Downton suspension mods .

[irlmin]

While browsing through Marks excellent Downton pages I came across an invoice for a No 5 conversion and reference to Koni shocks and 'Swedish' bump stops , I know these were the Special tuning progressive bump stops but my question is did Downton do any other suspension or indeed braking mods back in the 'day' ? or was the ethos just improved performance . G

[Simon776]

Swedish bump stops are not Special Tuning bump stops - they are 51 and 52 on the image below. Also fitted to cars for Denmark, Finland and Norway.

Untitled.jpg

[irlmin]

Swedish bump stops are not Special Tuning bump stops - they are 51 and 52 on the image below. Also fitted to cars for Denmark, Finland and Norway.
Untitled.jpg

Well You learn something new every day in all the years I have been involved with minis I have never heard of these and assumed incorrectly they were ST progressive bump stops which I have often used . how well did they work ? anyway thanks Simon for the clarification . G

[Ronnie]

I have a quote from Downton in 1972 (for my 1971 Mk3 S) and they also state "lowering suspension and fitting konis to the front and bump stops to the rear and modifying the rear wheel camber".

[winabbey]

Also fitted to cars for Denmark, Finland and Norway.

... and Australia

[Spider]

Also fitted to cars for Denmark, Finland and Norway.

... and Australia

As Winabbey mentioned, we had these here to, under an Australian P/Ns of AYA7068 and AYA7069. Those fitted to the cars of the European markets, what P/N did they have, were they ex-UK and is anyone still making them ?

[Ronnie]

August 1976 edition parts list 21A 1728-RH / 21A 1729-LH, listed under remarks "For countries to which headlamp ALIGNMENT regulations are applicable.

[Spider]

August 1976 edition parts list 21A 1728-RH / 21A 1729-LH, listed under remarks "For countries to which headlamp ALIGNMENT regulations are applicable.

Cheers for that, those do look like UK numbers. I was able to track them to Somerfords who may have them.

http://www.somerfordmini.co.uk/eshop/in ... ts_id=3355

[CALIMKIIIS]

Here's what they look like in the flesh. They are apparently quite rare, I found these something like 20+ years ago, 2 years apart to get a pair. Never got around to installing them on my '70 S. Since the car is currently apart whilst awaiting the return if my refurbished displacer from Hydragas and Hydrolastic Services Ltd that replaced the faulty hose on the L/H rear displacer, I considered ordering the more common competition bump stop kit C-AJJ 3313 that seems to be recommended but I'll be installing these instead as they're in good nick and why not as they don't do much sitting in their boxes in the shed..

P1012993.JPG

[mk1]

From ST sheets on main site.

buffers.jpg

[CALIMKIIIS]

Thanks for providing the excerpt from the S/T sheets. I have the perhaps later Leyland S/T sheets that haven't changed any of the information. I did notice that it states for the 'Swedish' type bump stops-"Special securing screws and washers" may be used? Looks to me that they mount with the single bolt and washer as the original 'pointy' bump stop. The S/T sheets also mention that for rally cars 300 PSI is the maximum to be used and as shown, 220 PSI as the minimum. Also mentioned therein is that after fitting new displacer units to take the pressure up to 400 PSI (wow), letting things settle then reducing it to 282 PSI for later cars such as mine with the double silver band displacers...

[Ronnie]

Thanks for providing the excerpt from the S/T sheets. I have the perhaps later Leyland S/T sheets that haven't changed any of the information. I did notice that it states for the 'Swedish' type bump stops-"Special securing screws and washers" may be used? Looks to me that they mount with the single bolt and washer as the original 'pointy' bump stop. The S/T sheets also mention that for rally cars 300 PSI is the maximum to be used and as shown, 220 PSI as the minimum. Also mentioned therein is that after fitting new displacer units to take the pressure up to 400 PSI (wow), letting things settle then reducing it to 282 PSI for later cars such as mine with the double silver band displacers...

The Swedish bump stops use a countersunk screw and countersunk spring washer unlike the standard bump stop which uses a standard set screw.

[CALIMKIIIS]

Quite right! I should have noticed the tapered hole on the Swedish bump stops as being a now obvious clue. Thanks for pointing it out! I doubt that the original countersunk screws could be found anywhere in a mini parts catalogue but I know of a specialty racing hardware supplier nearby that can likely provide what's needed. Can't say I've ever seen a spring washer made for a countersunk screw though, I reckon I'll find out soon...

[Ronnie]

Quite right! I should have noticed the tapered hole on the Swedish bump stops as being a now obvious clue. Thanks for pointing it out! I doubt that the original countersunk screws could be found anywhere in a mini parts catalogue but I know of a specialty racing hardware supplier nearby that can likely provide what's needed. Can't say I've ever seen a spring washer made for a countersunk screw though, I reckon I'll find out soon...

Any good fastener supplier's should be able to supply > https://www.bing.com/images/search?q=co ... BasicHover

[CALIMKIIIS]

Found these:

shop photoes 004.JPG

[attachment=1]shop photoes 004.JPG[/attachment

[CALIMKIIIS]

Thanks Ronnie, your source show many other kinds as well!

[Ronnie]

The original were oval head (csk & domed) but that would do.

[winabbey]

These are the rear bump stop components for one side as fitted to Australian hydro sprung cars, in this case my Cooper S.

Rear Bump Stop 2.jpg

The screw is part RMZ510 (5/16" UNF x 5/8") and countersunk shake proof washer part 6K9012 (5/16" external teeth). If you Google those part numbers several UK parts suppliers list them.

Rear Bump Stop Washers 2.jpg

I made my own countersunk star washers by squashing some flat external tooth star washers in a copper pipe plumbers flaring tool.

Rear Bump Stop Washers.jpg

[CALIMKIIIS]

Splendid! Thanks for providing the photo and specifications. I will want to use the domed head screws since that was the original type, I only showed the Allen head type as it was convenient from my supplier's web page. No one would ever see the type used but myself, my car is very original and I do try to keep everything period correct down to fasteners. Hopefully I'll be able to source exactly what you've shown from your car. I will likely have to buy 5 of each but better than a box of too many I'll never need. Having the part numbers is most useful indeed. Nice that you've engineered your own! Wouldn't want a box of those washers to come adrift on the garage floor if you are inclined to go barefoot!

[Tedwong]

Scandinavian bump stop as I was told when I bought them! Fitted to my MK3 S now.