Free Shipping Over $49.99 Learn More USA-Based Customer Service Learn More Price Match Guarantee Learn More

Knucklehead Engine

334ProductsProduct

Filters

Shop Your Ride

Eastern Motorcycle Parts Tappet Adjusting Screws For Harley Big Twin 1936-1952

Vehicle Specific

Eastern Motorcycle Parts Tappet Adjusting Screws For Harley Big Twin 1936-1952

V-Twin Mfg. Lower Collar Set For Harley FL EL 1936-1947

Vehicle Specific

V-Twin Mfg. Lower Collar Set For Harley FL EL 1936-1947

V-Twin Mfg. Rocker Cover Gaskets For Harley FL EL 1936-1947

Vehicle Specific

V-Twin Mfg. Rocker Cover Gaskets For Harley FL EL 1936-1947

V-Twin Mfg. Motor Builders Cam Chest Kit For Harley FL EL 1936-1947

Vehicle Specific

V-Twin Mfg. Motor Builders Cam Chest Kit For Harley FL EL 1936-1947

V-Twin Mfg. Replica Rocker Arm And Shaft Kit For Harley Knucklehead 1936-1947

Vehicle Specific

V-Twin Mfg. Replica Rocker Arm And Shaft Kit For Harley Knucklehead 1936-1947

V-Twin Mfg. Reverse Circuit Breaker Gear Kit For Harley FL / EL 1936-1969

Vehicle Specific

V-Twin Mfg. Reverse Circuit Breaker Gear Kit For Harley FL / EL 1936-1969

Sifton Tappet Assembly Set For Harley Knucklehead 1936-1947

Vehicle Specific

Sifton Tappet Assembly Set For Harley Knucklehead 1936-1947

$249^.²⁵$267.05

V-Twin Mfg. Rocker Cover Set For Harley Knucklehead 1936-1947

Vehicle Specific

V-Twin Mfg. Rocker Cover Set For Harley Knucklehead 1936-1947

V-Twin Mfg. OHV Big Twin Idler Gear For Harley FL EL 1936-1969

Vehicle Specific

V-Twin Mfg. OHV Big Twin Idler Gear For Harley FL EL 1936-1969

Jims Oil Pump Drive Shaft For Harley Big Twin 1936-1967

Vehicle Specific

Jims Oil Pump Drive Shaft For Harley Big Twin 1936-1967

Jims Wrist Pin Bushing +.005 For Harley Big Twin 1936-1999

Vehicle Specific

Jims Wrist Pin Bushing +.005 For Harley Big Twin 1936-1999

$51^.⁴⁵$61.47

V-Twin Mfg. Crank Pin Washer For Harley FL 1941-1969

Vehicle Specific

V-Twin Mfg. Crank Pin Washer For Harley FL 1941-1969

$33^.⁹²$33^.⁹³

Eastern Motorcycle Parts Crank Pin Washer For Harley FL 1941-1969

Vehicle Specific

Eastern Motorcycle Parts Crank Pin Washer For Harley FL 1941-1969

V-Twin Mfg. Oil Pump Gear For Harley FL / EL 1936-1967

Vehicle Specific

V-Twin Mfg. Oil Pump Gear For Harley FL / EL 1936-1967

V-Twin Mfg. Oil Pump Oil Adjusting Screw Kit For Harley FL EL VL 1932-1954

Vehicle Specific

V-Twin Mfg. Oil Pump Oil Adjusting Screw Kit For Harley FL EL VL 1932-1954

V-Twin Mfg. Idler Gear Bushing For Harley FL 1941-1969

Vehicle Specific

V-Twin Mfg. Idler Gear Bushing For Harley FL 1941-1969

S&S Cycle 1/2" Vent Screw O-Ring For Harley

S&S Cycle 1/2" Vent Screw O-Ring For Harley

James Gasket Rockr Cover Gasket For Harley EL / FL 1938-1947

Vehicle Specific

James Gasket Rockr Cover Gasket For Harley EL / FL 1938-1947

$3^.⁹⁵

V-Twin Mfg. Pressure Switch Sealing Washer For Harley FL 1946-1957

Vehicle Specific

V-Twin Mfg. Pressure Switch Sealing Washer For Harley FL 1946-1957

