Mon, 19 Nov 2012, 06:16 AM
2013 NHRA Pro Stock Motorcycle Engine Specifications
Courtesy of NHRA Communications
"NHRA spent countless hours speaking with the engine builders and manufacturers as well as the
race teams to come up with the final engine specifications for 2013," said Glen Gray, vice
president of technical operations, NHRA. "As a result, we believe NHRA fans are in store for some
exciting side-by-side racing in the Pro Stock Motorcycle category in 2013."
• V-twin design - up to 160 cid
• In-Line 4 cylinder type - up to 107 cid
• V-twin engine cylinder angle is 60 degrees. Maximum allowable cylinder angle from vertical
is 45 degrees.
• Maximum bore spacing is 98mm for In-Line. Maximum cylinder offset on V-twin is 1".
• All V-twin engines must use a push-rod, rocker arm design for the valve activation. Minimum
push-rod length is 8.0".
• All in-line 4 cylinder engines must use the overhead camshaft design.
• Maximum 2 valves per cylinder for all engines.
• The only exception is the Kawasaki engine. The Kawasaki engine is allowed maximum of 4
valves per cylinder.
• Variable cam timing devices, pneumatic actuation and finger followers are not permitted.
• Fuel injection permitted.
• Direct injection (into the combustion chamber) not permitted.
• All ECU systems must be NHRA accepted.
• Maximum one injector per cylinder.
• All ignition systems must be NHRA accepted.
• Aftermarket crank triggered, capacitive discharge (cd) ignition systems permitted.
• Magnetos are not permitted.
NHRA: 10 Most Recent Entries [ top ]
Mar 28- LAS VEGAS 1 - Clay Millican Remains Confident First Win Coming Approaching Denso Spark Plugs NHRA Nationals
Mar 27- Enders Voted into K&N Horsepower Challenge at Las Vegas
Mar 27- Toyota Extends Sponsorship as Official Car of NHRA
Mar 27- GAINESVILLE - Through the Lens of Gary Nastase
Mar 24- Tickets are Now On Sale for the Fastest Race in Texas
Mar 24- NHRA Highlights Sonoma Raceway 2017 Drag Racing Schedule
Mar 24- Bristol Motor Speedway/Dragway Executive Jeff Byrd Inducted into International Drag Racing Hall of Fame
Mar 24- HOUSTON - Event Preview
Mar 23- Wichita Raceway Park Joins NHRA Member Track Network
Mar 23- GAINESVILLE - Through the Lens of Ron Lewis