Home›Engines›Ford 6.8L

Ford 6.8L Engine

The Ford 6.8L is a 6.8 L 10-cylinder engine. It powers generator sets from Kohler, including the 125REZG.

Also known as: Ford 6.8L

Part of the Ford 6.8L engine family — 3 variants share parts & fitment.

6.8 L

Displacement

Cylinders

On this pageSpecs Generator sets Maintenance FAQ Torque & specs Fluids Procedures Wiring

Engine specifications

Displacement	6.8 L
Cylinders	10

Generator sets powered by this engine

Kohler 125REZG

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter			—	400 hr
Fuel filter			—	200 hr
Oil filter			120105	500 hr	Amazon eBay
Battery	Grp 24, Qty 1		—
Belt			—	400 hr
Coolant	-22F	10.0 L	—
Oil		5.68 L	—	500 hr
Spark plug			AGSF-22F-M1	800 hr	Amazon eBay $4.99

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

Service specifications

Type	Item	Value	Unit	Condition
Other	10 in. weld flange bolt circle diameter B	361.95	mm (14.25 in.)
Other	10 in. weld flange outside diameter C	406.4	mm (16.0 in.)
Other	10 in. weld flange quantity of bolts / bolt hole diameter D	12, 25.40	mm (1.00 in.)
Other	12 in. weld flange bolt circle diameter B	431.80	mm (17.00 in.)
Other	12 in. weld flange outside diameter C	482.6	mm (19.0 in.)
Other	12 in. weld flange quantity of bolts / bolt hole diameter D	12, 25.40	mm (1.00 in.)
Other	14 in. weld flange bolt circle diameter B	476.25	mm (18.75 in.)
Other	14 in. weld flange outside diameter C	533.4	mm (21.0 in.)
Other	14 in. weld flange quantity of bolts / bolt hole diameter D	12, 28.58	mm (1.13 in.)
Other	16 in. weld flange bolt circle diameter B	539.75	mm (21.25 in.)
Other	16 in. weld flange outside diameter C	596.9	mm (23.5 in.)
Other	16 in. weld flange quantity of bolts / bolt hole diameter D	16, 28.58	mm (1.13 in.)
Other	18 in. weld flange bolt circle diameter B	577.85	mm (22.75 in.)
Other	18 in. weld flange outside diameter C	635.0	mm (25.0 in.)
Other	18 in. weld flange quantity of bolts / bolt hole diameter D	16, 31.75	mm (1.25 in.)
Other	20 in. weld flange bolt circle diameter B	635.00	mm (25.00 in.)
Other	20 in. weld flange outside diameter C	698.5	mm (27.5 in.)
Other	20 in. weld flange quantity of bolts / bolt hole diameter D	20, 31.75	mm (1.25 in.)
Other	5 in. weld flange bolt circle diameter B	215.90	mm (8.50 in.)
Other	5 in. weld flange outside diameter C	241.30	mm (9.50 in.)
Other	5 in. weld flange quantity of bolts / bolt hole diameter D	8, 22.23	mm (0.88 in.)
Other	6 in. weld flange bolt circle diameter B	254.0	mm (10.0 in.)
Other	6 in. weld flange outside diameter C	279.4	mm (11.0 in.)
Other	6 in. weld flange quantity of bolts / bolt hole diameter D	8, 22.23	mm (0.88 in.)
Other	8 in. weld flange bolt circle diameter B	298.45	mm (11.75 in.)
Other	8 in. weld flange outside diameter C	342.9	mm (13.5 in.)
Other	8 in. weld flange quantity of bolts / bolt hole diameter D	8, 22.23	mm (0.88 in.)
Other	Weld flange angle A (10, 12, 14 in. nominal pipe size)	30	deg.
Other	Weld flange angle A (16, 18, 20 in. nominal pipe size)	22.5	deg.
Other	Weld flange angle A (5, 6, 8 in. nominal pipe size)	45	deg.
Pressure	LPG vapor withdrawal fuel supply pressure	1.24--2.74	kPa
Pressure	Maximum allowable back pressure	10.2	kPa	exhaust
Pressure	Natural gas fuel supply pressure	1.74--2.74	kPa
Speed	Rated rpm	1800	rpm	60 Hz
Temperature	Ambient temperature	50	C	radiator system
Torque	1-12 fastener	283.0 (209)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	1-8 fastener	259.0 (191)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	1/2-13 fastener	60.0 (44)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	1/2-20 fastener	66.0 (49)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	1/4-20 fastener	6.8 (60)	Nm (in. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	1/4-28 fastener	8.1 (72)	Nm (in. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	10-24 fastener	2.9 (26)	Nm (in. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	10-32 fastener	2.9 (26)	Nm (in. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	3/4-10 fastener	199.0 (147)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	3/4-16 fastener	222.0 (164)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	3/8-16 fastener	24.0 (18)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	3/8-24 fastener	27.0 (20)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	5/16-18 fastener	13.6 (120)	Nm (in. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	5/16-24 fastener	14.9 (132)	Nm (in. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	5/8-11 fastener	113.0 (83)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	5/8-18 fastener	128.0 (94)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	7/16-14 fastener	39.0 (29)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	7/16-20 fastener	43.0 (32)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	8-32 fastener	1.8 (16)	Nm (in. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	9/16-12 fastener	81.0 (60)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	9/16-18 fastener	91.0 (67)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 2 or 5
Torque	M10 x 1.25 fastener	31.0 (23)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 5.8 or 8.8
Torque	M10 x 1.50 fastener	30.0 (22)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 5.8 or 8.8
Torque	M12 x 1.50 fastener	56.0 (41)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 5.8 or 8.8
Torque	M12 x 1.75 fastener	53.0 (39)	Nm (ft. lb.)	Assembled into cast iron or steel, Grade 5.8 or 8.8

