Differences

This shows you the differences between two versions of the page.

Link to this comparison view

-Both sides previous revisionPrevious revision
-techtalk:ref:svcproc23 [2019/05/31 00:10]
– [Why Degree Your Cams?] hippysmack
+
+techtalk:ref:svcproc23 [2024/01/22 21:07] (current)
– hippysmack
@@ Line -3,5 +3,4 @@ removed created
 
 ====== Degree-ing Cams ======
 
 Degreeing cams is an expression used to mean measuring certain characteristics of the cam movements (cam specs). \\
 The act of degreeing cams doesn't change anything but gives you an understanding of what the cams are doing and when. \\
@@ Line -22,10 +21,8 @@ removed created
   * You can also degree the cams to eliminate errors in;
     * General manufacturing of the cams.
     * Proper cam installation. \\ A compression test will also immediately point out a cam timing problem. ((aswracing of the XLFORUM httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-engine-conversions/97704-so-i-put-my-bike-back-together-got-a-dyno-tune-not-happy/page3?p=2670787&highlight=degree#post2670787post2030753)) \\ See also [[techtalk:ref:svcproc20#cylinder_compression_test|Performing a cylinder compression test]] in the REF section of the Sportsterpedia.
 
 ====== Setting up the Equipment ======
  
 {{:techtalk:ref:tools:degreeing_cams_by_povertyflats.jpg?direct&400|}} ((photo by povertyflats of the XLFORUM httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/130556-fitting-buell-xb-cams-551-e-grind-to-xl/page2?s=03729fd1877416d73eb9535bdf896822&p=5503895#post4051327)) 
 
   * You'll need to [[techtalk:ref:svcproc22#finding_tdc_of_the_piston|Find True TDC of the Piston]] for precise measurements.
@@ Line -33,5 +30,5 @@ removed created
   * Or, for spot checking cam installation, a dial caliper placed in the spark plug hole and a degree wheel will do to find TDC.
     * See also [[techtalk:ref:svcproc22#find_true_tdc_using_a_dial_indicator_and_a_degree_wheel|Finding True TDC Using a Dial Indicator and a Degree Wheel]]
     * By using only a dial indicator on top of the piston, the point where the indicator falls off it's high point will be different. \\ (depending on which direction you rotate the engine to find the high point). ((rivethog of the XLFORUM httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/138903-ccing-my-combustion-chambers?t=1507847))
     * There will be a few degrees of interpretation before the piston rolls back down.
     * However, a cam gear off by a tooth will show much more of a degree change than the caliper dwell at TDC.
@@ Line -56,7 +53,6 @@ removed created
 
 ===== Equipment Specifics =====
 \\
 ==== Dial Indicator for Measuring the Cam Lobe Lift ====
 
 
 A dial indicator is set on top of the lifter body to measure the lift on each cam lobe, \\
 As well as the start and end times of the lobe lifts (corresponds to opening and closing of valves). \\
@@ Line -71,13 +67,13 @@ removed created
 
 |{{:techtalk:ref:tools:dial_caliper_by_jorgen.jpg?direct&300|}}|
 |Dial caliper mounted over lifter bore ((photo by Jorgen of the XLFORUM httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/92792-cam-choices/page4?t=761410&highlight=degreeing+cams&page=4))|
 
 ==== Piston Stop Tool ====
 |{{:techtalk:ref:tools:piston_stop_by_jorgen.jpg?direct&300|}}|
 |Commercial Piston Stop Installed ((photo by Jorgen of the XLFORUM httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/92792-cam-choices/page4?t=761410&highlight=degreeing+cams&page=4))| 
 ==== Degree Wheel ====
 
 ==== Degree Wheel ====
 |{{:techtalk:ref:tools:degree_wheel_by_jorgen.jpg?direct&300|}}|{{:techtalk:ref:tools:degree_wheel_by_hippysmack.jpg?direct&300|}}|
 |Degree wheel mounted on primary side ((photo by Jorgen of the XLFORUM httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/92792-cam-choices/page4?t=761410&highlight=degreeing+cams&page=4))|Degree wheel mounted to the pinion shaft ((photo by Hippysmack))|
 
 ====== Cam Spec Definitions and Measuring ======
@@ Line -99,6 +95,6 @@ removed created
 It also closes the valve at 46° after the intake stroke ends (or 46° degrees after bottom dead center). \\
 Each stroke is 180° long. \\
 
 The duration can be calculated from the published timing figures. \\
 
 ===== Cam Lobe Lift =====
 The actual cam lift is any amount of lift greater (taller) than the base circle. \\
@@ Line -121,11 +117,8 @@ removed created
 Check all four cams and compare the results. \\
 
 You can also measure cam lobe lift with the cams removed by using a caliper. ((rocketmangb of the XLFORUM httphttps://www.xlforum.net/forumsforum/showthread.phpvendors/hammer-performance/160789-gaterman-lifters-now-available-from-hammer-performance?s=73d24db8f0756ef41c6215fd92ad0055&p=4726240#post3437771)) \\
 The base circle is the smallest dimension of a cam lobe. \\
 If you measure the largest dimension of the lobe and subtract the smallest dimension you get the lobe lift. \\
 Multiply that by the rocker ratio and you get the valve lift. \\
 
 
 
 
 ===== Duration =====
@@ Line -145,5 +138,4 @@ removed created
 |  30° before \\ TDC Exhaust \\ or (BTDC)  |  180°  |  46° after \\ BDC \\ or (ABDC)  |  52°  |  180°  |  24°  |
 |  Calculated Intake Cam Duration: 30+180+46 = 256°  |||  Calculated Exhaust Cam Duration: 52+180+24 = 256°  |||
 
 
   * To measure advertised duration:
@@ Line -166,5 +158,4 @@ removed created
 Simply note the start degree before the initial lift and the end degree after the last fall of the indicator. \\
 Then calculate the distance in between as in the example above. \\ 
 
 
 ===== TDC Lift =====
@@ Line -173,5 +164,4 @@ removed created
 
 TDC Valve Lift is calculated by multiplying the cam lobe lift, at TDC exhaust, by the rocker arm ratio. \\
 
 
 Valve to piston clearance has nothing to do with maximum lift (which occurs with the piston well down the bore). \\
@@ Line -209,7 +199,6 @@ removed created
 |{{techtalk:ref:svcproc:2_cam_outside_gear_position_1_by_hippysmack.jpg?direct&500|}}|
 |#2 Cam, Outside Gear Location (91 and Up Models) ((photo by Hippysmack))|
 
 
 
 \\
 [[:techtalk:menu|{{:techtalk:gototechnicalmenu.jpg|}}]]

Trace: • EVO: Oiling & Lubrication • REF: Oiling & Lubrication