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Writing the rules. 9.1.7.f 3 & 4

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#41
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Rich, I'm no engine builder..................... My comments within your post below are items I read in the McKenzie Cylinder Head article and or viewed in the video.

 

 

David, I know where your coming from and don't disagree and respect where you are coming from. I am also trying to stay away from the quantitative aspect of this rules discussion for the most part as I will leave that to those with the most at stake.  

 

In the Mckenzie article the top right photo shows a head that appears to me to have been full bead blasted in preparation for the valve machining operation.  My concern is that it is a very common practice to use bead blasting to clean carbon from aluminum and most machine shop customers loose control over their parts once they are handed over for processing. < Understand and kind of how we got where we are today.

 

I perfectly understand that the SCCA rules are trying to convey that there is to be no actions taken that could be used to result in enhanced performance from the process.  They even say no chemical process should be used.  Does that mean that ultrasonic cleaning (which uses a chemical solution)  automatically renders a head illegal?  Ultra sonic cleaning could be used without a chemical.  Maybe the first head cleaning would be a water/soap hot tank soak, power rinse and non-chemical ultra sonic cleaning the remaining chamber carbon. We have to be careful to not overly wall ourselves in with rules that cannot be enforced < Agree or that overly restrict what goes on using standard machine shop operations. < Understand, standard machine shop operations is one cause that kind of how we got where we are today.   Yes, we should not allow people to use these processes to enhance the flow performance but if someone wants to bead blast their head's cambers and gasket surface strictly for purposes of cleaning the parts I see no reason to consider that head illegal. Even if folks used masked the head completly other than the chambers and gasket surface, the process would be out of control day one.

 

I think we got into this mess primarily because of the "absolute" type of rule wording relative to not removing "any" flash from the plunge cut.  This absolute instead introduced vagueness.  It is not in the nature of any good machinist to leave flash hanging and as a result what probably started as simple light flash clean up resulted in the rules "creep" we now have as SCCA TECH never paid close attention to this area and builders never bothered to seek rule relief since things were "getting by".  In place, there should be a standard machining/parting line clean up tolerance of some specified minimum/maximum value (as the case may be) that (unless otherwise specified in the rules) is allowed for all machining operations. 

 

While doing minimal research an article surfaced specifying a paint stripper that removes carbon from the exhaust runner and from the combustion chamber. Would need to experiement with paint stripper type methanol/labeled methanol-dichoride to observe if when soaking the chamber only (valves in head) to loosen/remove carbon if a smooth transmission occurs at the sharp edge (sharp edge by rule .5.) where the valve relief un-shroud cut meets the combustion chamber. If sharp edge by rule .5. is still there, head is legal. It may take hundreds of hours soaking to remove the sharp edge. Seems control would be less of an issue that bead blasting. Hey, the sky is blue when we focus. Some times trial and error accomplishes things.

 

carbonoose.jpg


After a rinse it looks like this.

combucham.jpg

 

 

 

 

 


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#42
Jaime Florence

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Come on guys.  Media blasting is not something that needs to be restricted.  If you can't afford to buy a media blaster you can go to any machine shop, right?  I mean not everybody has a tire machine, but we all figure out how to get our tires mounted right?

 

Believe me I love the smell of gnarly chemicals as much as the next guy, but California doesn't let much of the good stuff in any more.


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#43
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Come on guys.  Media blasting is not something that needs to be restricted.  If you can't afford to buy a media blaster you can go to any machine shop, right?  I mean not everybody has a tire machine, but we all figure out how to get our tires mounted right?

 

Believe me I love the smell of gnarly chemicals as much as the next guy, but California doesn't let much of the good stuff in any more.

And your answer to controling media blasting to only the combustion chamber is what? By SCCA rule, not allowed in the plunge cut or un-shroud area.


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#44
MPR22

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Come on guys.  Media blasting is not something that needs to be restricted.  If you can't afford to buy a media blaster you can go to any machine shop, right?  I mean not everybody has a tire machine, but we all figure out how to get our tires mounted right?

 

Believe me I love the smell of gnarly chemicals as much as the next guy, but California doesn't let much of the good stuff in any more.

If you don't write a letter to the CRB they will restrict it.  


