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Perkins N H1 (Engine) Engine

The Perkins N H1 (Engine) is an engine. It powers generator sets from Perkins, including the 1104.

Also known as: Perkins N H1 (Engine)

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

Engine specifications

Generator sets powered by this engine

Perkins 1104

How to read your Perkins engine serial & model number →

Common problems

The starting motor does not crank.
Fix: Check for the blocked engagement of the pinion gear and flywheel ring gear. Note: Blocked engagement and open solenoid contacts will give the same electrical symptoms.
The starting motor cranks slowly.
Fix: Remove the starting motor for repair or replacement.
Engine Stopping
Fix: Stop the engine according to the procedure in the Operation and Maintenance Manual, “Engine Stopping (Operation Section)” in order to avoid overheating of the engine and accelerated wear of the engine components. Use the Emergency Stop Button (if equipped) ONLY in an emergency situation. Do not use the Emergency Stop Button for normal engine stopping. After an emergency stop, DO NOT start the engine until the problem that caused the emergency stop has been corrected.
Engine Monitoring System
Fix: The following actions are available for engine monitoring control: • Warning • Derate • Shutdown The following monitored engine operating conditions have the ability to limit engine speed and/or the engine power: • Engine Coolant Temperature • Engine Oil Pressure • Engine Speed • Intake Manifold Air Temperature The Engine Monitoring package can vary for different engine models and different engine applications. However, the monitoring system and the engine monitoring control will be similar for all engines.
Engine Electronics
Fix: Correct grounding for the engine electrical system is necessary for optimum engine performance and reliability. Incorrect grounding will result in uncontrolled electrical circuit paths and in unreliable electrical circuit paths. Uncontrolled electrical circuit paths can result in damage to the crankshaft bearing journal surfaces and to aluminum components. Engines that are installed without engine-to-frame ground straps can be damaged by electrical discharge. To ensure that the engine and the engine electrical systems function correctly, an engine-to-frame ground strap with a direct path to the battery must be used. This path may be provided by way of a direct engine ground to the frame. The connections for the grounds should be tight and free of corrosion. The engine alternator must be grounded to the negative “-” battery terminal with a wire that is adequate to handle the full charging current of the alternator. The power supply connections and the ground connections for the engine electronics should always be from the isolator to the battery.
Cold start system malfunction 201
Fix: Do not use ether or other starting fluids to start the engine

Compiled from service & troubleshooting documentation across every generator set that uses the Perkins N H1 (Engine).

Maintenance schedule

Item	Capacity	Part #
Air filter		27610288	Amazon eBay
Fuel filter		27610307	Amazon eBay
Oil filter		27610291	Amazon eBay
Battery		101930351	Amazon eBay
Belt		—
Coolant filter		—
Oil	6.5 liters	U5MK1124	Amazon eBay
Spark plug		—

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

Service intervals

Item	Action	Hours	Months	Notes
Fuel Tank Water and Sediment	Drain	50 hr		Every 50 Service Hours or Weekly
Battery Electrolyte Level	Check	500 hr	12 mo	Every 500 Service Hours or 1 Year
Engine Air Cleaner Element (Dual Element)	Clean	500 hr	12 mo	Every 500 Service Hours or 1 Year - Clean/Replace
Engine Air Cleaner Element (Single Element)	Inspect	500 hr	12 mo	Every 500 Service Hours or 1 Year - Inspect/Replace
Engine Ground	Inspect	500 hr	12 mo	Every 500 Service Hours or 1 Year - Inspect/Clean
Engine Oil and Filter	Change	500 hr	12 mo	Every 500 Service Hours or 1 Year
Fuel System Primary Filter (Water Separator) Element	Replace	500 hr	12 mo	Every 500 Service Hours or 1 Year
Fuel System Secondary Filter	Replace	500 hr	12 mo	Every 500 Service Hours or 1 Year
Hoses and Clamps	Inspect	500 hr	12 mo	Every 500 Service Hours or 1 Year - Inspect/Replace
Radiator	Clean	500 hr	12 mo	Every 500 Service Hours or 1 Year
Engine Valve Lash	Inspect	1000 hr		Every 1000 Service Hours - Inspect/Adjust
Aftercooler Core	Inspect	2000 hr		Every 2000 Service Hours
Alternator	Inspect	2000 hr		Every 2000 Service Hours
Engine Mounts	Inspect	2000 hr		Every 2000 Service Hours
Starting Motor	Inspect	2000 hr		Every 2000 Service Hours
Turbocharger	Inspect	2000 hr		Every 2000 Service Hours
Water Pump	Inspect	2000 hr		Every 2000 Service Hours
Cooling System Coolant (Commercial Heavy-Duty)	Change	3000 hr	24 mo	Every 3000 Service Hours or 2 Years
Fuel Injector	Test	3000 hr		Every 3000 Service Hours - Test/Change
Aftercooler Core	Clean	4000 hr		Every 4000 Service Hours - Clean/Test
Cooling System Coolant Extender (ELC)	Other	6000 hr	36 mo	Every 6000 Service Hours or 3 Years - Add
Cooling System Coolant (ELC)	Change	12000 hr	72 mo	Every 12 000 Service Hours or 6 Years
Cooling System Coolant	Change		24 mo	Every 2 Years

