Inspection, Repair, and Assembly

Section X - Inspection, Repair and Assembly

1.  General

a.  This section contains complete instructions for the inspection, repair and assembly of the sub-assemblies and then the major component parts.  Descriptions are given by sub-assemblies in the proper order to facilitate assembly to their major assemblies for component parts, which in turn are assembled in proper order to the engine.

b.  Special precautions should be exercised during final assembly to observe any indication of loose studs.  That is noticeable only when pressure of an applied nut is brought to bear on the stud.  Equal precautions should be taken to prevent dirt or any foreign material from falling into the engine during assembly operations.

2.  Inspection

a.  All fits, clearances, etc. will be held to limits as set forth in the Table of Limits.

b.  Where out-of-round, taper or wear exceeds replacement limits, a new part, or permissible reworking will be accomplished to Warner oversize or undersize standards.

c.  Where some particular fit clearance of an assembly cannot be determined without the size of its mating mounting or attaching unit, the size value required will be exchanged between the inspection or assembly departments involved.

d.  The following inspection procedure will be generally applicable to all detail parts and assemblies, and will be performed in conjunction with such inspection as may be specified in this section for certain parts.

(1) STUDS - Examine all studs for tightness in their respective locations and for possible damage to external threads.

(2) BUSHINGS

(a) Examine all bushings for looseness with their respective parts.

(b) Examine condition of bores for scoring, pitting, galling and any other unusual wear.

(3) PAINT - Examine condition of paint on all painted surfaces and repaint if necessary.

(4) FORGINGS AND CASTINGS

(a) Examine for nicks, cracks and other possible damage.

(b) Examine all tapped holes for thread damage.

(c) Examine all flange faces for smoothness and remove remnants of old gaskets.

(5) STEEL PARTS - Steel parts which are subject to stress except anti-friction bearings, studs, exhaust valves, standard nuts and washers, should be subjected to magnetic inspection.

(6) GEARS AND SHAFTS

(a) Gears will be examined for uneven tooth bearing, cracks or other damage due to wear.

(b) Shafts will be examined for cracks, scoring and straightness.

(7) ANTI-FRICTION BEARINGS - Ball bearings will be inspected and lubricated.

(8) VALVES - Exhaust valves will be subjected to etching test.

(9) Backlash will be measured with the mating gear teeth clean and dry.

3.  Repair Procedures

(a)  Whenever drilling or reaming holes, break all sharp edges remaining around the holes and smooth away all burrs with a fine stone or crocus cloth.

(b) Never use emery cloth for cleaning and polishing engine parts nor for any other purpose unless particularly specified in this handbook.  The use of emery cloth may leave abrasive particles in the engine as well as scratches which may develop into cracks and ultimate failure of part and engine.

(c) The incorrect marking of parts or the marking of parts in certain areas may produce surface cracks which can progress into complete failure of the parts.  Marks placed on certain areas or parts by the factory are located at definite points where experience has indicated it will be safe to place them.  Other parts are identified through the use of special etching fluid.  This fluid may be used to saturate an ordinary ink stamping pad and is used with a rubber stamp.  After part is etched, the surface should be cleaned and well oiled with engine oil to prevent corrosion.

(d) To obtain alignment of an oil hole in a bushing with the mating hole in the mating part, draw a pencil or crayon line lengthwise on the outside of the bushing through the center of the oil hole and square with the face of the bushing.  Mark the edge of the hole which is to receive the bushing.  Install the bushing on its press-in plug.  Align the two marks and press in the bushing.

(e) Remove all nicks, scratches or undesirable marks from all parts prior to assembling.  These instructions apply especially to all mating bearing surfaces, and to any other place where nicks, scratches and marks might serve as a starting point for structural failure.

(f) STUDS

(1) Any loose, broken, or damaged stud, or any stud that has been turned until it does not have the proper height above its flange, will be removed and an oversize stud will be installed.  All the original studs have a .005" oversize pitch diameter at the screwed-in end to obtain a tight fit in the aluminum part.

(a) If a stud needs replacement it must be replaced by one with a larger pitch diameter.  These oversize P.D. studs are identified by - .005 added to their part number.  Example:  S-506 - .005 stud has a 3/8-24 thread with a .005" larger pitch diameter (.010" over basic thread) than the standard stud which is listed as S-506.

(b) These oversize studs should be used only when the thread in the aluminum is not damaged.

(2) If, by excessive tightening, the thread in the aluminum part is stripped, the hole should be drilled and tapped out to a 1/16" larger size and a stud with a 1/16" larger thread at the screwed-in end shall be used.

(a) The studs with 1/16" larger screwed-in end than the original studs are identified by "- .062" added to their part number.

Example:  S-506 - .062 stud has a 7/16-20 thread with a .005" larger pitch diameter (.005" over basic thread P.D.) on the screwed-in end as compared with the S-506 stud, which has a 3/8-24 thread with a .005" larger pitch diameter (.005" over basic thread P.D.)

(3) When installing an oversize stud into the 3/8-24 tapped hole the minor diameter of the hole should be cleaned up with an 11/32 drill or reamer in a tee-handled tap wrench and the chips then cleaned out with a standard pitch diameter 3/8-24 tap.  If the 3/8-24 thread is stripped or damaged, it shall be necessary to use a - .062 stud with a 7/16-20 thread by drilling out the old thread and tapping with a ground tap having a pitch diameter of .4081-.4101.  Engines already having - .062 studs installed should have the minor diameter cleaned up with a 25/64 drill or reamer and have chips removed with a standard 7/16-20 tap.  (See Warner Aircraft Corporation Service Letter No. A-17 for the replacement of No. S-506 cylinder hold down stud and nut N-511 with S-911 stud and N-910 nut.)

(4) The pitch diameter of the tapped holes for the studs should be from basic to .002" over.

(5) The following tap drill sizes must be used:

• For 5/16-24 thread use 17/64 drill
• For 3/8-24 thread use 21/64 drill
• For 7/16-20 thread use 3/8 drill

(g) Valves found warped beyond possible reconditioning will be discarded.

(h) New piston rings will be installed at every overhaul.

4.  Assembly Precautions

a.  The successful operation of the engine is entirely dependent upon the attention given to every detail in the inspection and assembly.  It should be born in mind by the inspector and mechanic that the slightest neglect on their part may result in the failure of the engine.

b.  Great care should be taken to prevent dirt, dust and cotter pins, nuts, washers and other small particles from falling into the engine during assembly.  Such foreign material can damage the gears and the bearings.

c.  Before assembly, all parts should be carefully cleaned.  The use of compressed air for this purpose is recommended.

d.  Completely finish each step in the process of assembly as the work progresses.  Do not leave a nut loose or uncottered with the intention of coming back to it later unless other specified.

e.  Do not slack off a nut to line up castellation with the cotterpin hole in the bolt or stud.  If it cannot be tightened without exceeding the permissible torque value, use a new nut.

f.  Use cotterpins that fit tightly in their bolt or stud holes.  Always install the head or loop end of the cotterpin to fit the castellation of the nut and not across or outside the castellation.  Bend one leg of the cotterpin up and back over the bolt or stud tip and the other down against the nut, except when installing cotterpins on link rod bolts.  See assembly of link rod to master rod for method of installing link rod bolt cotterpin.

g.  When using safety wire select a size which will fit the hole fairly tightly.  Twist the wire uniformly with pliers and obtain tight loops at each end.  The wire should be sufficiently tight to eliminate vibration which would cause breakage of the wire from wear.

h.  In places where there is possibility of oil seeping out from between machines surfaces, the surfaces may be coated with a gasket paste before assembly.  Install new gaskets under cylinder flanges, new seals on intake pipe seats, and new oil pump packing and seal.

i.  The oil pump will not being to deliver the regular supply of oil until the engine has turned over several revolutions.  For this reason is is necessary to coat all surfaces normally lubricated by oil from the pump, with a good supply of engine oil when the parts are being assembled.  All parts which are a drive or push fit should likewise be coated with oil to facilitate their assembly in the engine.  In order to avoid chafing or scoring of crankshaft when ball bearings are pressed in place, colloidal or micrographite should be used between the inner race of bearing and the shaft.  The shaft should be wiped clean with a dray cloth and a quantity of micrographite applied to the surface of the shaft and to the shoulder against which the inner race rests before pressing on bearing.  After the bearing is in place, the excess graphite should be removed.

