Lifter or Rocker Noise

Discussion in 'Engine, Fuel and Exhaust' started by ridinallthetime, Jun 19, 2012.

  1. ridinallthetime

    ridinallthetime New Member

    I have a 2003 Super Glide. Just had some mod's done: the 96 hydraulic tensioner upgrade, new SE 204 cams and adjustable pushrods and lifters installed. Didn't have any noise to speak of in the rocker boxes before this work. Have some valve train noise now. I decided to pull the pushrods to take a look. I put the Cams on the Base Circle positions to pull the pushrods out to reinstall and adjust to the new SE pushrod specifications of 2.5 turns from zero lash. 2 questions: (1) I assume the new lifters (HD 18538-99C) are okay with the 2.5 SE pushrod adjustment past zero lash. Can anyone verify this? Also, (2) I wiped the oil from the pushrods when I removed them but didn't oil the top and bottom ends when reinstalling them. Is this okay?
  2. HermitKing

    HermitKing Member

    I am sure some more experienced guys will help you out. But..I would be willing to bet the noise is actually comming from the evil auto chain adjuster you just installed. So...pending more expert advice, I would make sure it is not coming from your primary. When seated on the bike, the noise can sound like noisey tappets. If it is a little louder in your left ear than your is problably a loose primary chain.
  3. R_W_B

    R_W_B Senior Member

    There is "usually" a slight increase in valve train noise on a cam upgrade with HD engines. Some folks have solved the noise, others just live with it. The first thing I would do is pull the plugs and the system relay and turn the engine over a few times to make sure the lifters are pumped up. (unless you are real sure they were the first time you did the adjustment)

    The go thru the lifter adjustment process again. After you adjust the one, make sure you wait until you can feel the bleed down (twist the pushrod) before you move on to the next one.

    2.5 turns is only 15 flats, I may be mistaken but I thought I remember guys going 18 and 20 flats on these lifters, but that's just my own failing memory. In any case more flats would only be a safety feature of piston collision, it would not cure the noise.

    It is not always the lifters, some guys have problems with the rockers making noise after installing a cam. They put in shims (the old shovel shims) to try and compenstate for this. Sometimes it worked sometimes it didn't. This is the lateral slide movement of the rockers themselves.

    That's about all I can remember off the top of my head. Keep in mind if the sound is not excessive or you don't have evidence that you are mushrooming the ends of your valve tips then some sound is not a harmful thing. Engines in the old days (and many high performance engines) run solid lifters that have noise all the time. As teenagers we thought it was considered "cool" to have a cam in your cage that gave the tappet sound.

    You don't want to give the lifters less than the required turns of clearance in an attempt to silence the noise, since this could cause more serious issues if a higher rpm valve float occurred.

    Anyhow just trying to give you some insight into the situation from stuff I've read in the past. Good luck with it.
    Last edited: Jun 19, 2012
  4. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    I have talked about this a number of times in the past, but when I did my roller-chain conversion, I chased a "lifter tap" problem for a couple of months adjusting and readjusting the PRs, swapping out the lifters, and other time consuming solutions. Turned out to be an exhaust leak on the front header!!

  5. Midnight Reign

    Midnight Reign Active Member

    the number of flats you count after zero lash is based on the threads per inch of the adjustable push rods. The formula I use is to count the threads per inch and divide by ten, so if your pushrods are 25 threads per inch divided by 10 is 2.5 turns past zero lash or 15 flats, 32 threads per inch = 3.2 full turns , or 20 flats past zero lash. Or to put it another way , threads per inch divided by ten, multiplied by six (number of flats on the jam nut). What you are trying to achieve is a compression distance of ( If Memory serves) .20 inch I think, someone with better math skills than I could verify that number. Hope this helps more than adding confussion.
  6. R_W_B

    R_W_B Senior Member

    TQ makes an excellent point, noise is noise and sometimes a mechanics stethoscope can help to pin point it. I'd check those header bolts for sure and also listen for a washer "leak" of exhaust which sounds like a tap in a way.

    I got my wording backwards on the above previous sentence. I always confuse this since on cages you turn the rockers down into the preload. You do the same thing with pushrods on the bike but I get it turned around in my mind sometimes since you are expanding the pushrod to accomplish it.

    Correction-> more flats would in fact cure the lifter preload gap (noise), but care must be taken not to go beyond recommended flats (turns) or you could remove too much of the preload and cause valve float at high rpm, causing possibly other severe complications.

    Hmmm that's interesting I've never ran across dividing by 10 method. I will have to read up on that. I've always read you had to divide the number of TPI into the number of turns. I.e. 1/32 = the amount of distance 6 flats (one full turn) will give.

    Say with a pushrod that has 32 threads per inch. One full turn (6 flats) would = 1/32 or 0.03125 inch. (31 thousands)

    So 15 flats (2-1/2 turns) = 2.5 / 32 or 0.07812 inch. (78 thousands)

    Keep in mind this method is for single start threads, which I have never seen any pushrods or rocker studs with anything but single start threads. A double start thread would go twice the distance in one turn.