Ok so I aquired a set of Buick 45 fin drums and they have these 1/4 inch circle indents (about 1/32 deep) in the inside of the drum. Now I've read on here that this means they are worn out, but then again I've read that the first year production had them. I've got the right tool to measure the inside of the drum and they are just slightly under 12 1/16" which seems usable to me. Thoughts? Are these drums worn out or are they first years? There is alot of arguements saying if drums are good or not and these are kinda on the boarder line of it . Id attach a photo but I can't seem to get them on here from my iPhone, and I don't have a pc. Any help would be great thanks!
You REALLY need a digital micrometer to measure them...45 fin drums have a maximum allowable diameter of 12.100"...figure you need anywhere from .010"-.020" of a cut to do even a minumum clean up on the liners, that's if they're not pitted too bad...so, if you're drums measure 12.070"-12.080", after you turn them, you're not going to have any service life left... That's why I try to tell people to measure them BEFORE they buy them, to determine if they're worth using or not... ...also, if you have ANY of the white corrosion between the aluminum drum and the iron liner, more than likely, they will not be useable after turning...the corrosion pushes the iron liner away from the drum, and turning it will cause thin spots in the liner, where it has been pushed away.
Well I'm glad they were free then. it's ashame because the fins are in great shape and someone had already removed the hubs. Would have saved me work doing the conversion to the '40 ford spindles and backing plates. now with that said had anyone had there's relinned and feel it was well worth it?
These drums have been placed on countless dirt oval cars, including mine, and all sorts of hot rods. What with s**** so high and so many yards crushing, theses drums are getting hard to find. Recently I talked to Mr. Bob Wilson Wilson Welding and Machine, I asked him about his previously printed aim of repro drums to be for sale, in so many words he said too many projects too little time. Like me, he's getting old. Anyone heard of anyone coming up with a decent alternative, or a repro? Dave
Early production had the bonding holes in the iron liner, then they figured out they could use solid liners. Nothing wrong with that style drum. What is the "right tool" you are using, my drum micrometer measures in thousandths not sixteenths?
I actually sold a pair of the 45-finned drums to a guy about 6 months ago. Said he didn't even care what condition the liners were in because he was just going to use them to make a cast for repros... Shame, too, because they looked like new drums!
Like mentioned above, 12.090 ID is the stated allowable max. About 18 months ago there was some traffic on here from Aluminium Drum Man who was starting up a process to reline aluminium drums. You can search the thread. I, and many others, had some interest, but I never heard from anyone that actually had some done. His posted contact info at the time was: jgrelining@gmail.com 815-276-2578. Perhaps you can check it out. <!-- / message -->
I can't imagine anyone actually paying the $250-290+ PER DRUM to have them relined. There are a couple of places up north that I know of that reline them. I think Illinois or thereabout?
He is a member on this board Aluminum Drum Man J&G Drum Relining McHenry, IL 815-276-2578 Don Booker www.jgrelining.com
Early production used a cast iron liner with many 1/4" holes in it. When placed in the mold and hot aluminum poured into the mold, the aluminum flowed into the holes creating a mechanical lock between the two components. It was discovered that this process did not provide adequate heat transfer from the iron to the aluminum so the method was changed to what was known as the "Alfin" process wherein a red hot cast iron liner was dipped into a bath of molten PURE aluminum then quickly positioned into the mold; the mold closed and the aluminum alloy poured into the mold. The pure aluminum bonded totally with the hot iron; the molten aluminum alloy bonded to the pure aluminum. Ultimately even this method was changed to one called "Vibra Bond" wherein the pure aluminum step was eliminated and the alluminum alloy was again poured against the hot iron liner but the mold was vibrated during solidification and accomplished the same level of bonding as in the Alfin process.
Dunno why it's so expensive to have 'em relined. Was told it's because it's difficult to remove the steel sleeve. Hell, my wife does it every time she hits the brake, little bit by little bit... Then she asks why the car "sounds like thunder". Women.
I'd take them to a brake shop and have them check them with a correct brake caliper that goes with the drum lathe as MrG***er suggested. If there is enough iron left in the liner have them turned. If not you have some interesting decoration pieces. I've never see a drum gauge that measured in 16ths either as they always measure in 1000ths even the ones with an ****og gauge on it as all I ever used had. It's a terrible photo but most shops are going to use a gauge similar to this one. You can not only tell the ID of the drum but can usually tell if it is out of round.
I am pretty sure that you can have new liners pressed in them. I may be mistaken but it seem to me like you can. Edit damn it: Ok I didn't read the entire thread I knew someone offered that process.
10 thousandths diff. is practically nothing,about 3 c-hairs. I would think you could go a little farther than factory specs. What did those 59'buicks weigh? What us guys are building here are probably half that. Within reason I would say another .030 or .040 wouldn't hurt on the dia. Check the shoe contact area(radius) also.
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