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General Motors 5.7L V8 (350 CID) Engine

The General Motors 5.7L V8 (350 CID) is a 5.7 L 8-cylinder engine. It powers generator sets from KEM, including the GMG-857.

Also known as: General Motors (GM) 5.7L V8 (350 CID)

Part of the General Motors 5.7L engine family — 3 variants share parts & fitment.

5.7 L
Displacement
8
Cylinders

Engine specifications

Displacement5.7 L
Cylinders8

Generator sets powered by this engine

1

Common problems

2
  • Gas carburetion issues
    Fix: Measure gas inlet pressures at idle and full load with a water manometer. If pressure is correct, inspect diaphragm for holes or charring. Check air valve cup and gas jet for wear. Wash parts thoroughly in kerosene or detergent if needed. Reassemble and check for leaks.
  • Engine speed should be around 650 RPM
    Cause: Connecting alligator clip on long lead of initial timing connector to B+ voltage source
    Fix: Loosen distributor clamp screw and set base timing to specification

Compiled from service & troubleshooting documentation across every generator set that uses the General Motors 5.7L V8 (350 CID).

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filter—
Fuel filter—500 hr
Oil filter—125 hr
Coolant—500 hr
Oil—250 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

7
ItemActionHoursMonthsNotes
Oil and filterChange125 hr3 moGMC: change oil and filter every 125 hours or 3 months, whichever comes first
Oil filter elementReplace125 hrElement cannot be washed and reused
Engine oilChange250 hrFirst service — Replace after the first 60 hours and every 250 hours thereafter
CoolantReplace500 hrClean system before and after use of antifreeze
Fuel filter elementReplace500 hrBleed fuel system after installation
Cylinder head, manifold & mounting bracket installationCheckFirst service — Applicable to new engines only
Valve clearanceAdjustFirst service — New engines only

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

23
TypeItemValueUnitCondition
ClearanceMaximum allowable engine operating angle, front of engine down8.5degreeslubrication system
ClearanceMaximum allowable engine operating angle, rear of engine down18degreeslubrication system
ClearanceMaximum allowable engine operating angle, side to side20degreeslubrication system
GapSpark plug gap.025indual fuel engines
GapSpark plug gap.045ingasoline engines
GapSpark plug gapnot over .030ingas fuel
Injection timingInitial / total ignition timing0 / 20degreesIndustrial 181
Injection timingInitial / total ignition timing2 / 26degreesIndustrial 262
Injection timingInitial / total ignition timing6 / 28degreesIndustrial 350
Injection timingInitial / total ignition timing6 / 30degreesIndustrial 454
PressureOil pressure20 to 50PSI
ResistanceActuator resistance A to B (ACB225/ADB225)2.5ohms
ResistanceActuator resistance C to D (ACB225/ADB225)2.5ohms
ResistanceActuator resistance Red to White (ADC225)1.25ohms12V
ResistanceActuator resistance Red to White (ADC225)5.0ohms24V
SpeedElectronic governor factory set speedapproximately engine idle speed (1000 Hz Speed Sensor Signal)
SpeedEngine speed with initial timing connector connected to B+650RPM
SpeedIdle speed700RPM+/- 50 RPM
TemperatureCoolant temperature160-195°Fthermostat regulated
TemperatureOil temperature ideal running221°Fideal running temperature
TemperatureOil temperature lower limit176°Flower limit
TemperatureOil temperature upper limit266°Fupper limit
VoltageVolt meter12 - 15volts

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
Coolantsoft water with low impurity contentUse anti-corrosive in hot weather and anti-freeze in cold weather; use permanent type anti-freeze
Engine oilAPI-SHGMC requirements: SAE 30 for above 40°F; SAE 15W40 for above 0°F; SAE 10W30 for all temperatures
Engine oilAPI CD or higher, SAE 10W-30-30°C to 40°CSevere operating conditions or engine with turbocharger, 40 to -30°C
Engine oilAPI CC or higher, SAE 40above 40°CNormal operating conditions, 40°C or above
Gear oilAPI GL-3 SAE 80
GreaseMIL-G-3545BClutch shifter grease
GreaseMultipurpose type grease NGLI No. 2
OtherSAE J1703Brake fluid

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

10
Electronic Governor Performance Adjustment adjustment

⚠ To be performed by qualified personnel only.

  1. Check GAIN and STABILITY controls, and external SPEED TRIM control, are set to mid-position.
  2. Crank the engine with D.C. battery power applied to the governor system.
  3. If engine is unstable after starting, turn GAIN and STABILITY counterclockwise until stable.
  4. Rotate the GAIN adjustment clockwise until instability develops, then counterclockwise until stability returns, then 1/8 turn counterclockwise.
  5. Rotate the STABILITY adjustment clockwise until instability develops, then counterclockwise until stability returns, then 1/8 turn counterclockwise.
  6. Adjust dead time compensation using posts E1, E2, E3 as required.
High Energy Ignition (HEI) Distributor Timing adjustment

⚠ Connecting the initial timing connector to B+ before starting may damage the ignition control module (ICM).