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

Fluid	Grade	Standard	Ambient	Capacity	Notes
Fuel	LP Gas	Propane 85% min, Propene 5.0% max, C4 and higher 2.5% max, LHV 67.5 MJ/m3 min			LPG vapor withdrawal fuel supply pressure 1.24--2.74 kPa (5-11 in. H2O); dual fuel LPG pressure 1.24 kPa (5 in. H2O)
Fuel	Natural Gas	Methane 90% min, Ethane 4.0% max, Propane 1.0% max, Propene 0.1% max, C4 and higher 0.3% max, Sulfur 25 ppm max, LHV 26.6 MJ/m3 min			Fuel supply pressure 1.74--2.74 kPa (7-11 in. H2O)

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

Procedures

Common Hardware Application installation

Determine entry hole type: round or slotted.
Determine exit hole type: fixed female thread (weld nut), round, or slotted.
For round and slotted exit holes, determine if hardware is greater than 1/2 inch in diameter.
Hardware greater than 1/2 inch in diameter uses a standard nut and SAE washer.
Hardware 1/2 inch or less in diameter can use a properly torqued whiz nut or spiralock nut.
Always use a washer between hardware and a slot.
Always use a washer under a nut.
Use a washer under a bolt when the female thread is fixed (weld nut).

How to Find Part Numbers operation

Locate the generator set nameplate to identify the generator set spec number.
Locate the second nameplate listing accessories to identify installed modules; on some models it is inside the junction box.
Turn to the Specification Number Index; the first column lists generator set spec numbers.
Identify the group most likely to include the service part number.
Find the group variation number at the intersection of the spec number row and group column.
Page forward to locate that group or find the page in the Table of Contents.
Find the part on the illustration and note the item number, or find the part description in the parts list.
Select the part number that corresponds to your group variation using the column on the right side of the parts list table.

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

Voltage reconnection

Voltage	Phase	Connection	Leads	Notes
		12-Lead		Alternator Reconnections diagram ADV-5875B-M (page 16)
		4-Lead		Alternator Reconnections diagram ADV-5875A-M (page 15)
110-120/220-240	1	4 lead	4	4V11 alternator
Various	3	12 lead reconnectable	12	4S11 and 4S13 alternators

