AC ACE ALFIN BRAKE DRUMS
The plan is to use MGB brake drums for our project with an Alfin skin to get the look. You can follow the progress of this detail madness at the bottom of the page.
The original AC ACE had Alfin brake drums right around but an option was available from the outset of production for Girling Discs up front. I prefer the look of the drums that were used on the prototype and the AC ACE that was used at the motor show back in 1953. The Alfin drums on that car had cooling holes. There are period pictures below showing the drums.
The original AC ACE had Alfin brake drums right around but an option was available from the outset of production for Girling Discs up front. I prefer the look of the drums that were used on the prototype and the AC ACE that was used at the motor show back in 1953. The Alfin drums on that car had cooling holes. There are period pictures below showing the drums.
Alfin drums fitted
The Alfin Experiment
Big difference between the MBG drums and AC ACE Alfin type. The Alfins on the right below are pretty beat up but it maybe that they could be used as a skin, a bit like a giant spacer to create the look of Alfins on the Hawk AC ACE Replica? We will wait and see???
Looking at a size overlay it looks like one could make a dummy Alfin using MGB Hubs. The original Alfin drums for the AC Ace were 11 inch. MGB Rear Drum size is 10in. So with a little work on the lathe you could get the Alfin look at the right size yet retain the MGB workings and hub.
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Pictures. Blue Background = MGB hubs. Above = Alfin drums for the AC ACE. On the left = a size caparison between MGG and original ACE
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The first look at the Alfin drums in combination with the MGB hubs
This was the day I got the Alfin hubs home to match them up against the MGB hubs. It looks like, with a lot of messing about, an Alfin look may be achievable. It will take some lathe work an a lot of fitting and testing but....fingers crossed.
Back plate on axel with wheel fitted to hub
Below. This was loosely fitted back together to get a sense of how the Alfin drum could be attached or made to work as a cover for the Mob hub. Getting the backplate fixed to the axel is the datum point. New backplates for the MGB are NOT available as yet. So best to find a good used pair and refurbish them. A part like this I would normally powder coat but for an aluminium finish to match the Alfins it is better to use a spray paint that replicates aluminium and one that can withstand the corrosive effects of brake fluid.
Wheel on the MGB hub
Below. The original AC ACE wheel fits on the MGB hub no problem. You can see how the centre of the wheel covers the bolt heads that secure the brake drum to the splined hub for a need finish. The plan is to reduce the AC ACE Alfin drum centre to fit exactly around this centre. The depth of metal o the Alfin hub and the wheel cover plate are identical. So this means the fit should be flush and incredibly neat.
Securing the Alfin Drum to the MGB drum
After ensuring the drum will fit and how to reduce the metal in the centre to get a flush fit the question of securing the hub raises its head. I think the answer will be to drill out both hubs then thread the MGB hub to take a countersunk hub screw that is used on the Landrover Series 1&2 vehicles. Usually, 2 screws are used to secure a drum but on the AC I think we may use 5 to ensue a secure fit in a pentagon pattern. The Landrover screw takes a flat head screw driver as opposed to crosshead and will look more period. They are also a lot shorter than the MGB screws so may fit better and allow correct operation of the hub. It could be an option to put a retaining nut on the screws but they would probably interfere with the brake shoes and brake mechanism inside the drum. The pictures below left to right, MGB Hub with Triumph TR4A brake hub screw. Alfin Drum with TR4A Brake Screw to show metal differences. The shorter Landrover brake screws. The longer MGB screws.
Tyre width on the AC ACE took 165 16R = 16 Inch wheel with 16.5cm width. The MGB took 165 14 R. So there should be no offset issue on the Hawk but there is a 2 inch difference in Rim Diameter that make cause an issue and this is being investigated at time of writing.
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OffsetPicture above shows a 175 16R fitted to our Ace Wheels. This will be changed
The wheel offset is the distance from the hub face to the centre line of the wheel. Your tyre is then distributed equally about this centre line.
There are positive offsets which mean the centre line of the wheel is inwards from the hub face. And negative offsets which mean the centre line of the wheel is outboard of the hub face. |
Picture below: Ac Bristol ACE and Hawk ACE comparison.
Cleaning up the hubs
For some reason, someone had painted the alloy hubs silver. Acetone and a light wire wool brings them right up and provides an engineered look of the natural metal finish. You can see a little test area that was cleaned below. Some of the fins are going to need a little work with a file to make them straight. More time consuming than anything else.
New Alfin Brake Drums for the AC ACE
Alfin Drums for the AC Ace are available from these guys at £428.83 per drum. AC Ace 11" Aluminium Alfin® Brakedrum. Typecast Engineering Ltd. Unit 9, Leeside, Merrylees Industrial Estate, Leicester. LE9 9LG. Tel: 01455 822440. www.brakedrum.co.uk
Email: [email protected] They also used to make them for the MGB if you are using MGB running gear but it looks like these are no longer available. If they are available they are £395.34 each. |
MGB and Alfin Drums fixed together as a unit.
Below you can see the elfin hub after I have removed the centre section and reduced the width. Hex countersunk bolts have been used to affix the Alfin to the MGB hub. This has meant drill out exactly the holes and putting a thread in the holes in the MGB hub. Bolts were reduced in length and threaded to make sure there was no conflict with any braking workings.
The restored Alfin fixed to the MGB hub with Wire wheel splined hub in-situ
Below you can see the restored hub with the wire wheel attached. You can see the centre section of the Alfin that was reduced takes the centre of the wire when perfectly. It would have been possible to put the elfin behind the wire wheel but that would have pushed the wheel out another 5mm ad that would have had an impact on 'Offset'. The finished hub was given a light polish so as to keep the knocks and marks of time to help with an authentic look. Worth noting that the fins were skimmed to neaten them up as some were quite damaged.
Hub direct comparison.
You can see the state of the hub after the machining work was done. I think you will agree that it was worth spending a few extra hours cleaning them up to the finished state achieved.
The real McCoy.
These damaged Alfin hubs were scrap. But you can see that making them in to dummy covers gives them a new lease of life. The writing on the hub shows they are genuine Alfin drums made for the AC ACE. Made by Wellworthy the same people who make the pistons for the Ac 2 Litre AC ACE engine. the 'W' on Ac engines denotes 'Wellworthy.
Building up the brakes and hubs
Everything goes together pretty easily with a bit of brute force. The only mission was the brake shoe retaining springs. There must be an easy way of getting those on. I used thin-jaw mole grips to compress the spring and bullnose pliers to twist the retaining pin.I managed to get the thin head hub bolts from the MG Owners Club spares shop.
The axel is complete
Below you can see the finished axel with the hubs all built up and complete. Another big job crossed off the list. Can't wait to see how this looks on the car when it is finished. I bought 4 scrap Al-fin drums for this project and 2 of them were useable. Out of the 2, 1 is more pitted than the other so I will keep my eye out for another. It is not essential but if I see one I'll go for it. Now I know it can be done it will not take too long to cut down another Al-fin drum.
MGB / Al-Fin AC ACE Rear Brake Drum comparison.
Below you can see the difference between the MGB brake drums and the Original Al-Fin drums that I have altered to fit over the MGBs. The Al-fin gives the period correct look of a much larger brake drum. You ca see a lot less air through the wheel. The wire wheel featured here is the correct AC ACE 48 spoke wheel. The MGB wire wheel has a lot more spokes and gives a much denser look to the wheel.