________________________________________________________________________________

Wisconsin AEN Engine

The Wisconsin AEN is a single-cylinder, four-cycle, heavy-duty air-cooled internal combustion engine built by the Wisconsin Motor Corporation. Engineered for industrial, construction, and agricultural equipment, this engine features a rugged cast-iron block and crankcase construction. It is highly regarded for its reliability under continuous load conditions and its robust mechanical design. Variants such as the AENL and AENLD include long-life valve upgrades to handle extended operation in severe environments.

The engine features a side-valve (L-head) arrangement. The valves are positioned in the cylinder block parallel to the cylinder bore, actuated by a gear-driven camshaft. Premium variants utilize a Stellite exhaust valve and hard seat insert for superior heat and wear resistance. Cylinder Bore: 3.00 inches (76.2 mm). Piston Stroke: 3.25 inches (82.55 mm). Total Displacement: 23.0 cubic inches (377 cc).

Fuel System: The fuel system comprises a gravity-fed or pump-assisted circuit utilizing a balanced float-type carburetor (Zenith model). The carburetor contains an adjustable main jet, an idle speed mixture screw, and a manual choke plate for cold-engine starting. It delivers an optimized fuel-to-air ratio across all governor-regulated speeds and varying load parameters. Fuel requirements call for clean, regular unleaded gasoline rated at a minimum of 87 octane. Ethanol blends higher than 10 percent should be avoided on legacy components to prevent degradation of fuel lines and gaskets.

Lubrication System: Lubrication is accomplished via a mechanical splash system. An oil flinger or dipper attached to the connecting rod cap agitates the oil in the oil pan. This action creates a continuous oil mist that lubricates the internal bearings, cylinder wall, and camshaft assemblies. Oil Requirements: High-grade detergent oil, typically SAE 30 for operating temperatures above 32F (0C), or SAE 10W-30 for cold-weather conditions. Oil must never be mixed with the gasoline.

Cooling System: This is a forced-air cooling system requiring no liquid radiator or coolant. A combination fan-flywheel blower pulls ambient air in and blows it across the integrated cooling fins of the cylinder block and head. A sheet-metal shrouding and duct network directs the airflow uniformly around the high-heat areas. The engine must never be operated with any portion of this shrouding removed.

General Technical Data

Engine Specifications

Engine Model ............... Wisconsin AEN
Engine Type ............... 4-cycle single-cylinder L-head heavy-duty air-cooled gasoline
Number of Cylinders ............... 1
Cylinder Arrangement ............... Vertical single-cylinder
Engine Bore, in (mm) ............... 3.00 (76.2)
Engine Stroke, in (mm) ............... 3.25 (82.6)
Displacement, cu.in (cc) ............... 23.0 (377)
Maximum Power at 3600 rpm, hp (kW) ............... 9.2 (6.9)
Rated Power at 3000 rpm, hp (kW) ............... 7.5 (5.6)
Rated Power at 2400 rpm, hp (kW) ............... 6.0 (4.5)
Rated Power at 1800 rpm, hp (kW) ............... 4.7 (3.5)
Rated Engine Speed, rpm ............... 1600-3600
Peak Torque at 2200 rpm, lb-ft (Nm) ............... 15.3 (20.7)
Peak Torque at 3600 rpm, lb-ft (Nm) ............... 13.4 (18.2)
Peak Torque at 1600 rpm, lb-ft (Nm) ............... 14.8 (20.1)
Idle Speed ............... 600-800 rpm
Operating Speed ............... 1600-3600 rpm
Compression Ratio ............... 5.1:1-5.5:1
Camshaft Drive Method ............... Helical spur gear pairing direct crank engagement system
Crankcase Breather ............... Reed valve flapper positive pressure extraction assembly unit
Cylinder Block Type ............... Heavy cast iron integrated with crankcase
Cylinder Head Type ............... Cast iron removable L-head with deep cooling fins
Lubrication System ............... Splash system with oil pump plunger ejector
Oil Pump Type ............... Camshaft-driven plunger style
Oil Filter Type ............... Optional bypass mesh screen element
Cooling System ............... Forced air by flywheel blower shroud
Air Cleaner Type ............... Heavy-duty oil bath or dry element alternative
Starting System ............... Rope start standard or optional electric starter
Electrical System ............... 6V or 12V magneto system ignition

