Re: AHA! Yes! Question for Duke

[Duke W.]

Something doesn't jibe, Michael!

According to your 7/63 copy of the P&A catalog the front J-65 drum is 3830167. My original J-65 front drums are casting number 3828671 and the web thicknesses measure in the range of .130", so these two numbers are paired.

Also, missing from my data is the casting number for the base brake 3830166 front drum, and my bet is that it is either 3828670 or 672.

Duke

[Michael H.]

Re: AHA! Yes! Question for Duke

I haven't documented this yet Duke, but I believe the base and metallic front drums are the same casting number. I have a pair of NOS non met drums in the old orig tan boxes and their casting number is 671. Likely all that was different for met was the dish, (and the machined/ground working surface) not the outer circ of the drum.

Harry Sadlocks original front drum is also a 671.

If I remember correctly, the 672 casting number came in several years after the 63 run, on service drums. Pretty sure no originals would have been 672.

I'll look into this as soon as I can. I have the 66 apart and we have our latest hurricane on the way so that car has to be mobil, soon! I live VERY close to the water and 18' storm surge is a real possibility, and I'm about 4' above sea level.

[Duke W.]

Re: AHA! Yes! Question for Duke

I used to think base and J-65s were the same casting, but it was you who pointed out that the AMA Specs show a thicker web dimension for J-65 front drums, so now I'm a believer that the front castings are different.

I think we've established that rear base and J-65 drums are the same casting.

Don't worry about it until you get through the next hurricane!

Duke

[Michael H.]

Re: AHA! Yes! Question for Duke

Duke, I believe the difference in the std and met front drum is limited to the web and not the outer band. Because the web is installed in the band, they would have used the same web for both app's and since the casting number is on the band, it would remain unchanged. I don't have any paperwork on this but I have to believe this is the reason both std and met drums have the same casting number. Guess that means the casting number would be just for the band and not the drum assy with web.

Yep, Florida hurricanes, Calif quakes, midwest tornados.... I suppose if there is a good side to hurricanes, it's the fact that we get at least a few days or a week to prepare. I don't know which worse, knowing for a week that it's coming or just suddenly loosing everything in a tornado.

Does anything ever happen in Idaho...Montana??

[Duke W.]

Re: AHA! Yes! Question for Duke

How could they have used the same web for both applications? The metallic drum web is thicker. I can see that the mold could be the same, and isn't the web installed in the mold then the molten iron solidifies around it?

Once cast, how could they keep track of which was which since you have to measure web thickness with a caliper to differentiate them? It seems to me they would have had two sets of molds - the only differnce being the casting number and the required web part number to insert in the mold.

Duke

[Michael H.]

Met Drum ID

Was the other way around. Same band for both app's but different web for std than was used for met.

That way, the casting number for the drum/band portion would stay the same for both. I have to think there was some means of ID at the source, possibly as simple as a paint swipe or?

I've never studied or compared the web portions of std/met drum so I'm not aware of any differences, other than the thickness. Quite possible there may be some difference tho.....

[Harry Sadlock]

Re: Met Drum ID

Michael, the drum I have has a dark green paint swipe!!

Harry

[Michael H.]

Re: Met Drum ID

It's possible that has something to do with the thick/thin web. That may be the color used for the std thin web for the std lining drum.

Is this under a layer of what looks like chassis black, or is this drum raw iron with no coating? The early service drums that came in the tan boxes with redish brown printing were most likely the original run and would be coated but the drums that appeared in later 1964 in the white w/blue printing boxes were usually uncoated.

[Harry Sadlock]

Re: Met Drum ID

It's a brown cardboard box, the GM Logo is large and it it yellow and black. The date on the box is 12-63. The drum is natural steel, no paint except for the green swipe.

Harry

[Michael H.]

Re: Met Drum ID

That's interesting. That must be very close to the time that they stopped shipping black coated drums because almost all that I've seen in that style box were coated and all in the later white/blue printing box were natural. I don't think I have any like the one you have. Bet it's still correct, physically, for 63. I think the subtle changes started later, probably in mid or late 64??

[Harry Sadlock]

Re: Met Drum ID

Just got back from having a cigar. I took the magnifying glass and inspected the drum. There are traces of black paint around the weight and in some of the crevices. The drum had some very light surface rust when I got it and I now recall using some 000 steel wool on it. So it was painted black.

Harry

[Michael H.]

Re: Met Drum ID

OK, sounds like that's a real one. Btw, solvent quickly disolved/removed that black coating. (tar base) Possible that someone washed it before you got it.