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

Type	Item	Value	Unit	Condition
Clearance	Accessory drive gear backlash	0.11 to 0.17	mm
Clearance	Camshaft end play (new)	0.10 to 0.55	mm (0.004 to 0.022 inch)	Maximum permissible end play of a worn camshaft 0.60 mm (0.023 inch)
Clearance	Clearance between the bearing shell and the main bearing journals	0.057 to 0.117	mm (0.0022 to 0.0046 inch)
Clearance	Connecting rod bearing clearance	0.030 to 0.081	mm (0.0012 to 0.0032 inch)
Clearance	Connecting rod length (L), distance between bores	total difference from each side must not vary more than ±0.25	mm (±0.010 inch)	Measured at distance (K) 127 mm (5.0 inch) from both sides; reduced to ±0.06 mm (±0.0025 inch) if piston pin bearing not removed
Clearance	Coolant level below bottom of filler pipe	13	mm (0.5 inch)	Engine cold, not running
Clearance	Crankshaft end play	0.17 to 0.41	mm
Clearance	Crankshaft end play maximum	0.51	mm
Clearance	Crankshaft front seal installed depth	9 ± 0.2	mm	into front housing
Clearance	Cylinder bore	105.000 to 105.025	mm (4.1338 to 4.1348 inch)
Clearance	Cylinder head thickness	117.95 to 118.05	mm (4.643 to 4.647 inch)	Minimum thickness 117.20 mm (4.614 inch)
Clearance	Flywheel face alignment (difference between lowest and highest of four locations)	0.03	mm (0.001 inch) per 25 mm (1.0 inch) of flywheel radius	Crankshaft pressed toward front of engine
Clearance	Flywheel runout	0.30	mm (0.012 inch)	Maximum
Clearance	Maximum permissible wear for the cylinder bore	0 to 0.15	mm (0 to 0.0059 inch)
Clearance	Minimum cylinder head thickness after machining	117.20	mm (4.614 inch)	After resurfacing bottom face
Clearance	Original size of the connecting rod bearing journal	63.47 to 63.49	mm (2.4988 to 2.4996 inch)
Clearance	Original size of the main bearing journal	76.159 to 76.180	mm (2.9984 to 2.9992 inch)
Clearance	Rear wear sleeve flange distance from cylinder block	0.40 to 0.60	mm
Clearance	Valve guide inside diameter	9.000 to 9.022	mm (0.3543 to 0.3552 inch)
Clearance	Valve guide protrusion above valve spring recess	12.35 to 12.65	mm
Clearance	Valve guide radial movement check - valve head lift distance	15.0	mm (0.60 inch)	Lift edge of valve head before measuring radial movement
Other	Balancer weight	23	kg (51 lb)
Other	Bosch EPVE fuel injection pump plunger lift	1.55	mm (0.0610 inch)
Other	Cast iron oil pan weight	41	kg (90 lb)
Other	Compression Ratio	16.2:1
Other	Connecting rod torx screws - additional turn	120	degrees
Other	Crankshaft weight	30	kg (66 lb)
Other	Cylinder head bolts - additional turn (long bolts)	270	degrees
Other	Cylinder head bolts - additional turn (short bolts)	225	degrees
Other	Cylinder head weight	56	kg (124 lb)
