2 replies to this topic

[wheel]

The BoD passed a slightly different SM relief cut clarification for implementation on 1/1/2016.  It does not become official until published in the Fastrack, which will happen as soon as the new diagram is finished.  Due to member input, the bottom of the cut is now defined with a maximum blend of .010", rather than the .040".   I also must point out the the current rule, which calls for a "sharp edge" is still in effect.  If you intend on finishing in the top six at the Runoffs, I would suggest that you be sure your heads comply with this rule (as well as all the rest).  The fact that there is a clarification taking effect in 2016, might have some weight should a protest be filed and should it end up in a CoA.  I don't know how a CoA would rule on a protest or on and appeal, but you have been warned. 

 

New: 5. Unshrouding of valves is explicitly limited as follows: The wall of allowed relief cut must be a single cut parallel and concentric with the valve guide for the full depth of the cut. The cut must be cylindrical with no taper. The bottom of the cut must form a 90 degree angle with an allowance for a bevel or curve whose radius is not to exceed .010”. There must be a sharp, non-modified and non de-burred edge where the valve relief cut first meets the chamber. No part of this cut (except where it intersects the head gasket surface, which may be de-burred up to .040") is to be blended by hand, machined, or chemically processed to create a smooth transition. See diagram below.  The maximum dimensions, measuring guide center line to chamber edge:

[Ron Alan]

Well, consistancy is a good thing! They have again taking the rule as it was written and clarified with specifics what the intent of the rule always  was...IMO!

[Caveman-kwebb99]

I supported the rewrite but i dont agree with such an early sunset on this  could have been runnoffs 2016 or 1/1/17 IMO.

 

I personally think much more has been made of this that in reality its worth...  I have seen zero evidence that the radius cut adds anything, this from my one weekend ontrack this year, knowing who has what and i dont think it amounts to anything, I supported the rule simply because i am for making reading comprehension better in our class.