I recently started a thread eleswhere in TechTalk asking if anyone had developed a sump guard to protect the very exposed Cosworth dry-sump pan on CSRs. Some kind members (thank you!) were good enough to provide some ideas and even photos of what they had tried, but I felt a different approach could be worthwhile.
I thought that a wedge shaped affair, mounted securely ahead of the engine and the sump, would be a good approach - allowing the car, hopefully, to 'rise and glide' over any significant middle-of-road obstacles, without further reducing the already very limited ground clearance by fitting a shield running under the engine. After a lot of head scratching, I decided that a good approach would be to rigidly mount a solid, horizontal plate to the chassis cruciform area - a very strong and stiff area of the car, particularly on a CSR - and then mount the wedge securely to that. I explained the concept and a few members expressed interest, hence this thread to report back on what I have done.
Interestingly, some members asked whether the same approach would work on other Caterham derivatives, including later Series 3 cars with low-hanging wet sumps. My view is that, in principle, the answer is "yes" (the concept of strongly mounting to the cruciform appears to be a good starting point) BUT with two reservations:
- Firstly, I understand that the cruciform structure was considerably reinforced at the change to metric chassis, but earlier cars are known to be weaker in this area (tales of bent cross members when jacking under the cruciform on Imperial cars) so I'd suggest that the concept should be tried only on metric chassis.
- Secondly, having compared my own Series 3 car to the CSR, it's clear that there is a lot more bracing (vertical bracing at that) on the CSR than on the S3 so it feels to me that there is greater risk if adopting this idea to a S3 car. That said, the metric S3 cruciform looks to be both stiff and strong so I wouldn't rule it out - just weigh up the pros and cons carefully,
Anyway, I'll write a number of posts here to show the DIY design I developed - so give me a bit of time to write the words and post the images before wading in with too many comments, please. And it goes without saying, of course, that I offer no guarantees and accept no liabilities as to outcomes if you copy this idea!
But, in time-honoured Blue Peter style, I'll start here with an image of the finished article and then I'll provide more detail in subsequent posts.