Technical Bulletin #TB2016-001 Definitions

Subject: Definitions
From: Rick Parent, Technical Director

TB2016_001_Definitions (PDF)

Here are a few definitions to serve as a reminder to all SVRA competitors. These definitions are not new and have been part of the SVRA rules and regulations for years.


– Bore and stroke as provided by the manufacturer for make and model, Bore may be increased by .047ยด (1.2mm) (Group Rules)
– An overbore of 1.2mm or .047″ is permitted unless class rules state otherwise. The standard stroke must be retained. (General Rules)

Replacement Aftermarket Heads:

– Cylinder head must be series produced by manufacturer for make and model. Stock appearing aftermarket heads of correct material, valve angle and plug angle are permitted. (Group Rules)
– Blocks and heads must be of the same material and design as provided by the manufacturer. Modern aftermarket blocks and heads are prohibited unless they are identical to the originals. (General Rules)


– Wheels may be of an alternate material but must be of a period design. (Group Rules)
– Wheel diameter must be as originally fitted unless permitted in (the Spec Sheets). The standard width may be increased by 1.5″. Any other diameter or width must be a specifically listed option. Wheel design must look period correct. (General Rules)

Suspension Pickup Points and Geometry:

– The system of suspension (spring, shock type and control arms) may not be changed and must attach to the stock mounting locations. (General Rules)
– All hubs, spindles, axles, axle housings, drive shafts, lug bolts, mounting points and other suspension parts may be strengthened for safety as long as the track width, wheel base and geometry is not altered. (General Rules)


– Braking system must be of the same type as was standard or offered as an option. (General Rules)
– Alternate calipers or wheel cylinders must be of the same material, design and number of pistons as the original component. There must be no increase in the frictional surface of the pads or shoes. (General Rules)
– Disc brake calipers must be of same material, design, and number of pistons as standard unless listed as an option. (Group Rules)

Roll Cage:

– Suitable roll bars are required on all cars. The actual design is left up to the car owner, but should follow sound engineering standards. The SVRA publishes a separate sheet on roll bar guidelines. These are derived from SCCA specifications.

The basic purpose of the roll bar is to protect the driver if the car rolls over or is involved in a serious accident. Parts of the roll bar or roll cage deemed to serve no practical purpose other than chassis stiffening may be considered in violation of the intent of these rules and can be subject to weight penalty or reclassification.

The top of the main hoop must be 2″ inches above the driver’s helmet, there must be a padded headrest within 3″ of the driver’s helmet and all parts of the car or roll bar that could come in contact with the driver’s head must be padded. (General Rules)

If your car conflicts with any of the items listed above please send an updated ECF and or RCCF listing the items and your plan of action for correcting them.

Please keep in mind that all groups are limited to a specific point in time concerning car preparation.
– Groups 1&3) 1967
– Group 2, 5, 7, 9, 10, 11, 12) Cars must be prepared to their specific claimed point in time.
– Group 4) Pre 1960
– Group 6 & 8) 1972