Disk conversion

Post by **Hellfish** » Thu Feb 05, 2009 5:16 pm

Some of you may be familiar with the MiniMania disk conversion kit for Morris Minors. Will Austin Healey BN2 hubs or Bugeye sprite drum hubs work? MiniMania says "The simple conversion requires the use of Sprite/Midget front hubs, rotors and calipers". Are disk and drum hubs different? If so, how can you tell a disk from drum hub if it's off the car?

I'm not that familiar with these cars so I'm not sure which models' hubs are useable. I just know that wire wheel hubs are not.

Thanks!

Post by **bmcecosse** » Thu Feb 05, 2009 5:41 pm

The Spridget disc braked cars had different hubs to the early MK1 Sprite (your 'Bug-eye' - we say Frog-eye) drum hubs - which are identical to Minor hubs. Note that 'wire wheel' hubs are different again ! So - you would need the complete hub and disc assembly from a non-wire wheel Spridget, and then you need to make a bracket to carry the caliper. These discs are quite small - and may not give any better braking than the later 8" drum brakes that Minors had from ~ 1963 onwards when the larger 1098 engine was installed. What year is your Minor ?

Post by **Hellfish** » Thu Feb 05, 2009 9:04 pm

It's a 1958.

The MiniMania kit includes the bracket. I would just need disks and calipers.

Are Austin Healey BN2 hubs the same as Spridget hubs? Sorry, I'm used to American cars.

Is there any improvement in using Sprite drums?

Will '58 wheels fit over '63+ 8" brake drums?

Post by **Kevin** » Thu Feb 05, 2009 9:49 pm

Hellfish wrote:It's a 1958.

The MiniMania kit includes the bracket. I would just need disks and calipers.

Are Austin Healey BN2 hubs the same as Spridget hubs? Sorry, I'm used to American cars.

Is there any improvement in using Sprite drums?

Will '58 wheels fit over '63+ 8" brake drums?

Sorry I am not familiar with the Minimania kit as most of the disc brake conversions over here come from Morris Minor specialists although there is a Sprite disc conversion I dont think it is as great an improvement as the UK Morris Marina and Ford Escort conversions which are far more common (not much help to you over there)
As the Healey has 15" rims I would assume that the brakes are probably to big to fit, as for the Sprite drums I havent heard of them being used as an upgrade.

Post by **Hellfish** » Thu Feb 05, 2009 10:30 pm

here's the kit

http://www.minimania.com/web/Item/DSK100/InvDetail.cfm

Post by **Kevin** » Thu Feb 05, 2009 10:42 pm

Look a simple enough Kit and I checked the UK site and it doesnt appear to be listed so must be a Stateside only kit.

Post by **bmcecosse** » Thu Feb 05, 2009 11:06 pm

Sprite MK 1 drums were just 7" - same as Minor of that era. Very unlikely AH BN2 parts will fit! Yes - 58 Minor wheels will fit over 8" drums no problem at all - they didn't change.
There are some disc conversions about where discs are simply fitted over the Minor hubs (VW Polo discs being used for one of these) and then suitable brackets fabricated to hold calipers over the discs. It's a bit of a bodge because the discs have holes drilled for the VW pcd - and it just so happens they kind of fit over the Minor studs (which are 4" pcd) only really touching at the edges of the studs. The disc is then clamped in place by the wheel when it's fitted - although a couple of holes are usually drilled and tapped and little screws fitted -these do not add any strength, they just hold the disc in place until the wheel is fitted. One conversion in the UK fits the larger 9" front drums from a Wolseley 1500 - straight bolt-on conversion. I'm sure you don't have that car - but I believe the Nash Metropolitan (strange and unusual machine ! ) was sold in USA - and uses the Wolseley chassis - and presumably the same 9" drum brakes! May be worth a search. But simplest way forward will be to get hold of Spridget hubs/discs and calipers - I'm sure we can find a drawing of the necessary bracket for you!
If fitting discs - you need to take the master cylinder out and remove the little 'top-hat' seal that holds some residual pressure in the system. You may prefer to fit a new set of seals when doing this - or even to do the modification on a new master cylinder. Many also fit a remote fluid reservoir high up under the bonnet (hood) - again only considered necessary if fitting discs.