Fuel System

Carburetor Manufacturer ............... Zenith or Marvel-Schebler
Carburetor Type ............... Updraft single-barrel model with adjustable needle jets
Fuel Delivery Type ............... Gravity feed from mounted tank or mechanical fuel pump
Fuel Pump Type ............... Diaphragm mechanical driven by camshaft lobe
Fuel Pump Pressure, psi (kPa) ............... 1.5-3.0 (10.3-20.7)
Fuel Tank Capacity, gal (L) ............... 1.5-1.75 (5.7-6.6)
Main Jet Specification ............... Variable adjustable needle needle valve jet
Idle Jet Specification ............... Fixed low-speed orifice with adjustable air bleed needle
Choke Type ............... Manual butterfly disc with external control cable linkage
Governor Type ............... Mechanical centrifugal flyweight gear driven from camshaft
Governor Speed Regulation ............... Close regulation adjustable external spring load tension
Fuel Type ............... Regular unleaded automotive gasoline or kerosene alternative
Fuel Strainer Type ............... Sediment bowl style with fine mesh screen element

Dimensions and Weight

Overall Height, in (mm) ............... 22.5 (570)
Overall Width, in (mm) ............... 18.3 (465)
Overall Length, in (mm) ............... 17.5 (445)
Dry Weight, lbs (kg) ............... 110 (50)

Maintenance Data

Service Information

Spark Plug Gap, in (mm) ............... 0.030 (0.76)
Magneto Point Gap, in (mm) ............... 0.020 (0.51)
Ignition Timing Setting ............... 20 degrees BTDC
Intake Valve Clearance, Cold, in (mm) ............... 0.008 (0.20)
Exhaust Valve Clearance, Cold, in (mm) ............... 0.016 (0.41)

Engine Oil

Engine Oil Type .................. SAE 30, SAE 20W, or SAE 10W
API Service Classifications ......................... SE, SF, SG, or CC
Oil Sump Base Capacity, qt (L) ............... 1.5-1.75 (1.4-1.6)

Service Intervals

Change engine oil ............... Every 50 hours
Inspect air cleaner ............... Every 8 hours
Service air cleaner ............... Every 50 hours
Clean fuel strainer ............... Every 50 hours
Valve clearance adjustment ............... Every 150 hours
Fuel system inspection ............... Every 100 hours
Clean spark plug ............... Every 100 hours
Replace spark plug ............... Every 300 hours
Clean cooling fin ............... Every 50 hours
Flush/Clean fuel tank ............... Every 500 hours
Change reduction gear oil ............... Every 500 hours