5.  Ignition Harness Assembly

a.  REPAIR - Replace all ignition cables.  Replace clips, brackets, tube or terminals if they requirement replacement.  (See Table VIII below)

Table VIII - Table of Cable Lengths In Inches

Used terminals may be removed from the used ignition cables by heating the soldering iron between crimped wires and terminal guide and then pulling the terminals off the cable ends.

 b.  ASSEMBLY - Right magneto fires rear plugs and left magneto the front plugs.

(1) Trim the insulation off the end of the ignition cable 1/4" and install spark plug terminals.  Solder the wire to the spark plug terminal.  Do not use any more solder than is necessary to firmly fasten wire to terminal.

(2) For the purpose of identification the cables at the magneto block ends may be numbered by placing markers over the cables.  The cables should be installed at final assembly in accordance with the table shown above.  The engine firing order is 1, 3, 5, 7, 2, 4, 6.  The lead from No. 1 cylinder spark plug must be inserted in the No. 1 hole in the magneto distributor block and leads 3, 5, 7, 2, 4, and 6 must be inserted in the magneto distributor block holes 2, 3, 4, 5, 6, and 7 respectively.

6.  Spark Plugs

See paragraph on accessories in section IV of this handbook.

7.  Magneto Control Rod

a.  After cleaning, assemble all parts of magneto control rod.

8.  Magneto Coupling

a.  INSPECTION

(1) Check the holes in the magneto coupling flange.  If they have worn elongated the flange should be discarded.

b.  ASSEMBLY

(1) Assemble the rubber disc to the magneto coupling with the heads of the flat head screws against the rubber disc.

(2) Assembly the adjusting ring to the rubber disc.

9.  Magneto

See paragraph on accessories in Section IV of this handbook.

a.  INSPECTION - Before placing coupling assembly on tapered shaft of magneto, check the height of the Woodruff key above the tapered surface of the shaft.  This height must not be such that when the coupling is assembled to the shaft it would ride on the top of the key instead of on the taper of the shaft.  A minimum clearance of .003" is desired between the top surface of the key and the bottom of the key slot in the coupling.

b.  REPAIR - Remove all burrs and clean the tapered bearing surface of shaft and key with crocus cloth.

c.  ASSEMBLY

(1) Install coupling assembly.

(2) Install washer and nut and secure nut with cotter pin.  Take care that cotter pin is bent in such manner that there will be no interference between cotter pin and magneto rive coupling.

10.  Magneto Drives

a.  INSPECTION

(1) Check diameter of bearings in housing and on shaft (see table of limits)

(2) Check all ball bearings for wear.

(3) Check gear teeth and shaft for wear, nicks, scoring and scratching.

(4) Check to see if oil slinger has been bent in the disassembling of the drive.

(5) Check housings for cracks.

b.  REPAIR

(1) Remove any nicks, burrs, or scratches from gear teeth by light stoning.

(2) Clean shafts with crocus cloth and kerosene.

c.  ASSEMBLY

(1) Assemble in order, the housing, oil slinger, one bearing spacer, and second bearing.  Make sure that the slinger spacer and bearing are pressed tightly into place in the housing against the shoulder of the housing.

(2) Install cotter key on shaft.

11. Gearcase Oil Pressure Regulating Valve and Screen

a.  INSPECTION

(1) Oil Pressure Regulating Valve and Screen

(a) Inspect valve seat in bushing for wear.  Replace if seat is more than 3/64" wide.  If engine had indicated low oil pressure, the bushing should be discarded regardless of the appearance.

(b) Check screen assembly for breaks in the screen.

(2) Gearcase

(a) Inspect the gearcase for condition of all finished surfaces and for cracks.

(b) Check all studs for stretching and thread damage.

(c) Check bushing diameter (See table of limits).

b.  REPAIR

(1) Gearcase

(a) Make necessary stud replacements.

(b) Remove all nicks, burrs or score marks and clean all finished surfaces with crocus cloth and kerosene.

(c) If bushing needs replacing lay the gearcase down on flat surface.  Push the bushing out using drift FA-47-B with end opposite the flange inserted in the bushing.

(d) Pull out the bushing retaining pin if it remains with the gearcase.

(e) To install new bushing, lay the gearcase down on a 2 x 4 on edge against the starter mounting flange between the studs.  Make sure gearcase is not resting on magneto brackets.  Press in new bushing.  Use the same drift, FA-47-B, with the flanged end of the drift inserted in bushing.  Be certain that holes in bushing line up with oil passages in gearcase housing.

(f) Using a #31 (.120) drill drill a hole in the flange of the bushing 11/32 deep.  Make sure this new hole is not in the same location as the old one.  Countersink hole.

(g) Drive in new retaining pin.  End of pin must be 1/32 below face of bushing.

(h) Stake retaining pin.

Note

For the reaming and spotfacing of this bushing see the section on the repair of the induction housing.  This bushing is line reamed with the bushing in the induction housing and spotfaced afterwards.

c.  ASSEMBLY

(1) Install the pressure regulator valve bushing.  Bushing must be screwed in tightly to prevent oil leakage.

(2) Install oil screens, gasket, plug and acorn nut.  Lockwire nut.

12.  Oil Pump

a.  INSPECTION

(1) Check all clearances with Table of Limits.

(2) Inspect for burrs on gears and inside walls of pump housing.

b.  REPAIR

(1) Check inside surface of pumps and if scored or nicked remove nicks and scoring with crocus sloth and kerosene.

(2) Clean the finished surfaces of housings with crocus cloth and kerosene.  Make necessary stud replacements.

(3) Stone the teeth of the gears to remove nicks and burrs.

(4) Remove all burrs, clean the bearing surface of the shafts and examine the keyways and keys.  Usually it will be necessary to hand-fit replacement keys.

(5) Remove all burrs or score marks from gear spacers.

c.  ASSEMBLY

(1) Hold pump drive shaft in a vise by the slotted end.

(2) Install front section of oil pump over drive shaft.

(3) Install Woodruff key into pump drive shaft in the pressure pump gear key slot.

(4) Install driven gear into the place opposite the keyed driving gear.

(5) Install pump plate over drive shaft and against the pump front section exercising caution that the stamped numbers on the outside of the pump front section and plate are in line; also, that the recess in the drive shaft hole of the plate is facing toward the rear of the pump; that is, toward the fuel pump drive mounting flange.

(6) install Woodruff key into drive shaft in the scavenger pump gear key slot.

(7) Install scavenger gear on drive shaft.

(8) Install small retaining ring in recess on drive shaft.

(9) Driven shaft and Scavenger Gear Assembly

(a) Install Woodruff key in driven shaft.

(b) Install scavenger gear on driven shaft.

(c) Install retaining rings in recesses on each side of scavenger gear in shaft.

(10) Install driven shaft assembly into the pump with the fuel pump drive end facing toward the rear of the pump.

(11) Install rear section over pump shafts.

(12) Remove pump from vise and install four pump housing screws.  Before tightening screws in place, check to see that there is no binding when drive shaft is rotated by hand.

(13) Install new fuel pump drive shaft seal by inserting seal pilot No. FA-179 into end of fuel pump drive shaft and then pressing seal into recess in fuel pump drive mounting pad over pilot and shaft.

(14) Remove seal pilot

(15) Install fuel pump drive substituting cover gasket and substituting cover.

(16) Secure cover in place with washers, lock washers and retaining nuts.

13.  Assembly of Oil Pump to Gearcase

a.  Place cover on a flat surface.

b.  Install pump packing ring (which has been coated on front and back sides with "Permatite" or equivalent gasket paste) in the bottom of oil pump well.

c.  Install pump gasket in proper position over the studs on the flange of the oil pump mounting pad on the gearcase.

d.  Install pump into oil pump well.

e.  Secure pump to gearcase with washers, lock washers, and retaining nuts.

14.  Oil Sump

a.  REPAIR

(1) Clean the finished surfaces of the sump with crocus cloth and kerosene.

b.  ASSEMBLY

(1) Install gaskets and screen over studs on bottom of oil sump.

(2) Install oil sump bottom cover.

(3) Assemble plain washers, lockwashers and nuts.

15.  Cylinder Assembly

a.  CYLINDER

(1) Inspection

(a) Check cylinder bore for wear, corrosion, pit marks and out of round.

(b) Check studs for tightness, straightness and damage of threads.

(c) Check finished surfaces and flanges for burrs, nicks, chafing or gall marks.

(d) Check cylinder heads for cracks and for broken, corroded or bent finds.

(e) Check cylinder barrel for dents, bent skirt or damaged fins.

(f) Check intake and exhaust valve guides for looseness in the heads, cracks, galling, scuffings or wear of valve stem bores.

