Please reference the recent Member Advisory.
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Please reference the recent Member Advisory.
Thank you John.Quote:
Originally Posted by John LaRue
Marshall
What are the specifications one should check against?
I believe that GCR 9.1.1.12.e.4 is the appropriate section.
I find this frustrating. From the GCR:
Pistons
1. Standard or 0.005 inch oversize pistons shall be used.
2. Standard size AE pistons P/N 18649, casting P/N 18634, standard size CP piston, part # 81-2
FF1600, or CP oversize piston, part # 81-2- FF1600+5 as supplied by Ivey may be used. CP
pistons must bear the Ivey logo.
3. Alternate piston identified as follows is allowed: P/N AE-M717D, casting number 711 M 6110. AE
Hepolite P/N 20552, Casting # 20548A. Note: Mahle pistons are not allowed.
4. Dimensions and Weights
Maximum diameter:
Standard: 3.187”
0.005” o/s: 3.192”
Depth of bowl: 0.470” (minimum)
Maximum diameter of bowl: 2.44” AE Hepolite,
2.50” CP Piston
Centerline of wrist pin to crown: 1.702” +/- .002”
Overall height: 3.30” AE Hepolite
2.80” CP Piston
Minimum weight 515 grams (w/ clips, pins and rings)
Weight of pin: 115 +/- 2 grams
Ring Groove Widths: Top Groove: 0.064”
2nd Groove : 0.0795”
Oil Groove: 0.159”
5. Piston rings are unrestricted provided that:
A. One oil control and two compression rings are used.
B. No modification is made to the piston for the installation of rings.
C. Pocketing of the piston valve reliefs is allowed up to a maximum of .050” to obtain the
maximum combustion chamber volume.
6. Wrist Pins are unrestricted provided that:
A. Weight is 115 +/- 2 grams.
B. No modification is made to the piston for the installation of the wrist pins.
So what are the dimensions that were found out of spec? Where should the competitor start to look? Tech Inspector? Some of these measurements are difficult for most competitors to check for themselves without a signficant investment in precision measurement tooling and the required skill. Even as a tech inspector I find the advisory intentionally vague. Transparency from the club would be appreciated.
Regards,
Dan
Maybe I'm wrong (and please explain if I am) but putting this together with another thread it sounds like some people have acquired or had custom made pistons with the correct part number but NOT correct as to weight and dimensions and the club is simply stating that just because you found a way to counterfeit parts they must still meet the weights and dimensions. As to the expense of checking: you don't have the tools to verify weights and dimensions?
I know this is not the support you are looking for, but those specs are straight from the rule book. If you don't have the precision measuring equipment and required skill, then you should not be working in your engine.Quote:
Originally Posted by DanW
The most obvious benefits of cheater pistons would be boosting compression ratio, and/or improving ring performance by relocating and restyling the ring lands, and wrist pin relocation. Again, if you should be working on the internals of your engine, you should be capable of identifying "problems". If you cannot, then asking Roland, Jay, or someone in that crowd, would seem the next logical step.
Baloney. Maybe the numbers above are adequate. I have the skills and the equipment. But what is needed is a drawing because reference points count, and anybody with a background in machining knows that. What's listed above are reference dimensions, and a lot of them don't indicate tolerances, max, or min. It's another example of poor rules-making.Quote:
Originally Posted by problemchild
Perhaps I misunderstood Dan's point, and perhaps I am misunderstanding yours, but both points appear to be discussing completely different issues. Dan wants SCCA to tell him what is illegal about the cheater pistons. As much as I hate SCCA bureaucracy, I would not expect SCCA to issue anything but a basic warning, considering the issue is reportedly before the courts. Many other people know much more details, but are not issuing public statements.Quote:
Originally Posted by Rick Kirchner
If you have an issue with rules that are approaching 50 years old, then there are ways to deal with that.
"write a letter ................ join a committee ........... run to become a boardmember ........ blah, blah, blah"
I enjoyed that .;):confused::eek::):o:D:mad::ha:
If you are concerned about having legal parts here is the answer. It is really simple, buy pistons from either Ivey or Pegasus and they will be legal. I believe that most of the engine builders do that. My understanding about which dimensions must be checked to insure legality is yes.
