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[Johnny D]

Full.
http://cdn.growasset....pdf?1442847031

Club.
http://cdn.growasset....pdf?1442847033
J~

Recommended Items for 2016

SM
1. #16480 (Kyle Webb) Taping of Grill
Change 9.1.7.C.1.o.2 and .5:
2. Any radiator (and mounting brackets) may be used, provided it is mounted in the original location, maintains the same plane as
the original core, and requires no body or structure modifications to install. Any openings created by fitting an alternate radiator
must be blocked to prevent air from entering the engine compartment. At least one functional stock OEM cooling fan must be
maintained and mounted in the stock location. The fFan shroud and brackets may be modified for installation.
5. A radiator screen of 1/4 .125 inch minimum mesh may be added in front of the radiator. The screen must be a single layer and
installed behind the front bumper cover and attached to the air guide. Tape and/or other materials may not be applied to the mesh
or in the radiator opening in the bodywork. Tape or other materials may only be added directly to the radiator.

CLUB RACING TECHNICAL BULLETIN

Spec Miata
1. #17428 (Dan Tiley) Add tolerance specification to the SM exhaust tubing diameter
Effective immediately, in GCR section 9.1.7.C.1.m.4.a, clarify exhaust tubing size as follows:

“The replacement system retains the original configuration (i.e., single tube design) and the tubing is an absolute maximum of
2.25 2.3 inches outside diameter as measured at least 6” from downpipe flange or muffler.”

 

Note: See Racing Memo RM 15-10.

 

2. #17700 (SCCA Staff) Clarify the Plunge Cut Language

 

In GCR section 9.1.7.1.f.3, add the following language

 

“The throat area of the port consists of the 90 degree angle at the very bottom of the cast steel valve seat as it transitions to the
aluminum casting below. It is permitted to plunge cut the throats in order to correct for core shift that is commonly found in many
cylinder heads. The cut must be cylindrical and concentric to the valve guide axial centerline, within a tolerance of .005”, for the
entire length of the cut. The radius tangent to the cylindrical and bottom surfaces shall not exceed 0.375”. This cut cannot extend
further than the specified number below from the bottom of the ferrous valve seat. There can be no tooling or machine marks in
the head below this point (including OEM machine marks). The intersection of the machined surface of the plunge cut to the port
casting shall not be altered, except that the area under the short turn radius may be de-burred, with the de-burring not to exceed
1.5 mm in width. The 90 degree bend at the bottom of the valve seat and the aluminum directly below it will be measured with a
gauge and must conform to the maximum diameters and depths listed below.”

 
Note: See Racing Memo RM 15-13.