(2) Repair

(a) Cylinder Barrel Grinding

Note

The cylinder head and barrel are not serviced or repaired separately.  Under no circumstances should the nuts be removed at the joint between the cylinder barrel and cylinder head and these two items separated because this is a "permanent" joint.

(1) If after inspection it seems advisable to rind the cylinder barrel oversize, the barrel should be ground and honed to .012" oversize without removing the head from the barrel.  (Refer to table of limits for nominal piston clearances in barrel).

Note

It is recommended that all cylinders in one engine be ground to the same oversize dimension in order to eliminate the possibility of an oversize piston being installed in a standard size bore or vice versa.

(2) The barrel diameter is choked where the head is shrunk onto the barrel.  When regrinding, the barrel should be ground straight.

(3) It is sometimes possible to re-barrel cylinder assemblies in which the heads are in good condition.  For this operation it is necessary that the cylinder assemblies be returned to the manufacturer.

(4) Local wear such as ring steps, or slight scores or scratches may be removed by honing, providing the clearances specified in table of limits are not exceeded.

(b) Make whatever stud replacements are necessary.

(c) Repair fins on head by profiling.  If fins are broken to root of fin the cylinder and head assembly should be replaced.

(d) Clean all finished surfaces with crocus cloth and kerosene.

(e) Valve Seat Inserts

Note

If new valve guides are to be installed in head the valve seat inserts must be ground after the new valve guides are installed.

(1) The valve seat inserts should be ground whenever they are pitted, burned or not concentric with valve guides.

(2) Use valve seat grinding Tool No. FA-257-1 or other suitable grinding tool and grind inserts to desired finish.  The least amount of material should be removed from the valve seats.

(3) If, after "truing up", the 45° seat is wider than 1/8" it should be reduced to 1/8" with 15° and 75° grinding wheels.

(f) Valve Guides

(1) If after inspection it is not necessary to replace valve guides, clean the bores with crocus cloth and kerosene.

(2) If, after inspection, it is necessary to remove valve guides proceed as follows:

a. Before removing valve guides with Tool No. FA-199 remove all burrs from the O.D. of the protruding end of guides.

b. Heat the cylinder head to approximately 400°F (205°C).

c. Install puller screw (part number FA-199-B) into intake guide from inside of cylinder.

Note

Asbestos gloves should be used for this operation.

d. Install yoke (part number FA-199-A) over screw with large dia. and resting against bottom of rocker box.

e. Install the AN325-6 nut onto the screw and with a wrench tighten the nut.

f. After tension is established in the screw, tap against the yoke with a hammer.  This will loosen the valve guide and allow its removal.

g. To remove exhaust valve guide proceed as outlined above for intake guide.

(3) After the valve guides have been removed all the head to cool to room temperature.  Check the diameter of the bore in the cylinder head and the outside diameter of the valve guide to be used as replacement.  Refer to table of limits for correct shrink fit.  If the bore in the cylinder head has not been damaged, a standard valve guide may be installed.  If the bore has been damaged, it will be necessary to ream the bore oversize and install oversize valve guides.  Oversize guides are available in .003" and .010" oversize O.D.

(4) To install valve guides use following procedure:

Note

Valve guides when installed must be cold.

a. Heat the cylinder head to a temperature of approximately 350°F (177°C).

b. Using intake valve guide assembling drift FA-52-A, install intake guide.

c. Using exhaust valve guide assembling drift, FA-52-C, install exhaust guide.

Note

It is important that each guide be driven in until the shoulder on the guide rests solidly against its seat in the cylinder head and held there until set.

d. After guides are tight remove the installing tools and allow cylinder to cool to room temperature.  Ream the valve guide to proper size.  Clean the bore with crocus cloth.

e. Reface the valve seat inserts after installing new valve guides.

b.  VALVES, SPRINGS, WASHERS AND RETAINERS

(1) Inspection

(a) Valves

1.  Check valves for wear, warping, cracks, scuffing and scratches.

2.  Since the exhaust valve is made of austenetic steel, it cannot be magnetically inspected.  Inspect valve with magnifying glass.

3.  Any valve found to be badly warped should be discarded.

4.  Inspect the retainer grooves for nicks, wear or damage, and the stem tips for cracks and excessive wear.

(b) Valve Springs

1. Inspect springs for breakage and cracks.

2. Subject the springs to a tension test in a spring tester.  Reject any spring which does not come within the limits specified in table of limits.

(c) Washers - Inspect retaining washers for wear.

(d) Retainers - Inspect retainers for wear, cracks or burrs.  Keep intake retainers in pairs.

(2) Repair

(a) Valve

1. Stone light scores and remove all burrs from the valve retainer recess.

2. If valve face is pitted or slightly warped, reface it in a standard valve facing machine.  Angle of both intake and exhaust valve faces are 45°. Remove no more metal than is absolutely necessary to true up face.

3. If, after refacing, the thickness of the valve head is less than 3/64" at the extreme diameter at any point on the periphery the valve should be checked by the etching method as following to determine if the stellite seat has been ground off:

a.  Clean the surface of the valve so that it is free and clean of oil or grease.

b. Make an etching solution the same day by mixing two parts by volume of 10% Chromic acid and one part of Hydrochloric acid.  The 10% chromic acid stock solution is made by dissolving 100 grams of chromic acid (Cr O₃) in one liter (1000 C.C.) of water.

c. The face of the valve is immersed in the etching solution at room temperature for fifteen seconds, then washed and dried.

d. Any area in which the stellite has been ground through will be darkened.

Note

Serviceable valves are not damaged by etching and may be used without further grinding.

4. Remove scores, scratches or pit marks from valve stems and tips by polishing.

5. Polish head with crocus cloth and kerosene to remove all scratches.

6. After refacing the valves must be lapped with their mating valve seat.

7. Apply a light coat of 3M oil missed lapping compound, or equivalent, on the seating face of valve to be lapped, and insert the valve in its respective guide.

Note

It is important that each guide be driven in until the shoulder on the guide rests solidly against its seat in the cylinder head and held there until set.

8.  Oscillate the valve back and forth with a twisting motion using tool No. FA-105-A from the tool kit, attached to valve stem.  This process should be continued until there is a good bearing surface and full contact around valve seat and valve face.

9.  After the lapping operation, the valves and cylinders should be cleaned thoroughly to remove all traces of grinding compound.

(b) Washers and Retainers - Stone nicks and burrs from valve spring washers and from the retainers.

(c) Rocker Arms, Rocker Arm Bearings, Shafts, Socket Lock Nuts, and Sockets

1. Inspection

a. Rocker Arms and Bearings

1.  Check the condition of the rocker arm threads at the socket end.

2. Check oil hole for being clean.

3. Inspect the outer diameter of the rollers for chipping, nicks, or flat spots.

b. Rocker Arm Shafts, Socket Lock Nuts, and Sockets

1.  Check the rocker arm shafts for nicks, cracks, wear and damaged threads.  Check the oil holes for cleanness.

2. Check the sockets for condition of the threads, cracks and socket depth wear.

3. Check the lock nuts for wear, nicks and burrs.

2.  Repair

a. Rocker Arms

1. If roller, bushing or pin requires replacement use tool No. FA-204 to remove pin, also, for swedging ends of pin after roller and bushing are replaced.

2. Place rocker arm with one end of the roller pin over hole of the drilled anvil on Tool No. FA-204.

3. Drive pin out with a small punch.

4. Remove roller and bushing.

5. Check fork for burrs and nicks.  Clean with crocus cloth.

6. Install roller, bushing and new pin.

7. Place rocker arm on Tool No. FA-204 with one en of pin resting in depression of recessed anvil.

8. Peen over end of pin.

9. Place rocker arm with peened-over end of pin on the solid anvil.

10. Peen other end of pin.

11. The fork in the arm will not be closed up by riveting as the roller hub is slightly wider than the roller.

b. Rocker Arm Shafts, Sockets and Socket Lock Nuts

1. Remove any nicks or burrs on the rocker arm shafts.

2. Remove all burrs or nicks from the screw driver slot of socket. Clean the threads if necessary. Remove all sharp edges and clean the oil hole after polishing.

3. Remove burrs or nicks from socket nuts.

3. Assembly

a. To install new rocker arm bearings, smooth the bearing recesses in the rocker arm with crocus cloth and unleaded gasoline. Do not ream recesses.

b. If bearing to be replaced was loose in rocker arm use oversize outside diameter bearings.

c. To assemble bearings to rocker arm use Tool No. FA-195 and proceed as follows:

1. Place rocker arm over pin with one of the bearing recesses resting against the base.

2. Install bearing on the rocker arm recess with the sealed end facing away from rocker arm.

3. With drift No. FA-195-B, drive bearing into rocker arm recess.

4. Reverse rocker arm on assembling stand with driven-in bearing against base.

5. Place small spacer over pin and slide down against driven-in bearing.  Do not omit the spacer from assembly.

6. Place other bearing over pin against rocker arm.

Caution

Both bearings must have their sealed ends on the outside when installed in the rocker arm recesses.