Other	Flywheel housing weight	30	kg (66 lb)
Other	Flywheel weight	71	kg (155 lb)
Other	Maximum air pressure at nozzle for cleaning purposes	205	kPa (30 psi)
Other	Piston height above cylinder block	0.21 to 0.35	mm (0.008 to 0.014 inch)
Other	V-belt tension	535	N (120 lb)	Initial belt tension; used belt tension 355 N (80 lb)
Other	V-belt tension - initial (new belt)	535	N (120 lb)	Belt width 13.89 mm (0.547 inch); measure belt farthest from engine
Other	V-belt tension - used belt	355	N (80 lb)	Belt in operation 30 minutes or more at rated speed
Other	Water temperature regulator minimum stroke at full open temperature	10	mm (0.3937 inch)
Pressure	Cylinder compression variation between cylinders	350	kPa (51 psi)	If one or more cylinders vary by more than this, repair may be needed
Pressure	Cylinder compression variation limit between cylinders	350	kPa (51 psi)
Pressure	Cylinder head leak test pressure	200	kPa (29 psi)
Pressure	Engine oil pressure	280	kPa (40 psi)	Normal operating temperature and high idle (minimum)
Pressure	Engine oil pressure minimum at maximum engine speed and normal operating temperature	300	kPa (43 psi)	at maximum engine speed, normal operating temperature
Pressure	Fuel injector service setting injection pressure	29.4 ± 0.8	MPa (4264 ± 116 psi)	Leakage in 10 seconds = 0 drops
Pressure	Fuel pressure at idle (all fuel injection pumps)	25	kPa (3.6 psi)	at idle
Pressure	Fuel pressure at idle - Bosch EPVE	31	kPa (4.49 psi)	Idle
Pressure	Fuel pressure at idle - Delphi DP210	27.5	kPa (3.99 psi)	Idle
Pressure	Fuel pressure at rated speed (all fuel injection pumps)	23	kPa (3.3 psi)	at rated speed; maximum 75 kPa (10.9 psi)
Pressure	Fuel pressure at rated speed - Bosch EPVE	31	kPa (4.49 psi)	Rated speed
Pressure	Fuel pressure at rated speed - Delphi DP210	28	kPa (4.06 psi)	Rated speed
Pressure	Fuel tank pressurization for leak test	35	kPa (5 psi)	Do not use more than 55 kPa (8 psi)
Pressure	Fuel transfer pump combined flow (outlets A and B)	2	L/min (0.53 US gpm)	Minimum combined flow
Pressure	Maximum fuel injection pump pressure	80	kPa (12 psi)
Pressure	Pressure to open engine oil filter bypass valve (replaceable element)	130 to 170	kPa (19 to 25 psi)
Pressure	Pressure to open engine oil filter bypass valve (spin-on oil filter)	80 to 120	kPa (12 to 18 psi)
Pressure	Wastegate actuator air pressure	205	kPa (30 psi)	Do not exceed; apply pressure until rod moves 1 mm (0.0394 inch)
Speed	Operating range	750 to 2650	rpm
Temperature	Crankshaft gear installation heating temperature	200	C
Temperature	Crankshaft gear interference fit heating	150 ± 50	°C (302 ± 90 °F)	oven
Temperature	Flywheel ring gear installation heating	maximum 250	°C (482 °F)	oven

