153 replies to this topic

[Tom Sager]

If you want stock heads only, don't sign this.  This petition is an opportunity to vote thumbs down on the proposal for stock only heads.   The "no's" in the other thread on the new proposal are still over 70%, so let's get this signed.  

[Jim Creighton]

My bad, the .20 was a typo and should have been the .010 specified. But, it does get you thinking that a solution all could live with right away is what I suggested. I'm against junking the heads already done and believe this is a middle of the road suggestion. But, as I said, I'm an outsider in that I do not have a vested interest. My only interest is I've met a lot of great guys and gals racing in SM and I would like to see all of you treated equally, And I hope all of you who have met me will agree I always have the best interest of SM in mind.

 

 

 

 

[RWP80000]

Post 18

"Too clarify the .250 is from the bottom of the seat. It includes the .125-.150 of straight down plunge. It is not!! .250 after the bottom of the plunge "

Chris,

This helps but I think it makes the inspection process more difficult as you cannot bend a ruler around a tight radius and get a good reading.  Also, with valve seats being replaced, who is to keep someone from putting in a thicker seat.  We should be calling out a seat thickness specification which is about .230 if I remember correctly.

 

Steve/Jim

The fifteen pounds added for the .010 overbore calculates out almost perfectly on the basis of pounds of weight/ cc's displacement.  The 1.8L displacement factor calculates to something like 1.305 pounds per cc.

 

I am against adding weight to adjust for unknown performance potential.  I do not think that anyone is going to measure with any degree of certainty the horsepower affect of the blending given all the variation that happens when trying to make back to back dyno runs especially involving a cyl head change ( just the variation in the timing belt re-install ).

The plunge cut's increase in valve pocket throat diameter is the primary basis for the improved head performance while the blending is most likely helpful I would not want to be the one responsible for trying to quantify it.  I would believe a flow bench to provide much better insight here.  That's why I am in favor of clarifying the blending rule and making it available to everyone to use at their own discretion/convenience and get away from umpteen different weight breaks.

[Steve Scheifler]

My bad, the .20 was a typo and should have been the .010 specified. But, it does get you thinking that a solution all could live with right away is what I suggested. I'm against junking the heads already done and believe this is a middle of the road suggestion. But, as I said, I'm an outsider in that I do not have a vested interest. My only interest is I've met a lot of great guys and gals racing in SM and I would like to see all of you treated equally, And I hope all of you who have met me will agree I always have the best interest of SM in mind.

Agreed. I started pushing for the same thing soon after this broke. Someone else mentioned it first but it immediately sounded logical and that hasn't changed for me, assuming that specs can be written and checked.

[B(Kuch)Kucera45]

Thanks Frank and all the others involved in this effort.

My question is how can we reach the others that aren't on this sight so they can be apart of this as well ?

[Steve Scheifler]

Steve/Jim
The fifteen pounds added for the .010 overbore calculates out almost perfectly on the basis of pounds of weight/ cc's displacement. The 1.8L displacement factor calculates to something like 1.305 pounds per cc.

I am against adding weight to adjust for unknown performance potential. I do not think that anyone is going to measure with any degree of certainty the horsepower affect of the blending given all the variation that happens when trying to make back to back dyno runs especially involving a cyl head change ( just the variation in the timing belt re-install ).
The plunge cut's increase in valve pocket throat diameter is the primary basis for the improved head performance while the blending is most likely helpful I would not want to be the one responsible for trying to quantify it. I would believe a flow bench to provide much better insight here. That's why I am in favor of clarifying the blending rule and making it available to everyone to use at their own discretion/convenience and get away from umpteen different weight breaks.

Depending on who you ask, the smoothing/blend is half or more of the benefit on many heads. If you have a really bad one maybe the big help is the plunge but I'm getting the sense that it's often the after-work that counts. But others claim just the opposite. According to the letter from the committee they will be testing it. I'd be surprised if they pull together enough different heads or take the time to cover a range of scenarios but they are at least trying to put a rough number to each modification. Hopefully we will get those results. I wish we could nominate someone to represent the class at those tests (yes, I would volunteer as I can take the needed to do it but the main thing is to send someone not already chin deep in the issue).

