Here are the rest of the rules proposal decisions. Those that were voted yes will be sent to NASA for ratification.

2011-1) 3 Piece Crossmember - No

-Benefit was recognized, but thought to be too small to outweigh the additional complexity in compliance checking/management (potential for geometry change), and small but real potential for additional failures vs. stock part.

2011-2) Larger Jack pad reinforcement - Yes

-Slightly larger size is a better match for jack saddles, but will not be so large as to act as ballast or chassis stiffening.

2011-3) Allow 924S models to use 924 Carrera GT type flares on the rear. - No

-924S is competitive as is and aftermarket body parts add cost.

2011-4.) Lexan rear qtr windows - No.

-Ducting can be achieved through existing openings. OEM glass not subject breakage like the windshields. Adds some cost.

2011-5.) Clarify use of Fog light openings for “ram air” - Yes

-Already established as allowed. This makes it formal. A fog light ram air set-up can be created with $10 in materials and is easy to implement. The alternative is 100% stock airboxes as the only way to ensure air intakes do not get a ram effect. Ram air found to have minimal effect, if any, so far.

2011-6.) Publish rules in maximum head shave - Yes.

-Whistlers are not widely available on a local/regional basis. This makes for simple surrogate compliance check for use when a whistler is not available. This can be checked at home, and gives a good reference on engine building as well. 10.5 compression limit stays to ensure alternate methods not employed to bump the compression when a whistler is available.

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This wraps up the rule change season - back to building cars and racing!

Eric, thank you for listing the rest of your recommendations to NASA for the proposed rule changes.

My only concern with what you have listed is the head thickness issue. My concern has to do with what those are actually set at.

It seems to me that they must be set to numbers (one for early engines and one for 88 engines, I believe) that ensure that they will never DQ someone that would actually meet the compression limit. In other words, setting the actual numbers needs to be done by someone that has the expertise to take into account various deck heights, gasket thicknesses and valve positions so that an otherwise legal head (based on compression)is not made illegal.

From the earlier discussions on this proposed rule, Chuck verified that Porsche has head gaskets in various thicknesses. Is that correct? If so, are the thicker head gaskets legal in our class? If so, that should be taken into account in measuring the head thickness, it seems to me, as that would have an impact on the compression.

Another question for consideration; I was told that measuring the head thickness accurately requires removing the head. I do not know if that is true but it would seem to need to be answered by engine builder experts prior to implementing this rule. If that is true, it would seem to negate the thickness measurement as an easier solution. If the head needs to come off then it can be titrated to get an accurate compression value.

We don't need "unintended consequences" from new rule making that did not throughly consider all aspects of the proposed rule in advance and I think that some additional discussion to clarify these and, perhaps, other issues should be undertaken quickly so we all have answers prior to this rule going into effect. Perhaps a thread on just this rule can request more detail from everyone so the final rule can be well thought out and deal with some of the unknown issues that come out in that thread.

My 2 cents and intended in a constructive way.

Jim Foxx

Jim, we will clarify/specify a procedure for this soon. We don't want anyone caught out with a standard/legally built motor, and will word that carefully. Thanks for the input.

The procedure for checking the head thickness is in the service factory service manual, and is copied below. Because the measurement surfaces are easier to see in a picture, I've put a picture of a head below that. With regards to the 1.4mm gasket, this will be addressed in the wording of the rule. Briefly - installed on the motor, it make no difference wether you get thickness from the head itself, or the gasket, and the standard measurement applies. Joe will also adjust the bare head measurement, adjusted for the 1.4mm gasket, when it applies.

Eric, thanks for posting the information. I do have one quick question. You said that "installed on the motor, it makes no difference whether you get thickness from the head itself, or the gasket, and the standard measurement applies. Joe will also adjust the bare head measurement, adjusted for the 1.4mm gasket, when it applies."

The measurement, shown in the material you attached, is of the head only. I take it from your comment that there will be several measurements that would be legal depending on the gasket used. However, someone told me that one needs to remove the head to do a proper measurement of the head thickness. Of course, I do not know that of my own knowledge, only from "rumors and inuendeoes". If the intention is to be able to do a simple measurement of the head while it is installed, there will need to be a way to measure the gasket thickness as well in order to effectively use this measurement concept to DQ folks.

Is there a way to correctly do that?

It also strikes me that the actual issue here is compression. This proposed rule is to provide a simple way to check compliance at events where other tools are not available. It seems to me, therefore, that the rule should provide for the competitor to be able to contest a DQ based on the thickness measurement and opt for removing the head and doing a proper fluid check to get a precise determination of the actual compression of the engine in question. That would provide everyone with a way to be sure that no one was DQ'ed in error and that heads would not be made illegal without proof that there was an actual compression issue.

Jim

So now we come to a minor problem.

The 3 rd. Place car at the Nationals was deemed legal by means of the whistler. That head measures .925 at the pad on both ends after it was removed from the engine after Nationals. It is an 88 motor with the high compression pistons.

The proposed measurement of .927 would make this head illegal after it was deemed legal at Nationals.

Now my car did measure exactly at 10.5:1 at Nationals.

I believe that the measurement needs to be a little more liberal to allow for situations such as this.

I am opposed to any new rules but especially one that needs more work.

Mr. Foxx brings up many good points but especially about using this rule to require further inspection and measurement (fluid based) to check the actual compression of the head.

Thank you for your consideration of this issue.