2.120 valves allow for 5 or 6 angles on the seat, this really helps low lift flow and is independent of cam choice. Actually, with the smaller 585 cam it probably makes more difference, that's because the valve is at low lift twice per event, once upon opening and again when closing. The low lift flow (under .200-.250) is determined almost entirely by the valve job, not the port. This aids the port velocity over all and helps the engine "come on the cam" at a lower RPM in addition to aiding over all torque and HP.
I personally think the supplied 259 cam is fine for baggers if you aren't lugging it around all of the time. True, the idle will be worse, but you don't drive it around at idle and you do want everyone to know it does have cams in it! Drive a something with a 117 kit and the 259 cams before you make a choice anyway. I run a Breakout (much lighter bike, I know) with the 2.120 valves, modified stock 2 into 2 pipes, and porting with the 117 kit, tuned by a Thunder Max (which goes a long way cleaning up the idle and low rpm,) and absolutely hated the 259 cam. Peak power was at about 55-5600 rpm, and the idle was also milder than I expected. Last week I installed a Red Shift 627 cam (.625/.600 and 260/268 duration on a tight lobe center) power is peaking at 5800, but I can still pull 6th gear at under 2000 rpm easily. I am looking at a bigger cam already, again, and with the addition of a 2 into 1 header I am sure I'll like it.
Another issue is the compression ratio with the earlier intake closing of the 585s. Like most everything else the MOCO does, this kit is designed to be all things to all people, it isn't a race only kit, but a well thought out street combination of parts. If you are near Phoenix, AZ, drive mine and decide for yourself. JMHO TIMINATOR
Author
Topic: 117 kit reliability (Read 9396 times)