7. Drive second bearing into its recess.

8. After bearings are installed in rocker arm, check bearings for freedom of movement.

d. Install sockets and socket lock nuts into rocker arm and secure lock nut only finger tight.

c. ASSEMBLING OF CYLINDER

(1) Place valves into their respective guides.

(2) Place cylinder with valves on valve assembly stand No. FA-188.

(3) Install lower spring washers with the recess as the bottom side of the washer resting against the exhaust valve guide shoulder.

(4) Install inner and outer valve springs on exhaust valve.  Make certain that the dampener coils of the springs are against lower spring washers.

(5) Install upper spring washer.

(6) Using Spring Depression Tool No. FA-104 from the tool kit, depress springs and install into the exhaust valve retainer recess the narrow exhaust valve retainers.

(7) Remove spring depressing tool.

(8) Install intake valve parts in like procedure as was done in assembling the exhaust valve parts.

(9) Test valves for tightness as outlined below:

(a) Lay the cylinder on a bench with first the exhaust and then the intake ports facing upwards.

(b) In order to be acceptable the valves must not leak any gasoline for 1 minute.

(c) Fill each port with gasoline.

(d) Remove gasoline.

(e) If valve seating does not pass the above test the valves should be re-lapped and tested as outlined above until acceptable valve seating is obtained.

(10) Before installing the rocker arms into their respective housings place a rocker arm washer against each bearing in the rocker arm (2 per arm).

(11) Place rocker arm and washer into their proper positions and line up the group with the rocker arm shaft bores in the housings by using rocker arm shaft pilot No. FA-186.

(12) Install all the rocker arms into their boxes as outlined above.

(13) Install rocker arm washers and nuts and tighten to torque as specified in table of limits.

(14) Install rocker arm shaft cotter pins.

(15) Install all of the rocker arm sockets and locknuts with the socket screwed back, so that the socket can be screwed in to the required clearance when setting the tappets.

16. Push Rod Tubes and Intake Pipes

a. INSPECTION

(1) Check push rod tubes for cracks, burrs, dents and straightness.

(2) Check intake pipe for cracks and corrosion.

(3) Inspect the intake pipe finished surfaces for cracks, nicks and condition of finish.  Check the painted surfaces for general condition.

b.  REPAIR

(1) Straighten push rod tubes if not excessively bent.

(2) Remove push rod tube dents on a suitable mandrel.

(3) Remove any nicks or burrs from push rod with a fine file or crocus cloth.

(4) Remove all nicks, burrs and scratches from finished surfaces of intake pipe with crocus cloth.

(5) Repaint intake pipes and push rod tube as required.

17. Piston and Piston Pins

a. INSPECTION

(1) Check pistons for possible cracks, burned spots, scoring wear and general condition of all finished surfaces.

(2) Inspect piston pins for scoring, cracks and loose plugs.

b. REPAIR

(1) New rings should be installed at each overhaul.

(2) Replace old pistons which do not check within limits specified in the table of limits with new pistons.

(3) Polish all finished surfaces and piston pin bores with crocus cloth and kerosene.

(4) Clean piston pins with crocus cloth and kerosene.

(5) Check piston pins for loose plugs.

c. ASSEMBLY

(1) When installing new rings at overhaul it is important that the side and end clearances be within the limits specified in the table of limits.

(2) Check piston ring side clearance.

(3) Check ring gap with Tool No. FA-60-1 as follows:

(a) Place ring in checking fixture No. FA-60-A-1.  Hold ring in checking fixture with plate No. FA-60-B-1 and check ring gap with feeler gage.

(4) Use lapping holder No. FA-60-C-1 to lap any ring that does not have the desired clearance.

(5) Assemble rings in grooves.  They must be installed in the grooves for which they were lapped.  The two top rings must be assembled with marking "TOP" on the rings, toward the head of the piston.  The two bottom rings are tapered and must be installed with the tapered side, that is the small diameter, toward the head of the piston.

(6) Replace loose piston pin plugs.

d. OVERSIZE PISTONS AND RINGS

(1) Where is was necessary to grind the barrel oversize, it is important that the same desired clearance be maintained between the piston and barrel as with standard size pistons.

(2) Pistons and rings are available in .012" and .024" oversize.

18.  Push Rods and Rocker Arm Housing Covers

a. INSPECTION

(1) Check the rocker arm housing covers for cracks, galling of the parting surfaces and condition of the painted surfaces.

(2) Check the push rod ball ends for cracks, formation of projections due to wear, and looseness in the tube.  Check the tubes for cracks.  Do not attempt to remove the ball ends.

b. REPAIR

(1) Push rods which are bent must be discarded.  Check for straightness with "V" blocks and dial indicator.  Check the ball ends for tightness and the tubes for cracks after straightening.

(2) Clean the ball ends of the push rods with crocus cloth and kerosene.

(3) Rocker Box Covers

(a) Remove old gasket.

(b) Scrape out old sealing compound.

(c) Spread Permatex or equivalent sealing compound lightly on gasket.

(d) Set evenly in cover.

(e) Immediate install on rocker box until sealing compound is set.

Note

Care must be taken not to shift gasket when installing.

(f) Repaint covers as required.

19.  Thrust Cover and Thrust Nut

a. INSPECTION

(1) Check thrust cover for cracks.  Check finished surfaces for scratches, burrs and nicks.

(2) Check thrust cover ring in thrust cover for wear, gall marks and cracks.

(3) Examine thrust nut for marred or damaged threads.  Check for cracks and damage to wrench slots.

b. REPAIR

(1) Remove scratches, burrs and nicks from finished surfaces of thrust cover.

(2) If steel thrust ring is badly galled or grooved, the thrust cover assembly should be discarded as the ring cannot be removed without damage to cover.

20. Crankcase Front Section

a. INSPECTION

(1) Check the crankcase front section for cracks; any part of the case in which it is doubtful whether or not it is cracked should be inspected with a magnifying glass and, if necessary, etched.  The case should be most carefully inspected around the stud and bolt holes, and thrust bearing location, and at the parting surfaces.  Under no circumstances should a case that is cracked be used.  A cracked case cannot be welded.  Check the finished surfaces for scratches or nicks and high spots around the studs.

(2) Check all studs for tightness, stretch and condition of thread.

(3) Inspect the front bearing sleeve, (which is shrunk and pinned to the crankcase front section) for tightness, cracks, scoring and wear.

b. REPAIR

(1) Clean the finished surfaces of the crankcase front section.  Make whatever stud replacements are necessary.

(2) The crankcase bearing sleeve is not repairable at overhaul.  If proper limits between sleeve and standard or oversize O.D. bearings cannot be obtained due to excessive wear of the sleeve the crankcase must be returned to the manufacturer where sleeve replacement and proper line boring can be made.

21. Crankshaft and Coupling

a. INSPECTION

(1) Crankshaft for straightness.

(a) Place shaft in two "V" blocks which will support the shaft on the main bearing journals next to the crank cheeks.  Due to the difference in diameter between the front and rear ball bearing surfaces, it is necessary to shim up the rear "V" block .2058", which will bring the crankshaft in parallel with the surface plate.

(2) Rest the blocks on a surface plate in a manner which will allow the shaft to be rotated without touching the surface plate.

(a) While turning the shaft, an indicator must show not more than a total reading of .004" at the front end of the crankshaft.

(b) Inspect the crankpin for being parallel with the main journals.  This must be done in two positions, with crankpin located at the top and then with crankpin located at the right angle to first position.  In either position, the indicator must not show more than .002" variation between the two ends of the crankpin.

(3) Crankshaft Coupling and Pin

(a) Check fit of coupling in crankshaft.  Any coupling which is .002" or more loose on the diameter should be replaced as it would cause an excessive leak in the oil pressure system.

(b) Check fit of pin through crankshaft and coupling.  The pin must have a light push fit in the hole.  Do not use any pin having clearance in excess of a push fit.

(4) Examine the interior of the hollow crankpin for trapped sludge.

(5) Inspect crankshaft magnetically.

(6) Inspect crankpin fillets and bearing journal fillet for cracks.

(7) Check all threads on crankshaft and extension shaft.

(8) Inspect splines for burrs, nicks and wear.

(9) Check bearing journals for galling, scuffing and scoring.

