Packardkiwi Posted July 30, 2016 Share Posted July 30, 2016 I like to replace the current pressed steel brake drums on our 640 with a cast iron equivalent. Is there a firm which manufactures one? Link to comment Share on other sites More sharing options...
Owen_Dyneto Posted July 30, 2016 Share Posted July 30, 2016 You really don't want a simple cast iron drum, cast iron's strength is only in compression and when forced to expand from within by the shoes a simple cast iron drum would probably shatter quite quikly. However you do want the frictional properties of cast iron for the surface that the shoes contact so high quality drums are either a steel or cast steel outer shell with a centrifugally spun (or "centrifuse") iron lining. I know of no one that makes any replacement brake drums for Packards. Also, hopefully others who own and drive a 6th series Big Eight regularly will comment but the few times I've driven one I found the factory brakes to be extremely competent. Link to comment Share on other sites More sharing options...
Ozstatman Posted July 31, 2016 Share Posted July 31, 2016 No help to Arnold but here's a photo I took of his Packard in 2014. Link to comment Share on other sites More sharing options...
Packardkiwi Posted August 1, 2016 Author Share Posted August 1, 2016 Thanks for the reply. The steel drums on our car need machining and this could mean even less drum thickness, which lead to even quicker heat expansion during braking. The modern brake shoe lining friction coefficient is less than that of the original asbestos one.Steel offers less resistance than (special) cast iron. On our narrow, windy and hilly roads in New Zealand we found the Packard brakes wanting. Therefore my search for a cast iron type of drum to get a better braking performance and less drum expansion due to the thicker wall. Link to comment Share on other sites More sharing options...
Alfa Posted September 5, 2016 Share Posted September 5, 2016 A little off your pact, but you could speak to these people. www.brakedrum.co.uk/ Adam.. Link to comment Share on other sites More sharing options...
Packardkiwi Posted September 7, 2016 Author Share Posted September 7, 2016 Thanks for that. Had a look at their website. No Packard drums listed. Of course I could supply them with an engineering drawing. In the mean time I have obtained two old 640 front drums. After grid blasting I will put them in a lathe and see how true they run. If not too bad I can machine just a little bit of the braking surface without introducing to many different stresses in the steel which could cause ovality..Always nice to stay with the original Packard drums if course. Link to comment Share on other sites More sharing options...
Ozstatman Posted September 8, 2016 Share Posted September 8, 2016 (edited) Arnold, Know you've found a pair of drums, but have a look at this thread - http://forums.aaca.org/topic/281894-renewing-brake-drums/#comment-1518471 and the posts by Ivan Saxton in particular. Edited September 8, 2016 by Ozstatman (see edit history) Link to comment Share on other sites More sharing options...
Packardkiwi Posted September 10, 2016 Author Share Posted September 10, 2016 Thanks for that. There is some very useful info in that thread. Even at my advanced age and being an engineer you can always learn something! I have printed that article re. spot hardening causing distortion and how to avoid it. Maybe that is the problem with the drums I have on the car at present (not for long I hope). Link to comment Share on other sites More sharing options...
Otahuhu Posted September 10, 2016 Share Posted September 10, 2016 What you can do with a steel drum is shrink a steel band around the OD of the existing drum then machine with undercut rings to help reduce weight and a bit of air cooling This does work and makes braking better with correct lining as I have done it If you have deep pockets and want to race the car have some cast in Aluminum alloy with a steel insert There is a company in the UK that have cast this up for some very fast original vintage cars Paint these up and even the experts will be unable to tell Some of the American cars of your period had steel drums with outer rings as well as hydraulic power assist brakes as standard Link to comment Share on other sites More sharing options...
Packardkiwi Posted September 24, 2016 Author Share Posted September 24, 2016 Thanks Otahuhu. At the moment I have the recently obtained front drums checked for truness and hopefully they do not need machining. If it is only a very light skim I might get away with it. Once back on the car will find out if this have improved the braking performance and have a "closer" adjustment which means less pedal travel. Will keep you posted with the result. Link to comment Share on other sites More sharing options...
JoeMarsh Posted August 5, 2017 Share Posted August 5, 2017 Hi Otahuhu , I have a 1930 Model S Hupmobile with steel plate drums. The car is heavy, about 3800 pound and the brakes small Brake diameter 10.75", Brake Width 1.5". Yeah , any long hills are a problem unless you go in second at 20 MPH. I was thinking of venting the brake surface as recommended by http://www.chtopping.com/CustomRod4/ . It sounded like they have had good success with that method. However, I really like your suggestion of adding a steel band around the OD. Where can I get such a band ? What size is the band ? Could I roll my own and weld it in place ? Your comment about "Machine with under cut rings" are you saying to produce a cooling fin from the existing brake drum active area ? Have you considered welding 1/2" fins about 2" apart all the way around the brake drum active area for cooling ? Dura-Brake will cast custom brake drums with an 8 piece minimum @ about $350 a drum. Link to comment Share on other sites More sharing options...
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