Lotus Europa S1: Chassis strengthening plates

Hi everyone,

In this post I’ll show you the process of updating a series 1 Lotus Europa chassis with a series 2 modification.

You might remember from a previous post that I had to repair some cracking of the chassis around the rear radius-arm mounts. This was a common problem on S1 Europa’s and Lotus, always wanting to improve their cars, installed a strengthening plate on the later cars.

This is the inside of the rear Y-section and the place where the radius-arm bushings mount and where cracks would form.

I roughly copied the S2 strengthening plates, but I adapted them to my situation. The S2 plates would be thinner (1.6 mm in stead of my 2 mm) and the top of the plate would have a folded lip to increase the rigidity. I’m using a thicker steel because it will be easier to weld, it will give me some extra rigidity and it will provide some more offset of my custom racing radius-arm mounts with a spherical bearing (more on that in a later post). I couldn’t make them with the folded lip because I wouldn’t be able to spot-weld them and this was a much better solution in this case.

This is a picture of the plates all masked up ready to have the inside surfaces painted with zinc-spray.

The inside of the rear Y-section of the chassis get the same treatment.

Every part gets three coats of zinc-spray to make sure that rust won’t form between the plates.

When the paint has dried the plates get bolted down through the radius-arm mounting holes

I TIG welded the plates without using any filler material, I could do this because I made the plates extra thick and extra large so I wouldn’t have to sacrifice any material that I couldn’t miss.

I got full welding penetration and I had to grind off the excess on the sides of the chassis.

Well, this was a shorter post than usual, but I’m working very hard to get you the next update. I’ve been working on and of for quite a while on the backbone repairs. I only need a couple more days before I’ll be able to show you some real progress.

I hope you enjoyed this post!

If you have any questions or comments, don’t hesitate to send me an email via the contact page on this website.

Take care,

Serge