Lancer, that one is easy to answer. Suzuki pushed the Savage as a beginner's bike for inexperienced riders who wanted something bigger than a 250 Rebel. So they used a heavy flywheel and detuned the engine to make it more friendly for new riders. Which also explains the non-linear throttle action. The first few degrees of twist at the grip does not give the same number of degrees rotation at the throttle blade.As the grip is twisted further, the motion at the carb starts to become more linear then. All of those things would be desirable for someone just learning to ride.

Fast 650 wrote on 03/27/18 at 09:26:35:


Yes I did, I was wondering how the numbers change when measured at the same lift. And if I've understood correctly the Savage cam is measured with .050" lift.

In an ideal world ,we could put the DR650 head on the Savage ,run a stage 3 cam , and make 50 hp.  both these motors have nearly the same displacement ,but are completely different. If we assume the valve size is the same as FAST650 stated ( it would be hard to make them larger in a 4 valve head) ,then how does the DR650 draw in as much fuel and expel as much exhaust gases as the Savage ,with a stroke 13% shorter? Higher valve lift, longer duration, and a better designed exhaust passage. Is the high lift of the DR cam ideal ? Hardly ! but it was the ONLY way Suzuki had to make the motor work. The shorter stroke ( thus higher rpm/hp), and the cylinder leaning forward , allowed the frame of the bike to be more compact , and weight and seat height lower . (important for a dirt/race bike).the DR650 makes 47.5 hp stock with a 9.5:1 compression ,but printouts show it only making 46.3 hp in a Savage with  97mm piston at 10.5:1 compression, after market carb and exhaust. the DR cam has 30% more lift than Lancer's stage 3 cam ,but is only making  maybe 5% more power. It's my thought that the high lift of the DR cam is overkill and not suited for use in the Savage.

There is no doubt that a Wiseco, a performance cam, some head work, and a better muffler can make the bike run noticeably better and allow the bike to keep up with the others....and with some gearing changes you won't be left behind when the group hits the interstate.

A lighter flywheel, helps acceleration without any noticeable change in smoothness, and a non-CV carb helps a little bit with the response.

Unless you are looking for the last few tenths of Max HP.....any of the performance cams are going to make a noticeable increase in the performance..

DragBikeMike wrote on 03/28/18 at 00:03:15:


Actually those dyno charts aren't from my bike, although I'm going to get mine dynoed when I get it running properly, just to make sure of the jetting with the VM36.

Some of these threads just make me think I should burn my
Mechanic card.

Here are the actual timing numbers for a stock, 2016 LS650.  They were all obtained using a degree wheel and dial indicator with the exception of intake valve max lift.  I captured that number using a dial caliper (just not enough room with the engine in the frame to get a long travel indicator in there).  The valve lash was set to .004" on all 4 valves.

I don't claim to be the best mechanic on the planet, but I'm pretty decent.  I am confident these values are good within a degree or two.

I took the readings at both .040" lift and .050" lift per a great suggestion by Fast650.  He also provided me with the stock cam dimensions for base circle (BC) and lobe height.  BC is 1.183" on both lobes.  Lobe heights are 1.430" intake and 1.423" exhaust.  That works out to lobe lifts of .247" intake and .240" exhaust.

You will see that the lift at the valve is significantly higher than the lobe lift.  That's because the rocker arms are not 1:1 ratio.  The numbers indicate that the rockers are about 1.38:1 ratio, hence, lots more lift and duration at the valve.

The stock cam is a typical, emission compliant cam.  There is ZERO valve overlap.  That's because the government doesn't want the intake & exhaust open at the same time.  It prevents raw fuel vapor from heading out the tailpipe at slow speed operation.

Here's the no-bull data.

@.040" lift

IO: 16 ATC
IC: 53 ABC
Duration: 217 degrees
Max lift: .333"
TDC lift: .010"

EO: 40 BBC
EC: 5 BTC
Duration: 215 degrees
Max lift: .334"
TDC lift: .026"

@ .050" lift

IO: 20 ATC
IC: 50 ABC
Duration 210 degrees
Max lift: .333"
TDC lift: .010"

EO: 36 BBC
EC: 8 BTC
Duration: 208 degrees
Max lift: .334"
TDC lift: .026"

These numbers give us a good starting point for cam comparisons.  It's home base.  I have a 1995 DR650 cam and intend to do some timing checks on that.  It will be tricky because I intend to do the checks an a lathe and the convert the data to determine lift and timing based on rocker ratio of 1.38:1.  Preliminary measurements of BC and lobe height show that max lift on the DR cam with 1.38:1 rockers will be about .339" to .342" when compensated for .004" valve lash.  It should be pretty darned close to the real deal.  I will keep you posted.

I did a separate post on the DR cam.  There was just too much new info to tie into this old thread.