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
Coolant	Commercial heavy-duty coolant/antifreeze	ASTM D4985			Do not use coolant/antifreeze that only meets ASTM D3306. Perkins recommends 1:1 water/glycol, may be increased to 1:2 water to glycol
Coolant	Equal quantities of antifreeze and clean soft water (50 percent water and 50 percent antifreeze)	21825166 POWERPART antifreeze			Do not add pure antifreeze; concentrations less than 50% dilute corrosion inhibitor; more than 50% may adversely affect coolant performance.
Coolant	Perkins Extended Life Coolant (ELC) 1:1 water/glycol (premixed)	Perkins ELC; freeze protection to -36 °C (-33 °F)			ELC Concentrate lowers freezing point to -51 °C (-60 °F) for arctic conditions
Coolant	Perkins Liquid SCA + water	6 to 8 percent concentration of SCA			Part number 21825755; for stationary and marine applications without anti-boil or freeze protection
Coolant	50 Percent Ethylene Glycol	ASTM D4985	above -36°C	50.0 Percent	Freeze protection -36 °C (-33 °F), boil protection 106 °C (223 °F); 60 percent gives -51 °C (-60 °F) / 111 °C (232 °F)
Coolant	50 Percent Propylene Glycol	ASTM D4985	above -29°C	50.0 Percent	Do not use propylene glycol in concentrations that exceed 50 percent because of reduced heat transfer capability
Engine oil	SAE 0W20	EMA LRG-1 / API CH-4	-40°C to 10°C
Engine oil	SAE 0W30	EMA LRG-1 / API CH-4	-40°C to 30°C
Engine oil	SAE 0W40	EMA LRG-1 / API CH-4	-40°C to 40°C
Engine oil	SAE 5W30	EMA LRG-1 / API CH-4	-30°C to 30°C
Engine oil	SAE 5W40	EMA LRG-1 / API CH-4	-30°C to 40°C
Engine oil	SAE 10W30	EMA LRG-1 / API CH-4	-20°C to 40°C
Engine oil	SAE 15W40	EMA LRG-1 / API CH-4	-10°C to 50°C		Preferred oils: EMA DHD-1 multigrade, API CH-4 multigrade, ACEA E3. Minimum TBN of new oil = 10 times fuel sulfur level, minimum 5.
Fuel	Diesel - Group 1 (preferred) DERV to EN590, Gas oil to BS2869 Class A2, ASTM D975-91 Class 2D, JIS K2204 (1992) Grades 1,2,3 and Special Grade 3	Cetane number 45 minimum; Viscosity 2.0 to 4.5 cSt at 40 °C; Density 0.835 to 0.855 Kg/liter; Sulfur 0.2% of mass maximum; Distillation 85% at 350 °C; Lubricity 460 micrometers maximum wear scar on ISO 12156-1			Group 2 (permissible) and Group 3 (aviation kerosene) also listed. Biofuel: a 5% mix of RME to EN14214 in conventional fuel is permitted. Water emulsion fuels are not permitted.
Grease	21820221 POWERPART Red Rubber Grease				Used to lubricate O-rings and seals
Other	1766-501 Silicone Fluid MS200/1000				Used to lubricate new O-ring of Bosch EPVE fuel injection pump
Other	21820117 POWERPART Threadlock and Nutlock				Applied to reused setscrews after cleaning old sealant
Other	21820518 POWERPART Liquid Gasket				Applied to crankshaft wear sleeve inner surface
Other	21820603 POWERPART Retainer (oil tolerant)				Applied to accessory drive bearing surfaces
Other	21826038 POWERPART Silicone Rubber Sealant / Silicone Adhesive				Applied to cylinder block bridge and oil pan grooves

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

Procedures

Engine Valve Lash - Inspect/Adjust adjustment

⚠ To prevent possible injury, do not use the starter to turn the flywheel.

⚠ Hot engine components can cause burns; allow the engine to cool before measuring valve clearance.

⚠ To prevent accidental starting, turn the ignition switch to OFF, place a do not operate tag and disconnect and tape the stop solenoid electrical connection.

Tools: Feeler gauge, Soft mallet

Put No. 1 piston at top center on the compression stroke.
1104: with TC compression stroke adjust inlet valves 1,2 and exhaust valves 1,3 to 0.20 mm and 0.45 mm.
Lightly tap the rocker arm at the adjustment screw with a soft mallet; loosen the adjustment locknut.
Place the correct feeler gauge between the rocker arm and valve stem and turn the adjustment screw clockwise until slight drag is felt.
Tighten the adjustment locknut to 27 N·m (20 lb ft) without turning the adjustment screw; recheck valve lash.
Rotate the engine 360 degrees to TC exhaust stroke for cylinder 4.
1104: adjust inlet valves 3,4 and exhaust valves 2,4. 1103: adjust the number 1, 5, 2 and 4 valves.

