Differences

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--- techtalk:ih:engmech02 [2023/04/14 19:42] – [Pinion Gear] hippysmack
+++ techtalk:ih:engmech02 [2025/09/11 21:06] (current) – hippysmack
@@ Line 1: / Line 1: @@
 [[:techtalk:menu|{{  :techtalk:gototechnicalmenu.jpg|}}]]
 ====== IH: Engine Mechanicals ======
+====== Camshafts ======
+The Camshafts (4 of them) are used to operate the intake and exhaust valves by means of the lifters (AKA: tappets), the pushrods and the rocker arms. The #2 Cam is driven by the Pinion Gear. The Pinion Gear is mounted on the Pinion Shaft which is part of the Flywheel Assembly.
+#1 Cam - Rotates CW -- Operates Rear Exhaust Valve \\
+#2 Cam - Rotates CCW - Operates Rear Intake Valve - Driven by Pinion Gear \\
+#3 Cam - Rotates CW -- Operates Front Intake Valve \\
+#4 Cam - Rotates CCW - Operates Front Exhaust Valve \\
-====== Cam Gear Selection for Quiet Operation ======
+===== Cam Specs: =====
+  * PB Cams: ((HD PB Cam Gear Set Instructions rev 11-1972)) \\ Timing is checked at .005" tappet lift with no tappet clearance. \\ Caution: Because of valve lift, (.400" on intake and exhaust), exhaust and intake valve to piston clearance must be checked. \\ A minimum of .060" is required.
+    * Intake: Opens 77° BTC
+    * Intake: Closes 87° ABC
+    * Exhaust: Opens 92° BBC
+    * Exhaust: Closes 74 ATC
+===== Cam Gear Selection for Quiet Operation =====
   * Timing gears for 1000, 1200 and 1340 models are originally installed and are supplied through parts order in matched sets to provide the proper gear lash (tooth clearance) for quiet operation. Select gears were also made for all models (1954-1979) ((HD Service Bulletin #M-743 dated April 3, 1979))
   * **Gear Measurements**:
@@ Line 56: / Line 68: @@
 |Front Exhaust|(seven part #s-84)|Range Brown - Black|||||
+===== Removing Cams =====
-====== Removing Cams ======
+  * Slow and steady as she goes. That mind set will be very helpful in keeping problems to an absolute minimum. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/139758-1968-xlch-dust-off/page3?t=1515914&page=5))
-  * Slow and steady as she goes. That mind set will be very helpful in keeping problems to an absolute minimum. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1515914&page=5))
   - Get a good helper
   - Get a magnet on a stick ( and pray you won't need to use it).
@@ Line 74: / Line 85: @@
 ====== Gearcase Cover ======
-|  68 Gearcsae Cover ((photo by Bobeaser of the XLFORUM http://xlforum.net/forums/showthread.php?t=563241))  |
+|  68 Gearcsae Cover ((photo by Bobeaser of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/78212-67-ironhead-oil-routing?t=563241))  |
 |{{:techtalk:ih:engmech:68_cam_cover_by_bobeaser.jpg?direct&300|}}|
 ====== Cam Bearings / Bushings ======
@@ Line 82: / Line 94: @@
 |{{:techtalk:ih:engmech:78_cam_bearings_by_dirtycory.jpg?direct&400|}}|
-|  78 Cam Bearings ((photo by by DirtyCory of the XLFORUM http://xlforum.net/forums/showthread.php?t=1297584&page=7))  |
+|  78 Cam Bearings ((photo by by DirtyCory of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/127032-getting-this-78-back-to-the-way-it-should-be/page7?t=1297584&page=7))  |
 ====== Camshaft Timing ======
-There is no relationship between the timing of the cams and the position of the crankshaft timing mark in the hole. Just line up the cam marks and the pinion gear mark and you are done. ((IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions&page=3))
+There is no relationship between the timing of the cams and the position of the crankshaft timing mark in the hole. Just line up the cam marks and the pinion gear mark and you are done. ((IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead/page3?t=239641&highlight=cam+positions&page=3))
 ====== Installing Cams ======
-|Use some clothes pins to hold the lifters out of the way ((photo by supr2nr of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions))|
+|Use some clothes pins to hold the lifters out of the way ((photo by supr2nr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead?t=239641&highlight=cam+positions))|
