NHRA Rules Bulletin!

NHRA releases PSM engine specs for 2013

story and photos by Tim Hailey


After some speculation that there would be differening engine configurations for the Harley and S&S V-twins, the NHRA has instead kept it simple. And yet, NHRA VP of technical operations Glen Gray claims this was a difficult task. “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 Gray, who apparently turned a deaf ear to those insisting the Vance & Hines Harleys follow the availability rule required of all other manufacturers. Barring any off-season shenanigans, here are the rules—which still leave the winless-for-2012 Suzukis at a disadvantage:

· 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.

o Maximum 2 valves per cylinder for all engines.
o 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.

“As a result," Gray added, |We believe NHRA fans are in store for some exciting side-by-side racing in the Pro Stock Motorcycle category in 2013.” Like before the OHC rules change 4 years ago?

EARLIER: Holy Crap! NHRA outlaws Harley's 4V OHC for 2013!

Match-ups between Harleys like Andrew Hines' (near lane) and the rest of the field should be more even in 2013

In an after-hours press release (received tonight (9/19/12) at 8:18 Eastern time, the NHRA finally took back the big mistake made three and a half years ago when they slipped in a 4 valve head, overhead cam option for the Harley-Davidsons only. That obvious performance advantage ignited an outroar that has flared and waned over the years, but has recently been revived by George Bryce, half of the G2 team that developed the Buell concept around the S&S Pro Stock engine. Bryce left NHRA Pro Stock Motorcycle racing at that time, but has returned this year and been relentless in his criticism.

The NHRA release reads as follows:

Today NHRAannounced changes to the Pro Stock Motorcycle category. For 2013, Harley-Davidson and Buell will both be allowed a maximum 160-cubic inch displacement (cid), for a 60-degree, two-valve, pushrod engine. Minimum weight for both motorcycles will be set at 625 pounds. The four-valve Harley-Davidson engine combination will no longer be allowed. Suzuki will still have a maximum of 107-cid, for a two-valve engine. Minimum weight on the Suzuki will be 595 pounds. NHRA also will discontinue the four-valve option on the Suzuki motorcycle.

In the interim, NHRA announced a minimum weight increase of 10 pounds for Harley-Davidson competitors in the Pro Stock Motorcycle class. The change will be in effect at this weekend’s 27th annual AAA Texas NHRA Fall Nationals at the Texas Motorplex in Dallas. The new minimum weight for Harley-Davidson motorcycles will be 670 pounds.

“We have been working on a long-term solution for the Pro Stock Motorcycle class for the last several months,” said Glen Gray, vice president of technical operations, NHRA. “Today’s announcement is part of our ongoing effort to provide great side-by-side racing for NHRA fans.”

Racer Reaction

"For next year, the rules change is going to be good for everyone and it'll level the playing field in the class," said Buell rider Hector Arana Jr, who along with his father are qualifiers 3 & 4 behind the Harleys at virtually every race this year. "For this year, I don't see the extra 10 pounds on the Harleys making much of a difference."

For Suzuki campaigners, it looks like another long year. "Nothing will change for the Suzukis," said Gary Stoffer. His team, with rider/wife Karen, is losing their sponsor GEICO next season—perhaps because as consistently the quickest Suzuki, they are always behind the Harleys & Hectors. But without a sponsor, it would be tough for them to pony up for billet heads and cases—the next step up for the tired, old GS motors.

This is what George Bryce had to say about the old (current through 2012) rules

And the last word from Bryce himself, who currently fields two Buells: "VHR will continue to win..winners win," George said about his old nemesi. "But some other racer may have a chance now. I’m really happy with NHRA’s decision on the rules. It’s going to make the class more exciting, more fun to watch and we’ll potentially get some new interest in our class because it’ll be more exciting and fun. THANK you to all of you that helped make the loud noise that NHRA heard!"

“I think it’s great that they’re finally doing something about the unfair Harley advantage," said Bryce's rider Scotty Pollacheck. "It’s not going to really help us much this year because the 10-pound thing isn’t a big deal for the Harleys. Next year it’ll make the class better, though, and will help the morale of the teams and racers.”