Technical Suspension upgrade 500N 1958

[Orbish]

Hi,

I´ve decided to upgrade the drive line on my 500N to a 600cc with synchro mesh gearbox and so far all good, until we found out the the new axle coupling does not fit the old/original suspension arms from 1958.

To resolve this I have bough a new pair of suspension arms from a 500L but now there is another issue. On the original arms the coil spring sits on top of the arm (it´s like a "lid" in the corner) while on the new arm the coil spring sits in the bottom of the arm. This makes the spring 8-10cm too short. Picture attached.

As far as I know there are no taller springs than what I already have got, 220mm!?

Is there anyone who has done the same modification and if so, how to solve this issue? Any ideas are appriciated.

Thanks!!

 

[the hobbler]

Personally I would have left the drive-train as was, and just fitted a '126' bell-housing to the gearbox---there is nothing wrong with the original gear-box. What is it that people have against double-de-clutching? The layout of the 500s pedals is perfect for heel 'n' toeing.
To answer your question; the only way that I can think round the problem is to have a machine shop make you an aluminium spacer. The space to have a shape at the bottom the will fit INTO the wishbone and the top have a up-stand section that will fit INTO the bottom of the spring. The section into the spring only needs to be high enough that it will fit into the the bottom coil (and maybe the bottom 1-1/2 coils) to securely locate it. Make sure that when the spring is down to the bump-stop, the spacer isn't restricting spring compression. Finally, is a 500L or 'D' spring of too big a diameter to fit into the spring-location point on the 'N'?

 

[Bigvtwin996]

I can understand the reasoning for upgrading to later drive train...
From what have been told you basically use everything from a later car, inc springs brakes and hubs etc......
I am sure that the later springs are longer...

It does make life easier if you use the car a lot as later couplings etc are easer to obtain, plus if you do upgrade the engine the later couplings/axles can cope

Do you have the 3 or 4 bolt couplings?
I think you can get some 25mm axle outer ends that mate with the later N 4 bolt couplings...

One reason i looked at this was the cost of N Couplings...
so swapping the rear to later wishbones allows the cheaper later couplings if you use rear axles and hubs etc...

 

[jolly500]

Hi.

Yes I have done the same conversion as you are busy with and experienced the same issues.

With reference to the springs, I had a local spring maker make me replacement springs which, from memory, I calculated needed to be 285mm long. They were made with the same compression ratio as the originals (if that's the correct terminology?) I can remember it was a real struggle to get them into the recess in the body.
I have been running with a tuned 650cc engine, 126 bellhousing and standard non-synchro box and the suspension arms from a 'L' with the 25mm driveshafts for a number of years now and have been very happy with the setup.

I think if I did it again I would probably add 5mm to the spring length (make them 290mm long). But if you measure the height difference between the mounting plates of the 2 different types of suspension arms, you would probably come out at a similar measurement.

Hope that helps
Steve

 

[the hobbler]

That is the beauty of this forum---somebody has a problem and instead, as some forums are know to do, taking the mickey out of the guy, somebody will come up with a sensible answer. Thanks Steve--you have increased my knowkedge on how to get round a problem I didn't know anything about.

 

[Orbish]

Thanks a lot for the valuable insights! I´ve been thinking in this direction and will for sure explore it more when I know it worked out well for you. I will make sure to mesure the difference but great to have some indication on the lenght.

André