Post by **plastic_orange** » Fri Feb 06, 2009 10:55 am

The Metropolitan had the Austin Devon/Somerset chassis/running gear with a 1500 B series engine fitted - brakes not interchangeable with a Minor as far as I know. I had 3 Devons, and the brakes were as good (bad) as a Minor.

Pete

Post by **jaekl** » Fri Feb 06, 2009 1:05 pm

The Spritget conversion is an easy conversion here in the States. As stated previously there is no significant improvement over the drum brakes. The olny benefit is vast reduction in fading. If you come down many hills you would be glad you have them. If you are looking for a bolt in upgrade that is readily available in the States, go with the 8 inch drum upgrade that came with the 1098. If you are going to increase the power any and want to drive in traffic, you are going to need to do some designing.

Thanks guys for answering the Metropolitan question. I've wondered about their brakes but never had a specimen handy to check.

linearaudio · Post by **linearaudio** » Fri Feb 06, 2009 7:59 pm

For the general VW disc fitting info- search on "disc brakes for about £100" in useful tips ( first posted nov 07). That gives excellent info on how to graft them on!

Post by **Hellfish** » Fri Feb 06, 2009 9:15 pm

Thanks for all the help!

We don't have the VW Polo or the Wolseley over here.

We live in the middle of the US, which is pretty flat, but we have a lot of traffic. My wife wants the car to be safe and be able to handle traffic here, as well as stopping in it... and eventually be a good driver for our daughters. It doesn't sound like the Spridget conversion is really worth it. Maybe the 8" drums would be easier and better.

Has anyone tried drilling venting holes in the drums to reduce fade?

I've heard some positive feed back about this guy, as well as some naysayers

http://www.chtopping.com/Home/index.html

Post by **plastic_orange** » Fri Feb 06, 2009 11:30 pm

With the current exchange rate would it not be an idea to import a quality brake kit from the likes of JLH?

Pete

Post by **bmcecosse** » Sat Feb 07, 2009 5:28 pm

You won't get fade with 8" drums in flat country! Only steep hills are likely to bring on serious fading - unless you upgrade the engine - and need repeated hard stops in a short time. Don't be put off the Spridget disc conversion - it will be better than the original 7" drums and may be more easily obtained than the later 8" drums where you are.
I was sure the Nash had thr W 1500 underframe - it was made long after the Devon had faded away - about same time as the W 1500 and R 1.5.

linearaudio · Post by **linearaudio** » Sat Feb 07, 2009 7:16 pm

[quote="Hellfish"]Thanks for all the help!

We don't have the VW Polo or the Wolseley over here.

I think you may know it as a VW Rabbit? Probably any small modern VW would be OK, it's the wheel hole pattern that needs to be close,-as BM says its not same as Moggy, but works as location is by the central hole.

Post by **bmcecosse** » Sat Feb 07, 2009 7:18 pm

The Rabbit used to be the European Golf equivalent - the Polo being a smaller model. However - the Rabbit may well have suitable discs.

Post by **plastic_orange** » Sat Feb 07, 2009 9:05 pm

http://www.stevvia.demon.co.uk/metro.htm

Pete

Post by **bmcecosse** » Sat Feb 07, 2009 11:58 pm

Good site! Mad cars. But doesn't give any clues about chassis ? The 1200 Devon engine was indeed the pre-cursor of both the A and B series engines.

Post by **plastic_orange** » Sun Feb 08, 2009 10:23 am

I used to have a manual which showed the grease points. The Devon 1200 engine was physically smaller than a 'proper' B series, but they did produce a 'proper' 1200 B series in an A40 cambridge. I'd assume it was this version the Metropolitan used for the US.

http://www.uniquecarsandparts.com.au/na ... ations.htm

http://www.independent.co.uk/life-style ... 54616.html

http://www.dugdalevms.com/www/Motor%20A ... olital.htm

Post by **lalaw** » Mon Feb 09, 2009 7:18 pm

On my minor I use brakecalipers(ATE) (rabbit) MK1 they are identical to the Polo ones.
The Discs are diffrent but they where used by a Audi model also.
Brembo Partnr 08.2878.10
I've used this setup for 2 years now and it works very good.
I also added a brakeservo which is only connected to the front brakes.
Lars