(10) Check the oil passages.

(11) Inspect rear main bearing retaining nut for galling, nicks and damaged threads.

b. REPAIR

(1) Crankshaft must be replaced if the following conditions are present:

(a) Bent shaft.

(b) Damaged splines or threads.

(c) Severe scoring and galling.

(d) Any fatigue cracks.

(e) Damaged coupling pin holes.

(2) Crankshaft Coupling and Pin

(a) If coupling is replaced, fit to the crankshaft with .001 looseness.  Hone if necessary.

(b) If a new pin is used it must have a light push fit in hole.  Hone if necessary.  A coupling furnished for service has the hole reamed to size and no other reaming is necessary.

(3) Polish the crankpin with crocus cloth and kerosene.  Slight scratches, nicks or burrs may be removed using a fine round stone.  Use a rocking motion when stoning to avoid flat spots.  Lightly stone the crankpin fillets to remove scratches or light burrs.

(4) Stone any nicks or burrs from the splines.

(5) Any areas there slightly galled or scuffed should be smoothed with crocus cloth and kerosene.

(6) Remove any burrs from the rear main bearing journal bore.

(7) Remove any roughness or galling from the crankpin plug by light stoning or cleaning with crocus cloth and kerosene.

(8) If, after inspection, it is determined that the crankpin is worn beyond limits established in table of limits it should be ground to 1.867" plus or minus .0005.  Crankshaft with ground crankpins should be tagged so that .008" undersize master rod bearing shells will be installed at assembly of shaft and master rod.

(9) If, after inspection, it is determined that the crankpin is only slightly worn beyond the limits established in the table of limits the crankpin should be cleaned up with crocus cloth and kerosene and tagged so that .002" undersize bearing shells can be fitted to the shaft at assembly of shaft and master rod.

c.  ASSEMBLY

(1) Check spline blocking screw.  If this item has been removed install new screw in place.

(2) Clamp crankshaft in vise on the rear cheek as shown in Figure 16.

(3) Install crankpin plug in crankpin bore.  Care should be exercised that the oil holes in the plug and in the crankpin are in line.

(4) Install crankpin plug cotter pin.

(5) Install crankshaft coupling.

(6) Install coupling pin.

(7) With crankshaft clamped in vise coat rear main bearing journal with colloidal or micrographite and start rear main bearing on its journal in such a manner that the chamfered end of the inner race faces the rear crank cheek.

(8) Using a suitable hollow bearing driver approximately 16" long and having an inside diameter of 2-1/2", drive bearing onto journal until the face of the inner race is well seated against the journal shoulder.

(9) Install rear main bearing retaining nut using wrench No. FA-71-1 as shown in Figure 14.  Check to see that nut is tight against bearing.

(10) Observe and mark the hole that is in line on the retaining nut and rear main bearing thread.  Into this hole will be installed the tongue of the rear main bearing nut lock ring.

22. Cam and Magneto Drive Shaft

a. INSPECTION

(1) Check shaft and starter clutch assembly for nicks, scratches, burrs and cracks.

(2) Inspect pins through starter clutch for looseness.  This can be evidenced by observing the edges of the peening on the pins which show sharp edges not solid against the shaft when loose.  If the pins are loose to any extent, they must be replaced

b. REPAIR

(1) If starter clutch pins are to be replaced, drive out old pins with a drift.

(2) Install new pins and peen over.

(3) File pins flush with shaft.

(4) Use care in filing and do not file the diameter of the shaft just ahead of the front pin as this will damage the bearing surface.

23. Master Rod and Link Rods

a. INSPECTION

(1) Link Rod Inspection

(a) Check the link rods for cracks, nicks, burrs and condition of piston pin bushing.

(b) Check piston pin bushings for clearance with piston pin in accordance to table of limits.

(c) If it is determined that the piston pin bushings need replacement tag or label the rods with the necessary information.

(d) Check the wrist pin bore and wrist pin clearances in accordance to the table of limits.

(e) If wrist pins are loose or push fit in the link rods the wrist pins must be replaced with oversize wrist pins.  Wrist pins are available in .0005, .001, .0015 and .004 oversize.

(f) When standard wrist pins are replaced with oversize wrist pins it may be necessary to ream the wrist pin bushings in the master rod to the new oversize clearances, which will be in accordance to limits in table of limits.  If it is established that the wrist pin bushings in the master rod must be reamed, the link rods and their master rod must be tagged or labeled with the information that oversize wrist pins are to be used and that the wrist pin bushings in the master rod are to be reamed to have proper clearance with the oversize wrist pins.

(g) Check link rods for straightness before rebushing.

(2) Master Rod Inspection

(a) Check the master rod for cracks, nicks, burrs, and condition of bushings.

(b) Check all the bushings for clearances as specified in table of limits.

(c) Check the condition of the crankpin bearing bore in the master rod for burrs and nicks.

(d) Check the distance between the front and rear wrist pin bushings installed in the master rod which must be .875" minus .000" plus .002".

(e) Check all oil holes to determine if any wrist pin bushings may have become loose and rotated thus blocking the oil passage.

(3) Link Rod Bolts, Master Rod Bolts, Wrist Pins and Crankpin Bearing Shells Inspection

(a) Check all bolts for nicks, burrs, scratches, galling, condition of threads and cracks.

(b) Check wrist pins for cracks, nicks, burrs, wear and clearances in link rods and bushings in the master rods.

(c) Check the crankpin bearing shells for size using inside micrometers or other suitable instruments.  Take readings at several locations while bearing shells are clamped in the master rod.  Check for end clearances.

(d) Check bearing shells for scoring, wear, nicks, scratches, and burrs.

(e) Check oil holes in bearing shells for being clean.

b. REPAIR

(1) Link Rods

(a) To not attempt to straighten a bent rod no matter how slight the bend.  Bent rods should be discarded.

(b) Nicks, burrs and slight scratches should be removed with crocus cloth and kerosene.

(c) Clean wrist pin bore in link rod with crocus cloth and kerosene.

(d) Replace loose, worn or cracked piston pin bushings.  Piston pin bushings are available with .002 oversize O.D. and .009 undersize I.D.

(e) If a piston pin bushing must be replaced use the following procedure:

(1) Place the link rod piston pin boss into recess on stand No. FA-50-B.

(2) Install the 59/64" dia. x 7/8" long end of the drift No. FA-50-A into the bushing and press out bushing with an arbor press.

(3) Clean piston pin bushing bore in link rod boss of any score marks.

(4) Place new bushing on the 59/64" dia. x 1-3/8" long end of the drift No. FA-50-A and press into place in link rod.

(5) Using a 1/8" drill, drill two holes into the new bushing, through the oil holes in the top of the piston pin boss.

(f) After a new piston pin bushing is installed it must be reamed to size on Reaming Fixture No. FA-56-D-1 with a No. FA-56-F piston pin bushing reamer.

(1) Place the rod in reaming fixture with the numbered side facing outward and with the wrist pin bore on the pilot near the center guide pin.  Do not tighten nut until after rod is aligned.

(2) With adjustable anvil lowered away from the piston pin boss, remove burrs from oil holes and install reamer No. FA-56-F into bushing so that approximately 7/8" of the flutes on the reamer are in the bushing.

Caution

The floating block in which the adjustable anvil is located must be free enough so that when the reamer is installed in the piston pin bushing it will center itself without binding against the bushing.

(3) Tighten the nut and retaining washer on the pilot, against the wrist pin boss of the link rod.

(4) Adjust the anvil by screwing it up against the end of the piston pin boss just so that it will provide a support for that end of the rod while the bushing is being reamed.

Caution

Do not adjust the anvil against the rod so that it will spring the rod even a slight amount, because this would cause misalignment of the piston pin bushing and the wrist pin bore after the bushing has been reamed.

(5) Using cutting oil and feeding the reamer very slowly through the bushing, ream the piston pin bushing to size and check for alignment as outlined under "Inspection".

(2) Master Rod

(a) Remove nicks, burrs and slight scratches by light stoning.

(b) Remove burrs from crankpin bearing bore in master rod with crocus cloth and kerosene.

(c) Use only carbon tetrachloride to clean bushings.

(d) The bushings in the master rod are replaced only when they are loose, damaged or worn.

(e) When it is determined oversize wrist pins are to be used with link rods and if the wrist pin bushings are in good condition it is not necessary to replace the wrist pin bushings.  They should be reamed oversize if necessary.

(f) When wrist pin bushings are to be reamed to an oversize inside diameter it is important that the guide pin be used to locate the master rod in reaming fixture No. FA-56-D-1 for proper alignment.  Use applicable oversize reamers.