$1^.⁹⁹

Eastern Motorcycle Parts Transmission Plunger Ball Spring For Harley 1936-1978

Vehicle Specific

Eastern Motorcycle Parts Transmission Plunger Ball Spring For Harley 1936-1978

V-Twin Mfg. Shaft Nut Lock Plate For Harley 1932-1973

Vehicle Specific

V-Twin Mfg. Shaft Nut Lock Plate For Harley 1932-1973

$2^.⁹⁹

V-Twin Mfg. Oil Pump Cover Gasket For Harley FL 1941-1949

Vehicle Specific

V-Twin Mfg. Oil Pump Cover Gasket For Harley FL 1941-1949

$1^.⁹⁹

V-Twin Mfg. Distributor Drive Cam Gear with Holes For Harley FL EL 1936-1969

Vehicle Specific

V-Twin Mfg. Distributor Drive Cam Gear with Holes For Harley FL EL 1936-1969

V-Twin Mfg. 61" Flywheel Assembly For Harley EL 1941-1952

Vehicle Specific

V-Twin Mfg. 61" Flywheel Assembly For Harley EL 1941-1952

V-Twin Mfg. Replica Knuckle Cylinder Set For Harley EL 1936-1940

Vehicle Specific

V-Twin Mfg. Replica Knuckle Cylinder Set For Harley EL 1936-1940

V-Twin Mfg. Lower Valve Spring Cup Kit For Harley FL / EL 1938-1947

Vehicle Specific

V-Twin Mfg. Lower Valve Spring Cup Kit For Harley FL / EL 1938-1947

V-Twin Mfg. Lower Valve Spring Cup Kit For Harley EL 1936-1937

Vehicle Specific

V-Twin Mfg. Lower Valve Spring Cup Kit For Harley EL 1936-1937

V-Twin Mfg. 3.5 " Stroke Flywheel Set For Harley EL 1936-1940

Vehicle Specific

V-Twin Mfg. 3.5 " Stroke Flywheel Set For Harley EL 1936-1940

Eastern Motorcycle Parts Replacement Front Cylinder For Harley Knucklehead 1936-1947

Vehicle Specific

Eastern Motorcycle Parts Replacement Front Cylinder For Harley Knucklehead 1936-1947

Jims Right Side Case Bearing Race +.005 For Harley FL EL 1940-1948

Vehicle Specific

Jims Right Side Case Bearing Race +.005 For Harley FL EL 1940-1948

V-Twin Mfg Tappet Block Set For Harley Knucklehead 1936-1947

Vehicle Specific

V-Twin Mfg Tappet Block Set For Harley Knucklehead 1936-1947

Andrews S Series Camshaft For Harley Knucklehead 1936-1947

Vehicle Specific

Andrews S Series Camshaft For Harley Knucklehead 1936-1947

Andrews N Grind Series Camshaft For Harley Knucklehead 1936-1947

Vehicle Specific

Andrews N Grind Series Camshaft For Harley Knucklehead 1936-1947

V-Twin Mfg. 8 Finned Cam Cover For Harley FL 1941-1947

Vehicle Specific

V-Twin Mfg. 8 Finned Cam Cover For Harley FL 1941-1947

V-Twin Mfg. Cam Cover For Harley Knucklehead 1936-1947

Vehicle Specific

V-Twin Mfg. Cam Cover For Harley Knucklehead 1936-1947

Eastern Motorcycle Parts Piston Kit For Harley 1932-1973

Vehicle Specific

Eastern Motorcycle Parts Piston Kit For Harley 1932-1973

Sifton Lightning Cams For Harley Knucklehead 1936-1947

Vehicle Specific

Sifton Lightning Cams For Harley Knucklehead 1936-1947

Jims Pinion Shaft Kit For Harley 1937-1952

Vehicle Specific

Jims Pinion Shaft Kit For Harley 1937-1952

V-Twin Mfg. Rear Motor Mount And Front Trans Mount For Harley FL / EL / UL 1936-1957

Vehicle Specific

V-Twin Mfg. Rear Motor Mount And Front Trans Mount For Harley FL / EL / UL 1936-1957

