Search for in
NHRA LODRS IHRA PDRA Drag News Photos
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."

MAXIMUM DISPLACEMENT:
• V-twin design - up to 160 cid
• In-Line 4 cylinder type - up to 107 cid

ENGINE CASE:
• V-twin engine cylinder angle is 60 degrees. Maximum allowable cylinder angle from vertical is 45 degrees.

ENGINE BLOCK:
• Maximum bore spacing is 98mm for In-Line. Maximum cylinder offset on V-twin is 1".

CYLINDER HEAD:
• 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.

VALVETRAIN:
• 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 SYSTEM:
• Fuel injection permitted.
• Direct injection (into the combustion chamber) not permitted.
• All ECU systems must be NHRA accepted.
• Maximum one injector per cylinder.

IGNITION SYSTEM:
• 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 ]

Dec 09- Courtney Force Announces Sponsorship Relationship with Advance Auto Parts Starting in 2017
Dec 08- Drag Racing Champions Jeg Coughlin Jr., Erica Enders Return to Chevrolet
Dec 06- Team Kalitta Announces Driver Changes
Dec 05- Operation Appreciation (Day 4)
Dec 04- Operation Appreciation (Day 3)
Dec 01- Operation Appreciation (Day 2 Continued)
Dec 01- Operation Appreciation 2016 (Day 2)
Nov 30- Operation Appreciation 2016 (Day 1)
Nov 25- One-on-One with NHRA Mello Yello Drag Racing Series Champion Ron Capps
Nov 24- One-on-One with NHRA Mello Yello Drag Racing Series Champion Jason Line

Copyright ©2016 AUTOSALES INC, dba Summit Racing Equipment
Ready to take your order at 1-800-230-3030 | Customer Service 1-800-517-1035