1977/11/14 Caterpillar

Exhaust Valves With 30° Face Angle Now Used For Parts Service{1101,1103,1105}

Usage:

G343 Gas Engines

Description of Change: Exhaust valves with 30° face angle are now used for parts service on G343 Gas Engines instead of the former exhaust valves with 20° face angle. Also, a new cylinder head assembly with 30° angle exhaust valves is used for parts service. The new exhaust valves will prevent carbon build-up (layer that becomes thicker with time) and give longer service life than the former exhaust valves.

The 7L843 Exhaust Valve Insert is changed so it can be used with either the new or former valves. The part number of the insert did not change.

Adaptable To: To all G343 Gas Engines when the new parts are used together. The new valves can be installed in the former cylinder head assembly if the exhaust valve inserts are machined to the correct angle.

Caterpillar Information System:

1977/11/14 New Electric Starting Motor Has Longer Brush Life{1453}

1977/11/07 Precision Oil Pump Bearings Now Available{1304}

1977/11/07 Improved Crankshaft Main Bearings And Connecting Rod Bearings With Higher Strength Aluminum Alloy{1203,1219,1230}

1977/11/07 Crankshaft Support Groups Are Available To Measure Bent Crankshafts{0653,1202}

1977/10/31 Some Wobble Is Acceptable In Rubber Vibration Dampers For Crankshafts{1205}

1977/10/31 With New 5P7448 Adapter, Earlier Fuel Injection Valves And Nozzles Can Be Tested And Adjusted On The 5P4150 Nozzle Testing Group{0651,1254}

1977/10/31 New Governor Spring Changes Speed Regulation{1264,1286}

1977/10/31 New Hydraulic Flow Meter Has Many Improvements To Make It Easier, Faster And Safer To Use Than The Former Flow Meter{0651,5050}

1977/10/24 Replacement Bearings Have Aluminum Alloy With More Strength{1203,1213,1230}

1977/10/24 New Piston Group Has Improved Iron Band In The Piston Body{1214}

1977/10/24 Adjust Shop Tire Pressures For Operation In Cold Temperatures{4203,4204}

1977/10/24 Assembly Procedure For The 5P4721 Tube (Part Of The 5P4149 Conversion Group And 5P4150 Nozzle Testing Group){0650}

1977/11/14 New Exhaust Manifolds Made Of Stronger Material{1059}

1977/11/21 New Elbow Between Turbocharger And Air Inlet Manifold Has Hole For Ether Starting Aid{1058,1456}

1977/11/21 New Crankshafts Do Not Have Lightening Holes And Lubrication Passages Connected Together{1202,1219}

1977/11/21 Larger Diameter Holes Are Now Used In The Rocker Arm Shaft To Give More Oil Flow To Rocker Arm Bearings{1102}

1977/11/21 Improved Shaft Seal Material Used In All Vane-Type Hydraulic Pumps; Seal Kits Are Canceled{5055}

1977/11/21 New Housing And Impeller Assembly For Water Pump And Drive Group{1361}

1977/11/21 Add Chamfer To Cartridge Assembly Bearings To Prevent Oil Leakage{1052,1053}

1977/11/28 Reference Chart For Main And Connecting Rod Bearings{1203,1219,1230}

1977/12/05 Water Separators Needed On Machines And Engines In The Field With SMFS{1250,0336}

1977/12/05 New Oil Filter Base Has Reinforcement Around The Center To Prevent Possible Cracks{1306}

1977/12/05 Use The 5P8610 Auxiliary Fitting Group To Charge Two Suspension Cylinders At The Same Time{0690,7201}

1977/12/05 New Fuel Injection Valve Assembly Has Improved Internal Components{1254}