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IH: Engine Mechanicals - Sub-03F
1983 Valve Guide Changes
- In 1983, the Moco raised the compression ratio (8.8-1) with a new piston design (.040“ higher crown surface) 1) 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. 2)
- 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. 3)
- 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.
- New intake valve guides should protrude .594”-.604“ above the head casting.
- New exhaust valve guides should protrude .640”-.650“ above the head casting.
- Outer Spring Load:
- Valve Closed, 52-67 lbs. @ 1-3/8”
- Valve Open, 171.6 - 194.4 lbs. @ 3/32“
- Inner Spring Load:
- Valve Closed, 20.9 - 29.1 lbs. @ 1-13/64”
- Valve Open, 79.7 - 90.3 lbs. @ 25/32“
- Spring Free Length:
- Outer Spring, 1-9/16”
- Inner Spring, 1-11/32“
- 1970-1979 Intake Valve:
- Both 1954-1978 Parts Catalogs (99451-78A issued in April of 1981 & 99451-78B copyright 1989) list the intake valve for 1970-1978 as the newer (Nittan 18027-80 or Eaton 18028-80 w / 3 angle seat) but these -80 valves began use in 1980. The 1979 parts catalogs (99451-79 & 99451-79A) and the 1979-1980 (99451-80) still show the 18070-70 intake valve as the current part number.
Head Sets with Year Changes
| 1957-1959 XL 1958 XLC | 1958-1969 XLH/XLCH | 1970-1979 XLH/XLCH | 1980-1985 XL / XLS / XLX | |||
|---|---|---|---|---|---|---|
| (F) 16677-57 (R) 16678-57 (57-58) (replaced in 59 by ↓) | (F) 16673-58 (R) 16674-58 (58 only) (replaced in 59 by ↓) | (F) 16673-70 (R) 16674-70 (70 only) | (F) 16673-80 (R) 16674-80 (80 only) |
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| (F) 16677-57A (R) 16678-57A | (F) 16673-58A (R) 16674-58A | (F) 16673-71 (R) 16674-71 (71 only) | (F) 16673-73C (R) 16674-73C (available in 81) (for 79-83) |
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| (F) 16673-72 (R) 16674-72 (for 72-E73) | (F) 16673-73D (R) 16674-73D (79-E85) |
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| (F) 16673-73 (R) 16674-73 (L73-78) | (F) 16673-84 (R) 16674-84 (L85) |
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| (F) 16673-73A (R) 16674-73A (79 only) | ||||||
| (F) 16673-73B (R) 16674-73B (available in 80) (for 79-82) | ||||||
| (F) 16673-73C (R) 16674-73C (available in 81) (for 79-83) |
Intake Valves and Components with Year Changes
| Intake Group | 1957-1959 XL 1958 XLC | 1958-1969 XLH/XLCH | 1970-1979 XLH/XLCH | 1980-1985 XL / XLS / XLX | ||||
|---|---|---|---|---|---|---|---|---|
| Valve | 18070-57 (1-11/16” Dia)4) | 18070-58 (1-13/16“ Dia) 5) | 18070-70 | 18070-70 (last use in 80) 18027-80 (Nittan) 18028-80 (Eaton) either brand is standard for 79-85 |
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| 18027-80 (Nittan) 18028-80 (Eaton) either brand is standard (added in 81) (replacement for 1979) | ||||||||
| Valve Guide | 18176-57 (Std) 18179-57 (.001” OS) 18180-57 (.002“ OS) (replaced in '59 by ↓) | 18176-57 (Std) 18179-57 (.001” OS) 18180-57 (.002“ OS) (replaced in '59 by ↓) | 18176-57A (Std) 18179-57A (.001” OS) 18180-57A (.002“ OS) (replaced in '80 by ↓) | 18176-80 (Std) (80 only) 18176-57B (Std) (80) 18179-57B (.001” OS) 18180-57B (.002“ OS) 18191-79 (.004” OS) (81) (All replaced in '83 by ↓) |
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| 18176-57A (Std) 18179-57A (.001“ OS) 18180-57A (.002” OS) | 18176-57A (Std) 18179-57A (.001“ OS) 18180-57A (.002” OS) | 18176-57B (Std) 18179-57B (.001“ OS) 18180-57B (.002” OS) 18191-79 (.004“ OS) (81) (for 79-82) (replaced in '83 by ↓) | 18176-57C (Std) 18179-57C (.001“ OS) 18180-57C (.002” OS) 18191-79A (.004“ OS) (for 79-85) See also 1983 Valve Guide Changes |
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| 18176-57C (Std) 18179-57C (.001” OS) 18180-57C (.002“ OS) 18191-79A (.004” OS) (for 79-85) | ||||||||
| Valve Guide Retainer Ring | 18120-80 (80 only) | |||||||
| Valve Seat Repair Insert | 18055-58 (added in 74) (for 58-69) | 18055-58 (added in 74) (for 58-69) | 18055-70 (added in 74) (for 70 up) | 18055-70 | ||||
| Spring Collar (lower) | 18220-57 | 18220-57 | 18220-57 | 18220-80 (80 only) 18220-57 (57-E81) 18220-81 (L81-E83) 18220-83 (L83-85) |
