Got deduct at Texas regional on oil pressure gauge, says 'white rectangles' missing. Can someone clarify what that means? Also got deduct for tach bounce, have now just sent the cluster to D & M, they had done the resto already, but want it correct. Thanks, John
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Re: 67 427/435HP oil pressure gauge markings
It would help if you posted a photo of your gauge
. Here is a 67 390/427 cluster with original gauge faces for comparison.
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Re: 67 427/435HP oil pressure gauge markings
Sorry, already sent my cluster off to D & M for tach fix, no picture now.Comment
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Re: 67 427/435HP oil pressure gauge markings
When you get a deduct it's a good idea to ask exactly what they mean if there's any confusion. Maybe they were talking about the 2 rectangles on the top arc of the gauge face, or the 3 white rectangles that protrude below the lower arc? Unless you know exactly what they were referring to it may be impossible to know. Maybe call D&M and ask them to send you a picture of the gauge face so you can compare.
Here are some close-ups of a '67 427/435 original oil gauge on it's "LB" labeled cluster.
Rich
P3150003.jpg P3150007.jpg P3120036.jpg P3120042.jpgComment
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Re: 67 427/435HP oil pressure gauge markings
I have the LB label on the back for sure. Asked D & M to advise on the oil pressure gauge markings. They should receive it late next week. Hopefully they will know what is supposed to be correct. Just did not get the question answered on that particular deduct, so once I got the judging sheets I did not know the details on that one. Can't recall, but maybe mine was only marked with lines and not the 'rectangle markings. We will see once D & M has it. Appreciate the pictures to help me.Comment
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Re: 67 427/435HP oil pressure gauge markings
John,
I'm glad the pictures may help you. I can attest that the oil gauge I pictured is the real thing from a real L71. If your cluster label is LB then that is the correct identification feature for your L71 to identify the oil gauge pressure and tachometer redline features.
It's unfortunate that the judges were not a little more descriptive in their notation, but their time is limited and there's not much room on the sheets for additional notes. Your question got me thinking a bit more....
I now suspect they were referring specifically to the rectangles on the upper arc of the gauge face.
I've looked at many gauge faces over time while restoring C1 and C2 instrument clusters and have seen many unique features of the gauges. Those little white rectangles can be seen on many faces, and I believe they may be there as calibration aids when the gauges were tested during manufacturing. They seem to be present only the "mechanical" type C2 oil gauges and not the electrical types or the speedometers or tachometers. But they're present on most all '53-'62 small gauges I've worked on, both mechanical and electrical, and also including the speedometer. I can't recall if on the C1 tachometers.
Note on the C2 80 lb oil gauge, the rectangle on the left has a smaller arc than on the right. They're likely "check ranges" used during test and calibration. Probably apply a fixed pressure, check if the needle is within the rectangle space, then increase pressure to a higher setpoint, and check the needle is within that wider rectangle range, which at higher pressure may be less accurate. This is all speculation on my part but it may be sensible.
I'm curious about your findings when you get the info back from D&M. I suppose it's possible your gauge in fact does have the white rectangles and may be just dirty or the judges just couldn't see them clearly.
RichComment
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Re: 67 427/435HP oil pressure gauge markings
Rich, I think you are right on with your notes on those rectangles, now I know what they are!. The cluster had been restored by D & M already, so maybe they missed this last time around and can 'fix' this deduct. Thank you, I think it clears up this one for me. Appreciate your detail knowledge.Comment
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Re: 67 427/435HP oil pressure gauge markings
John - I'm pretty sure the deduction you received was for the missing dashes at the very top of the gauge face. This item showed up in the latest version of the '66 manual and is now being looked for on the judging field. I believe the 80lb gauge has 2 dashes (a short one on the left and a longer one on the right) and the 60lb gauge has only one. Last I checked the reproductions, they were either manufactured with no markings or only a single marking on the 80lb gauge. Best to check with D&M and see what they use and if they even have access to a correct one. TimComment
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Re: 67 427/435HP oil pressure gauge markings
Tim, Good info....
Looks like maybe the early gauges were deficient. The latest available reproductions appear to have 2 dashes on both 60 & 80 lb gauges. So maybe now the 60 lb gauges are wrong with two dashes. If so, eventually they'll get 'em right.
Rich
60 lb
80 lb
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Re: 67 427/435HP oil pressure gauge markings
Both gauges should have calibration arcs per the GM B/P I'm looking at. I would say the repros you're showing are very close to the drawing dated 4/65.Comment
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Re: 67 427/435HP oil pressure gauge markings
Here is a photo of my original 67 427/390 60# gauge showing 1 "tick" mark.Comment
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Re: 67 427/435HP oil pressure gauge markings
Also have the single longer tick on my 67 327/300 60# gauge.Comment
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