Advancing cam on HS?

wheelbender6

wheelbender6

Well-Known Member
I was reading on ADVrider where a member advanced his exhaust cam one tooth on his KLR-650 and it really woke up the performance. Has anybody tried that on a 50cc Huashang?
I realize the HS has only one cam, but I was trying think of some mods that don't cost much. Last I heard, performance cams are no longer available for the HS.
 
For more top end you usually retard cam timing on a 4 stroke.
On my Suzuki Sierra(Sameri) I have retarded cam timing, and she turns into a motorcycle engine at about 3500 RPM, but significant drop in low end torque.
Has made the engine a pig on the road, but a lot of fun in the bush.
Advancing cam timing will improve low down but sacrifice top end.
 
Altering lift or duration on a cam will give you something and take something away. You either build for low end or high end. Whichever you build for will make the opposite end suffer. Same for advancing or retarding the valve position at a given crankshaft location.

In short, there's no free lunch.

Tom
 
The guy that advanced the exhaust cam on the KLR 650 said it eliminated some flat spots in the torque curve. Perhaps, since he advanced only the exhaust cam, he added some torque without sacrificing much top end performance.
 
To affect the timing of only the exhaust valve I suppose that you could weld and re-profile the Exhaust cam guide. Put a concave arc to it so it lifts the valve later but still gives full lift travel.
 
I've got an AGK race cam in one of my HS49's.......it's the fastest HS49 in town! But it has more mods than just the cam ;)

If you want proof just let me know.
 
You must log in or register to reply here.
Back
Top