Service Specifications

Cylinder Bore Inside Diameter, in (mm) ............... 3.0000-3.0005 (76.200-76.213)
Cylinder Bore Maximum Out of Round, in (mm) ............... 0.0010 (0.025)
Cylinder Bore Maximum Taper, in (mm) ............... 0.0015 (0.038)
Crankshaft Main Journal Diameter, in (mm) ............... 1.3750-1.3755 (34.925-34.938)
Crankshaft Main Bearing Clearance, in (mm) ............... 0.001-0.004 (0.025-0.102)
Crankshaft End Play, in (mm) ............... 0.004-0.006 (0.102-0.152)
Crankpin Journal Diameter, in (mm) ............... 1.6250-1.6255 (41.275-41.288)
Connecting Rod Bearing Clearance, in (mm) ............... 0.0010-0.0022 (0.025-0.056)
Connecting Rod Side Play, in (mm) ............... 0.005-0.010 (0.127-0.254)
Piston to Cylinder Clearance, in (mm) ............... 0.0035-0.0040 (0.089-0.102)
Piston Pin Bore Inside Diameter, in (mm) ............... 0.7501-0.7503 (19.053-19.058)
Piston Pin Outer Diameter, in (mm) ............... 0.7500-0.7503 (19.050-19.058)
Piston Pin to Piston Pin Bore Clearance, in (mm) ............... 0.0001-0.0004 (0.003-0.010)
Piston Pin to Con Rod Bushing Clearance, in (mm) ............... 0.0005-0.0009 (0.013-0.023)
Top Ring Groove Width, in (mm) ............... 0.1240-0.1250 (3.150-3.175)
Second Ring Groove Width, in (mm) ............... 0.1240-0.1250 (3.150-3.175)
Third Ring Groove Width, in (mm) ............... 0.1240-0.1250 (3.150-3.175)
Oil Ring Groove Width, in (mm) ............... 0.1865-0.1875 (4.737-4.763)
Top Ring Groove Side Clearance, in (mm) ............... 0.0020-0.0035 (0.051-0.089)
Second Ring Groove Side Clearance, in (mm) ............... 0.0015-0.0030 (0.038-0.076)
Third Ring Groove Side Clearance, in (mm) ............... 0.0015-0.0030 (0.038-0.076)
Oil Ring Groove Side Clearance, in (mm) ............... 0.0015-0.0030 (0.038-0.076)
Piston Ring End Gap, in (mm) ............... 0.0070-0.0120 (0.178-0.305)
Cylinder Head Deck Flatness Surface Distortion, in (mm) ............... 0.0030 (0.076)
Cylinder Block Deck Flatness Surface Distortion, in (mm) ............... 0.0030 (0.076)
Intake Valve Head Diameter, in (mm) ............... 1.375 (34.925)
Exhaust Valve Head Diameter, in (mm) ............... 1.250 (31.750)
Intake Valve Stem Outer Diameter, in (mm) ............... 0.3110-0.3115 (7.900-7.912)
Exhaust Valve Stem Outer Diameter, in (mm) ............... 0.3105-0.3110 (7.887-7.900)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0020-0.0035 (0.051-0.089)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0035-0.0050 (0.089-0.127)
Valve Guide Inside Diameter, in (mm) ............... 0.3135-0.3140 (7.963-7.976)
Valve Spring Free Length, in (mm) ............... 1.750 (44.45)
Valve Seat Angle, deg ............... 45.000
Valve Face Angle, deg ............... 45.000
Valve Seat Width, in (mm) ............... 0.045-0.060 (1.14-1.52)
Camshaft Main Journal Diameter (Flywheel), in (mm) ............... 0.8745-0.8750 (22.212-22.225)
Camshaft Main Journal Diameter (PTO), in (mm) ............... 0.8745-0.8750 (22.212-22.225)
Camshaft Bearing Oil Clearance, in (mm) ............... 0.0015-0.0030 (0.038-0.076)
Camshaft End Play Clearance, in (mm) ............... 0.002-0.004 (0.051-0.102)

Tightening Torques

Cylinder Head Bolt, lb-ft (Nm) ............... 22-24 (29.8-32.5)
Connecting Rod Bolt, lb-ft (Nm) ............... 18-20 (24.4-27.1)
Flywheel Retaining Nut, lb-ft (Nm) ............... 70-80 (94.9-108.5)
Crankcase Base Cover Bolt, lb-ft (Nm) ............... 10-12 (13.6-16.3)
Spark Plug Installation, lb-ft (Nm) ............... 25-30 (33.9-40.7)
Magneto Mounting Bolt, lb-ft (Nm) ............... 14-16 (19.0-21.7)
Gear Cover Plate Fastener, lb-ft (Nm) ............... 8-10 (10.8-13.6)
Manifold Flange Fastener, lb-ft (Nm) ............... 12-14 (16.3-19.0)
Carburetor Mounting Flange Nut, lb-ft (Nm) ............... 6-8 (8.1-10.8)
Oil Sump Drain Plug, lb-ft (Nm) ............... 15-20 (20.3-27.1)
Valve Cover Plate Nut, lb-ft (Nm) ............... 4-6 (5.4-8.1)
Governor Lever Clamp Bolt, lb-ft (Nm) ............... 5-7 (6.8-9.5)
Main Bearing Cap Adapter Bolt, lb-ft (Nm) ............... 20-22 (27.1-29.8)
Fuel Pump Mounting Fastener, lb-ft (Nm) ............... 8-10 (10.8-13.6)
Air Shroud Panel Screw, lb-in (Nm) ............... 35-45 (4.0-5.1)
Breaker Point Assembly Mounting Screw, lb-in (Nm) ............... 15-20 (1.7-2.3)
Condenser Retaining Screw, lb-in (Nm) ............... 15-20 (1.7-2.3)

________________________________________________________________________________________

• Wisconsin Engines Specs
  
• Wisconsin AENL Specs
  
• Wisconsin AENLD Specs
  
• Wisconsin AGND Specs
  
• Wisconsin AKN Specs
  
• Wisconsin AKS Specs
  
• Wisconsin BKN Specs
  

________________________________________________________________________________

________________________________________________________________________________________

_______________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________