paul_w

More photos here As I'm going to be taking over my father's HPC BDR and need money for recommissioning it over the winter, I'm putting my faithful Sigma car up for sale. It's not the best time of year to sell, but was waiting until after our annual late summer blat around France, which is completed without a hitch. 29,000 miles 1.6 Sigma 140bhp Supersport Lightweight flywheel Tillets, standard roll bar, Adjustable platform dampers Adjustable rear ARB plate-type LSD Higher first gear upgrade on rebuilt 5 speed box (great upgrade!) heater, full weather equipment USB on the dash ally rad Green Stuff front pads lowered floors, black pack lowered headlights Toyo R888 tyres QR Momo wheel, starter button Braided rear brake hose conversion removable spare wheel (This can be taken off and returned to standard as I haven't drilled the rear panel - I only use it on longer trips and so have a strap like the early cars used and unbolt the rack the rest of the time) Clear lenses carbon stone, sill guards and no plate light cover Fresh MOT - two new Toyo tyres will be fitted before sale, they were ordered before the MoT but delivery problems prevented them being fitted hence the advisory. ULEZ compliant Battery cut off It's an ex-Academy Sigma from 2010, and one of the ARs had it reskinned by Arch after its racing was done. I bought it in June 2018 with a full cage and one seat, and converted it to be more road-friendly. I fitted a second new Tillet, a standard bar and new A-frame and driveshafts shortly after getting it, and in July 2020 S&C upgraded it to 140bhp Supersport spec - cams, light flywheel, mech tensioner, new airbox - and did full geo on it and put on a set of Toyos. The gearbox was rebuilt with the higher first gear, and a low-mileage diff with a ZF LSD was checked and set up, both by R&R. The diff still has some whine at 40-50 on light throttle but from what I understand it is rare that cars of this age with the Ford diff are much better. It's now great to drive, the rear ARB allows you to tune between over and understeer tendencies as you wish. I've only done two track days in it but it kept up with a few more powerful cars and was really forgiving to drive, so it's a great all-rounder. I recently replaced the nose cone and both rear wings with Caterham parts. The front wings have some small star cracks and crazing. There's a small tear in the centre tunnel cover and the heated screen isn't connected and I don't know if it works. There are some small stone chips in the screen, but they've got through the last couple of MoTs without a problem. UPDATE (4/6/23) - This was SORNed over the winter and I'm now putting it up for auction with Car and Classic, so have edited to reflect improvements I've made since I put the ad up.

I live in the ULEZ zone and can confirm my 2010 Sigma is ULEZ exempt

Many thanks all. The engine is as built by Langford and Peck and at 30k miles. I don't know how they prepped the cranks so will keep it to the 6750 advised by Caterham. If even a Scat crank is limited at 7200 I'm not sure why Burton and others would state a stock crank is good for 8000rpm - maybe in Burton's case they figure they'll sell you more parts if you blow it up! Guess I'll have to start saving for a rebuild with steel bits in the future if I really want it to wail...

Looking for some advice on the rev limit for an unmodified 1700 BDR, as reading this useful article there is a note that Cosworth stated a rev limit of 6200, I seem to remember that there was a note in the contemporary owners manual that crossflow and Cosworth cars weren't suitable for sustained revs above 6750, and peak power was quoted at 6500 by Caterham. Given peak torque isn't until 5500, and the engine loves to rev, these limits seem pretty low, especially as if you read any crossflow tuning guides the stock crank and rods are supposed to be good for 7500-8000rpm before you need to switch to steel. Any BDR people know why Cosworth's limit was so low, and can advise on a safe limit? I'm interested as I'm going to recommission my father's car in the coming months and fit mapped ignition. I know it's been the far side of 7000 in his hands and survived but keen to get input on not blowing it up!

(duplicate post)

I repacked my 2010 Sigma exhaust that looks similar, I had a buzzy resonance that I worked out was the rivets at the front having worked loose. Was a pretty easy process except that the replacement rivets I bought needed an industrial strength rivet gun, not the normal handheld one I had, so see if you can borrow one if you're going to give it a go.

The cover would be handy for me, I'll message you Cheers, Paul

That square building is actually the old showroom and drawing office as pictured below. Jewsons have applied to demolish it at least once, but permission was refused. They have recently added the picture of a 7 you can see on the right hand side of the front window in your picture, so seem to be coming to terms a bit more with it staying standing.

Another vote for the adjustable load leveller/balance bar/angle of the dangle tool which I've found makes it way way easier. I have one you can borrow if you are near London (it's currently in South London, but could easily be picked up from N4 as well)

Thanks Ian, that's really good of you, pm sent

Managed to lose one of the bolts/screws that hold the lens onto the rear light cluster. Given how often rear lights get cracked and damaged I thought it was worth asking if anyone has a spare please? I know it's a tiny thing but worth a try! Cheers Paul

Thanks Dave, I'll try to hunt one down

bumping this as I've not been able to find it and can't see anything written on the sensor itself. Pretty sure from previous threads it's faulty - mine a 2010 fixed cam Sigma upgraded to 140bhp - MoT runs out this week and on Saturday it started missing once warmed and the revs going up and down at idle, so a quick lambda swap might cure it given I've only a couple of days to do so and there's a lot of threads pointing to the lambda going on Supersport cars.

based on my experience 1) it is worth sleeving the perforated tube, as I didn't do it and I think it would better support the end cap joint if there was a short sleeve locating it rather than it simply butting up to the end cap and 2) if like me you get stainless rivets then you need a serious pop riveter not the usual type of hand held one as it won't be up to the task even in the unlikely event that you have hands like Geoff Capes...

