JP

Well, I didn't get round to changing the IACV and on my run out today, it faltered a few times while initally warming up. The revs would drop momentarily to 500 or so and either recover spontaneously or recover and stabilise with a blip of throttle. Once warm I had no odd behaviour. I'll switch over the IACV this weekend hopefully all will be good...

I'd still like one if anyone only wants 4...

So, having done a bit of research, I'm now starting to reach different conclusions about the ride height issue. I would be grateful for any comments (including to be told that I've got it all wrong)... 1. The key issue with the starting point for the front ride height is that the bottom wishbone should be horizontal when weighted and at rest. If one seeks to raise the front to get 75mm under the sump with 185/60/13s , then the front wishbone will have to have a steep downward slope from the chassis to the wheel, which will upset the rest of the suspension / steering geometry and function. 2. If that is correct, I do not see that it is possible for a wet sumped K-series to have 75mm of ground clearance under the sump if it is on 185/60/13s, given how low the sump sits in the engine bay. 3. The Caterham / Bilstein shocks for the std fixed set up and the adjustable set up are the same core shock - the latter just has adjustable platforms added (ie the full open length is the same). If all that is right, I just need some stiffer and slightly longer springs as my front wishbones are ever so slightly angled upwards at the wheel. If anyone is interested, the full open eye-to-eye length of my old std Bilsteins was 38cm/15". My Pro-techs are the same. The stroke of the Bilsteins is about 60mm. The Protechs are 115mm. I guess, on a wet sump K-series, that if one is concerned about ground clearance, the best solution is to use 14" wheels for regular road use and reserve the 13"s for track days... Grateful for any comments...

So, having measured my old non-adj bilsteins (with spacer for sidetrack) against the new Pro-tech shocks, the total opening length is the same. I am starting to think that the original non-adj suspension could never have been right for a 14" wheel; car moving to 13"s...were the adj bilsteins for widetrack longer when fully open than the non adjust ?

I went 185/60/13 R888Rs all round in the end. Don't need fat rear tyres for my level of performance, I think.

Thanks @SM25T - it looks as if mine will be coming off again shortly anyway...☹️ This is really irritating. I was really looking forward to getting the last of the key bits of the rebuild done and just enjoying the car again...

Cheers @7 wonders of the world - I did ask Pro-Tech before flipping them and they said that it wouldn't be an issue, but I'll check again with them when I discuss the solution to the ride height problem. Cheers for the heads-up.

Cheers @ScottR400D - I'll get on to Protech and PT who will do the setup. I was rather hoping that there might be an obvious solution that I can address before the appointment next week. I fear I may have to post-pone the setup...

If I go with longer springs, does a 9" spring sound right? I think my current springs are std 7" (1.9"ID) 150lb - the markings are not clear. On the car they are approx 5" long and I think 2" compression with about 130kg on them sounds about right for a 150lb spring? So if I want an extra 20mm sump clearance I think need a little over 1" extra spring length (assuming the spring is at roughly 45degrees) and say another 1" so that the spring adjuster isn't right at the end of the threaded portion of the shock? Should I change the spring rate too? Its a road car with occasion track days, say 3-4 per year max...

So...I planned to do a rough check of ride height today, just to get it in a safe ball park range for a first longer drive out to get a full flat floor set up next week. I seem to have fallen at the first hurdle in that I've run out of front spring adjustment with a sump that is way too low at 55mm. My car was originally a SS with widetrack non-adjustable suspension on 14" wheels. In my rebuild I switched to Pro-Techs, but re-used the front springs because they were more or less new when I took the car off the road. I sent the old front shocks to Pro-Tech so they could see that they were for wide track (they have the extension piece at the top). Here is the position today on 185/60/13 R888Rs: 55mm sump clearance (without me in the car): And shock adjuster position: Do I just need longer springs, or should the shocks go back to Pro-tech for longer shocks? If I just need springs, any recommendations? Need quick delivery becuase the car is booked in for a FF setup on Thursday...

Just had a look in my assembly guide for a k-series: My K-series SS was on 14"s and did not have adjustable suspension. Perhaps adjustable was only std on those Ks with 13"s? With 14"s, you would have an extra 12-13mm of clearance. 66mm might be the diameter of a coke can, but 75mm is roughly the length of a SwissCard...of course, that's not much use if you don't have one...

OK, I'll have a rummage in the shed at the weekend and report back...

Will do! Right now I just want to make sure I can get to PT safely and without grounding my sump! My car is currently as I have rebuilt it - with components fitted out of the box and applying the general guidance from the build manual. Looking forward to getting it properly set up...

Thank you! I had tried the search...honest...

I had a flakey hazard light switch. New one was £9 from Redline - now fine. One of the side terminals had broken loose on my old one.

Just picking up this thread from the one on coil over adjustment. I need to get my suspension ride heights into the correct ballpark before a longer drive to get it properly flat floored / cornered. My question is where does one measure the ride height at the rear? I am sure I have seen a diagram of this somewhere but cannot find it ion my assembly guide or owners manual. So, do I set the front with, say, 75mm sump clearance, then measure the front ride height under the chassis say at the rear leg of the front suspension wishbone, then add 15mm rake but then measure the rear height where? At the front A-frame mount? Where is the reference point for measuring rear ride height?

Or a vehicle endoscope thingy. I got a reasonably cheap one off Amazon and it has been good enough to enable me to do a few jobs where I could get a hand but not a direct line of sight..

I might still have my old one, but it is 15 years old and would need a rebuild. If that would work let me know and I'll go on a hunt in the shed...

Here is the part number in case there are other sources to try...

Jonathan also helpfully added info on correct voltages in my thread below about my 1.6K cutting out at idle..

I'm sure it did JK, but, for clarification, it was only charged in the course of driving. I haven't had it on a charger.

Out for a short spin today ~30 mins. No idle problems at all. Here are some further voltage readings for comparison after this morning's drive: Everything off, FIA off: 12.84V Everything off, FIA on: 12.84V Lights on for 10s, then switch off: 12.72V Cranking: No initial momentary large drop visible on my multimeter. Initial cranking at 10.90V, which dropped smoothly while cranking to a steady 10.71V. And looking at the revs drop as per @revilla posting above, I think I see a momentary pause during the fall: Videopro 20240427 110103-1.mp4 So, I now have a new IACV sitting in a box. I guess I might as well fit it...

If anyone only wants 4 of these, I would be happy to take the 5th - I'm after a spare.

I'll recheck it after driving, but I don't think I should have to put a new battery on a charger...

Battery and IACV arrived today. Battery fitted, but not test driven yet. However, I thought I would test the voltages on a fresh battery straight out of the box from Tayna. Here are the numbers for comparison: Voltages: Everything off, FIA off: 12.54V Everything off, FIA on: 12.54V Lights on for 10s, then switch off: 12.40V Cranking: No initial momentary large drop visible on my multimeter. Cranked steadily at 10.35V. Engine started (on the button, no throttle needed), idling at 13.95V. No 3000rpm voltage tested this time. Current IACV could be felt "stepping" briefly after switch off. I'll drive the car over the weekend. If it fails at idle again, I'll change the IACV. If I get to Sunday and it hasn't failed, I might change the IACV anyway, because the new one is shiny and new...