7 replies to this topic

[Bench Racer]

Darrell, please splane this Tech Bull.


DATE: July 20, 2012
NUMBER: TB 12‐08
FROM: Club Racing Board
TO: Competitors, Stewards, and Scrutineers
SUBJECT: Errors and Omissions, Competition Adjustments, Clarifications, and Classifications
All changes are effective 8/1/2012 unless otherwise noted.

NOTE: This preliminary version of the Club Racing Technical Bulletin is provided at this time as a service
to the membership. These items may be corrected and will not be official until published on the Fastrack
page of the scca.com website on or about July 20.

Spec Miata
1. #8730 (Jim Drago) Clarify the use of shot peening.
In section 9.1.8.C.1.c.1, clarify the crankshaft language by adding the following:
"The stock Mazda Miata crankshaft must be used with no modifications except for machining to allow
the use of main and rod bearings as allowed in 2 below. Shot peening to stress relieve the crankshaft
after machining is permitted. The following table lists the permitted crankshaft for each model year and
the minimum weight (not including pilot bearing or hardware)."

[pat slattery]

Must be one of those everyone is doing it deals so lets make it legal

[Jim Drago]

Since allowing the cranks to be turned( cost saving, not performance enhancing) when the 09 engine rules and specs went into the GCR, people obviously started turning their cranks when they lost a bearing rather than replacing the cranks. Shot peening is spelled out "legal" in other classes where it is legal to turn cranks, since turning cranks is legal in SM and our rules are so specific, The CRB decided to spell it out in SM as well, it is SOP and ma be considered implied when the rule passed, we chose to make clear by spelling it out. Any machine shop that is competent enough to turn a Miata crank correctly, will shot peen to stress relieve the journals. This is not a performance enhancement, unless you count a hard journal that will not deteriorate and cause yet another bearing failure, a performance modification. This is ancient ( literally) technology, nothing new, google is your friend




Jim

[DES4]

Edited to "nevermind"...

[Bench Racer]

This is ancient ( literally) technology, nothing new, google is your friend
Jim

Since allowing the cranks to be turned( cost saving, not performance enhancing) when the 09 engine rules and specs went into the GCR,

Since you have implied that I have no knowledge of technology and don't know how to use Google, I sure as well can't read/understand the GCR SMCS, therefore will you please specify the 09 or 10 engine rules and specs within the GCR SMCS that allows cranks to be turned.

If I were writting a rule, I'd use the word grind relative to decreasing the size of crank journals, turning is a lathe single point tool process. I could talk further about shoot peening, but that would only complicate and clutter the discussion.

[Jim Drago]

You asked to explain, I did.( against my better judgement) nothing was implied... If you are not happy with current rule or want this rule or any other written differently or further clarified, you know that process as well, Send in a letter stating as much.

[Bench Racer]

You asked to explain, I did.( against my better judgement) nothing was implied...

Since you have implied that I have no knowledge of technology and don't know how to use Google, I sure as well can't read/understand the GCR SMCS, therefore will you please specify the 09 or 10 engine rules and specs within the GCR SMCS that allows cranks to be turned.

Come on Jim, your a note motor builder and on the CRB, you should be able to support a SCCA member finding the rule within the GCR SMCS that allows cranks to be turned.

[Jim Drago]

<sup>David
Your first post, I was foolish enough to think you wanted an answer to the question you asked. You asked to explain the addition to a rule that is almost three years old?Your 'asking" now to point out a rule that allows cranks to be turned, In actuality, your not asking, (you are challenging or questioning the validity) As you are aware, you quoted it in your first post.

You don't like the word "machining" , in order to install smaller rod/main bearings, you must "machine",( but again, you know this as well) if you don't like that word and would prefer another like "turn" or "grind", send a letter. I think it is clear, but have no issues adding other words as well. But won't do so less a letter from someone asking as much.

Or do you have a problem with cranks being turned/ground or machined?


This is my last post on this matter. If you need further clarification, you can email or call me directly.</sup>