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 Ford 6.8L family

157

Part #	Description	Category
10019453	CLEANER,AIR,FORD PROPANE,CV	air_filter
10019950	ELEMENT,AIR CLEANER,FORD	air_filter
10025981	ELEMENT,AIR CLEANER,EXTERNAL,FORD	air_filter
10042727	CLEANER,AIR,2016 FORD BBCV	air_filter
10049894	ELEMENT,AIR CLEANER,FORD,GEN 4	air_filter
0A1232	D.C. ALTERNATOR ASSY	alternator
0D3488	BELT SERPENTINE (67.16" LG) (3000 RPM)	belt
0D3488A	BELT SERPENTINE 70"	belt
0D8030	TENSIONER ENG. AUTOMATIC BELT	belt
10023178	BELT,ENGINE,WITH A-C,FORD 6.8L	belt
10042725	BELT,DRIVE,FORD 6.8L,2016,1ST SHEAVE,NO A-C,CV	belt
P11BB-8620-BA	BELT,ENGINE,WITHOUT A-C,FORD 6.8L 10023179	belt
P16BB-8620-AA	BELT, MAIN SHEAVE FULL CONTENT	belt
10023471	FILTER ASSY,PROPANE,ROUSH,FILL INLINE,CV	fuel_filter
10028883	FILTER,FUEL,IN-LINE,ROUSH PROPANE	fuel_filter
10052665	ELEMENT,FILTER,CNG,FFC110L	fuel_filter
P-10S200-AA	FUEL FILTER, IN-LINE, 1 UM	fuel_filter
P14BB-FLTRFILL-AA	FUEL FILL - FILTER ASSEMBLY, BLUEBIRD	fuel_filter
0A6765	RING GASKET 2.5 DIA	gasket
0C9785	GASKET POWER FLOW 50 & 60 ADAPTOR	gasket
0D2698	GASKET ADAPTER THROT BODY	gasket
0D34540151	GASKET, OIL PAN	gasket
0D34540154	GASKET, OIL FILTER ADAPTER	gasket
0D34540170	GASKET, CYLINDER HEAD, RH	gasket
0D34540171	GASKET, CYLINDER HEAD, LH	gasket
0D34540202	SILICONE GASKET & SEALANT	gasket
0D34540206	GASKET, FRONT COVER, LH	gasket
0D34540207	GASKET, FRONT COVER, CENTER	gasket
0D34540208	GASKET, FRONT COVER, RH	gasket
0D34540233	GASKET, WATER PUMP	gasket
0D34540247	GASKET, INTAKE MANIFOLD TO CYLINDER HEAD	gasket
0D4255	GASKET EXHAUST MANIFOLD	gasket
10017551	GASKET,BASE,COMPRESSOR,GM 8.1 PROPANE	gasket
10040975	GASKET,ADAPTER,OIL FILTER.6.8L,FORD	gasket
10042103	GASKET,FUEL SENDER,GAS,FORD	gasket
10045899	GASKET,MANIFOLD,EXHAUST,3 PORT,6.8L	gasket
10045900	GASKET,MANIFOLD,EXHAUST,2 PORT,6.8L	gasket
10049308	GASKET,OIL,PAN,FORD	gasket
10049309	GASKET,TUBE,COOLANT,LH, FORD	gasket
10049310	GASKET,TUBE,COOLANT,RH,FORD	gasket
10049866	GASKET,HEAD,CYLINDER,LH,6.8L,FORD	gasket
10049867	GASKET,HEAD,CYLINDER,RH,6.8L,FORD	gasket
10049868	GASKET,VALVE COVER,RH,6.8L,FORD	gasket
10049869	GASKET,VALVE COVER,LH,6.8L,FORD	gasket
10049871	GASKET,COVER,FRONT,LH,6.8L,FORD	gasket
10049872	GASKET,COVER,FRONT,RH,6.8L,FORD	gasket
10049873	GASKET,COVER,FRONT,CENTER,6.8L,FORD	gasket
10050283	GASKET,VALVE COVER,RH,GEN 4,6.8L,FORD	gasket
10050284	GASKET,VALVE COVER,LH,GEN 4.6.8L,FORD	gasket
10054880	GASKET,MANIFOLD,INTAKE (10 REQUIRED)	gasket
10057220	GASKET,OIL,RH,ACCESSORY COVER,ENGINE	gasket
10057433	KIT,GASKET,TOP END,6.8L,WITH PLASTIC CAM COVERS	gasket
10057434	KIT,GASKET,BOTTOM END,FORD 6.8L	gasket
10057491	GASKET,OIL,LH PLATE,FRT OF CYL HEAD,6.8L	gasket
10057700	GASKET,COOLANT TUBE,RH,FORD 6.8L	gasket
10057701	GASKET,COOLANT TUBE,LH,FORD 6.8L	gasket