Jims Pinion Right Side Case Race For Harley UL 1940-1948

Vehicle Specific

Jims Pinion Right Side Case Race For Harley UL 1940-1948

Jims Right Side Case Race For Harley Big Twin 1940-1954

Vehicle Specific

Jims Right Side Case Race For Harley Big Twin 1940-1954

V-Twin Mfg. Rocker Box Set For Harley Knucklehead 1936-1947

Vehicle Specific

V-Twin Mfg. Rocker Box Set For Harley Knucklehead 1936-1947

$117^.⁹⁹$481^.³⁵

V-Twin Mfg. Rocker Shaft For Harley Knucklehead 1936-1947

Vehicle Specific

V-Twin Mfg. Rocker Shaft For Harley Knucklehead 1936-1947

V-Twin Mfg. Sprocket Shaft For Harley 1932-1973

Vehicle Specific

V-Twin Mfg. Sprocket Shaft For Harley 1932-1973

V-Twin Mfg. Oil Pump Governor Cover Kit For Harley FL / EL 1941-1947

Vehicle Specific

V-Twin Mfg. Oil Pump Governor Cover Kit For Harley FL / EL 1941-1947

Eastern Motorcycle Parts Knucklehead Case Races 1936-1939

Vehicle Specific

Eastern Motorcycle Parts Knucklehead Case Races 1936-1939

V-Twin Mfg. Rocker Cover Strip And Gasket Kit For Harley FL EL 1936-1947

Vehicle Specific

V-Twin Mfg. Rocker Cover Strip And Gasket Kit For Harley FL EL 1936-1947

V-Twin Mfg. 61" Piston Ring Set For Harley Knucklehead 1936-1940

Vehicle Specific

V-Twin Mfg. 61" Piston Ring Set For Harley Knucklehead 1936-1940

Eastern Motorcycle Parts Right Side Case Race For Harley 1936-1973

Vehicle Specific

Eastern Motorcycle Parts Right Side Case Race For Harley 1936-1973

V-Twin Mfg. Complete Engine Gasket Set For Harley FL EL 1941-1947

Vehicle Specific

V-Twin Mfg. Complete Engine Gasket Set For Harley FL EL 1941-1947

V-Twin Mfg. Oil Pump Cover Set For Harley FL / EL 1941-1949

Vehicle Specific

V-Twin Mfg. Oil Pump Cover Set For Harley FL / EL 1941-1949

V-Twin Mfg. Motor Mount For Harley EL 1936-1937

Vehicle Specific

V-Twin Mfg. Motor Mount For Harley EL 1936-1937

V-Twin Mfg. Oil Pump Hardware Kit For Harley EL 1936-1940

Vehicle Specific

V-Twin Mfg. Oil Pump Hardware Kit For Harley EL 1936-1940

Sifton Breather Gear For Harley Big Twin 1948-1977

Vehicle Specific

Sifton Breather Gear For Harley Big Twin 1948-1977

Hastings Piston Ring Set For Harley EL 1936-1952

Vehicle Specific

Hastings Piston Ring Set For Harley EL 1936-1952

$76^.⁹⁵$81^.⁹⁹$76.99$81.99

Eastern Motorcycle Parts 3-Hole Crank Pin For Harley EL UL 1940-1952

Vehicle Specific

Eastern Motorcycle Parts 3-Hole Crank Pin For Harley EL UL 1940-1952

$90^.⁹³$101.42

Eastern Motorcycle Parts Left Case Race For Harley 1936-1973

Vehicle Specific

Eastern Motorcycle Parts Left Case Race For Harley 1936-1973

Eastern Motorcycle Parts Right Case Race For Harley 1936-1952

Vehicle Specific

Eastern Motorcycle Parts Right Case Race For Harley 1936-1952

Eastern Motorcycle Parts Oversized Left Case Race For Harley 1936-1973

Vehicle Specific

Eastern Motorcycle Parts Oversized Left Case Race For Harley 1936-1973

V-Twin Mfg. Valve Seat For Harley FL / EL 1936-1947

Vehicle Specific

V-Twin Mfg. Valve Seat For Harley FL / EL 1936-1947

Eastern Motorcycle Parts Crankpin Nut Lock Kit For Harley Big Twin 1941-1984

Vehicle Specific

Eastern Motorcycle Parts Crankpin Nut Lock Kit For Harley Big Twin 1941-1984

V-Twin Mfg. Complete Gasket Kit For Harley FL EL 1941-1947

Vehicle Specific

V-Twin Mfg. Complete Gasket Kit For Harley FL EL 1941-1947

Sifton Oil Pump Drive Shaft Kit For Harley Big Twin 1936-1967

Vehicle Specific

Sifton Oil Pump Drive Shaft Kit For Harley Big Twin 1936-1967

Colony Head Bolt Kit For Harley Flathead 45" With Cast Iron Heads

Vehicle Specific

Colony Head Bolt Kit For Harley Flathead 45" With Cast Iron Heads

$49^.³⁷$50.80

V-Twin Mfg. Crank Pin Nut For Harley EL UL 1936-1952

Vehicle Specific

V-Twin Mfg. Crank Pin Nut For Harley EL UL 1936-1952

Eastern Motorcycle Parts Oversize Cam Cover Bushing For Harley 1936-1953

Vehicle Specific

Eastern Motorcycle Parts Oversize Cam Cover Bushing For Harley 1936-1953

Jims Idler Shaft And Bushing Kit For Harley Big Twin 1936-1969

Vehicle Specific

Jims Idler Shaft And Bushing Kit For Harley Big Twin 1936-1969

James Embossed Copper Cylinder Head / Base Gaskets For Harley Knucklehead 1936-1947

Vehicle Specific

James Embossed Copper Cylinder Head / Base Gaskets For Harley Knucklehead 1936-1947