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#45
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You'll all be thankful this is my last post with reference to 9.1.7.f.3. and .4. My continually harping about Mazda providing their OEM plunge cut tool and plunge cut manufacturing process is the starting point. From my observations of Miata heads, they make the plunge cut and do not require a secondary process other than mayby a high pressure water wash to eliminate any burrs or hanging stuff after the plunge cut. Point being we could learn from the Mazda process.They do have considerable skin in this game. While talking with my OEM head manufacturing tooling source mentioned in an earlyier post in this thread he flat out stated that the automotive head manufactures (major players in the USA he works with) do no secondary process to eliminate any burrs or hanging stuff after the plunge cut other than a high pressure water wash. They as tool manufactures don't have ump-teen different tool dsigns to machine the plunge cut. Depending on the aluminum alloy silica content after gasket surface milling, manufactures may soft brush the milled surface with high pressure water wash to eliminate any burrs or hanging stuff. More silcia content within the alloy helps create less burrs and hanging stuff. 

 

It's now time for a rule 9.1.7.f.3., .4. and .5. clarification letter to the CRB and to the provided Mazda MotorSports address.  


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#46
john mueller

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Come on guys.  Media blasting is not something that needs to be restricted.  If you can't afford to buy a media blaster you can go to any machine shop, right?  I mean not everybody has a tire machine, but we all figure out how to get our tires mounted right?

 

Believe me I love the smell of gnarly chemicals as much as the next guy, but California doesn't let much of the good stuff in any more.

 

Media blasting can not be tech'ed so it's a waste of time, as is chemical treatment...  Cant be checked.


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#47
Johnny D

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Media blasting can not be tech'ed so it's a waste of time, as is chemical treatment...  Cant be checked.

 

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#48
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Media blasting can not be tech'ed so it's a waste of time, as is chemical treatment...  Cant be checked.

 I know, no more posts for me within this thread. ^  :bs:   as is the satement that one can not tech for REM.

 

When you require a consultant at your NASA races please advise through the site pm.

 

 :wave2:      For good with this thread.


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#49
Karl

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Wow...."Guess who's back..."   Actually there are a few other lines Eminem has in that song that I could reference here.

 

I need to dig up the email I wrote to Mike and Jim and maybe even John on how to define the plunge and other cuts.  It would show how all of the specific "engineer speak" was removed.

 

So, I'm glad to see this will finally end here.  (Can you hear the irony in the bitterness  :pessimist:  )

 

1-The object from the beginning was to create inexpensive and equal.  Inexpensive compared to other forms of racing, BUT understanding that all racing at the front of the pack is more expensive than at the back of the pack.  Equal was taken out by the big guys when the NB was introduced, but we can still find “equal” within each platform.  Once you really have that, you can then “attempt” parity across the models.

 

2-I’m glad to see that Mazda is finally going to get involved.  I hope their involvement is limited to exposing the tricks of the front runners.  i.e. “It was determined that the cylinder head from the 2001 ARRC winning spec miata had machined the original valve seats to provide a better seal and to volume match each of the four combustion chambers.  This sunk some of the seats enough that extra valve spring shims were added to restore the original spring pressures.” or “It was determined at the 2014 Runnoffs that the short side radius was…..”  Mazda, please explain how all of the winners are making your product better.  It’s okay to say, “In order to get you fun cars at an attractive price, some processes cannot be cost effectively optimized.  As a result, we are happy to provide you the read with the following speed secrets.”  

 

3-It’s a given that not all heads are cast to the same mold or are machined the same.  So, what do you do?  You let people try to make them all the same.

 

4-Let’s go back to 1 above.  We need to accept that EVERYONE who wants to race near the front is going to take their motor apart.  These rules need to be written for them.

 

Forget about writing rules to prohibit when it comes to modification of the OE machining.  John, when you write, “The Clarification will allow some deburring but not egregious blending”, you miss the point of 1 above (if you don’t mind me saying so).  When the literature to define the plunge cut (along the axis of rotation around the valve stem and limited to the diameter specified in the current rules) was not included, you (the rules makers) set yourselves up for the current protest.  You can solve the problem by allowing the DQs to stand (good faith for who don’t trust the rules makers who are also racing) and modifying the rules so….

 

Rule XX.yy.z1.32a.2 Ferrous valve seats can be no more than xx.xx in thickness and xx.xx in diameter (SBI offers cheap standard seats for these heads.  Find the right ones and spec right off of those.  Measure the OEs first and go with the slightly larger or equal SBI). The aluminum under the seats can be removed down the bowl to a distance of xx. 

 

This allows everyone with a little round file and little money to blend the multitude of OE short side geometries into a nearly uniform radius across the class.  Remember….EQUAL, and everyone who was found to have a non-compliant head this year will still be able to use it next year.  So, take your DQ this year and save on the motor budget for next year.  Reasonable?

 

p.s. There are expensive head cutting machines that can machine the short side radius in much the same way all of you can with a little round file.  Actually, the little round file can do a better job on the short side radius than these machines, unless the machine is programmed for each bowl and that IS expensive.     


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