Ideas & Suggestions For a 107 Build?

Discussion in 'Engine, Fuel and Exhaust' started by Rod Stewart, Dec 16, 2013.

  1. Rod Stewart

    Rod Stewart Active Member

    Hi All;
    I just picked up a mint low mileage 2007 Road King Classic. Nice straight bike and it runs well.
    Its a stock 96" 6 speed with Rinehart True Duals and 3-1/2" Rinehart mufflers, K&N, and a Power Commander III USB.
    I am thinking of big boring it out to 3-15/16" as I understand that's as big as you can go without case boring.
    Thinking also of getting some headwork done, maybe some porting and flow test work, and milling off about 20 thou.
    I have SE 203 cams in my 2004 95" and they work well.
    I don't want anything too crazy, just a good solid drivable build with a little more pizzaz.
    What would you all suggest about the above, and what else should I be looking at?
    Where is good to get the jugs and pistons?
    Where is good for the headwork?
    We are located in SW Florida.

    Thanks all,
  2. tourbox

    tourbox Senior Member

    You would have to use a different cam than the 203. I believe it was designed for the TC88's. A SE 255 would be more inline with your build. I'm not real good with cam selections versus builds but Dolt and Bubbie should be along shortly. They seem to know a lot about durations,overlap,compressions etc. I usually talk to a lot of people, read and research or have personnel knowledge on what I've used in the past. That's mainly on Shovels & Evo's.
  3. dolt

    dolt Senior Member

    Lots of ways to go. Based on your criteria "I don't want anything too crazy, just a good solid drivable build with a little more pizzaz", you can acheive that goal without head work.

    Send your cylinders to Hillside Cycles; they will bore to 3.932" for 107" displacement; I think they have a deal going on right now.

    Bore your cyls to 98" and set compression @ 10.0 cr via piston dome machining, all Cometic gaskets, with ring end gap set, and installed.
    S&S .570 E-Z start cam kit
    K&N oil filter
    Barnett clutch sping
    NGK plugs
    Under $1000.00........

    I can't speak for Scott but if you wanted a different cam set, say like the Andrews 54 (a good choice for a 103" motor) he would probably work with you. Just need to agree on cam set so he can mill the piston dome, if necessary, to set compression at the sweet spot for whatever cam set you choose.

    Have heads cleaned up, new guide seals, good SERDI valve job and have the chambers measured (for Scott so he will know how much to mill the piston dome) and chamber volume balanced. Assemble with a .030" MLS head gasket; keep the RH TDs and get her tuned.

    Your SE 203 cams won't work in the later cam chest and, even if they would, there are too many better choices.

    If you want to spend a bit more money, send your heads to Hillside along with your cylinders and let them port to Stage I, II, or whatever you want.

    The plan is pretty basic, bore for more displacement, select a cam set and build around the cam set. Have heads worked which could be a clean up, new seals and SERDI valve job, to basic "street" port or a "pro street port"; your call. Discussing this with Scott or whatever head porter you might choose would be wise.
  4. dolt

    dolt Senior Member

    Forgot to mention gearing; also a great way to improve performance.

    The secondary gearing on the '07-'08 touring models can be improved by installing a 30T trans pulley, which may require a belt change. Some claim to have installed the 30T trans pulley and used the OEM belt; others say no. Some have changed trans pulley to 30T and wheel pulley to 68T (Sportster) and used the OEM belt. Either way will make a more efficient use of the six speed and improve low and mid range pull.

    Combine better gearing with the motor upgrades and the Road King will be a different bike.