Chassis inspection

[EPC 394J]

I have a 1969 Plus 2 that hasn't been on the road for 28 years. (1984) It has had a replacement Lotus (non galvanised) chassis covered in bitumen which didn't do many road miles before being (dryish) stored. Car has a total of 59k genuine miles on the clock, but only an absolute max of 5 'road' years and 30k miles on the current metal. This chassis was apparently recently inspected by a Lotus specialist before I purchased it, and was described as sound. Nothing I can see on it leads me to believe otherwise. The towers certainly look solid, but I'm no expert!

I would prefer not to remove the body from the chassis during the refurb if I can avoid it. But obviously this would be stupid if the chassis is not in good nick.

I will obviously have it checked out by a specialist before commencing anything. Maybe by Spyder?? (Though they sell chassis and may have a vested interest in the verdict!)

My question is this: is the Mk1 eyeball the only method available for inspection? Is the Mk1 eyeball sufficient? Is there any form of NDT type testing available to detect otherwise hidden/latent problems?

Very many thanks for your help.

Andy

[UAB807F]

Hi Andy,

There's nothing wrong with the Mk1 Eyeball but personally I'd augment it with the Mk1 screwdriver. With underseal in place you could be hiding some serious corrosion, but I think that's unlikely given the history.

The places my chassis rusted through were the bottoms of the front towers and rather surprisingly, the backs of the towers just above the front cross member, as viewed from the engine bay. The tops of the towers supporting the springs were rusty but solid at both front & rear.

If I were you I'd simply get the car on axle stands or whatever you have available and then prod around with a screwdriver, starting with the suspension mounting points. If it's solid, fine. If the bitumen flakes off then just replace with a more flexible protection that's unlikely to dry & flake.

Problems such as cracking around engine mounts or the rear A frame/differential tie rod mounts are usually mileage related and 5 years doesn't sound long enough for such things to appear. Again, my chassis had a crack at one of the differential tie rod mounts, easily visible from underneath the car but that was on the OEM chassis and over 100k miles. (I think that was caused by poor maintenance rather than design failure.)

As an aside, one sign of impending doom for me was driving at night. It seems obvious with 20/20 hindsight, but I spent ages wondering why the headlamps would dip if I gave full throttle. I renewed everything I could see in the circuit, including the vacuum pods and still couldn't solve it. Yep, the vacuum chamber in the front cross member was leaking due to those holes in the front towers, found only after changing the chassis !

Brian