Boyce Caps

George Hurlbert Boyce founded The Boyce MotoMeter Company of Long Island, NY andpatented The Boyce MotoMeter in 1912.  Non-pressurized thermosiphon cooling systems common until the mid thirties had lower boiling point and the aftermarket driver-visible gauge showed the temperature of the radiator. 

Later, vehicle builders began to offer them as standard or optional equipment, and dealerships began to offer them also, sometimes as give-away or incentive items. The MotoMeter Company soon delivered these with metal dials inside that showed the maker's or dealer's logo with script printed on it. 

The standard motometer came in three sizes: for small cars, medium cars, and large cars and trucks. There were also slight changes to each of the original models and new designs, and accessories such as hood ornaments, toppers, illuminating devices or locks.

Toppers were small metal castings that fitted to a bracket on the motometer. They were used in a similar way as modern decals showing the vehicle owner's heritage, profession, preferences, his business, his preferred sports, or even a political statement. Toppers were also offered by other novelty producing companies, Ronson among them. By 1927 Boyce company was offering a wide variety of motometer, but the device became obsolete when dash-mounted temperature gauges appeared around 1930. 

Cap Number OD - TPI   Cap Number OD - TPI
Boyce 1554 1 3/4 - 16tpi   Boyce 1570 2 1/2 - 16tpi
Boyce 1555 1 1/2 - 16tpi   Boyce 1596 2 - 16tpi
Boyce 1556 2 1/8 - 16tpi   Boyce 1601 2 3/8 - 16tpi
Boyce 1557 2 1/8 - 16tpi   Boyce 1603  
Boyce 1558 2 - 18tpi   Boyce 1556A 2 - 16tpi
Boyce 1559 2 1/8 - 14tpi   Boyce 1557A 2 1/8 - 18tpi
Boyce 1560 2 - 18tpi   Boyce 1560A 2 - 16tpi
Boyce 1561 1 7/8 - 16tpi   Boyce 1570A 2 1/2 - 14tpi
Boyce 1562 2 1/4 - 16tpi   Boyce 1596A 2 - 18tpi


Applications sorted by Manufacturer Applications sorted by Part number
Apperson 1921 & Later 1570A Chevrolet 490 Late Model 1554
Auburn 1557 Maxwell 1915-1918 1554
Briscoe 1561 Oldsmobile, Light Six, 1924 1554
Buick 1557 Star 1554
Buick, 4 Cylinder, 1924 1603 Chevrolet 490 1554A
Buick, 6 Cylinder, 1924 1601 Reo 1554A
Cadillac 1562 Chalmers 1556
Chalmers 1556 Davis 1556
Chalmers, 1922, 1923 1562 Empire 1556
Chandler 1559 Haynes 1556
Chevrolet 490 1554A Interstate 1556
Chevrolet 490 Late Model 1554 King 1556
Chevrolet Baby Grand 1562 Iternational 1556
Chevrolet Little Six 1557A Lexington 1556
Chevrolet Royal Mail 1562 Liberty 1556
Cleveland 1560 Mitchell 1556
Cole 1559 Moon 1921, 1922, 1923 1556
Davis 1556 Oldsmobile 1937,1945,1943,1946-1947 1556
Dodge 1560 Pierce-Arrow 1556
Durant 4 Cylinder 1557 Premier 1556
Durant 6 Cylinder 1562 Saxon, 6 Cylinder 1556
Earl 1561 Scripps-Booth, Late Models 1556
Elgin 1918 & Later 1559 Standard Car, 8 Cylinder 1556
Empire 1556 Stearns 4 & 6 Cylinder, 1923-1924 1556
Essex 1562 Stephen 1556
Ford 1558 Templar 1556
Gardner 1562 Wescott Including 1920, 1922, 1923 1556
Grant 1562 Winton 1556
Gray 1562 King 1556A
Haynes 1556 Auburn 1557
Hudson 6-40 1562 Buick 1557
Hudson Super Six 1562 Durant 4 Cylinder 1557
Hupp 1918 & Later 1561 Marmon All Before 1921 1557
Interstate 1556 Nash 1557
Iternational 1556 Oakland 1557
Jackson 1562 Chevrolet Little Six 1557A
Jeffrey 1559 Marmon 1921-1924 1557A
Jewett 1559 Ford 1558
Jordon 1917 1656 Chandler 1559
King 1556A Cole 1559
King 1556 Elgin 1918 & Later 1559
King 1923 1559 Jeffrey 1559
Kissel-Kar 1919 & Later 1579A Jewett 1559
Lexington 1556 King 1923 1559
Lexington 1923 1562 McFarlan 1559
Liberty 1556 Oldsmobile 1942, 1943 1559
Lincoln 1562 Owen Magnetic 1559
Marmon 1921-1924 1557A Paige 1559
Marmon All Before 1921 1557 Stearns-Knight, 4 Cylinder 1559
Maxwell 1915-1918 1554 Stevens-Duryea 1559
Maxwell 1919 & Later 1560A Cleveland 1560
Maxwell Special 6 3/4 Inch 1596A Dodge 1560
McFarlan 1559 Studebaker 1560
Mercer 1562 Maxwell 1919 & Later 1560A
Mitchell 1556 Overland, 4 Cylinder, 1923 1560A
Moline 1562 Rickenbacker 1560A
Moon 1921, 1922, 1923 1556 Willys-Knight 1922, 1923 1560A
Moreland 1596A Briscoe 1561
Nash 1557 Earl 1561
National 1570A Hupp 1918 & Later 1561
Oakland 1557 Cadillac 1562
Oldsmobile 1937,1945,1943,1946-1947 1556 Chalmers, 1922, 1923 1562
Oldsmobile 1942, 1943 1559 Chevrolet Baby Grand 1562
Oldsmobile, Light Six, 1924 1554 Chevrolet Royal Mail 1562
Overland, 4 Cylinder, 1923 1560A Durant 6 Cylinder 1562
Owen Magnetic 1559 Essex 1562
Paige 1559 Gardner 1562
Patterson 1562 Grant 1562
Peerless 1562 Gray 1562
Pierce-Arrow 1556 Hudson 6-40 1562
Premier 1556 Hudson Super Six 1562
Reo 1554A Jackson 1562
Rickenbacker 1560A Lexington 1923 1562
Saxon, 6 Cylinder 1556 Lincoln 1562
Scripps-Booth, Late Models 1556 Mercer 1562
Standard Car, 8 Cylinder 1556 Moline 1562
Star 1554 Patterson 1562
Stearns 4 & 6 Cylinder, 1923-1924 1556 Peerless 1562
Stearns-Knight, 4 Cylinder 1559 Stearns-Knight, 6 Cylinder 1562
Stearns-Knight, 6 Cylinder 1562 Wills-Saint Claire 1562
Stephen 1556 Willys-Knight 1921 1569
Stevens-Duryea 1559 Velle 1920 & Later 1570
Studebaker 1560 Apperson 1921 & Later 1570A
Templar 1556 National 1570A
Velle 1920 & Later 1570 Kissel-Kar 1919 & Later 1579A
Wescott Including 1920, 1922, 1923 1556 Moreland 1596A
Wills-Saint Claire 1562 Maxwell Special 6 3/4 Inch 1596A
Willys-Knight 1921 1569 Buick, 6 Cylinder, 1924 1601
Willys-Knight 1922, 1923 1560A Buick, 4 Cylinder, 1924 1603
Winton 1556 Jordon 1917 1656