Quote:
Originally Posted by Bob Bidonde
NDI will not determine the remaining fatigue life of the metal fan blades. NDI is to check for cracks that may already exist in the metal.
There has been so many fan blade departures that have destroyed / severely damaged original hoods, original radiators and original water pumps that it is foolish of the judging committee not to accept aluminum reproductions for the sake of preservation of parts and safety.
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Mr. B, while what you are saying is correct about any non-destructive inspection not being able to predict cycle failures, however the purpose for me crack checking is ensure the item is as free of visual defects as possible which could later resurface as a stress crack.
The reason for wanting to use an original fan is Bob (-the original poster Bob
) is he is trying to make his vehicle replicate the timeframe when it was first assembled. Restoring a fan using some/all of the techniques I mentioned above is more than sufficient to meet the requirements of Fine Point adjudication. I don't believe any of us are advocating the use of an original two-blade fan without constant inspection for fatigue. FWIW, in the history of Fine-Point adjudication in either club, I do not believe there has ever been an occasion in Start & Idle, -or on the Mandatory Tour where an original fan came apart and damaged a radiator or sheetmetal. Therefore, I believe if a restorer will do their due-diligence on the front side, the likelihood of a fan failure during the judging process is very, very low in percentages.
And just so everyone is clear about repro fans. The JSC and/or Area 3 Judges
will accept a reproduction two-blade Fan in F/P competition. If memory serves me correctly, all the
Standards say is something to the effect of "a significant point deduction will be given".
So let's discuss this. With the expanded 5,000 point judging system, the entire Area 3 Cooling is only worth 150 points of that entire 5,000 points. (Very small percentage in that category considering the overall point system.) Of that 150 points, there is a sub-area in Area 3 that is combined of adjudicating the Cooling Fan, the Fan Belt, and the Fan's Castle Nut, -and that section is only worth 20 points total. So all three of these items make-up a total of 20 points, -or 2 points out of 500. Breaking this down in real-world numbers, ...let's say the Judges interpret that "significant deduction" to mean 50% of the total allowable points that can be deducted, ...that means that only 10 points will be deducted, -or 1 point out of 500.
So if someone has a fine-point vehicle that scores 481 points in F/P competition with a reproduction aluminum two-blade fan, then theoretically if that same exact car would have been judged with a perfect NOS fan, the highest that car would have scored would have been 482. Only ONE point difference for having a repro fan vs. a perfectly restored original fan. And ironically, ...if the Judges had only deducted 8 points out of the 20 points allotted (i.e.: 40% Fan, 40% Belt, & 20% for the Nut), then that car with the reproduction fan would have also scored 482 because of point rounding. That in a nutshell is why I believe it really isn't that big of a deal, -and also why I feel there isn't a need for the JSC to accept reproduction fans without a point deduction. Does this make sense??