047290	HOSE 3/8 ID SINGLE BRAID (16” LG)	hose
050968	HOSE COOL 3/4 ID 20R3 (22" LG)	hose
083982	HOSE 3/8 ID 100R6 OIL LINE	hose
0A6283	HOSE PREFORMED BLOCK HEATER	hose
0D34540236	TUBE-WATER	hose
10020922	HOSE ASSY,VENT,ROUSH ENGINE	hose
10020936	TUBE,SUPPLY,ROUSH PROPANE,TANK TO BLKHD	hose
10020937	TUBE,RETURN,ROUSH PROPANE,TANK TO BLKHD	hose
10020943	HOSE ASSY,SUPPLY,FUEL RAIL,ROUSH PROPANE	hose
10020944	HOSE ASSY,RETURN,FUEL RAIL,ROUSH PROPANE	hose
10022860	HOSE ASSY,PROPANE,FRWD FUEL LINE FEED,ROUSH,CV	hose
10022862	HOSE ASSY,PROPANE,FRWD FUEL LINE RETURN,ROUSH,CV	hose
10023439	HOSE,PRESSURE,RELIEF,ROUSH PROPANE	hose
10028872	FUEL RETURN CIRCUIT ASSEMBLY,ROUSH PROPANE	hose
10043121	HOSE ASSY,FUEL/VPR VENT	hose
10043124	HOSE ASSY,FUEL/VPR RETURN,GASOLINE	hose
10053703	FUEL FILL LINE,STR	hose
10053704	FUEL HOSE,REMOTE 9	hose
10053706	FUEL,RETURN,LINE AS	hose
10053707	FUEL,SUPPLY,LINE AS	hose
10057699	TUBE,COOLANT,BY-PASS,FORD 6.8L	hose
P-10D121-C-367	FUEL FILL LINE, 90 X STRAIGHT	hose
P-10D121-C-436	FUEL FILL LINE, 90 X STRAIGHT	hose
P-10D122-C-963	FUEL FILL LINE, STRAIGHT X STRAIGHT	hose
P-10D124-C-1766	RBO - FUEL FILL LINE, 45 X STRAIGHT	hose
P-10G110-A-3962	HOSE, PRESSURE RELIEF 1" ID	hose
P-10G217-C-2846	10019624 HOSE ASSY PROPANE BLEED LINE ROUSH	hose
P-10R100-C-7680	RBO (G3) - PT - 273 WB FUEL RETURN LINE, 1/4" FLEXIBLE	hose
P-10S100-C-7665	RBO (G3) - PT - 273 WB FUEL SUPPLY LINE, 3/8" FLEXIBLE	hose
P-10S100-C-7861	RBO (G3) - PT - 280 WB FUEL SUPPLY LINE, 3/8" FLEXIBLE	hose
P-10S400-A-6223	INTERMEDIATE SUPPLY LINE - 238 WB	hose
P11BB-6758-AB	HOSE, PCV CLOSURE	hose
P11BB-6A836-AD	OIL RETURN LINE, AIR PUMP	hose
P11BB-6K817-AB	HOSE, CRANKCASE VENT	hose
P11BB-9D676-AD	PT - HOSE ASSY, CANISTER PURGE LINE	hose
P11BB-HOSEKIT-AA	HOSE KIT, BLUEBIRD	hose
P16BB-2B878-AB	OIL FEED LINE, AIR PUMP	hose
10028688	INJECTOR,FUEL,DEKA II,ROUSH PROPANE	injector
P11BB-9F899LH-AE	FUEL INJECTOR RAIL SYSTEM - LH	injector
P11BB-9F899RH-AF	FUEL INJECTOR RAIL SYSTEM, RH	injector
0D5419	OIL FILTER, FORD V-10 ENGINE	oil_filter
10028130	FILTER,OIL,ENGINE,FORD 6.8L	oil_filter
120105	Engine Oil Filter	oil_filter
0D34540114	PISTON RING SET STD (2 PISTONS)	other_service
0D34540115	PISTON RING SET .020"/.50MM O/S	other_service
0D34540213	CHAIN-TIMING	other_service
0D34540249	COIL & BOOT ASY-IGNITION	other_service
0D6742	VALVE PCV (FORD 6.8L)	other_service
10026469	SWITCH,BRAKE,FORD, 2 POLE	other_service
0D34540146	PUMP ASSY-OIL	pump
0D34540232	PUMP, WATER	pump
10023205	PUMP ASSY,WATER,FORD 6.8L	pump
10028891	FUEL PUMP ASSEMBLY,ROUSH PROPANE	pump
10050855	KIT,FUEL PUMP,ROUSH	pump
10053705	FUEL,PUMP,ASSEMBLY	pump
P16BB-PUMPKIT-AA	SRV - GEN 4 FUEL PUMP (INCLUDES FILTER)	pump
0D34540126	SEAL, CRANKSHAFT REAR OIL	seal
0D34540148	SEAL, SCREEN AND COVER	seal
