Differences

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

--- techtalk:evo:engmech02a [2020/08/27 18:08]
hippysmack [The Exact Position of the Timing Marks May Have To Be Interpreted]
+++ techtalk:evo:engmech02a [2020/10/25 00:38]
ixl2relax [Cam Timing Mark Identification]
@@ Line 41: / Line 41: @@
 **Note**: If your cams have “V” markings on them, disregard those markings. The “V” markings on the cams are not used for timing Sportsters. ((Turbota of the XLFORUM http://xlforum.net/forums/showthread.php?t=26379)) {{:techtalk:evo:engmech:cam_markings_by_bsaman.jpg?direct&400|}} ((photo by bsaman of the XLFORUM http://xlforum.net/forums/showthread.php?t=693559&page=2)) {{:techtalk:evo:engmech:cam_timing_by_austinxl.jpg?direct&400|}} ((photo by AustinXL of the XLFORUM http://xlforum.net/forums/showthread.php?t=1701132))
-Here's a Buell XB using the 'V' timing marks on the cams. ((photo by soulhamster of the XLFORUM http://xlforum.net/forums/showthread.php?t=1321505&page=3)) \\
+Here's a Buell Blast (single cylinder) using the 'V' timing marks on the cams. ((photo by soulhamster of the XLFORUM http://xlforum.net/forums/showthread.php?t=1321505&page=3)) \\
 {{:techtalk:evo:engmech:buell_v_mark_on_cams_by_soulhamster.jpg?direct&500|}}
 ==== Working Around the Lifters If Installed ====
@@ Line 111: / Line 111: @@
   * Sometimes, the cam marks leave room for interpretation as in don't quite line up dead bang. \\ The root cause of the problem is the clearance between the camshafts and their respective bushings. \\ Without the cover in place, the cams hang down some. \\ Some hang down more than others because they have less support. \\ It's particularly bad on the #1 cam, as pictured, because the #1 cam sags down and the #2 cam doesn't (it's supported by the pinion gear). \\ And, you're relying on a mark on the #1 cam that's not directly on the teeth. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=693559))
+  * If it's advanced a tooth, you'll lose power by opening the exhaust too early, essentially dumping power right out the exhaust before it's done pushing on the piston. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=693559&page=3)) You may even make your pipes glow red. You'll also lose a lot of overlap, meaning you'll lose exhaust augmentation of intake flow, again costing power.
+  * If it's retarded a tooth, you'll likely get valve to piston contact. The piston chases the exhaust valve closed, and if the valve is that late getting closed, the piston will likely catch it. If you're using cams with very little overlap to begin with, say "D" cams, you might get away with it, but with most any performance oriented grind, you don't have that much margin.
 {{:techtalk:evo:engmech:cam_alignment_by_hippysmack.jpg?direct&400|}} ((photo by Hippysmack)) {{:techtalk:evo:engmech:cam_timing_2_by_austinxl.jpg?direct&400|}} ((photo by AustinXL of the XLFORUM http://xlforum.net/forums/showthread.php?t=1701132))

Trace:

Differences

Navigation

Search

Toolbox