![[Datsun 1200 encyclopedia]](/wiki/upload/wiki.png)
| Revision as of 23:59, 3 December 2015 ddgonzal (Talk | contribs) (->Damage) <- Previous diff |
Revision as of 00:25, 4 December 2015 ddgonzal (Talk | contribs) (->Damage) Next diff -> |
||
| Line 180: | Line 180: | ||
| = Damage = | = Damage = | ||
| + | == Flywheel Loosening == | ||
| The Datsun factory balanced every engine. But when parts are changed, it will get out of balance. In worst case scenario, this leads to shaking and eventual loosening of the [[flywheel]] bolts. | The Datsun factory balanced every engine. But when parts are changed, it will get out of balance. In worst case scenario, this leads to shaking and eventual loosening of the [[flywheel]] bolts. | ||
| Line 189: | Line 190: | ||
| <br>[http://datsun1200.com/modules/myalbum/photo.php?lid=24122 http://datsun1200.com/uploads/thumbs/24122.jpg] | <br>[http://datsun1200.com/modules/myalbum/photo.php?lid=24122 http://datsun1200.com/uploads/thumbs/24122.jpg] | ||
| [http://datsun1200.com/modules/myalbum/photo.php?lid=24123 http://datsun1200.com/uploads/thumbs/24123.jpg] [http://datsun1200.com/modules/myalbum/photo.php?lid=24124 http://datsun1200.com/uploads/thumbs/24124.jpg] | [http://datsun1200.com/modules/myalbum/photo.php?lid=24123 http://datsun1200.com/uploads/thumbs/24123.jpg] [http://datsun1200.com/modules/myalbum/photo.php?lid=24124 http://datsun1200.com/uploads/thumbs/24124.jpg] | ||
| + | |||
| + | == Cracked Crank == | ||
| + | All A-series crankshafts are forged, but can still crack if abused. | ||
| + | |||
| + | Causes: | ||
| + | * Dropping the crank during or before engine assembly | ||
| + | * Unbalanced engine. After replacing a piston, a rod or the crank, have the engine re-balanced | ||
| + | * Detonation (pinking) can put massive stresses on the engine | ||
| + | |||
| + | The forging line can be seen in this photo | ||
| + | <br>[http://datsun1200.com/modules/myalbum/photo.php?lid=19917 http://datsun1200.com/uploads/thumbs/19917.jpg] | ||
| [[Category:Engine Mechanical]] | [[Category:Engine Mechanical]] | ||
Revision as of 00:25, 4 December 2015
The crankshaft is interchangeable between early A12, A12GX, late A12, late A13 and A12A. Only the flywheel bolts differ, after 1974 using metric bolts.
Contents |
Overview
All Datsun A-series crankshafts are forged, and stroke comes in four sizes:
- 70mm (2.76 in.) stroke: A12/A12A/A13(1980)
- 77mm (3.03 in.) stroke: A13(1974)/A14
- 82mm (3.23 in.) stroke: A15
Flywheel Bolts
- 1966-1973: crank uses english-system 3/8" x 24 UNF bolts
- 12315-18000 BOLT-flywheel & drive plate 6 A10
- 12315-H1001 BOLT-FLY WHEEL 6 A12 MANUAL
- Will ARP 206-2802 work? For BMC A-series engines (UHL Under Head Length 0.900") $18 USD/set of 6
- 1974-up: crank uses Metric M10 1.25 bolts (from '73-7)
- A12,A13,A14,A12A,A15
- 12315-H6900 BOLT-FLYWHEEL 6 $4.83 USD
- replaced 12315-H6200
- Will ARP 203-2802 work? For 4AGE engines (UHL Under Head Length 1.050") $22 USD/set of 8
Misc
Also see: Bored And Stroked for crankshaft modifications you can perform at home.
Apparently there are two forgings of crankshaft:
- Heavy duty
-
- Light weight: thinner straight sided counterweights that also have small scallops out of them. Late model factory crank (from B310 Sunny)
-
- Twin-carb engine (A12GX, A12T and A14T) crankshafts are the same as a standard engines.
- 1974-up cranks use metric flywheel bolts. Early engines used British threads. See A Engine Redesign
- Front bolt, that holds the front pulley on, is:
- Part Number: 12309-78200 ($4.58)
- M16 x 1.50 (fine) pitch
- 15mm diameter
- 27mm long
- The head is ?mm hex and about 15 mm thick.
- Torque specification: 15-16 kg/m (108-116 ft. lb.)
Identification
A12: 12200-H5000/12200-H5001 < 12200-H1000/12200-H1001 -7909
A12/A13 70mm 9.51 kg scalloped crank throws, 12200-H8560/12200-H8500 7910- <2,0> 12200-H5001
A14 H62 12200-H6200 starting 1973 -7909
A14 H89, scalloped crank throws, 12200-H8900 starting 0879 <> 12200-H6200
G34 block with scalloped crankshaft
A15 12200-G3400 MT, 12200-H9700 AT
A14 M23 F10 M49 F10
Crankshaft Pulley
Lightened Crankshaft
Discussion: JTS Cranks
A14 knife-edged
Counterweighted Cranks
All A-series crankshafts are counterweighted and will rev smoothly to 8500+ RPM.
