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 ]

Jun 28- CHICAGO - Coming Home Means a Great Deal to Top Fuel Driver Terry Mcmillen
Jun 28- CHICAGO - Fact Sheet
Jun 28- NORWALK - Sunday Videos
Jun 28- 'Voice Of The NHRA' Dave McClelland to be Inducted into MSHFA June 29
Jun 27- NORWALK - Lucas Oil Drag Racing Series Wrap Up
Jun 27- NORWALK - Special Awards
Jun 26- NORWALK - Pro Mod Sunday Wrap Up
Jun 26- NORWALK - Sunday Wrap Up
Jun 26- NORWALK - Championship Points
Jun 26- NORWALK - Pro Mod Championship Points

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