Engine Valve Lash - Inspect/Adjust (1104 engine) adjustment

⚠ To prevent possible injury, do not use the starter to turn the flywheel.

⚠ Hot engine components can cause burns.

Tools: feeler gauge

Remove the valve mechanism cover.
Rotate crankshaft clockwise; when No. 4 inlet opened and No. 4 exhaust not closed, measure No. 1 valves.
Loosen the valve adjustment screw locknut on adjustment screw.
Place the appropriate feeler gauge between the rocker arm and valve.
Turn the adjustment screw until correct valve lash is achieved.
Tighten the locknut while holding the adjustment screw from turning.
Repeat for No. 3, No. 4 and No. 2 cylinders per engine sequence.
Install the valve mechanism cover.

Finding Top Center Position for No. 1 Piston adjustment

Tools: 27610211 Crankshaft timing pin, 27610212 Camshaft timing pin

Remove the valve mechanism cover, glow plugs and front housing cover.
Rotate the crankshaft in the normal direction until the inlet valve of No. 4 cylinder has just opened and the exhaust valve has not completely closed.
Align the hole in the crankshaft with the hole in the cylinder block and timing case and insert the 27610211 Crankshaft Timing Pin fully.
Insert the 27610212 Camshaft Timing Pin through the camshaft gear into the timing case body.
Remove the timing pins from the camshaft gear and crankshaft web.

Fuel Injection Pump Timing - Adjust (Bosch EPVE) adjustment

⚠ This procedure must only be carried out by a person with the correct training.

⚠ Do not rotate the fuel injection pump if the fuel injection pump shaft is locked.

Tools: 27610248 Bosch EPVE fuel injection pump timing adapter, Dial indicator

Set No. 1 piston at top center on the compression stroke and remove the rocker shaft.
Remove the high pressure fuel lines. Remove plug and washer and install 27610248 adapter with dial indicator.
Rotate the crankshaft counterclockwise until the plunger is at the bottom. Set dial indicator to zero.
Rotate the crankshaft clockwise until the required plunger lift is achieved.
Lock the pump shaft: loosen locking screw, remove washer, tighten locking screw to 31 N·m (23 lb ft).
Remove the water pump, front cover and fuel injection pump gear.
Set No. 1 piston at top center and install the fuel injection pump gear, front cover and water pump.
Install a new washer to the plug and install the plug. Install the rocker shaft and high pressure fuel lines and eliminate air.

Rocker Shaft and Pushrod - Install adjustment

Tools: 27610227 Rocker Assembly Tool

Lubricate both ends of pushrods with clean engine oil; install.
Loosen adjustment screw and nut on each rocker arm.
Position rocker shaft assembly onto cylinder head.
Install torx screws; longest screw at front of cylinder head.
Tighten torx screws from center outward to 35 N·m.
Remove rocker assembly tool.
Adjust inlet valve lash to 0.20 mm, exhaust to 0.45 mm.

Air in Fuel - Test diagnostic

⚠ Work carefully around a running engine; hot or moving parts can cause personal injury.

⚠ Always wear eye and face protection when using pressurized air.

Tools: Fuel flow tube with visual sight gauge, Pressure gauge 0 to 80 kPa (0 to 12 psi)

Examine the fuel system for leaks. Check fuel line fittings and fuel level.
Install a fuel flow tube with sight gauge in the fuel return line, in a straight section at least 304.8 mm (12 inches) long. Observe flow during cranking.
If excessive air is seen, install a second sight gauge at the inlet to the fuel transfer pump and observe.
Pressurize the fuel tank to 35 kPa (5 psi), maximum 55 kPa (8 psi). Check for leaks between tank and transfer pump.
If the source is not found, disconnect the supply line from the tank and connect an external fuel supply to the transfer pump inlet.

