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I have a 98 Evo FatBoy with a set of true duals. Looking at installing a cam. Some thing with good low to mid torque. Some 2 up riding, mostly solo. Motor is stock, only a SE air cleaner set up. Any suggestions. Thanks Double Pipes!drunk!
 

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double pipes said:
I have a 98 Evo FatBoy with a set of true duals. Looking at installing a cam. Some thing with good low to mid torque. Some 2 up riding, mostly solo. Motor is stock, only a SE air cleaner set up. Any suggestions. Thanks Double Pipes!drunk!
pull the heads, have a nice blend and a good valve job, get so you have around 9.5 compression ratio get a 27 andrews cam and degree it in and you will have a really nice runner!! there is some good people here who can really shed more light on this than me but i ran a evo with a 27 cam and 3angle valve job and a nice blend but i was running maybe a tad too much compression in a flhs and a compufire adjustable ign. and tweeeked the voes switch a bit to stop detonation from occuring.. i run it at 200 ccp and that bike for what it was would haul the mail. and was reliable made real goood hp and tq. also still got decent milage when touring too.
 

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How much do you want to spend? I run a Wood W6H, but that "H" cost a lot. The W6H is a .590 lift, whereas the W6 is something like .510 (bolt in). Getting that extra .090 lift required roller rockers, hi-performance spring kits, adj pushrods, clearancing of the case around the cam bearing to make room for the first lobe, clearancing of the tappet blocks, new tappets for peace of mind with such aggressive lift, and no small amount of apprehension because I didn't clay the heads. However, now that it's done I have a very potent 80" engine. In hindsight I may consider going with an EV27 or W6 and having a couple grand in my pocket. Also, I'm not sure if the advantage of the extra .090 lift of the W6H can be fully realized with stock heads.

Check out www.nightrider.com to see what stock heads can do with a good valve job and quality valves. If you're building a low to mid range torquer engine big valves and radical porting is actually a detriment. Big holes are good for big flow, which happens at high RPMs. At low RPMs the same big holes cause lazy fuel charge flow, fuel droplets falling out of suspension, poor turbulence, all of which reduce your margin to detonation. I recommend a good 3-angle valve job with new Manley valves (better shape than stock) of the stock size. The stock valves give higher velocities and turbulence past the seats so you keep good turbulence in the low and mid RPMs where your engine is designed for. Unshrouding the valves will help flow but I'm not sure it's worth the expense for a torque engine. I'd rather spend the money on a better ignition system or carb.

Chilly
 
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