(g) Replacing Piston Pin Bushing

(1) Place the master rod piston pin boss into recess on stand FA-50-B.

(2) Install the 59/64" dia. x 7/8" long end of the drift No. FA-50-A into bushing and press out bushing with an arbor press.

(3) Clean the piston pin bushing bore of any score marks.

(4) Place new bushing on the 59/64" diameter x 1-3/8" long end of the drift No. FA-50-A and press into place in master rod.

(5) Using a 1/8" drill, drill two holes into the new bushing through the oil holes in the top of the piston pin bore.

(h) Replacing Wrist Pin Bushings

Note

Use Tool No FA-54 to remove and install wrist pin bushings in the master rod using the following procedure:

(1) Assemble master rod to mating cap.

(2) Place master rod on stand No. FA-54-A in arbor press.

(3) Using drift No. FA-54-B press out bushings from one side and then turn rod over and press out bushing from other side.  Bushings are pressed into and removed from the link rod space between wrist pin bushing bosses of the master rod.

(4) Clean wrist pin bushing bores in master rod with crocus cloth and kerosene before installing new bushings.

(5) Check clearances between the wrist pin bushing outside diameters and the wrist pin bushing bores in the master rod in accordance with table of limits.

Note

Sometimes it is necessary to replace a wrist pin bushing that may have become loose in the master rod and enlarged the wrist pin bushing bore in the rod.

(6) When loose bushings are being replaced, oversize wrist pin bushings should be used.  Wrist pin bushings are available with .002 oversize O.D. and .005 undersize I.D.

(7) Place master rod on stand No. FA-54-A in an arbor press.

Note

When new wrist pin bushings are pressed into the master rod, the space for the link rod boss between the two bushings must be maintained at .875" minus .000 plus .002"  This is accomplished by the use of locating block No. FA-54-C which has one end ground to .875" plus .001 minus .000 think and the other end ground .891" plus .001" thick.

(8) Place the thicker end of the locating block into the space between the wrist pin bosses and press the new bushing into its boss until it bottoms against the locating block.  Drift No. FA-54-B should be used to press in the bushing.  Proceed in the same manner until all the bushings are pressed in on one side of the master rod.

(9) Turn the rod over and place the narrower end of the locating block into the space between the wrist pin bushings in such a manner than when the second bushings are pressed in they will bottom against the locating block, thereby establishing the desired .875 plus .002" minus .000 dimension.

(10) Press in the second group of bushings using drift No. FA-54-B.  Make certain that the master rod is well seated on the stand when the bushings are being pressed in because if the master rod is not well seated, the first group of bushings will be pushed out where bottoming the second group of bushings.

(11) After the bushings are in place, separate the master rod and its cap and drill 12 oil holes into the new bushings using a 1/8" drill and drilling through the oil holes that are located in the crankpin bearing bore of the master rod and cap.

Caution

Drill through only one side of each new bushing.

(i) Reaming Piston Pin Bushing and Wrist Pin Bushings

(1) Remove the link rod wrist pin bore "pilot" from the reaming fixture No. FA-56-D-1 by unscrewing pilot nut on the back of the fixture and then tap out the pilot.

(2) Place master rod into fixture on the center guide pin.

Note

The bearing shells are not used when the master rod is placed on the center guide pin.

(3) With the adjustable anvil lowered away from the piston pin boss start the piston pin bushing reamer No. FA-56-F about 1/8" into the bushing.  This procedure will align the master rod in the fixture.

(4) Loosen the piston pin reamer slightly and then place the circular top plate over the three guide pins and tighten securely against the master rod with the slotted washer and the nut.

(5) With the piston pin reamer No. FA-56-F still in place, adjust the anvil by screwing it up against the end of the piston pin boss just so that it will provide a support for that end of the rod while the bushing is being reamed.

Caution

Do not adjust the anvil against the piston pin boss so that it will spring the rod even a slight amount because this would cause misalignment of all the bushings with each other and the crankpin bearing bore after the bushings have been reamed.

(6) Using cutting oil and feeding the reamer very slowly through the bushing, ream the piston pin bushing to size.

(7) Remove the reamer from the bushing and insert in its place the alignment pin.

(8) Read under paragraph 23 a. Inspection 1 d-e-f and before reaming wrist pin bushings determine what size wrist pins are going to be assembled to the master rod and link rods and then ream bushings accordingly, using reamer bushing No. FA-56-J and reamer collar No. FA-56-K and the desired reamer.  See below for reamer to be used:

Condition of Bushing	Wrist Pin to be used with Link Rod	Use Reamer Number
Slightly worn	.0005" oversize	FA-56-E-3
Slightly worn	.0015" oversize	FA-56-E-1
New	standard	FA-56-E

(9) After the size of the reamer is determined proceed to ream the wrist pin bushings.

(10)  After all the bushings are reamed, remove the rod from the fixture and remove any burrs that may have resulted from the reaming operation.

(11) Check rod for alignment as outlined in paragraph on Inspection (See 23-a).

(3)  Link Rod Bolts, Master Rod  Bolts, Wrist Pins and Crankpin Bearing Shells Repair

(a) Bearing shells are not repairable if they are worn, scratched, galled, scored or cracked.  Replace with new bearing shells after determining the size required by measuring the crankpin on which they will be assembled.  Bearing shell assemblies are available in .002 and .008 undersizes.

(b) If bearing shells are usable they may be lightly scraped to remove slight scratches, or scoring.  Do not clean bearing shells with any abrasive material.

(c) Clean wrist pins, master rod bolts and link rod bolts with crocus cloth and kerosene.

(d) Replace any link rod bolts and master rod bolts that are scored, cracked or have damaged threads.

c.  ASSEMBLY OF MASTER ROD AND LINK RODS

(1) Assemble master rod and cap with the four master rod bolts and their retaining nuts.  Tighten nuts on finger tight.

(2) Place master rod with the numbered side up in an arbor press and install a link rod between its corresponding wrist pin bushings.

(3) Install a small steel wedge between the lower surface of the link rod and the steel boss around the lower wrist pin bushing.  Do not put the wedge on the lower bushing because this bushing would be pushed out when the wrist pin is being installed into the link rod.

(4) Carefully press or tap the wrist pin through the wrist pin bushing and the smaller end of the link rod after "lining up" this notched in the wrist pin with the link rod bolt holes in such a manner that the link rod bolts can be easily installed into the link rods.

(5) Proceed to install the rest of the link rods and wrist pins as outlined above, at the same time being careful that the small wedge is used under each link rod when its wrist pin is being installed.

(6) If after the wrist pins are installed, the notch in the wrist pins does not properly "line up" with the link rod bolt holes use wrench No. FA-63 to turn the wrist pins the required amount so that the link rod bolts can be easily installed.

(7) Install link rod bolts, tighten retaining nuts and secure cotter pins as outlined below:

(a) Install all link rod bolts with the threaded end toward cylinder No. 1 and their cotter pin holes at 45° to the link rod.

(b) Install and tighten nuts snugly with a wrench in order to draw the head of the bolts against the link rods.

(c) Loosen the retaining nuts and then re-tighten only finger tight.

(d) Observe and note the positions of the cotter pin hole in the link rod bolt and the first and second castellations to the left of the hole.

(e) Tighten the nut from approximately 3/8 of a castellation (22-1/2 degrees) to a maximum of 1-1/4 castellation (75°).

Note

This method of tightening has been found more satisfactory than using a torque wrench which is influenced by the amount of lubrication and fit between the nut and bolt.

(f) Install cotter pin.  Be sure to bend both legs of the cotter pin as indicated because if one of the legs were bent over the bolt end an adjacent link rod may strike it.

24.  Assembly of Master Rod and Link Rods to Crankshaft

a.  Secure crankshaft in a vise by clamping on the front crank cheek with copper covered jaws.

b.  Lightly tap into place the upper and lower master rod bearing shells in their respective halves of the master rod.  The bearing shell with the offsets in the center assembles to the upper half of the master rod and the bearing shell without the offsets assembles to the master rod cap.  Check the alignment of the oil holes after the shells are installed in the master rod.

c.  Assemble the master rod to the crankpin so that the numbered side of the master rod and link rods faces the splined end of the crankshaft.

d.  Before installing the master rod bolts measure their length with a micrometer.  The dimensions will aid in determining the amount of tightening of the nuts necessary to obtain the right stretch when the bolts are secured to the master rod.

e.  Install the master rod bolts and nuts to the rod and tighten all nuts with a small wrench to take up all slack.  Then loosen one nut at a time and draw up to remove all clearance only.  Check the positions of the holes in the bolts and the slots in the nuts.  These should be in line.  If the hole and slot do not line up, remove the nut and install it on another bolt.  Proceed in this selection until all nuts and master rod bolts are matched.

f.  Next, tighten all four nuts, evenly, one castellation in order to obtain a stretch on the bolts of .003" minimum to .006" maximum.  This stretch can be measured over the entire bolt with a micrometer.

g.  Install and secure cotterpins to the master rod bolt retaining nuts.

h.  Remove crankshaft and master rod assembly from vise.