Anyway, whether the number they come up with is more of a range, this seems like a case where perception is very important. Even if the weight adjustment is small at least those who have followed the rules explicitly don't feel penalized for doing so. That matters.

[FTodaro]

Look folks let me make a few comments about the size of the deburr that your all clamoring about.

I consulted the only motor builder in the room to discuss factually what he saw.

 

Next we had to take into consideration the number of heads, the different year of heads, and the different equipment used to have a margin of error to included those heads, but the PRIMARY issue is that DUE TO VARIANCES IN THE HEADS we had go with this number to make it work.

 

Due to those variances, if we go with .150 we will get DQed heads.

 

As for the size of the spec, again for the benefit of you non motor builders, If you have not done your homework, Blending, porting, flowing a head, does not necessary improve a Plate motor. Its more complicated than that to get HP from a Plate head.

 

My Point when you are discussing going to .150" from .250" you may see no gain or it may be less hp. But for sure it will not move the needle much.

 

So Unless you have some Data that the difference is even a benefit. I would not get hung up on that detail. The effort is to save 75% of the heads. and move on.

 

As to adding wt, This will be tested, I understand its being tested as we type. if it is deserving of a Wt increase it will be done on the basis of fact, not emotion of a penalty.

 

So you can debate the menusha all you want. If you have a better idea get on it.

 

This is the best reasoned approach considering all the factors that we had to take into consideration.

 

Please get behind it if your not wanting this to continue for two years.

[pat slattery]

Come on guys, we have to let scca know we are not happy about going back to stock heads. If you want stock heads don't sign, but we can't have everyone trying to put there little spin in the petition, or nothing will get done.

Pat

[James York]

Let me second Pat's comment.  A overwhelming majority must be behind a single proposal, or the existing proposal of requiring all to go back to stock heads will stand.  Nothing will be perfect for everyone, but if those NOT in favor of returning to stock head don't get in alignment with the proposal worked on by members of the forum then stock heads is what will be forced on you.

 

These guys took the effort to get the wording as close as they could and worked with Stewart to come up with something to save most all our heads but still prevents liberties in the blending of the plunge cut.  Submitting in letter debating the content of what is on the petition will be viewed by the SCCA/NASA as not uniformly against.  So if 10 different options on details come across their desks with 10% support each, you will end up with stock heads.

 

I hope you all can get on board that don't want stock heads.

[Bench Racer]

 

Look folks let me make a few comments about the size of the deburr that were all communicating about.

 

I consulted the only motor builder in the room to discuss factually what he saw.

Frank, I uderstand you believe what you believe and you fully suport what you believe.

 

Are you suggesting at the summit, there was only one motor builder that viewed the heads? I count at minimum three motor builders in the summit group. Please don't forget about Lisa. 

 

^ My final clamoring within this thread.

 

 

 

 

[Danny Steyn]

Frank and all the guys involved with this - thank you.

 

While I can easily afford  to go with a stock head, the 2-3 year period that it will take to get the stock head rule implemented across ALL drivers, along with the parity adjustments that will need to follow, just puts way too much uncertainty into the class, and IMHO I believe it will chase many drivers away. 

 

I sincerely hope that Mazda, SCCA and NASA listen carefully. 

 

I URGE all spec miata drivers to sign this, even if the alternate proposal isn't in a perfect form yet - we need to stop the new stock head rule from moving forward.

[RWP80000]

Frank,

I appreciate all of your effort and do not fault you at all on why I have an issue with how it is being presented.  I am in 100% agreement with what you doing here but have a concern with the diagram as presented and the size of the .250 dimension being proposed.  I think it is going to lead the creative types to double down on what they were doing because it will now provide cover to allow potentially "blending back into the plunge cut of the seat since this area is now included in the dimensional spec.  

