V-Twin 18mm Doering Spark Plug Set for 1924–1936 Harley VL RL
The V-Twin 18mm Doering Spark Plug Set recreates the authentic Doering design for air-cooled Harley-Davidson VL and RL engines from 1924 to 1936, delivering restoration-quality ignition with a large hex that mirrors the original equipment.
Designed for early Harley models that use a 7/8 inch thread, including Knucklehead and IOE configurations, this set features ventilated brass collars for improved cooling and a nickel-plated full-size hex for durability and a secure fit during installation and maintenance. The plugs include terminal nuts and seal washers to ensure proper sealing and electrical contact.
- Large 1-3/8 inch hex for secure installation in early Harley models with large-hex requirements
- Ventilated brass collars promote effective cooling in air-cooled engines
- Nickel-plated full-size hex enhances durability and fit
- Designed for 7/8 inch thread Harley-Davidson engines
- Includes a round feeler gauge; gap set at.025 inches for optimal performance
- Some head fins may require clearancing to fit large hex plugs
- Made in Taiwan; manufactured to original-era standards with OEM cross references
- Compatible with Harley-Davidson G, J, JD, RL, VL, U, and W models from the 1920s through the 1940s
The set is complemented by accessory items such as a matching spark plug socket and additional plug sets to support comprehensive maintenance and restoration projects.
Large hex original design for air cooled engines #3 heat range terminal nuts and seal washers included.
Designed specifically for 1924 to 1936 Harley Davidson VL and RL models, the V-Twin 18mm Doering Spark Plug Set offers authentic restoration quality with features that match the original equipment. The set includes spark plugs with a 1-3/8 inch large hex, ideal for early Knucklehead and IOE engine types that require a 7/8 inch thread. Crafted with ventilated brass collars, these plugs facilitate effective cooling, mimicking the original Doering design established in Brooklyn, NY in 1918. The nickel-plated full-size hex ensures durability and a secure fit during installation and maintenance. This set is perfect for vintage motorcycle enthusiasts seeking an authentic restoration experience, combining historical accuracy with reliable performance. The plugs are manufactured to the standards of the original era, offering excellent compatibility with early Harley models, and are suitable for use in air-cooled engines where space permits the large hex size. The set is complemented by accessory items like a matching spark plug socket and additional plug sets, ensuring comprehensive maintenance options. Proper installation requires setting the gap to.025 inches, and some head fin clearancing may be necessary to accommodate the large hex plugs. Made in Taiwan, this set adheres to OEM cross references, providing a trusted solution for vintage Harley Davidson restorations.
Features:
- Includes ventilated brass collars for optimal cooling
- Large 1-3/8 inch hex for secure installation in early Harley models
- Nickel-plated full-size hex for durability and secure fit
- Set designed for 7/8 inch thread Harley Davidson engines
- Includes a round feeler gauge for accurate gap setting
- Manufactured to original standards of the early 20th century
- Some head fins may require clearancing to fit large hex plugs
- Set gap at.025 inches for optimal performance
Fitment:
Harley Davidson G 1936
Harley Davidson G 1937
Harley Davidson G 1938
Harley Davidson G 1939
Harley Davidson G 1940
Harley Davidson G 1941
Harley Davidson G 1942
Harley Davidson G 1943
Harley Davidson G 1944
Harley Davidson G 1945
Harley Davidson G 1946
Harley Davidson G 1947
Harley Davidson J 1926
Harley Davidson J 1927
Harley Davidson J 1928
Harley Davidson J 1929
Harley Davidson JD 1924
Harley Davidson JD 1925
Harley Davidson JD 1926
Harley Davidson JD 1927
Harley Davidson JD 1928
Harley Davidson JD 1929
Harley Davidson JD 1930
Harley Davidson RL 1930
Harley Davidson RL 1931
Harley Davidson RL 1932
Harley Davidson RL 1933
Harley Davidson RL 1934
Harley Davidson RL 1935
Harley Davidson RL 1936
Harley Davidson U 1937
Harley Davidson U 1938
Harley Davidson U 1939
Harley Davidson U 1940
Harley Davidson U 1941
Harley Davidson U 1942
Harley Davidson U 1943
Harley Davidson U 1944
Harley Davidson U 1945
Harley Davidson U 1946
Harley Davidson U 1947
Harley Davidson U 1948
Harley Davidson VL 1930
Harley Davidson VL 1931
Harley Davidson VL 1932
Harley Davidson VL 1933
Harley Davidson VL 1934
Harley Davidson VL 1935
Harley Davidson VL 1936
Harley Davidson W 1937
Harley Davidson W 1938
Harley Davidson W 1939
Harley Davidson W 1940
Harley Davidson W 1941
Harley Davidson W 1942
Harley Davidson W 1943
Harley Davidson W 1944
Harley Davidson W 1945
Harley Davidson W 1946
Harley Davidson W 1947
