SV Minor brake drums wanted
Moderators: Ian Grace, Will Grace
SV Minor brake drums wanted
Does anyone have any SV Minor brake drums? I'm looking for four, but would be happy to buy them individually to build a set.
Re: SV Minor brake drums wanted
Hi Ian,
I have a couple of steel brake drums that came with a cable braked Minor front axle. I don't know if they are the same as the SV model though.
Regards
derek
I have a couple of steel brake drums that came with a cable braked Minor front axle. I don't know if they are the same as the SV model though.
Regards
derek
Re: SV Minor brake drums wanted
Hi Derek,
The OHC and SV drums are both 8 inches, but the SV drums have wider flanges - about 3/4". So the backplates are different too - with the SV ones slightly larger to accommodate the wider flange.
More importantly, the OHC drums were steel pressings, while the SV drums were more rigid castings. These early OHC drums distorted when under braking which is why they squeal or ring so loudly when the brakes are applied. And of course this drum distortion also reduces brake efficiency. Anti-squeak bands don't seem to make much difference.
So I am looking for a set of SV drums which I could machine down the flanges to OHC drum diameter.
Incidentally, established folklore is that the flanges were widened to deter water ingress into the brakes. But since the gap between the flange and the backplate are the same, I believe the wider flange was an attempt to further stiffen the drum. The M Type used the same drums as the Minor, but with cast-on aluminium triple fins. I'm not sure this did much to stiffen the drums, but would have helped with heat dissipation.
For comlpeteness, the 1932 season OHC LWB models were fitted with 9" Lockheed hydraulic brakes and these had drums with triple steel cast fins, which certainly mahe them stiffer. If you come across any of these drums that are not finned, they will have come off a Wolseley Hornet.
Derek, I'll contact you offline regarding your drums. Thanks.
The OHC and SV drums are both 8 inches, but the SV drums have wider flanges - about 3/4". So the backplates are different too - with the SV ones slightly larger to accommodate the wider flange.
More importantly, the OHC drums were steel pressings, while the SV drums were more rigid castings. These early OHC drums distorted when under braking which is why they squeal or ring so loudly when the brakes are applied. And of course this drum distortion also reduces brake efficiency. Anti-squeak bands don't seem to make much difference.
So I am looking for a set of SV drums which I could machine down the flanges to OHC drum diameter.
Incidentally, established folklore is that the flanges were widened to deter water ingress into the brakes. But since the gap between the flange and the backplate are the same, I believe the wider flange was an attempt to further stiffen the drum. The M Type used the same drums as the Minor, but with cast-on aluminium triple fins. I'm not sure this did much to stiffen the drums, but would have helped with heat dissipation.
For comlpeteness, the 1932 season OHC LWB models were fitted with 9" Lockheed hydraulic brakes and these had drums with triple steel cast fins, which certainly mahe them stiffer. If you come across any of these drums that are not finned, they will have come off a Wolseley Hornet.
Derek, I'll contact you offline regarding your drums. Thanks.
Re: SV Minor brake drums wanted
Ian
A very informative reply. If you don't find any SV drums then why don't you consider having a batch of cast iron drums made? A batch of two dozen might prove economically viable. I suspect there are many OHC Minors out there that would benefit from new, stiffer drums.
A very informative reply. If you don't find any SV drums then why don't you consider having a batch of cast iron drums made? A batch of two dozen might prove economically viable. I suspect there are many OHC Minors out there that would benefit from new, stiffer drums.
Re: SV Minor brake drums wanted
Derek, the thought had crossed my mind (it was not a long journey ...). I wonder how many OHC Minor owners are suffering with the tin brake drums.
Re: SV Minor brake drums wanted
Just a thought; I found today in the garage what I believe to be the brake drum from an early Mini. I think it might be possible to machine them to suit the Minor. Worth a look. They are 8" dia. The best bit is they are only about £12 new.
Re: SV Minor brake drums wanted
Interesting Derek. Definitely worth exploring. It might also be true for other cars - like the Morris 8, which I seem to recall had a 'curly' flange which could probably also be machined off.
Re: SV Minor brake drums wanted
Would there be an issue with converting from 4-stud to 3-stud?
Re: SV Minor brake drums wanted
For the Morris 8 drums? I believe they were six stud. Or do you mean the Mini drums? If the latter had four studs, the drums would need to be drilled very carefully and countersunk at the correct angle to take the wheel nuts.
Re: SV Minor brake drums wanted
Forgive me, I'm still pretty clueless about many details of the Minor and Eight. I was referring mainly to the drums fitted to Minis, which are 4-stud. There have been plenty of 3-stud fixings on many French cars, but they'll all be in metric, which most likely won't help. Stuff like the 2CV, Visa, AX/Saxo, Renault 4, etc.
Re: SV Minor brake drums wanted
Understood - thanks. I'd like to see a Morris 8 drum next to an OHC Minor drum and see if the latter could be machined from the former. With six studs, only the rim would need machining, assuming the width is the same, which I think it will be. I was told about 35 years ago that the Morris brake drums were virtually the same from the Minor right up through the post-war Minor.
Re: SV Minor brake drums wanted
Yes Mini drums are drilled for four wheel studs. With luck they might even be on the same PCD as a Minor so one of them could be used. New holes would need to be drilled and this would best be done on a milling machine with a rotary table but when you are getting the drums so cheap it would be worth paying someone to do this.