25.  Crankcase Rear Section, Cam Followers, Cam Follower Guides, Cam Ring and Cam Follower Guide Crabs

a. INSPECTION

(1) Crankcase Rear Section

(a) Check the crankcase rear section for cracks.  Any part of the case in which it is doubtful whether or not it is cracked should be inspected with a magnifying glass and, if necessary, etched.  The case should be most carefully inspected around the stud and bolt holes and at the rear main bearing sleeve location and at the parting surface.  Under no circumstances should a case that is cracked be used.  A cracked case cannot be welded.

(b) Check the finished surfaces for scratches, nicks and high spots around the studs.

(c) Check all studs for tightness, straightness, stretch and condition of thread.

(d) Check all clearances between cam follower guides and their bosses.  The cam follower guides should have a light push fit into their respective bosses.  (Refer to table of limits).

(e) Check clearances of cam ring and its bushing on the rear main bearing sleeve.  (Refer to table of limits).

(f) Check the rear main bearing and the rear main bearing sleeve for clearances as established in the table of limits.

(g) Check rear main bearing sleeve for galling, scoring and cracks.

Note

The rear main bearing sleeve must not be removed from the crankcase rear section because it is shrunk in place and then line reamed with the front main bearing and thrust bearing sleeves.

(2) Cam Ring

(a) Inspect the cam ring for wear, nicks, scratches, cracks and scoring.

(b) Check condition of teeth on cam ring gear.

(3) Cam Follower Guides, Cam Followers, Crabs and Crankcase Bolts

(a) Check cam follower guides for wear, nicks, burrs, scratches and cracks.

(b) Check cam follower guides for clearances as established in the table of limits with the crankcase rear section bosses and with the cam followers.

(c) Check cam followers for clearances as established in the table of limits.

(d) Check cam follower rollers for wear, cracks and scoring.

(e) Check cam followers for scratches, nicks, burrs, cracks and for condition of push rod socket.

(f) Check crabs for nicks, burrs and cracks.

(g) Check crankcase bolts for nicks, cracks, scoring and condition of threads.

b. REPAIR

(1) Crankcase Rear Section

(a) Clean all finished surfaces of the crankcase rear section.  Make necessary stud replacements.

(b) If oversize cam follower guides are to be installed in crankcase rear section, it may be necessary to ream cam follower guide bosses to the desired bore.

(c) Remove any nicks, burrs and scoring from rear main bearing sleeve by light stoning.

(d) If the rear main bearing sleeve is worn or cracked and needs replacement it will be necessary to send the entire crankcase to the manufacturer for replacement of bearing sleeves and proper line reaming.

Note

Oversize rear main bearings are available for slightly worn rear main bearing sleeves in .002 and .0035 oversize.

(2) Cam Ring

(a) Clean all surfaces and gear teeth by lightly stoning nicks, burrs, slight scratches and scoring.

(b) Worn cam ring should be replaced.

(c) Remove nicks, burrs, scratches or scoring from cam ring bushing by light scraping or stoning.  Do not use crocus cloth or emery cloth.

(d) Remove any nicks, burrs and scoring from cam ring bushing retainer by stoning.

(3) Cam Follower Guides, Cam Followers, Crabs, and Crankcase Bolts

(a) Clean all finished surfaces of the cam follower guides with crocus cloth and kerosene.

(b) Replace worn cam follower guides.

(c) Replace worn cam followers, rollers, sleeves or pins.  Drive out old pin and replace new roller, sleeve and pin.  Peen over ends of new pin so that the ends are within a 39/64" maximum diameter.

(d) Remove nicks, burrs, scoring and scratches from usable cam followers with crocus cloth and kerosene or light stoning.

(e) Remove nicks, burrs and galling from cam follower guide crabs with crocus cloth and kerosene or light stoning.

(f) Remove nicks, burrs and scoring from crankcase bolts using crocus cloth and kerosene.

Note

When cam follower guides are replaced with new guides the new guides should be stamped with the same letter as appears on the guide being replaced.

<< INSERT FIGURE 17, Page 62 >>

c.  ASSEMBLY OF CRANKCASE REAR SECTION

(1) Place crankcase rear section on a flat, smooth surface so that the rear of the crankcase rear section is facing upward.

(2) Install the cam ring bushing into the cam ring from the cam lobe end.

(3) Install cam ring and bushing on the rear main bearing sleeve in such a manner that the gear end of the cam ring will be to the rear and cam lobes will be to the front when cam ring is in place.

(4) Install cam ring retainer, making certain that it is well seated in the groove and slot in the rear bearing sleeve.

(5) Install the cam followers in the cam follower guides.  In each of the six guides for the lower part of the crankcase install the spring washer, flat washer, two new packing and packing nut, proceeding as follows:

(a) Install in order the spring washer, flat washer, one packing and packing nut.

(b) Tighten the nut lightly to set the first packing.

(c) Remove the packing nut and install the second packing.

(d) Reinstall the packing nut, tighten lightly to set the packing, then tighten approximately one sixth of a turn until a flat on the hex of the nut is parallel to the flat on the guide.

Caution

Do not tighten excessively as this may cause cracking of the guide.

(6) Before installing the cam follower guides check the stamped letters on the guides and the stamped letters on the crankcase to make certain that the cam follower guides are assembled in their corresponding bosses.

(7) Install gasket on each guide in addition to a small sealing ring in each of the two bottom guides.

(8) Install cam follower guides with cam followers and gaskets into their correspondingly stamped bosses.  After cam follower guides are installed make certain that the machined seats for the forked crabs are in such position that the forked crabs can be easily installed.

(9) Install cam follower guide crabs with the forked ends squarely seated on the milled shoulders of the guides.  Secure crabs in place with retaining nuts tightened with the proper torque (see table of limits) and install cotterpins.  (See Figure 18 for position of crabs).

<< INSERT FIGURE 18, Page 62 >>

(10) Install crankcase bolts, with flat washers under their heads, into their bosses in the crankcase rear section.  Do not tap the bolts completely through, only up to the front parting surface.

(11) Install induction housing to crankcase gasket to the rear face of the crankcase rear section, being very careful that the gasket is not damaged when being pushed over the studs.

26.  Induction Housing, Cam Drive Idler Shaft and Tachometer Drive Shaft

a.  INSPECTION

(1) Induction Housing

(a) Inspect the housing for cracks.  Any part of the housing in which it is doubtful whether or not it is cracked should be inspected with a magnifying glass, and, if necessary, etched.  The housing should be carefully inspected around the stud and engine mounting holes at the different bushing bosses, flanges and parting surfaces.  Under no circumstances should a housing that is cracked be used.

(b) Check the finished surfaces for scratches, burrs, nicks, galling and high spots around the studs.

(c) Check all studs for tightness, straightness, stretch and condition of thread.

(d) Check all oil passages for being clean and clear.

(e) Check all bushings for scoring, scratches, burrs and wear.

(2) Cam Drive Idler Shaft and Tachometer Drive Shaft

(a) Check gears and shafts for wear, nicks, scoring and cracks.

(b) Check all clearances and fits with table of limits.

(c) Check cork plug in tachometer drive shaft for looseness and deterioration.

(d) If gear hub has become loose on cam drive idler shaft, hub, gear and retaining bolt should be discarded.  Hub and shaft cannot be replaced separately as the retaining bolt hole is reamed at assembly.

b.  REPAIR

(1) Induction Housing

(a) Make necessary stud replacements.

(b) Clean all finished surfaces with crocus cloth and kerosene.

(c) Remove all nicks, burrs and the high spots around studs.

(d) Induction housing bushings may be cleaned by light scraping.  Care should be exercised that the scraping will not cause the bushing and gear clearances to exceed those established in the table of limits.

(2) Removing and Installing Induction Housing Bushings

(a) Cam and Magneto Drive Shaft Bushing

(1) Lay a piece of tubing approximately 2" I.D. x 2" long on an arbor press and rest the rear side of the induction housing on the tube with the bushing inside of the tube.

(2) Remove bushing by pressing out with rive FA-47-B.

