR650 cams to make the engine run more optimally at 70-75mph. The engine should handle it okay because the 500 motors seem to do best with an additional 4-6 degrees of ignition advance. The extra .3 compression should make the stock ignition advance about right or at least closer to it. Anyway, just thought I'd post in case anyone was interested in these dated but rock solid bikes. __________________ Good design is simple. Getting there isn't.