Sifton Solid Pushrod Set For Harley Knucklehead 1941-1947

Vehicle Specific

Sifton Solid Pushrod Set For Harley Knucklehead 1941-1947

V-Twin Mfg. Crank Pin Lock Kit For Harley EL UL 1936-1952

Vehicle Specific

V-Twin Mfg. Crank Pin Lock Kit For Harley EL UL 1936-1952

V-Twin Mfg. Cam Bushing For Harley FL EL 1936-1954

Vehicle Specific

V-Twin Mfg. Cam Bushing For Harley FL EL 1936-1954

V-Twin Mfg. Top End Gasket Kit For Harley FL EL 1941-1947

Vehicle Specific

V-Twin Mfg. Top End Gasket Kit For Harley FL EL 1941-1947

V-Twin Mfg. Rocker Cover Nuts For Harley Knucklehead 1936-1947

Vehicle Specific

V-Twin Mfg. Rocker Cover Nuts For Harley Knucklehead 1936-1947

V-Twin Mfg. Connecting Rod Race Set For Harley 1936-1999

Vehicle Specific

V-Twin Mfg. Connecting Rod Race Set For Harley 1936-1999

Eastern Motorcycle Parts Cam Bushing For Harley Side Valve Big Twin 1936-1948

Vehicle Specific

Eastern Motorcycle Parts Cam Bushing For Harley Side Valve Big Twin 1936-1948

Eastern Motorcycle Parts Oversize Cam Bushing For Harley 1936-1969

Vehicle Specific

Eastern Motorcycle Parts Oversize Cam Bushing For Harley 1936-1969

V-Twin Mfg. Valve Spring Set For Harley G 1932-1940

Vehicle Specific

V-Twin Mfg. Valve Spring Set For Harley G 1932-1940

Eastern Motorcycle Parts Connecting Rod Race Sets For Harley Big Twin 1941-1999

Vehicle Specific

Eastern Motorcycle Parts Connecting Rod Race Sets For Harley Big Twin 1941-1999

Sifton Steel Exhaust Valve For Harley U Models 1937-1948

Vehicle Specific

Sifton Steel Exhaust Valve For Harley U Models 1937-1948

V-Twin Mfg. Upper Collar Set For Harley Big Twin 1936-1984

Vehicle Specific

V-Twin Mfg. Upper Collar Set For Harley Big Twin 1936-1984

V-Twin Mfg. Nitrate Valve For Harley FL / EL 1938-1947

Vehicle Specific

V-Twin Mfg. Nitrate Valve For Harley FL / EL 1938-1947

$43^.⁹⁸$49^.⁰⁵

Sifton Steel Inlet Valve For Harley U Series 1937-1948

Vehicle Specific

Sifton Steel Inlet Valve For Harley U Series 1937-1948

V-Twin Mfg. Crankcase Pinion Shaft Retainer Cage For Harley FL EL UL 1936-1954

Vehicle Specific

V-Twin Mfg. Crankcase Pinion Shaft Retainer Cage For Harley FL EL UL 1936-1954

Colony Knucklehead Rocker Mounting Kit For Harley E / F 1936-1947

Vehicle Specific

Colony Knucklehead Rocker Mounting Kit For Harley E / F 1936-1947

$27^.⁸⁰$34^.⁹⁸

V-Twin Mfg. Steel Valve Collar For Harley 1932-1973

Vehicle Specific

V-Twin Mfg. Steel Valve Collar For Harley 1932-1973