0D34540185	SEAL-VALVE STEM	seal
0D34540217	TIMING COVER CRANKSHAFT SEAL	seal
0D34540235	SEAL-THERMOSTAT (O-RING)	seal
10028685	ORING N0299-50 2-108	seal
10028686	O RING,NBR,0.296 ID X 0.139 X-SECTION	seal
10028868	O RING,5-1/2 ID X 0.210 VITON,ROUSH PROPANE	seal
10028871	O RING,NBR,1.487 ID X 0.103 C/S,ROUSH PROPANE	seal
10043645	SEAL,FRONT,CRANKSHAFT,FORD 6.8L	seal
10043646	SEAL,O-RING,THERMOSTAT,FORD 6.8L	seal
10052622	O RING,PV1855BRCN	seal
22S-S04	O-RING PLUG 10028681	seal
N0299-50-2-108	O-RING 0.237" ID 0.103" X-SECT 10028685	seal
035606	SENSOR HI COOLANT SHUTDOWN	sensor
053666	SENDER OIL PRESSURE	sensor
053667	SENDER WATER TEMP	sensor
0A8584	Switch	sensor
0D2244M	ASSY MAGPICKUP (3/8-24 MALE)	sensor
0D34540230	SENSOR, CAM	sensor
0D34540231	SENSOR ASSY-CRANKSHAFT	sensor
0E0561	ASSY WATER LEVEL SENSOR C/E PL	sensor
10019951	SENSOR,AIR,MAF,FORD	sensor
10020830	SENSOR,EXHAUST,Y-PIPE,FORD,8F9A	sensor
10020831	SENSOR,EXHAUST,CATALYTIC CONVERTER,FORD, BL3A	sensor
10025984	INDICATOR,AIR CLEANER,RESTRICTION,FORD	sensor
10028687	FUEL,IPTS,10K OHM THERMISTOR,ROUSH PROPANE	sensor
10028859	FUEL,FUEL SENDER ASSY,14 TANK,ROUSH PROPANE	sensor
10042394	SENDER,FUEL,GASOLINE,FORD,DC24	sensor
10042606	SENSOR,EXHAUST,FORD P558 CATALYST,CV	sensor
10042607	SENSOR,EXHAUST,FORD P558 Y-PIPE,LHS,CV	sensor
10042712	SENSOR,CAMSHAFT,FORD PROPANE,1WZZ-6B288-AB	sensor
10043647	SENSOR,PRESSURE,ENGINE OIL,FORD 6.8L	sensor
10044803	SENSOR,EXHAUST,FORD P558 Y-PIPE,RHS,CV	sensor
10049895	SENSOR,AIR,MAF,FORD,GEN 4	sensor
10050856	DIAL FUEL SEND	sensor
10054718	SENSOR,CRANKSHAFT,FORD	sensor
10056049	SENSOR,TEMPERATURE,CYL HEAD,FORD 6.8L	sensor
59-00345	SRV - FUEL SENDER HALL EFFECT DIAL KIT	sensor
P16BB-10A614-AA	FUEL SENDER ASSEMBLY, 14" TANK	sensor
0D34540186	SPARK PLUG (PLATINUM) .044 GAP	spark_plug
10043644	PLUG,SPARK,FORD 6.8L	spark_plug
0D5418	STARTER MOTOR FORD V-10 ENGINE	starter
0D34540238	THERMOSTAT ASSY-WATER	thermostat
10043643	THERMOSTAT,ENGINE,FORD 6.8L	thermostat

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

Also used in

Ford E-SERIES VAN — Light Truck
Ford EXCURSION — Light Truck
Ford F-250 — Light Truck
Ford F-350 — Light Truck
Ford F-450 — Light Truck
Ford F-550 — Light Truck
Ford F-650 — Truck
Ford F-750 — Truck
Ford F-SERIES PICKUP — Light Truck

Other equipment known to use this engine, via filter-application cross-reference — useful for sourcing parts even when your exact machine isn't listed elsewhere on this page.

Common questions

What is the displacement of the Ford 6.8L?

The Ford 6.8L has a displacement of 6.8 liters with 10 cylinders.

Which generators use the Ford 6.8L engine?

The Ford 6.8L powers 1 generator set(s), including Kohler 125REZG.

How often should you change the oil in the Ford 6.8L?

The Ford 6.8L oil change interval is every 500 hours.