 |{{:techtalk:ih:engmech:installing_76_cams_1_by_supr2nr.jpg?direct&300|}}|
-|Start with the pinion gear in around this position → ((photo by supr2nr of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions))|CAM 1 → ((photo by supr2nr of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions))|CAM 2 → ((photo by supr2nr of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions))|
+|Start with the pinion gear in around this position → ((photo by supr2nr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead?t=239641&highlight=cam+positions))|CAM 1 → ((photo by supr2nr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead?t=239641&highlight=cam+positions))|CAM 2 → ((photo by supr2nr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead?t=239641&highlight=cam+positions))|
 |{{:techtalk:ih:engmech:installing_76_cams_2_by_supr2nr.jpg?direct&300|}}|{{:techtalk:ih:engmech:installing_76_cams_3_by_supr2nr.jpg?direct&300|}}|{{:techtalk:ih:engmech:installing_76_cams_4_by_supr2nr.jpg?direct&300|}}|
-|CAM 3 → ((photo by supr2nr of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions))|CAM 4 → ((photo by supr2nr of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions))|All done. ✔((photo by supr2nr of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions))|
+|CAM 3 → ((photo by supr2nr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead?t=239641&highlight=cam+positions))|CAM 4 → ((photo by supr2nr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead?t=239641&highlight=cam+positions))|All done. ✔((photo by supr2nr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead?t=239641&highlight=cam+positions))|
 |{{:techtalk:ih:engmech:installing_76_cams_5_by_supr2nr.jpg?direct&300|}}|{{:techtalk:ih:engmech:installing_76_cams_6_by_supr2nr.jpg?direct&300|}}|{{:techtalk:ih:engmech:installing_76_cams_7_by_supr2nr.jpg?direct&300|}}|
@@ Line 104: / Line 116: @@
 ====== Gearcase Cover ======
-===== Sub-Documents =====
-* . . . [[techtalk:ih:engmech02a|Gearcase Cover Removal]]
   * Caution: Improperly intermixing components can cause loss of top end oil pressure and subsequent damage. After replacing any of these components, check top-end oil circulation to ensure proper operation.
   * **Late 1981 and Early 1982 engines may have one of two different types of gear case cover and crankcase set combinations**. ((HD Service Bulletin #M-841 dated October 16, 1981))
@@ Line 140: / Line 148: @@
 |{{:techtalk:ih:engmech:pinion_gear_pic2_24011-37_by_evilgeniushd1936.jpg?direct&300|}}|{{:techtalk:ih:engmech:pinion_gear_pic1_24011-37_by_evilgeniushd1936.jpg?direct&300|}}|
-|1977-1985 Pinion Shaft Timing Mark ((photo by IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions&page=3))|
+|1977-1985 Pinion Shaft Timing Mark ((photo by IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead/page3?t=239641&highlight=cam+positions&page=3))|
 |{{:techtalk:ih:engmech:pinionshafttimemark_by_ironmick.jpg?direct&200|}}|
@@ Line 148: / Line 156: @@
 ===== Pinion Gear Fit on Shaft =====
 ==== 1957-1976 gear ====
+These are OD measurements of 3 OEM pinion shafts as measured by needspeed (.7844", .7840" and .7840"). ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/205118-pinion-gear-fit-1968-xlch#post4631012)) \\
 Comments by Dr Dick; \\
 Installing a tight gear: If you tap the gear on the shaft you are tapping on your flywheel assembly in a direction not supported by anything. NOT recommended. \\
 You should utilize the 5/16"-24 left hand threads tapped in the pinion shaft to counteract installing force (press it in). \\
-The 1957-1976 pinion gear needs to be a tight fit and was a factory press fit. However, it's a common problem to find them loose on a used engine. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1072235)) \\
+The 1957-1976 pinion gear needs to be a tight fit and was a factory press fit. However, it's a common problem to find them loose on a used engine. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/113036-pinion-gear?t=1072235)) \\