Tools: timing light with inductive pick-up

  1. Do not use a timing light that requires piercing of the secondary insulation; use inductive pick-up or jumper type.
  2. Install timing light at #1 spark plug lead per manufacturer's instructions.
  3. Do not connect the alligator clip of the initial timing connector to a B+ source until after the engine is started.
  4. Start the engine and warm to operating temperature.
  5. Connect alligator clip on long lead of the initial timing connector to a convenient B+ source to remove all advance.
  6. Loosen distributor clamp screw just enough to rotate distributor and set base timing to specification.
  7. Secure distributor with clamp screw and tighten clamp screw to torque specified.
  8. Recheck timing and disconnect the initial timing connector from B+ source.
  9. Label the initial timing connector by folding the adhesive label over one of the wires.
Velocity Governor Sensitivity Adjustment adjustment

⚠ Only in rare instances should the sensitivity adjustment be changed.

  1. Remove the plug covering the sensitivity adjusting screw by drilling a 1/8 diameter hole and prying it out.
  2. If engine is too sensitive, turn the SENSITIVITY SCREW 1/4 turn clockwise and readjust the MAIN ADJUSTMENT.
  3. End each adjustment with a clockwise turn of the screw; repeat as needed.
  4. If engine speed drops excessively when loaded, turn SENSITIVITY SCREW 1/2 turn counter-clockwise, then 1/4 turn clockwise.
  5. Readjust MAIN ADJUSTMENT and repeat as needed.
  6. Seal the adjusting screws using HOOF SEAL KIT 200-940 or force silicone sealer into the cavity.
225 Series Electronic Actuator Installation installation

⚠ The actuator must be rigidly mounted as close as possible to the engine throttle lever.

  1. Drill the actuator mounting holes in a pre-fabricated mounting bracket.
  2. Affix the actuator bracket to the selected location on the engine.
  3. Attach the actuator securely to the mounting bracket.
  4. Adjust and secure the linkage rod and rod end bearings.
  5. Fabricate a cable harness to connect the speed control unit to the actuator.
  6. Connect A and D of the military connector or the 2 pin connector harness to the speed control unit.
  7. Push the actuator lever to the maximum full fuel position and verify smooth return to minimum fuel.
Carburetor Air-Gas Valve Inspection and Cleaning maintenance

⚠ Do not attempt to measure gas pressure with a mercury manometer.

Tools: water manometer

  1. Measure gas inlet pressures at idle and full load with a water manometer.
  2. Remove the air valve cover and lift out the spring and air-gas valve with diaphragm.
  3. Inspect diaphragm for holes, charring or stiffness.
  4. Check inside diameter of the air valve cup and fins of the gas jet for wear.
  5. Inspect the inside diameter of the gas jet and O.D. of the small tapered gas valve for wear.
  6. Wash all parts thoroughly in kerosene or equivalent (water and detergent for digester gas).
  7. Reassemble cleaned or replaced parts in the bowl, centering the spring on the air valve.
  8. Replace and fasten the cover; lift valve several times to assure free travel.
Cyclone Type Air Cleaner Element Service maintenance

⚠ If left loose, dust will be drawn in and the air cleaner will fail to function properly.

  1. Remove the dust cup and withdraw the element.
  2. On double element type, do not remove the inner element when cleaning the outer element.
  3. Remove inner element only when the outer element is replaced; replace both at the same time.
  4. Clean the inside of the case and dust cup before installation.
  5. Slowly insert the element; if horizontal, install dust cup with direction mark face upward.
  6. Ensure element and dust cup are securely installed.
Fuel Filter Element Replacement maintenance

⚠ The element cannot be washed and reused.

⚠ Wipe away spilt fuel as it could start a fire.

  1. Remove the element, using care not to spill fuel.
  2. Install the new element.
  3. Bleed the fuel system and check for fuel leaks.
Oil Filter Element Replacement maintenance

⚠ The element cannot be washed and reused.

Tools: filter wrench

  1. Remove the element by turning counterclockwise; use a filter wrench if hard to loosen.
  2. Apply a thin coat of engine oil to the packing of the new element.
  3. Tighten the element fully with a filter wrench.
  4. If only the element was replaced, replenish oil to proper level.
  5. Wipe away spilt oil, start the engine and check for leaks from the packing.
Replace Coolant and Clean System maintenance

⚠ Use soft water; well or river water may cause scaling or rusting.