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| Valve Spring (inner) | 18204-57 (replaced in 71 by ↓) | 18204-57 (replaced in 71 by ↓) | 18204-57 (replaced in 71 by ↓) | 18204-57A (71-E83) 18204-83 (L83-85) |
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| 18204-57A (for 57-E83) | 18204-57A (for 57-E83) | 18204-57A (for 57-E83) | ||||||
| Valve Spring (outer) | 18203-57 (replaced in 71 by ↓) | 18203-57 (replaced in 71 by ↓) | 18203-57 (replaced in 71 by ↓) | 18203-57A (71-E83) 18203-83 (L83-85) |
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| 18203-57A (for 57-E83) | 18203-57A (for 57-E83) | 18203-57A (for 57-E83) | ||||||
| Spring Collar (upper) | 18221-57 (replaced in '59 by ↓) | 18221-57 (replaced in '59 by ↓ ) | 18221-57A (replaced in 82 by ↓ ) | 18221-57A (L58-81) 18221-57B (82) (for 79-85) |
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| 18221-57A (for 57 up) | 18221-57A (for 58 up) | 18221-57B (for 79-85) | ||||||
| Valve Keepers (keys) | 18228-30 | 18228-30 | 18228-30 | 18228-30 | ||||
| Valve Stem Cap | X | X | X | X |
Exhaust Valves and Components with Year Changes
| Exhaust Group | 1957-1959 XL 1958 XLC | 1958-1969 XLH/XLCH | 1970-1979 XLH/XLCH | 1980-1985 XL / XLS / XLX | ||||
|---|---|---|---|---|---|---|---|---|
| Valve | 18080-57 | 18080-58 (58-62 XLH) (58-61 XLCH) (obsolete for 63) | 18080-58A | 18080-58B (last use in 80) 18033-80 (Nittan) (81) 18036-80 (Eaton) (81) either brand is standard for 79-85 |
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| 18080-58A (63 and up XLH) (62 and up XLCH) (58 and up replacement) | 18033-80 (Nittan) 18036-80 (Eaton) either brand is standard (added in 81) (replacement for 1979) | |||||||
| Valve Guide | 18170-57 (Std) 18171-57 (.001“ OS) 18172-57 (.002” OS) | 18170-57 (Std) 18171-57 (.001“ OS) 18172-57 (.002” OS) | 18170-57 (Std) 18171-57 (.001“ OS) 18172-57 (.002” OS) (replaced in '80 by ↓) | 18170-80 (Std) (80 only) 18170-57A (Std) (80) 18171-57A (.001“ OS) 18172-57A (.002” OS) 18168-79 (.004“ OS) (81) (for 79-82) (All replaced in '83 by ↓) |
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| 18170-57A (Std) 18171-57A (.001” OS) 18172-57A (.002“ OS) 18168-79 (.004” OS) (81) (for 79-82) (replaced in '83 by ↓) | 18170-57B (Std) 18171-57B (.001” OS) 18172-57B (.002“ OS) 18168-79A (.004” OS) (for 79-85) See also 1983 Valve Guide Changes |
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| 18170-57B (Std) 18171-57B (.001” OS) 18172-57B (.002“ OS) 18168-79A (.004“ OS) (for 79-85) | ||||||||
| Valve Guide Retainer Ring | 18120-80 (80 only) | |||||||
| Valve Seat Repair Insert | 18052-58 (added in 74) (for 58-85) | 18052-58 (added in 74) (for 58-85) | 18052-58 (added in 74) (for 58-85) | 18052-58 | ||||
| Spring Collar (lower) | 18220-57 | 18220-57 | 18220-57 | 18220-80 (80 only) 18220-57 (57-E81) 18220-81 (L81-E83) 18220-83 (L83-85) |
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| Valve Spring (inner) | 18204-57 (replaced in 71 by ↓) | 18204-57 (replaced in 71 by ↓) | 18204-57 (replaced in 71 by ↓) | 18204-57A (71-E83) 18204-83 (L83-85) |
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| 18204-57A (for 57-E83) | 18204-57A (for 57-E83) | 18204-57A (for 57-E83) | ||||||
| Valve Spring (outer) | 18203-57 (replaced in 71 by ↓) | 18203-57 (replaced in 71 by ↓) | 18203-57 (replaced in 71 by ↓) | 18203-57A (71-E83) 18203-83 (L83-85) |
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| 18203-57A (for 57-E83) | 18203-57A (for 57-E83) | 18203-57A (for 57-E83) | ||||||
| Spring Collar (upper) | 18222-57 (57-E58) | 18222-57 (57-E58) | 18221-57A (replaced in 82 by ↓ ) | 18221-57A (L58-81) 18221-57B (82) (for 79-85) |
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| 18221-57A (L58 up) | 18221-57A (L58 up) | 18221-57B (for 79-85) | ||||||
| Valve Keepers (keys) | 18228-57 (57-E58) | 18228-57 (57-E58) | 18228-30 | 18228-30 | ||||
| 18228-30 (L58 up) | 18228-30 (L58 up) | |||||||
| Valve Stem Cap | 18234-57 (57-E58 only) | 18234-57 (57-E58 only) | ||||||
| (L58 up - Obsolete) | (L58 up - Obsolete) | X | X |
3)
HD Service Bulletin #M-870 dated April 15, 1983
