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| techtalk:ih:engmech02 [2025/08/01 17:42] – [Sub-Documents] hippysmack | techtalk:ih:engmech02 [2025/09/11 21:06] (current) – hippysmack | ||
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| ====== IH: Engine Mechanicals ====== | ====== 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)) | * 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**: | * **Gear Measurements**: | ||
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| |Front Exhaust|(seven part # | |Front Exhaust|(seven part # | ||
| - | ====== 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:// | * 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:// | ||