 The trick in selecting the right fit part during assembly. The gear is supposed to be "size for size" with the major diameter of the shaft splines. \\
 The "press" actually is between the sides of 1 male shaft spline and it's matching female spline in gear. \\
@@ Line 162: / Line 171: @@
 It's usually not "destructive" problem to leave it as is and you can't use an adhesive to "glue" the pinion gear on. \\
-(1) - A loose gear doesn't mess with breather timing too much. A correctly positioned gear sits .312" above the gasket surface. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?p=4332256#post4332256)) \\ The cover bushing face sits .312" below gasket surface. So the gear clears the bushing by 1 gasket thickness. \\ A loose gear rides on the bushing face. There is virtually little breather timing difference between the tight position and the loose one. \\ A shim between gears can make up for the loose position. This shim mustn't self destruct and get caught in cam train. \\
+(1) - A loose gear doesn't mess with breather timing too much. A correctly positioned gear sits .312" above the gasket surface. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/147814-pinion-gear-questions#post3152926)) \\ The cover bushing face sits .312" below gasket surface. So the gear clears the bushing by 1 gasket thickness. \\ A loose gear rides on the bushing face. There is virtually little breather timing difference between the tight position and the loose one. \\ A shim between gears can make up for the loose position. This shim mustn't self destruct and get caught in cam train. \\
 (2) - A loose gear will make a valve tapping type noise. No mechanical problems, just a tad noisy. Looser = noisier. \\
 (3) - The gear press isn't diametrical. Its lateral. When loose both gear and shaft wear. \\ When a loose gear is removed you will see the wear on shaft spline flanks. \\
-{{:techtalk:ih:engmech:1957-1976_pinion_gear_press_fit_pic1_by_dr_dick.jpg?direct&400|}} ((photo by Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?p=4332256#post4332256)) \\
+{{:techtalk:ih:engmech:1957-1976_pinion_gear_press_fit_pic1_by_dr_dick.jpg?direct&400|}} ((photo by Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/147814-pinion-gear-questions#post3152926)) \\
 ) Bikes using stock valve springs can use a 45" flat head gear to regain some fit. \\ I have done this many times. Probably 50 times. \\
 These gears are OEM WWII surplus (-29 pn). Many times marketed as XL but they are not the real XL gear. The real xl gears have been obsolete for decades. \\
@@ Line 173: / Line 182: @@
 I suggest never to use the 45" gears on unworn shafts. Or with cams that require heavy springs. \\
 {{:techtalk:ih:engmech:1957-1976_pinion_gear_press_fit_pic2_by_dr_dick.jpg?direct&400|}}
 ==== 1977-1985 Gear ====
-The 79-85 pinion gear slides up on a timing mark on the pinion shaft and corresponding to a timing mark on the pinion gear. These must line up. ((IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=239641&highlight=cam+positions&page=3))
+The 79-85 pinion gear is a slip fit and slides up on a timing mark on the pinion shaft and corresponding to a timing mark on the pinion gear. \\
+These must line up. ((IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead/page3?t=239641&highlight=cam+positions&page=3))
 ====== Tappets (Lifters) ======
@@ Line 184: / Line 192: @@
 ====== Installing Tappets ======
-When installing the tappets, the valve may be recessed in the head a bit. ((Iron Mick of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077007&page=2)) \\
+When installing the tappets, the valve may be recessed in the head a bit. ((Iron Mick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/52923-how-to-install-cam-gears-in-your-ironhead/page3?t=239641&highlight=cam+positions&page=3)) \\
 You can gently lever up on the pushrod to allow it to pop in the tappet cup. \\
 Just be sure you have some free play remaining once it is in the cup and before clearance is adjusted. \\

Trace: • IH: Engine Mechanicals - Sub-01D • EVO: Engine Mechanicals - Sub-01C

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