32 replies to this topic

[Kyle Freiheit]

On the Dyno?

[Steve Scheifler]

Steve,

I suspect the point may have been if you allow it to knock off the globs and such, you will have someone take it too far "into the grey". Just another repeat of the head story.

Whether its right or wrong, smart or dumb to allow, I am not debating. I just guess the point is that if allowed, some knee jerk reaction could happen when someone goes too far with it done the road. And then of course, how would you measure this allowance?

I get it, but there is only so much you can do without altering tubes or configuration and part of my question is how much room does that leave for abuse, or more importantly, work that requires special tools like a flow bench. Any guy with a file or rotary grinder can clean up the inside for free. How much "better" can one be made by playing around with a flow bench. The last thing we need is another part that the "pro" builders control, but the supply of old parts is shrinking and "new" parts wouldn't pass tech. So what are the options?

[Steve Scheifler]

I have cleaned up a 1.6 exhaust manifold and tested it.
There is very little to be gained, in fact not even measurable.

And that is a big question. I expect fairly little regardless of flow bench numbers because the exhaust does not seem like a limiting factor for these cars and is rarely as sensitive as the intake.

[James York]

I get it, but there is only so much you can do without altering tubes or configuration and part of my question is how much room does that leave for abuse, or more importantly, work that requires special tools like a flow bench. Any guy with a file or rotary grinder can clean up the inside for free. How much "better" can one be made by playing around with a flow bench. The last thing we need is another part that the "pro" builders control, but the supply of old parts is shrinking and "new" parts wouldn't pass tech. So what are the options?

I was only directing my input about the notion of cleaning up the manifolds factory welds to "equalize" and avoid cherry picking. An exterior weld to repair a crack seems reasonable. I bought 3 when I had my 1.6 .......just in case..

[Steve Scheifler]

But, the new ones direct from Mazda have had file/grind marks. So if you can't even rely on a factory part passing badic tech, what is your next move? I know, we've been here before, or at least people have tried the same claims to justfy things, but that doesn't change the facts.

[Bench Racer]

 

/rant

If I had one nit to pick about the SCCA it's this: the lack of forthcoming of data regarding violations (irrespective of this SM one).  Is it an effort to keep folks from further investigation on the potentially exploitable condition/variable?  Is it to save face on the aspect of 9 competitors being "DQ'ed" in this instance?

 

As others have noted, having pictures to reference, in terms of extremes in this case, would be a significant boon to builders and competitors.  For reviewing particular procedures (for the builders) and current status of parts (competitors) it would be immensely helpful to determining whether something could be considered compliant vs. not should a tech inspection be performed.

 

/rant

Point one of your rant, they were not DQ'ed, they were moved to last finishing position.

 

Point two of your rant, the SCCA rotary street port legal or illegal is described with pictures. No question pictures could be taken of OEM STR and plunge cut and massaged STR and plunge cut with comments, legal, not legal.

 

Along with the GCR rules have a second offense drive train death penalty rule to cure selective rule reading.

[Johnny D]

Brandon have you been here folowing along or checking the sites ??  Doesn't sound like it.

 

Look at post #11, I guess look at all of them. Their not done yet, but their letting us know stuff, John M posts here too. Collins answers questions.

 

http://mazdaracers.c...rbonneau/page-1

J~

[chris haldeman]

!

Attached Files

•  image.jpg   38.35KB   7 downloads
•  image.jpg   31.89KB   6 downloads

[Brandon]

Oh brother!  Pedantic racer is pedantic Mr. Bench!  Sheesh!

I try and keep things generalized and not confrontation and see what I get?!

Anyway...I have been following this from day one so don't even get started down that road.

 

To address all points here goes: 

Trying to drop some technical knowledge on the masses here (if you know this already, sorry) - the specific reason why the rotary porting is explicitly diagrammed & illustrated as such is port modification is difficult to police for any violations and because of the significant gains in a rotary to be had via this machining practice.  On a rotary, this is the mechanism to modify the timing of their intake/exhaust opening/closing/duration/overlap along with lift & 'lobe shape'.  As some classes permit rotor-based engines, which also allow camshaft swaps, they needed to give them 'something' thus the "street port per this diagram" was developed & published in the GCR.  I do recall something similar to how the FV ports/heads/something were also equally diagrammed & illustrated within the GCR but can't be sure...

 

How this relates to what we (SM) should be doing with our allowed machining I feel won't be easily addressed due to the variability of our source components.

 

My rant specifically about pictures/diagrams was solely isolated to these SM violations and how they were identified & thus determined to be non-compliant and whether there could be additional data/information disseminated to the membership that could help both the builders remain compliant (with new work potentially) and competitors could participate with confidence their components were compliant per these diagrams/descriptions/pictures...sorry for the run-on sentence.

 

Additionally, the fact they were not disqualified but merely put to the back of the field is not lost on me; never was in my mind & didn't think my replies/responses gave rise to indicating so.

 

Why this particular decision was made has been opaque (and I don't necessarily expect total clarity) but it poses some interesting questions and possibly helps to expose some of the reasoning behind their (the "SM Head Working Group" consisting of SCCA, NASA, & Mazda) initial announcements and further communications.

 

Again, I'm not new to the discussion, have not been behind on the topic(s) at hand, and have been participating when/where I can with constructive replies which (I guess) are apparently too long for some to read or something as I've not been a stranger to this whole subject!

 

Bench, Johnny, Chris - everyone on the same page now?

 

Now, back to the subject at hand: if we construe previous allowances regarding the use of helicoils to repair stripped spark plug threads (which have no explicit call-out within the FSM), I could foresee a similar allowance for repairing a cracked header/manifold.  I think someone just needs to submit a letter to the CRB/SMAC as a proposed rule for 2015 to permit a welding of the exhaust manifold on the OUTSIDE ONLY (to eliminate anyone from getting cheeky with the allowance) and see what happens.

 

Thanks,

Brandon

[Bench Racer]

Really two quite simple items which you Brandon may have issues understanding.

 

A DQ is 4 points, loosing finishing position is 2 points, decided by the SOM.............................

 

Anyone who can't visually compare a OEM picture and a massaged SRT, plunge cut or port runner maybe shouldn't be quite so vocal about other people that have said capabilities.

 

[Brandon]

Nice ad hominem there'ra Mr. Bench...Sling Blade I'm not.

I try and keep it professional and this is what you get...

 

Going forward, "Vertical File 13" is where your replies/responses will be mentally filed on whatever topic I happen to find your name...

 

Cheers!

[FTodaro]

Ralph:

 

I would think welding a cracked header "adding metal to the header" as a repair would be permitted. Its the removal of metal that could cause a problem. I cannot see laying metal over metal welds would or should be considered Modifying that could be considered a performance gain.

 

I do not disagree that this should be addressed, but would have a hard time getting DQ's if i merely re-welded a cracked weld.

 

"Brandon", i read your posts I am with you buddy.

 

I agree, it sure would be nice to see some high resolution pictures of what is complaint and what is not, or what needs weight added or not, if that is what the resolution is.

 

Steve, if you have not submitted a question to the CRB on the repair you should, its not asking for a new rule but a clairification. Tubular headers  are on the 1.6 and the VVT motors and do fail.

[tom1977]

I know... Old thread.  I just found a 1/8" crack on my exhaust manifold and can repair it now before it costs me $$$$ $$   When can I legally zap the crack and re install it on my 1.8 NA?