  1. Open the radiator cap and drain cocks of engine crankcase and radiator to remove coolant.
  2. Close drain cocks, pour coolant into radiator, run engine until coolant is heated to about 80°C.
  3. If considerable scale or rust, pour in cleaning solution and heat to about 80°C.
  4. Continue to idle the engine for about 30 minutes.
  5. Stop engine, open drain cocks and drain coolant completely.
  6. Close cocks, pour in coolant and rinse until dirty water no longer runs out.
  7. Fill until coolant flows out from the overflow pipe.
  8. Run engine, stop, check and replenish coolant level.
Replace Engine Oil maintenance

⚠ A badly contaminated or deteriorated oil should be replaced regardless of the replacement intervals.

  1. After shutdown, remove the oil while it is still hot; replace the oil filter at the same time.
  2. Install the drain plug and pour in fresh engine oil up to the FULL mark on the level gauge.
  3. After running the engine at idle for several minutes, recheck the oil level.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Parts cataloged across the General Motors 5.7L family

39
Part #DescriptionCategory
K032049ALTERNATOR, 12V 51 amp MANDOAlternator
1989880BRUSH, DISTR CAP (AC-Delco #1989880)Brush
10046089GASKET, VLV RKR ARM CVRGasket
10105135GASKET, WAT OTLTGasket
10108445GASKET, DISTR (AC-DELCO #10108445)Gasket
12550283EXHAUST FLANGE GASKET 5.7 IND.Gasket
125524695.7L EXH. MFLD. GASKETGasket
12553106GASKET, WAT OTLT (PART OF 69) (1.252) (AC-Delco #12553106)Gasket
14091870VALVE COVER GROMMETGasket
3754587GASKET, W/PMPGasket
KM21555.7L INTAKE GASKETSGasket
3952301OIL FILTER ADAPTOROil filter
6438261FILTER, OIL (AC-Delco PF25)Oil filter
PF25OIL FILTEROil filter
1103799COIL ASSY. 5.7/7.4 TBIService part / kit
1104067DISTRIBUTOR (INCL 1-21, 75) (AC-Delco #1104067)Service part / kit
1106010PLUG WIRE SET 5.7 & 7.4 IND.Service part / kit
12388069CLUTCH KIT, ENG (W/PRESS PLT & DRVN PLT) (AC-Delco)Service part / kit
12550034V8 DELCO EST DISTRIBUTORService part / kit
25095452VALVE, PCV (CV895C, 1 VACUUM PORT) (AC-Delco #CV895C)Service part / kit
6487532VALVE, PCV (AC-Delco #CV769C)Service part / kit
12529508PUMP KIT, WAT (AC-Delco #251-568)Pump
12529560PUMP KIT, WAT (AC-Delco #251-537)Pump
12532528PUMP KIT, WAT (AC-Delco #251-579)Pump
12555283PUMP, OIL (.742 DIA. TUBE)Pump
12555284PUMP, OIL (.620 DIA. TUBE)Pump
10088158SEAL, CR/SHF RR OIL (PART OF 43) (NORMAL ROTATION)Seal
10228655SEAL, CR/SHF FRT OIL (68MM OD W/PART NUMBER STAMPING)Seal
10243247SEAL, CR/SHF FRT OILSeal
1950569SEAL, DISTR HSG OIL (O RING) (AC-Delco #A05069)Seal
1052040Teflon sealer (for knock sensor installed in water jacket)Sensor
25036979SENSOR, ENG COOL TEMP (2 BLADE TERM) (AC-Delco #213-72)Sensor
25162556SPARK PLUG (41-932) (AC-Delco #41-932)Spark plug
5613438SPARK PLUG (AC-DELCO #MR43T)Spark plug
5613689SPARK PLUG (AC-Delco #MR44T)Spark plug
5614210SPARK PLUG (AC-Delco #MR43LTS)Spark plug
10202456THERMOSTAT, ENG COOLThermostat
10207381THERMOSTAT, ENG COOL (AC-Delco #131-75)Thermostat
12555290THERMOSTAT, ENG COOL (180 DEG) (AC-Delco #131-100)Thermostat

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Common questions

What is the displacement of the General Motors 5.7L V8 (350 CID)?

The General Motors 5.7L V8 (350 CID) has a displacement of 5.7 liters with 8 cylinders.

Which generators use the General Motors 5.7L V8 (350 CID) engine?

The General Motors 5.7L V8 (350 CID) powers 1 generator set(s), including KEM GMG-857.

How often should you change the oil in the General Motors 5.7L V8 (350 CID)?

The General Motors 5.7L V8 (350 CID) oil change interval is every 250 hours.

What is a common problem with the General Motors 5.7L V8 (350 CID) engine?

A commonly reported issue on generators using the General Motors 5.7L V8 (350 CID) is: Gas carburetion issues. Fix: Measure gas inlet pressures at idle and full load with a water manometer. If pressure is correct, inspect diaphragm for holes or charring. Check air valve cup and gas jet for wear. Wash parts thoroughly in kerosene or detergent if needed. Reassemble and check for leaks..