63 Brake drums

[Carl S.]

Since I recently cleaned up my brake drums as part of my body off restoration I went down and took a look at my drums. the front drums are as removed.
LF 3828671 W-2 with F on the face and anti-squeal spring
RF 3828671 w-10 with F on the face and anti-squeal spring

LR 3828688 W 10 No dash after the W and no spring
RR 3828688 W6 no dash or space afrer the W and no spring

[Michael H.]

Anyone Else Have 63-64 Casting Numbers

Thanks Carl. We'll add your brake drum casting numbers to the survey list. Would you happen to know if the car was originally equipped with metalloc or standard brakes?

Anyone else happen to have their original 63 or 64 brake drums? Still need a little more input on this. Thanks.

Michael

[mike cobine]

Re: Anyone Else Have 63-64 Casting Numbers

I have a pair but I'll have to wait until Saturday to get over to see them. I also hae a pair that came off a '63 Bel Air so it might be interesting to see the numbers from them.

[Michael H.]

Re: Anyone Else Have 63-64 Casting Numbers

Thanks Mike. No hurry. Would you happen to know if the Corvette had metallic lining?

[mike cobine]

Re: Anyone Else Have 63-64 Casting Numbers

Since I never got the drums off, I can't be sure. But since the car was a low horse, I'd assume they were standard.

[Gordon Peterson #4961]

Re: Anyone Else Have 63-64 Casting Numbers

Not sure if you have my info. Same casting numbers as Carl, '63 coupe, 300HP, J65 metallics.

Pete

[Michael H.]

Results

Thanks Gordon,

I have your info from the previous post. I believe we now have enough info on this matter to conclude that the 3828671 was the only casting number found on ORIGINAL 63-64 front drums, and the 3828672 was a later service replacement. This would include both standard and metallic brake packages, as the casting number would be the same for both. (not Z06)

If anyone has info to the contrary, please let us know. If not, I'll consider this research project concluded and in the history books.

Here are the findings. Casting numbers are...

63-64 FRONT drum, all, except Z06.....3828671

63-64 REAR drum, all, except Z06.....3828688

Michael

[Ray C.]

Re: Anyone Else Have 63-64 Casting Numbers

Hi! Mike

I just checked the drums on my 63 SWC restoration project. The coupe was ordered with metalic brakes. Rear left and right: 3828688

Front: left and right 3869532

One drum has the flollowing: MAX DIA 11.090 W4 the other drum does not have this information.

The front drums had springs and the rea did not.

Ray

[Michael H.]

Re: Anyone Else Have 63-64 Casting Numbers

Ray,

Sounds like you have a correct set of rear drums but the fronts would be replacements. In April of 1970, the original 1963 front drum for metallic brakes, part number 3830167, was replaced by part number 3872384, which would have had the casting number 3869532.

1970 was just about the same time that the "Max Diameter" became mandatory on all new drums and rotors, give or take a year. Thanks Ray,

Michael

[Wayne M.]

Jan '64 car rear drums 3828688 (W12 and W8) *NM*

[Duke W.]

Re: Results

The handful of scattered anecdotal evidence presented here over the last couple of days would certainly not lead me to make any definitive conclusions.

A serious historian would demand a lot more evidence and a resolution to the known ambiguities.

The possiblity that two different end item part numbers could come from the same casting number, when those castings were poured with different web inserts just doesn't make any sense.

Duke

[Michael H.]

Re: Results

Duke,

In a string of previous posts on this subject, (Tuesday,10:30 PM) John Hinckley posted tonight and explained how these drums were made and how the web, or dish section, would have been the first piece in the mold before the rim was poured onto it. That means either thin or thick web could have been used with the same ring and casting number. It's basically what I've been trying to say for weeks but John made it much more understandable. Below, in John's own words.

"All of those drums were centrifugally cast. Whatever web was required for the finished assembly was placed in the prepared lower half of the mold (which held the periphery of the web up about 1/4" off the floor of the mold), the upper half of the mold was added and clamped in place, the iron was poured, and the mold was spun to evenly distribute the iron as it cooled, in a continuous process. The sprues were on the inboard flange of the drum surface, and disappeared during finish machining".

[Duke W.]

Re: Results

Yes, I understand how they are made, and maybe the same tooling can be used for different web thicknesses, but you still end up with two different finished castings because of the different webs.

Certainly the drawing did not show both the "thin" and "thick" webs leaving it up to the manufacturing people to use whichever one was convenient.

There had to be a sure fire way to ID the thin and thick web drums to select the proper casting to produce finished 166 and 167 drums.

Maybe the "X" or or something else stamped on the web was used to ID the two different castings, but I'm just speculating. We do know that there were multiple mold sets - the "W-..." molded into the casting is the mold number, and it would have been very simple to have a set or sets of molds with a different number to positively ID the two drums that were basially identical other than a slight difference in web thickness.

The 672 drum in the 166 box is very interesting because it could not have been a later design. The number is in sequence with the 671 drum, which is why I think either 670 or 672 may have been used to indicate the base drum casting with the thinner web. The finished drum part numbers are sequential because they were probably designed on the same EO, and possibly likewise with the casting drawings.

Duke