How would this part judge? (new Long Island exhaust extensions)

[Wayne M.]

Re: How would this part judge? (new Long Island exhaust extensions)

Look how thin these are; 0.0132" at one point; no seam; not the slightest bit magnetic; no visible part # (is the number found near the slotted end, if present ?)

[William C.]

Re: How would this part judge? (new Long Island exhaust extensions)

Based on known originals, I think the JG will catch up to the thought that the originals did NOT have part numbers when the cars were built. I did not hat the time to go thru the entire catalog to find the things (link goes to catalog not to the part)

[Wayne M.]

Re: How would this part judge? (new Long Island exhaust extensions)

... I have a 65 and the manual for that car says there is no part number so I guess one does not fit all......

John -- my 5th edition of the '65 TIM&JG says "bottom welded seam; most have visible stamped part #s". I've got a feeling that this may change in the next revision .

[John D.]

Re: How would this part judge? (new Long Island exhaust extensions)

Repro Tail Pipe Bezels > good link #07-01
yes with seam , magnetic s.s. , no part #

the older repros: with seam, part #, s.s. not magnetic #07-01b

Kim

For full disclosure should you not reveal you are representing LICS in this post ?


john

[Michael H.]

Re: How would this part judge? (new Long Island exhaust extensions)

There are over 50 different grades of stainless steel, depending on how much chromium, nickel and molybdenum is present.
Here's a "SS for dummies"-type quote I got off a Google search.

5. Is stainless steel magnetic? Answer: There are several "types" of stainless steel. The 300 series (which contains nickel) is NOT magnetic. The 400 series (which just contains chromium and no nickel) ARE magnetic.

I think the amount of magnetism decreases as the amount of Chromium in the mix of steel/chromium increases. I vaguely remember that a typical range of chromium is between 10% and 20%.
That would put the GM tail pipes in the upper 1/4 of the range at 15-18%.

If that's the case, original pipes may be "somewhat magnetic". The GM pipes I have are somewhat magnetic.

[William C.]

Re: How would this part judge? (new Long Island exhaust extensions)

I believe you are correct. A couple of us "old timers" scoured our shops one day a couple of years ago, and looked at all the extensions we had pulled off "real" cars over the last 30+ years. The consensus: NO SEAMS! My personal experieance with this was with a '65 original owner car I was "dressing up" about 1974 and after I had paid a king's ransom (about $10 each) for a new set of extensions, I looked at the originals and lookes at the replacements and the replacements Had a *!XY! Part number stamped in them. I was usually broke at that time (racing and drinking will do that) but I never forgot how pissed I was with the replacements! Occasionally changes to service parts were made so long ago that many have never seen a real part. There is a thread on this from a year or two on the board when Mike and I went over this, it just takes time for the Judging manuals to get updated.

[Gary B.]

Re: How would this part judge? (new Long Island exhaust extensions)

On the NOS example I have the thickness measures around 0.027", so 0.002 more than the max spec on the drawing. So GM didn't get it spot on.

Regarding the apparent thickness of the LIC item, the thickness will appear larger than it really is if you're looking at the end that is cut at a an angle. With the NOS example of mine, I was certain it wasn't going to be close to 0.025" based on looking at the slanted end.

Gary

[Gary J.]

Re: How would this part judge? (new Long Island exhaust extensions)

It has already caught up to the new 1966 judging manual. Not in its entirety but here is the jest of it...

"the extensions are constructed of a thin sheet of low grade polished magnetic stainless steel with a smooth welded seam along the bottom. The extensions, without part numbers...."

[Russ S.]

Re: How would this part judge? (new Long Island exhaust extensions)

On the NOS example I have the thickness measures around 0.027", so 0.002 more than the max spec on the drawing. So GM didn't get it spot on.

Regarding the apparent thickness of the LIC item, the thickness will appear larger than it really is if you're looking at the end that is cut at a an angle. With the NOS example of mine, I was certain it wasn't going to be close to 0.025" based on looking at the slanted end.

Gary

My new ones from LIC are the correct .025 thick. Magnetic,seamed.and no part number.

[Alan D.]

Re: How would this part judge? (new Long Island exhaust extensions)

The other point is that of the "smooth welded seam along the bottom"
It's spec on the print as +/- 30 degrees off the bottom, so when you get questioned that's it not on the bottom, ie +/- 0 degrees, the call is wrong.

[Wayne M.]

Re: How would this part judge? (new Long Island exhaust extensions)

More info on my two examples of different exhaust extensions. First pic is GM service part, probably bought by me in 1980 or '81. It is magnetic, the weld seam is visible at the bottom and you can feel it without looking. The wall thickness is 0.026". Looks like the letter 'A' prefix on the part # stamping.

2nd thumbnail is of the same part I described in post #31, above. First, let me apologize for mis-reading the scale on the caliper. Thickness is 0.032" (not 0.0132). No part # stamped; non-magnetic [so probably a 3xx series stainless]. However, when cleaning the inside a little more, I see a weld seam exposed at 90 degrees from the top. So I went to the other tip (same purchase, unknown provenance, but came with '64-5 bezels, so probably someone converting to N14 ), and found the seam on the inside (again, not visible or by feel from the outside. But this seam is at about 105 degrees from the top.

One other feature -- the GM service tip with the seam at the bottom has the lower 1" long slot cut moved off to the side (shows in 1st pic) so as not to lie on the weld. The other extensions with the inside weld line NOT at the bottom have the slots at exactly the top and bottom.