Here is my outlook on this issue, and I am sure that there will be many that disagree with my perspective.
IMHO what we all want is Spec Miata to be a great competitive class where we can all race heads up on an equal playing field.
Back when SM started, long before I as involved, the class was “fast and loose†and over the years the CRB and SMAC have worked to tighten up the specs, and as a result our racing is closer than ever before. We have an amazing class, filled with talent and drivers that can and do succeed in the pro ranks. The fact that this class, more than any other class, attracts so many pro drivers to keep their skills sharp is something that we should all be proud of.
So far this year, as far as I know, there have only been two compliance issues and I am embarrassed to say that I was one of them. There also have been no protests. But if one thing that STR and Compression Gate have taught us recently is that there will always be areas that people are playing in to gain an advantage, and there will be those that keep us straight by protesting non-compliant vehicles.
To many, the practice of radiusing the Valve Unshroud cut appears to be an area of competitive advantage. So lets take a look at this area of contention….
As I said the SMAC and CRB have worked hard over the past few years to tighten up the specs for the Spec Miata heads since the stock heads, as delivered from the factory, had significant variation in compression, plunge cuts, valve unshroud cuts etc. So specs were drawn up, close to the upper limits of what had been found on stock heads, and these specs allowed heads that were under these tolerances to be machined so that they could be “equalized†to those at the upper end of the limit.
It was well known and understood by the SMAC and CRB that there might still be some outlier stock heads that exceeded some of these dimensions, and those heads would have to be relegated to another class, but they would not be compliant in Spec Miata
Current and past members of the SMAC that were involved with drawing up the valve unshroud rule 9.1.7.C.1.a.1.f.5, knew the intent of the word “SHARP†and the words "That edge must be present and unmodified. This area is not to be blended by hand, machined, or chemically processed to create a smooth transitionâ€. Stock heads have ZERO Radius in the valve unshroud cut.
But just as some builders chose to ignore the STR spec, some builders chose to ignore the UNSHROUD spec and produced heads with a radiused / blended transition.
For many this is not considered a gray area or a creative interpretation! For them cutting valve unshrouds with a radius, is an outright contravention of the spec.
So looking forward, what do we do? Do we, in the interest of the class, just rollover and move the spec to accommodate the radiused valve unshroud cut? Or do we stick to the spec as intentioned, define sharp as 90 degrees with a small allowance for tool wear. In the short term moving the spec to accommodate this seems like a sensible thing to do, but if we keep on pushing out the spec to accommodate the manipulation of the spec, we will chase away even more drivers from this class.
At which point do we send a message that says this continual pushing of the rules has to stop???
Each of you will have your own opinion on this matter, so I urge you to write your letter and get the CRB to implement the clarification that you want. Go to http://www.crbscca.com/ and write your letters.