 

To me, the only issue that should be addressed is the massaging/blending/de-flashing of the plunged cut to bowl/port "parting or transition line".  The original rule was very clear there was to be no touching of this "plunge cut line" however it was never "tech'ed"  and has gotten out of control. That is why I want the petition to focus specifically on the issue which is out of control and propose a tolerance specific to that and NOT combine the dimensions of the overall length(depth) of the plunge cut WITH the now required new "parting/transition line" blending/chamfer'ing allowance.  

 

In another post I have submitted pictures of simple tech'ing and measuring of this parting line with the most basic of tools.  I did not describe exactly how to use them but just let me say here that with the mirror it is very easy to view every portion of the plunge cut machining "line" on the port and short turn radius floor including the transitions between them and there is no necessary reason to integrate the plunge cut machining into the transition line "clean up" dimensions.  

[RWP80000]

I am with Danny on this but if the powers that be were to accept it as written I really fear we would be opening a new can of worms.  Just asking to get the petition to be more specific or allow for the debate on dimensions to be resolved later and maybe by a third party.

 

Rich Powers

[Mastek]

I have signed the petition.  Thank you VERY much to those that worked on it. 

 

I presume it is also appropriate to send a letter directly to the SCCA???

If so, can someone please post a link and advise any specific protocol.

 

Thanks, Mike

[Caveman-kwebb99]

I dont disagree with either of you. I was at first confused by the pic myself.

The pic is helpful to understand for most of us but then confusing as to where the .250 begins...

Let's not argue we are not on the rules comittee , the proper wording and pic can be changed at that time in committee... The wording is solid and if you remove the pic it is simple.

The pic should not be the rule the wording is the rule. Just like writing. A check if the number does not agree with the written calculations guess what you get what amount was written on the check.

I have no problem with the removing of the picture but it was put on there for idiots like me confusing or not.

[Caveman-kwebb99]

Letting the number be debated later will not get the number of votes here as those engine builders will tell their people don't vote for this as it will not cover your engine.

[James York]

I have signed the petition.  Thank you VERY much to those that worked on it. 

 

I presume it is also appropriate to send a letter directly to the SCCA???

If so, can someone please post a link and advise any specific protocol.

 

Thanks, Mike

 

Mike,

 

I would recommend sending copies to:

 

go to the CRB letter submittal site and input here:  http://crbscca.com/

 

email copies to:

 

BOD@scca.com

JohnMueller@DriveNASA.com

[DrDomm]

If 0.25" is the dimension that we need to keep current heads compliant, then that's what we should endorse.  Perhaps if it is adopted, there will be a caveat to the rule stating a more thorough spec to prevent any creep will be forthcoming in an effort to keep the builders "honest".  

 

Thanks Frank, Tom, Craig and anyone else. 

[Mastek]

Mike,

 

I would recommend sending copies to:

 

go to the CRB letter submittal site and input here:  http://crbscca.com/

 

email copies to:

 

BOD@scca.com

JohnMueller@DriveNASA.com

 

Thanks James, I will do so today.

I would suspect it helpful if SCCA receives a letter from every signer of the petition.

Mike

[Brocodile]

Thank you Frank and others who took the initiative to craft this proposal. Like every product of human endeavor, it is not perfect. The appropriate number is debate-able and will be determined in the end by the BoD, whose discretion is in no way limited by the number proposed in the petition; however, the number is irrelevant unless the BoD can be convinced that the class feels that the reversion to stock heads unfairly penalizes those who complied with the existing rule.

 

While I have reservations about some of the specifics, I am signing the petition. I feel that this is the most effective way to reopen the discussion at the BoD level.

 

I will write a separate letter to the BoD addressing the details. I encourage each of you to do so as well.

 

While we may differ on the details, it is imperative that we speak in a single voice in opposition to reverting to stock heads.