Alternator - Test diagnostic

Tools: Multimeter

Warning lamp does not illuminate: check the light bulb and replace if broken.
Check battery voltage with the ignition switch OFF.
Check voltage between terminal A and ground; it should equal battery voltage.
Turn ignition switch ON and check voltage between terminal B and ground; if more than 2 volts the alternator needs replacement.
Warning light on while running: run the engine at fast idle and measure voltage at terminals A and B.
Voltages should be 13 to 15 volts (12 volt system) or 26 to 30 volts (24 volt system); if not, replace the alternator.
Increase to high idle with an electrical load ON and repeat voltage measurement; replace the alternator if voltages do not match.

Compression - Test diagnostic

Tools: compression gauge

Ensure the battery is in good condition and fully charged and the starting motor operates correctly.
Set the valve lash correctly; remove all fuel injectors; disconnect the fuel supply.
Install a gauge for measuring cylinder compression in the hole for a fuel injector.
Operate the starting motor to turn the engine and record the maximum pressure indicated.
Repeat for all cylinders.
Compare cylinders; if one or more vary by more than 350 kPa (51 psi) repair may be needed.

Cooling System - Check (Overheating) diagnostic

Check the coolant level in the cooling system; low level allows air into the system.
Check the antifreeze and water mixture; should be 50 percent water and 50 percent 21825166 POWERPART antifreeze.
Check for air in the cooling system from incorrect filling or combustion gas leakage.
Check the sending unit, the radiator for restrictions, the filler cap, and the hoses and clamps.
Check for restrictions in the air inlet and exhaust systems.
Check the water temperature regulator and the water pump impeller.
Consider high outside temperatures; maximum ambient air should not exceed 50 °C (120 °F).
Consider excessive load applied to the engine causing reduced coolant flow.

Electric Starting System - Test diagnostic

⚠ Do not crank the engine for more than 30 seconds. Allow the starter to cool for two minutes before cranking again.

Tools: Multimeter, Ammeter

Measure the battery voltage across the battery posts while cranking. Compare with expected cranking voltage table.
Measure the current sent to the starting motor solenoid from the positive battery post with an ammeter.
Measure the voltage of the starting motor while cranking and compare with the temperature range table.
Measure voltage drops in the cranking circuits and compare with the maximum acceptable voltage drop table.
Rotate the crankshaft by hand to ensure it is not stuck; check oil viscosity and external loads.
Attempt to crank the starting motor; if it cranks slowly remove for repair or replacement.
If the starting motor does not crank, check for blocked engagement of the pinion gear and flywheel ring gear.

Engine Oil Pressure - Test diagnostic

Tools: Suitable pressure gauge

Use a suitable pressure gauge to test the pressure of the lubrication system.
Run the engine at normal operating temperature and high idle.
Oil pressure must be a minimum of 280 kPa (40 psi); a lower pressure is normal at low idle.

Fuel Injection Pump Timing - Check (Bosch EPVE) diagnostic

Tools: 27610248 Bosch EPVE fuel injection pump timing adapter, Dial indicator

Set No. 1 piston at top center on the compression stroke.
Remove the high pressure fuel lines from the fuel injection pump.
Remove the plug and washer and install 27610248 timing adapter with a dial indicator set to approximately 3 mm (0.1181 inch).
Rotate the crankshaft counterclockwise until the plunger is at the bottom of the stroke. Set the dial indicator to zero.
Rotate the crankshaft clockwise until the crankshaft timing pin can be pushed into the crankshaft web.
Check the dial indicator reading at top center and compare to Specifications, Fuel Injection Pump.

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

Common questions

Which generators use the Perkins N H1 (Engine) engine?

The Perkins N H1 (Engine) powers 1 generator set(s), including Perkins 1104.

What is a common problem with the Perkins N H1 (Engine) engine?

A commonly reported issue on generators using the Perkins N H1 (Engine) is: The starting motor does not crank.. Fix: Check for the blocked engagement of the pinion gear and flywheel ring gear. Note: Blocked engagement and open solenoid contacts will give the same electrical symptoms..