Here is the difference between counterweighted and "fully counterweighted" (L/Z cranks shown):
Fully counterweighted means each journal has it's own counterweights. Theoretically it means better torsional vibration control.
Either way, both types of Datsun cranks are precision balanced from the factory.
A15 crank is fully counterweighted: there are four counterweights, one for each crank throw.
In comparison, the E16 crank has two counterweights per crank throw, which helps reduce the overall diameter of the crank.
Smaller counterweights == smaller crankcase.
A12 full counter Billet Pitroad A12 Crankshaft
Of full counter crank benefits advantageous to the vibration reduction high-speed and high output, disadvantage weight increase and manufacturing cost. Crankshaft for race for achieving both the lightweight and stiffness UP is
[downside] 800 g weight increase
Seals
Rear Main Seal
Installation
12279-H2301 Rear Main Seal
Also apply sealant here
Removal
- Remove oil pan
- Remove rear main bearing
- Lift out old seal
If replacing the rear main seal when changing a clutch, you may remove it with the oil pan still in place:
- Puncture seal with an awl, tiny screwdriver, or similar implement. Punch through the eddge of the seal, by gently tapping through with hammer
- Carefully pry out slightly and work your way around the circumference until free
Part Numbers
12200-H8500 CRANKSHAFT ASSY B310 A12S, A13S 12200-H8515 A12/A12A CRANKSHAFT 70mm/2.76" stroke 12200-H5720 A12 COMPETITION CRANKSHAFT 70mm/2.76" stroke 12200-H8915 A13/A14 CRANKSHAFT 77mm/3.03" stroke * Weight 26.2 lbs 12200-G3400 A15 CRANKSHAFT 82mm/3.23" stroke
Old Numbers: 12200-H1000 ASSY-CRANKSHAFT 1 A12 MANUAL - $624.02 12200-H1001 CRANKSHAFT 1 A12 -671 12 12200-H1000 superceded 12200-H1000 CRANKSHAFT 1 A12 0671- 2 12200-H1001 superceded 12200-H5000 CRANKSHAFT 1 A12 0572- 2 12200-H1000 $624.02
BEARINGS * See main article: Bearings
SEAL, Front 13042-18000 SEAL-OIL CRANKSHAFT FRONT 1 A12 - superceded 13510-H1000 SEAL-OIL CRANKSHAFT FRONT (NOK) 1 A12 0271- 2 13042-18000 $7.24 RockAuto * National 223830 * Beck/Arnley 0521989 Specs * Shaft size: 38 mm * Housing bore: 55 mm * Outer diameter: 55.3 mm * Width: 7 mm
SEAL, Rear 12279-18000 SEAL-OIL CRANKSHAFT REAR 1 A12 - $81.18 12279-18010 SEAL-OIL CRANKSHAFT REAR (NDK) 1 A12 0271- 2 12279-18000 NLA 12279-H2301 * supercedes 12279-H1000 SEAL-OIL CRANKSHAFT REAR (NOK) 1 A12 0271- $81.18 12279-H2311 NDK make
12279-H2301 is for all A12/A14/A14 engines. Seal specifications * Shaft Size 60 mm * Housing Bore 82 mm * Outer Diameter 82.2 mm * Width 12 mm aftermarket RockAuto * Fel-Pro BS27493 * National 712006 * Corteco/Detroit Gasket 17209
PILOT BUSHING * see Pilot Bushing
SLINGER 12302-18000 THROWER-OIL CRANKSHAFT 1 A12 - $1.57
FLYWHEEL BOLTS 12315-H1001 BOLT-FLY WHEEL 6 A12 MANUAL - $4.38 12315-H1000 BOLT-FLY WHEEL 6 A12 AUTOMATIC - $3.51 12330-20300 PILOT-CONVERTER 1 A12 AUTOMATIC - $18.66 12333-20300 PLATE-CRANK CONVERTER 1 A12 AUTOMATIC - $9.44
Damage
Flywheel Loosening
The Datsun factory balanced every engine. But when parts are changed, it will get out of balance. In worst case scenario, this leads to shaking and eventual loosening of the flywheel bolts.
I started to hear a hell of a noise and shaking under acceleration and reving ... the flywheel bolts have given up the ghost.
For best practices, see Flywheel#Bolts.
Flywheel bolts failure - crank now needs repair
Cracked Crank
All A-series crankshafts are forged, but can still crack if abused.
Causes:
- Dropping the crank during or before engine assembly
- Unbalanced engine. After replacing a piston, a rod or the crank, have the engine re-balanced
- Detonation (pinking) can put massive stresses on the engine
The forging line can be seen in this photo