I've still got that bench seat you were interested in if get a car without one

yes, they have a boss in the tube, but it wouldn't be hard to drill through the back of the tube and make something to avoid crushing it when you tighten it, easier I would have thought than the other options if the distance between the mounts is the same (certainly easier than making the bungs and welding on a new tube like I did with my S1)

for my Lotus S1 I went through a process of turning bar to make inserts and bending and welding on a new rear section, but on a later car (without the undertray S1s have) I would measure the distance between the existing holes and see if you could fit a later bolt on one from a metric car. I've just measured the metric one I have from my Caterham and it is 443mm centre to centre on the studs that go into the chassis, so if the holes are near that on an imperial car you should be able to make use of the bolt on type I would have thought.

For some reason it won't let me correct my post above despite several attempts - I meant to say that the 750 pump unit was not used in period. They are eligible for use now in 750MC historics but I don't think they get used much.

First thing to note is that there are two types of Climax fire pump, the far more common one on eBay being the smaller 750cc unit that is like a scaled-down FWA and used in period (apart from a couple of Le Mans specials for the Index of Performance). There is a lot of work and expense to convert a pump engine but it can be done. I was told I'd have to budget around £10k for a half-decent Climax motor which is why my S1 has an A-series in it! Mike Brotherwood supplies flywheels, sumps etc. Lower spec engines have been done for less, but one of the challenges is that the compression ratio is low on the pump engines and I think the heads are usually welded up and the combustion chambers reshaped to resolve this. I have pondered whether a cheap AMR500 supercharger bolted on a pump engine would be the way to go for budget fun but I've too many projects as it is...

No experience of the Nankangs (so maybe this isn't helpful!) but I fitted the R888Rs last summer (185/60 13s) to my Sigma car and love them. Road use only but have had the chance to drive them very hard at times in France and North Wales. Loads of grip, progressive breakaway, seem perfect for the car to me. I was worried about them in the wet but in comparison to the normal treaded tyres I've used in the past (last being the CR322s) they don't seem any worse and possibly actually better on damp roads if it's not too cold. I find 7s need to be treated carefully in the wet anyway so even when caught in torrential rain in France the Toyos weren't too bad. The only time I've been wary of them was when forced to use them on damp roads in sub-zero temps when for the first few miles they weren't great, but again, I just drove accordingly. I doubt you'd regret getting a set.

You can see the red colour in the fluid above, it's not that rusty orange that old fluid goes, sadly don't have a pic of the cleaner fluid that came out of the reservoir that was more clearly red with less black goo in it.

hmm. It was bright red, just like ATF. I wondered if ATF had been used, but I am assuming that S&C will have disturbed and re-bled the clutch hydraulics when they did the flywheel swap and gearbox rebuild, and that would seem to be an unlikely error for someone with their reputation. Prior to that I had no issues with the clutch for 5000 miles after buying the car with 12k on the clock. Had been discounting the slave as I figured I'd be losing fluid into the bell housing if the issue was at that end, which Tim at S&C concurred with. Plus of course I'm trying to avoid taking the engine out if I can help it!

Thanks all - had two hour-long journeys in the car yesterday with no problems at all, so it does seem it takes a long motorway run to trigger. Fluid is looking increasingly dirty though. No drop in the fluid level. Have checked the breather, no problem there. Both the master cylinders are the Caterham-fitted originals like this, the first one to fail was the car's original 20,000 miler, the one in now is a known good 5000 mile one from a car that was uprated at Premier Power that I got in a job lot of parts leftover from the upgrades. Wouldn't usually have fitted a second hand part but as I say I was stuck up in Wales and happened to have it. I think the next step is to strip and inspect the one that came out and if the bore is good I'll kit it. I agree that sticking a new master on it makes sense, but having just dropped nearly £500 on a service and clutch diagnosis at S&C and with a suspicion that something is causing the cylinders to fail, I'm going to hold off spending another £80-100 right now. I'm not earning at the mo cause I'm looking after my folks. The only other odd thing was that when I changed the first cylinder the fluid that came out was red (as well as being filthy) which I've not seen before - I know you can buy red fluid but I don't know if it is a different formulation - could mixing fluids have caused an issue with the seals maybe?

It's odd that the second master cylinder I tried has the same issue straight away though, when I know it was a good one - on what car did you have your problem on Anker? Your Supersprint is a cable clutch right?

Hmm, thanks Kelvin. If the cap fixed it I wonder if the breather was blocked, the seal just stops spillage, but if there was no breather it could feasibly cause issues. Will check mine