cams

Discussion in 'Softail Models' started by saintNH, Jul 16, 2011.

  1. saintNH

    saintNH Member

    87
    0
    0
    My 01 fatboy is going to a local mechanic tomorrow for new cams, bearings and gear drive. He told me that he is putting in Andrews tw31s cams. I was just looking at the Andrews parts catalog online and that particular cam is under "tc88 chain drive cams". Will this cam work for the gear drive setup? If I'm reading it right, I should be using the 31g that's listed under "gear drive cams".
    [​IMG]
     
  2. BUBBIE

    BUBBIE Well-Known Member

    4,959
    83
    113
    The 31g just tells it is a tw 31 Gear drive.. If he said he is installing a Gear drive this 31g is what he'll use. MAKE SURE Gear Drive Not the chain drive IF that is what you want..
    COMMUNICATION

    Make sure he is replacing the INA (HD style) bearings with full cage bearings..

    He Knows....


    signed....BUBBIE
     
  3. saintNH

    saintNH Member

    87
    0
    0
    We are replacing all the bearings with torrington bearings. And I am definitely getting the gear drive. So maybe he was mistaken when he told me the 31s. He ordered all the parts. Cams, gears, bearings and seals.
    [​IMG]

    ==================================================

    As it turns out, the parts supplier sent him the chain drive cams by mistake. So I will be getting the 31g.
    [​IMG]
     
    Last edited by a moderator: Jul 17, 2011
  4. R.Bingham

    R.Bingham Active Member

    317
    0
    4
    Are these cams going into a stock motor? If so you might want to reconsider your selection. The 31G has an intake valve closing @46* and will be a dog at anything below 4000rpm. Your stock cams will perform better IMO. That cam needs 10.5-11:1 compression to be happy. I put the Andrews 21G cams in my 03 Fatboy. These cams work well with stock compression up to 9.6:1 compression. They have an intake valve closing @30* which bumps up the corrected compression and gives the motor more torque and power over the stock cams.
     
  5. kemo

    kemo R.I.P

    1,690
    48
    5
    Bingham is right, if your motor is stock those cams are going to be too much. I just did a hyd tensioner conversion and we used 21N. The guy guy went out with his wife and did a pull from 55 mph and said the thing pulled stong, a big improvement.
    Ken
     
  6. BUBBIE

    BUBBIE Well-Known Member

    4,959
    83
    113
    YES on both the above post...

    Looking at cams..... BIG doesn't mean more power..... The Later Intake valves close the MORE compression it takes to off set the Lost compression on the later closing (cam timing)..

    Bingham is Really knowledgeable here... NO Doubt.

    If You are ONLY doing the cams and bearings and Gear drive, I would reconsider on the cams OR you Will be sorry IF built using those Late closing cams without compression replacement.....

    Cams are a give and take.. Example on my bike 09 96" TC... stock closing on the intake valve is 30*... I did go to SE 255's, the intake closes at 25* (earlier than stock 30* Holding IN more compression).... Hence More Compression is made = More Power at lower RPM needed to make it.......

    now If i went with a cam that the intake closed at 40*(many do) I would Need to UP the compression LOST by the Later closing intake valve..Needing Higher RPM to make Power...

    Easy to see Where and How a cam works by Judging it by the intake close...

    Now IF you are going to have like 10.5/1 pistons and a little head work done, You'll be fine..

    signed....BUBBIE
     
  7. R_W_B

    R_W_B Senior Member

    2,425
    0
    23
    Yep those guys are right about your cam unless you are drag racing only above 4 grand rpms .

    Let me know how that gear drive works out. I kinda like those gear setups but folks say they whin loud. Would like to know how yours sounds when you get it on.
     
  8. BUBBIE

    BUBBIE Well-Known Member

    4,959
    83
    113
  9. saintNH

    saintNH Member

    87
    0
    0
    I ended up using Andrews 37g cams and the gear drive. Also replaced all 4 bearings. I got it back yesterday and I really like it. Yes, there is a little more noise that wasn't there before, but from what I understand this is the normal noise with this setup. There is definitely more punch all around and I think it made the exhaust a little louder and has a better note. I also noticed that going downhill and letting off the throttle the bike doesn't slow way down quickly like it did before. Maybe because there's less restriction? All around I like it so far.
    [​IMG]