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techtalk:ih:engmech03f [2018/01/20 23:42] hippysmack [Exhaust Valves and Components with Year Changes] |
techtalk:ih:engmech03f [2018/01/21 00:03] hippysmack [1983 Valve Guide Changes] |
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| ====== 1983 Valve Guide Changes ====== | ====== 1983 Valve Guide Changes ====== | ||
| - | * Beginning with crankcase number 783, new style intake and exhaust valve guides were introduced XL 1000cc engines along with new flat lower spring collars and longer inner and outer springs. ((HD Service Bulletin #M-870 dated April 15, 1983)) | + | * In 1983, the Moco raised the compression ratio (8.8-1) with a new piston design (.040" higher crown surface) ((HD Service Bulletin #M-856 dated August 6, 1982)) and the use of the earlier style thinner head gasket. This higher compression ratio along with a new two stage ignition system (VOES), provided increased performance while allowing the use of leaded regular grade gasoline. ((HD Service Bulletin #M-856 dated August 6, 1982)) |
| + | * Part of this performance upgrade, (beginning with crankcase number 783), was the introduction of new style intake and exhaust valve guides for XL 1000cc engines along with new (flat) lower spring collars and longer inner and outer springs. ((HD Service Bulletin #M-870 dated April 15, 1983)) | ||
| * The longer springs provide increased spring tension. __But__, the new lower spring collars and longer springs can only be used with the new style valve guides. The new springs were identified as having red or orange paint on several springs. | * The longer springs provide increased spring tension. __But__, the new lower spring collars and longer springs can only be used with the new style valve guides. The new springs were identified as having red or orange paint on several springs. | ||
| * The new style (shoulder-less) valve guides were also used for service replacement of the old style guides on all 1000cc engines and do allow the use of all old valve train components. Because the new style valve guides do not have a shoulder as the old ones did, a special valve guide driver (HD-33871) must be used to control the guide installed height. | * The new style (shoulder-less) valve guides were also used for service replacement of the old style guides on all 1000cc engines and do allow the use of all old valve train components. Because the new style valve guides do not have a shoulder as the old ones did, a special valve guide driver (HD-33871) must be used to control the guide installed height. | ||
