I'm not sure what your question is, but your engine code means this: 640th 4" bore crankcase produced in 2003. D='03 production year. C=4" bore crankcase. "Super Sidewinder" is stamped into the 4" and 4 1/8" bore engines. The 4 1/8" bore engines are actually known as "Super Sidewinder Plus" engines. They are denoted by an "E" as the second letter in the code.
It doesn't really mean anything. It's just a name S&S gives to their engines. 3 1/2" bore motors are "Super Stock". 3 5/8" bore are called "Sidewinder". 4" bore are "Super Sidewinder". 4 1/8 bore are "Super Sidewinder Plus".
Is that any indication what size cam it might be since it's 4 " bore ? Thanks Brother
Nah, you will either have to open up the cam chest to see what's in there, or you can try this. Put your bike on a stand and remove the spark plugs. Collapse one of your intake pushrod covers. Rotate the rear tire and use a set of calipers and measure how far the nut on your pushrod moves from fully open to fully closed. If you have solid pushrods, wrap a piece of tape around it. Just remember to take it off when done. Take that measurement times 1.625. That number will get you close enough to tell what it is. For instance, if it's near .600, it's the 600 cam.
You could call S&S and give them your engine numbers. They should be able to tell you what cam was installed at their factory, but you never know if a previous owner upgraded the cam. If they tell you that they installed the 600, then I doubt the cam would have been changed, as the 600 is a really good cam. If they tell you that they installed an epa cam like the 520 or 546, then I would try the pushrod trick before you open the cam chest just to find that someone already upgraded the cam. Make sense?
Wonder how this turned out….