V-Twin Mfg. Nitrate Exhaust Valve For Harley FL EL 1938-1947

Vehicle Specific

V-Twin Mfg. Nitrate Exhaust Valve For Harley FL EL 1938-1947

V-Twin Mfg. Crank Pin Nuts For Harley FL 1941-1953

Vehicle Specific

V-Twin Mfg. Crank Pin Nuts For Harley FL 1941-1953

V-Twin Mfg. Crank Pin Lock Kit For Harley FL 1941-1953

Vehicle Specific

V-Twin Mfg. Crank Pin Lock Kit For Harley FL 1941-1953

V-Twin Mfg. Flywheel Crank Pin Thrust Washer Set For Harley EL UL 1936-1952

Vehicle Specific

V-Twin Mfg. Flywheel Crank Pin Thrust Washer Set For Harley EL UL 1936-1952

V-Twin Mfg. Inside Flywheel Thrust Washer For Harley EL 1936-1952

Vehicle Specific

V-Twin Mfg. Inside Flywheel Thrust Washer For Harley EL 1936-1952

Eastern Motorcycle Parts Left Case Oil Slinger For Harley Big Twin 1940-1954

Vehicle Specific

Eastern Motorcycle Parts Left Case Oil Slinger For Harley Big Twin 1940-1954

V-Twin Mfg. Tank Emblem Gasket For Harley FL EL UL 1940-1946

Vehicle Specific

V-Twin Mfg. Tank Emblem Gasket For Harley FL EL UL 1940-1946

V-Twin Mfg. Rocker Cover Screw Set For Harley FL EL 1936-1947

Vehicle Specific

V-Twin Mfg. Rocker Cover Screw Set For Harley FL EL 1936-1947

Eastern Motorcycle Parts Connecting Rod Rollers For Harley Big Twin 1941-1972

Vehicle Specific

Eastern Motorcycle Parts Connecting Rod Rollers For Harley Big Twin 1941-1972

V-Twin Mfg. Replacement Welch Plug For Harley Big Twin 1936-1984

Vehicle Specific

V-Twin Mfg. Replacement Welch Plug For Harley Big Twin 1936-1984

$19^.⁹⁹$23^.⁶⁸

V-Twin Mfg. Oil Pump Mounting Screw For Harley FL 1941-1949

Vehicle Specific

V-Twin Mfg. Oil Pump Mounting Screw For Harley FL 1941-1949

1 2 3 4 of 4

$39.99/yr.

Spend Less. Ride More.

5% RPM Cash Back*
10% Off Over 70 Brands
$15 in RPM Cash When You Join
Free 2-Day Shipping & Free Returns*
And more!

Become a member today! Learn More

By purchasing and enrolling in Riders Preferred Membership, you agree to the Program Terms and Conditions. *Some exclusions apply: 10% RPM discount applies on full price and sale price Exclusive Brands. 10% RPM discount applies on additional select brands at full price. Exclusions apply. RPM free 2-day shipping applies on qualifying items, contiguous U.S. only. Not available for AK, HI, or U.S. Territories. View shipping policies. RPM free returns apply on qualifying items and are processed on standard return timeline, contiguous U.S. only. View return policy.