I believe that the tolerances for measurements are set out in Appendix G of the GCR. Those control unless otherwise specified. Also, if in doubt, you can utilize the compliance review process outlined at GCR 8.1.4.
Quote:
Originally Posted by Rick Kirchner
Rick,
Thanks for your endorsement of encased meats. "Maybe" is the operative word.
Yes, a drawing is required to ensure the correct measurements are made. I have most of the required tools, but not all. I am not a machinist, but I have assembled and tuned my engines and I have also had engines built by very reputable builders.
Greg Rice -
I'm unable to argue the finer points because of my lack of knowledge. My point is the SCCA's advisory creates significant uncertainty about what constitutes a legal or illegal piston. The club was very clear when the Miata "Plunge Cut" decision was handed down with drawings and dimensions.
I buy my motor parts from Jay Ivey. I build my motors according to the rule book and Jake's book. I have had two motors built by Arnie. Arnie's motors are better than mine. Rebuild lead times tend to drive my decision to build myself or not.
I'm just a humble regional/vintage hacker who likes to go to the track, hang out with my friends and turn my money into noise with no other aspirations other than to become a competent driver.
This advisory is a Terrible way to let the members know there is a problem with "some pistons". As somebody with very limited funds to go racing with, I shouldn't have to worry about what piston my builder or anyone else's builder put in these engines. If there is an issue with a seller of pistons or part number, then make a drawing and more information available to all the members so we can remedy the situation quickly and easily, with out any major cost!! If that means identifying the actual seller of the illegal parts, then DO IT!!! stop protecting anyone who CHEATS!! their bad for the club, sport and prob bad for any business. PERIOD..
SCCA is great at doing nothing when something, anything must be done. And they wonder why car counts are down. Not all of us can check the pistons without tearing down the engine. And that costs Money, why should I have to spend money because SCCA dosen't want to give us the whole story. Absolutely Ridiculous!
We don't want to be another Spec Miata class, where every race the top 3 to 10 cars need to be torn down.
-Bob
The CRB (RRB) was made aware that there may be an issue with the pistons thus the MA - nothing more. The manufacturer and the part numbers were noted in the MA. Feel free to call CP and quiz them about the matter. To my knowledge none of these pistons have been found in an SCCA tear down. The CRB (RRB) would have no ability to know if these parts are being run in SCCA events until they are found in tech.
It is the competitor's responsibility to field a legal car. If in doubt call your engine builder and quiz them as to the pistons that were used. If it is one of the primary engine builders they are probably well versed on this issue and can put your mind at rest. If you built your engine then you should know. If you want to pull the pistons and send them to me I'll be glad to measure them. My opinion won't be official, but I will try to help in any way that I can. For that matter I would suspect that Quicksilver, Ivey, Butler, Elite, Loyning, Hasselgren or any of the other 1600 builders would be willing to make a quick check of them for you. If you want an official opinion then utilize the review process outlined in the GCR.
John
I totally agree with Bob's comments about not protecting cheaters, and I understand your frustration, but this does not appear to be a SCCA situation. SCCA BS has cost me 10s of thousands of dollars, just in the last year, and I refuse to participate in their races, or corruptive process, but I do not understand how you can blame them for warning you that some vintage racers are building cheater engines. The Spec Miata situation was a SCCA matter and a full explanation was appropriate. If you must blame someone, blame your suppliers for keeping quiet, or other knowledgeable people who only answer your request for details about the cheater specs with a "yes". I am quite content to blame SCCA for all they do wrong, but appreciate something they have done right, namely warning us of a potential problem in vintage racing, that could spread into SCCA club racing..Quote:
Originally Posted by DanW
If these pistons had subtle tweeks, then there would not be an issue, so one can assume, the differences are easily detected. If you buy parts from Jay, then it would appear your parts are legal and the SCCA warning is unnecessary for your interest.