(3) Pull out the 1/8 retaining pin.

(4) To insert new bushing rest the front side of the induction housing on stand FA-47-A with the bushing boss in the large counterbore of the stand.

(5) Push in new bushing with drive FA-47-B making sure oil hole is in line with the oil passage in the crankcase.

Note

When executing this operation the large shoulder of the drift must be pressing against the shoulder of the bushing.

(6) Using a #31 (.120) drill drill a hole 11/32 deep in the shoulder of the bushing.

Note

Make certain the new hole is drilled away from the old retaining pin hole.

(7) Drive in new retaining pin.  End of pin must be 1/32 below face of bushing.

(8) Stake retaining pin.

<< INSERT FIGURE 19, Page 64 >>

(b) Cam Drive Idler Gear Bushing

(1) Lay the front side of the induction housing down on an arbor press and press out bushing using drift FA-49.

(2) Pull out bushing retaining pin.

(3) Rest the rear face of the induction housing on the arbor press and press in new bushing with FA-49 making sure that the oil hole in the bushing lines up with the oil passage in the induction housing.

Note

When executing this operation the large shoulder of the drift must be pressing against the shoulder of the bushing.

(4) Using a #31 (.120) drill drill a hole 11/32 deep in the shoulder of the bushing.

Note

Make certain the new hole is drilled away from the old retaining pin hole.

(5) Drive in new retaining pin.  End of pin must be 1/32 below face of bushing.

(6) Stake retaining pin.

(c) Tachometer Drive Shaft Bushing

(1) Remove, insert bushing, and drive in new pin using the same procedure as outlined under (b) above, but using drift FA-51.  There is no oil hole to line up in this bushing.

(3) Reaming and Spotfacing Induction Housing Bushings and Gearcase Bushings

(a) Reaming Cam and Magneto Drive Shaft Bushings

(1) Assemble gearcase, induction housing, crankcase rear section and crankcase front section together as shown in Figure 20.

<< INSERT FIGURE 20, Page 64 >>

(2) Install assembly on reaming base No. FA-45-1.

Note

The cam and magneto drive shaft bushings require special reamer No. FA-55-A.  This reamer "line-reams" the cam and magneto drive shaft bushings in line with the crankcase main bearing sleeves.

(3) With crankcase set up on a bench carefully install the reamer into place through the crankcase front section as shown in Figure 21.

<< INSERT FIGURE 21, Page 65 >>

(4) Ream the cam and magneto drive shaft bushings.

Caution

So as to not cause the reamer to follow the bore in the bushing but to ream true with the centerline of the crankcase, the reamer should be fed into the bushings slowly as it is being rotated.  A slow feed of the reamer will give better reamed bushing.  Reamer must be fed clear through to the stop.

(5) After the reaming is completed, remove the reamer and the reaming stand from the crankcase, and separate the two crankcase sections, induction housing and gearcase.

(b) Reaming cam idler shaft bushing and tachometer drive shaft bushing (See Figure 20).

(1) Using FA-59-E reaming fixture, insert the pilot into the reamed cam and magneto drive shaft bushing from the rear.

(2) With FA-59-D reamer, ream through the cam drive idler shaft bushing.

Note

If tachometer drive shaft bushing is not being replaced insert reamer FA-59-C into the fixture and bushing to act as a pin for holding the fixture in place while reaming the idler shaft bushing.

(3) Insert pin FA-59-F into the reamed cam drive idler shaft bushing.  This pin keeps the fixture from rotating while reaming the next hole.

(4) With FA-59-C reamer, ream the tachometer drive shaft bushing.

(5) Remove fixture.

(c) Spotfacing cam and magneto drive shaft bushing in gearcase with gearcase tool FA-85-H spotface the flange of the bushing in the gearcase to a distance of 1.942 - 1.846" from the gearcase front mounting face to the flanged face of the bushing.  The shank of the spotfacing tool is a #2 Morse taper for use in a drill press.

(d) Spotfacing cam and magneto drive shaft bushing in the induction housing.

Note

This bushing must be spotfaced so as to allow .007 minimum end play of shaft when installed.  To obtain this, proceed as follows:

(1) Assemble induction housing, cam and magneto drive shafts, gearcase gasket and gearcase.

(2) Determine approximately by the gap between the induction housing face and gearcase face, how much must be removed from the face of the bushing.

(3) Disassemble and measure distance from the face of the flange of the bushing to the rear face of the induction housing before spotfacing.

(4) With the same spotfacing tool FA-85-H spotface the flange of the bushing down equal to the amount of the gap measured between induction housing and gearcase faces.  Check by measuring from face of bushing to rear face of induction housing.

(5) To obtain the .007 maximum clearance end of the shaft, continue to spotface slightly.

(6) Again assemble parts and insert a feeler gauge through the magneto drive opening in the gearcase between the bushing and thrust face of the shaft to determine the end play obtained.

(7) Repeat operations 5 and 6 until the desired end play is obtained.

(e) Spotfacing cam drive idler shaft bushing.  This bushing must be spotfaced down to allow .007 minimum end play of the shaft and hub.  To obtain this proceed as follows:

(1) Using spotfacing tool FA-85-G, spotface flange of bushing to a distance of 2.028 maximum from the face of the bushing flange to face of the boss on the induction housing.

(f) Spotfacing tachometer drive shaft bushing.  This bushing must be spotfaced down so as to allow .007 minimum end play of the shaft and gear.  To obtain this proceed as follows:

(1) Spotface the flange of the bushing to a distance of 1.457 maximum between the two faces of the bushing.

(4) Cam Drive Idler Shaft and Tachometer Drive Shaft

(a) Stone the teeth of gears to remove nicks and burrs.

(b) Remove all burrs and clean bearing surfaces of the shafts with kerosene and crocus cloth.

(c) If gear is loose on tachometer drive shaft or if either gear on shaft is to be replaced, assemble shaft and gear together setting them in a position so that the distance between the thrust faces is 1.464-1.466.  Line up the holes and line ream for a #0 taper pin through the hub and shaft.  The standard taper pin which was remove is #00.

c.  ASSEMBLY

(1) If the 1/8 pipe plug has been removed, re-install the plug into the primer connection at the top of the induction housing.

(2) Cam Drive Idler Gear

(a) Install the cam drive idler gear into the induction housing from the front.

(b) Install the key to the shaft.

(c) Assemble the cam drive idler gear hub and pump drive coupling to the rear end of the shaft lining up all of the holes in the flange, shaft, and coupling.

(d) Assemble the bolt through the holes and install nut and cotter pin.

(e) Check end play of the shaft with bushing.  See table of limits.

(3) Tachometer Drive Shaft

(a) Install the tachometer drive shaft into the induction housing from the rear.

(b) Assemble the tachometer drive gear on the shaft with the face of the gear against the bushing flange.

(c) Drive a new taper pin through the gear flange and spread the end of the taper pin.

(d) Check end play of gear with bushing flange.  See Table of Limits.

27.  Assembly of Crankcase Front Section And Crankshaft With Master Rod Assembly

a.  Place crankshaft and master rod assembly in an upright position on a wood or fiber block, which has a 3-1/8" diameter hole in it, in such a manner that the rear bearing rests on the block and the end of the coupling extends through the hole.

b.  Rotate the master rod assembly to approximately the same position as shown in Figure 25 and install crankshaft jack No. FA-202 between the counterweights.  Tighten crankshaft jack in position shown just enough so that the crankpin will not be sprung when the front main bearing is driven in place.

c. Coat the inner diameter of the front main bearing race and the front main bearing journal of the crankshaft with colloidal or micrographite, and install front main bearing on the crankshaft with the chamfered end of its inner race facing the front cheek of the crankshaft.

d.  Using the same bearing driver that was used to install the rear main bearing, drive front main bearing on its journal until it is well seated against the shoulder of the front crank cheek.

e.  Install bearing spacer on the crankshaft making certain that it is well seated against the inner race of the front main bearing.

f.  Next, install the thrust bearing into the sleeve in the crankcase front section.  Carefully install the crankcase front section on the crankshaft in such a manner that the master rod will protrude at the No. 1 cylinder opening and the link rods will protrude at their respective cylinder openings.

g.  With driving tube resting on thrust bearing inner race, drive until thrust bearing seats solidly against the bearing spacer.  This will force the crankcase into place over the front main bearing.

h.  Install oil slinger on crankshaft with flange rim of slinger facing toward the splined end of the shaft.

i.  Install thrust nut using wrench FA-274, if necessary, to screw down nut against the oil slinger but do not tighten more than finger tight.

j.  Install lock ring on the rear main bearing retaining nut.