Tony P

Yes, I suppose it's that too. I switched to a half-hood a long time back and, at my age, it's easy to forget...!

Tonneau cover. (If we are thinking of the same stud.) Not a daft question at all if you are new to the Seven - there so many details you are faced with for the first time.

Ah, so it does Andrew, thank you; I should have noticed that when comparing pictures. But if that was required to get fit the VTA in, that kind of suggests that there was no need to move the drive train backwards? Perhaps then the Vegantune thing is a red herring in the history of this chassis...

More on the the aforementioned Vegantune engine… The picture is from a road test report in the long-defunct ‘Automobile Sport’ magazine, forty-odd years ago.This is the ‘VTA’ iteration with their own twin cam heads (1600, two-valve on the slightly taller 225E block) in a live-axle (obviously), long-cockpit chassis. The square-section lateral tube ahead of the engine was a feature of S3 Lotus twin-cam engined era cars, so, comparing pics of those, it doesn’t appear that the VTA required any more space at the front than a Twink (for e.g. to clear its timing gear and requiring the drive train shifting) - if, indeed, the chassis in question here had been adapted for the VTA, a possibility hinted at upthread. The magazine article also reckons that the VTA was available “in sizes from 997cc to 1600cc”. I’ve never seen or heard of the smaller version in a Seven - or anywhere else. I do recall, way back when, meeting a handful of young owner-builders who had fitted 1300cc Xflows as it had made insurance more attainable, with plans to upgrade in the future. I suppose a one-litre, belt-driven twin-cam might have been an attractive proposition?

All of the replacement/spare arb balls I’ve had in the past have already been machined around the circumference to relieve the moulding ‘seam’. Is that no longer done? I don’t think they are anything special though: aren’t they just the off-the-shelf drilled-and-tapped balls used on the handles and levers of machine tools?

From memory, the Vegantune engine was a short-lived option to replace the no-longer-available Lotus Twin-cam (but based on the same engine architecture - and, I assume, the same block casting?). I don’t remember ever seeing one (at least not a close inspection) but I’d have thought any differences in dimensions (i.e.length) were down to ancillaries or bellhousing etc, or a different gearbox rather than the engine having been moved back, especially as you say there is no space for an engine to have been any further forward. EDIT: Ah… according to ‘Coulter’ (a reliable Seven ‘bible') there were three versions of Vegantune engine used: 1) their version of the Lotus Twin-cam (essentially the same spec) 2) a similar unit built on the taller 225E block (resulting in an extra 40cc) 3) the VTA, also on the 225E block, but with belt-driven cams like the BD Though that doesn't help much - - not immediately clear to me what differences in the chassis that would require - Bruce would surely be the best source for info on that… It seems the Vegantune-built engine was done for first by a lack of the original blocks, hence the switch to the 225E, then Lotus running out of Twin-cam heads. As an aside, early problems with (and subsequent unavailability of) the Vegantune engine prompted development of the twin-carb Kent (‘crossflow’) engines - the Supersprint version leading in turn to the enlarged 1700 version of Cosworth’s 1600 kit engine, the BDR. Neither ‘Coulter’ nor ‘Weale’ appear to suggest what, if any, drivetrain mounting changes were required. So… sorry, no help there, but hope the background might be of interest.

I've found these folks good to deal with: prompt service and sensible delivery charges: https://www.vehiclewiringproducts.co.uk

I have half of this problem... Mechanical speedo, driven from gearbox; speedometer works, odometer and trip don't. I'm assuming (for now) that this is a problem with the instrument. Has anyone had, or solved, this problem?

Not sure if this helps, but… I have the 158-page spiral-bound, illustrated “De Dion Parts Catalogue”. I can’t find an issue date in it, though fairly sure it was late 20th Century, and some parts are specified for cars ’96 and on. The only 14” wheel shown is the Minilite/Minator/Supalite style, in one - unspecified - width (presumably 6"?). It’s indicated to be ‘standard’ for the XFlow Supersprint (and for Rover 1.4, 1.6 and 1.8 cars though ‘optional’ for VVC and VX cars) with all the other wheels, including 13”, being ‘options’ for the Supersprint There is no mention of the earlier KN alloy (not K&N!) with the polished front face to the spokes, which I think may have come in both 13” and 14”. (The ‘latest’ wheel shown is the 13” 5-spoke split rim which appeared on the Superlight R.)

More generally: I’ve seen friction welding in connection with an Engineering business I did some design work for. It was a rather specialized and precisely controlled procedure - but that was making propshafts for huge marine engines and the hydraulic shafts on earth-moving and mining equipment. It never occurred to me that it would be practical (or economically viable) to use (successfully) down at the scale of making a few gearboxes for fairly obscure sportscars. And maybe it isn’t? Or is this now a widely used process?

If you wanted to go the Toyo route, try Adams & Page in High Wycombe. In the past I've found them very good (often the best) on price and on service too (and they know how to take good care of your wheels). I

Fuel vapour can eventually permeate most hoses. Even the fancy Goodridge braided - and presumably other 'aeroquip' style stuff - is not approved by the maker for passing through the cabin of a closed car (they have a special, even-more-expensive line for that!). I've no idea if the advent of E10 makes this more, or less, of a problem; but given other warnings I'm guessing the former is possible.

I’ve had one of those rubber (or whatever it is) gaskets disintegrate completely (does it melt in the fumes, I wonder?) and leave sticky black blobs in the tank, which are a pain to remove. Won’t be using one of those again. I prefer a cork/nitrile composite one, or just one made from that hard pinkish compressed paper stuff used for pump gaskets and the like (it’s good enough for the sealing washers on carburettor banjos, so it should be plenty good enough for the sender).

When I've fitted these in the past, they were supplied in two sizes - the smaller ones fitting the forward bushes of the rear radius arms and the forward bushes of the upper front wishbones. The implication here, surely, is that you fit them everywhere.

And very generous with your time and expertise...

If you haven't solved this in the meantime, I'll measure my tank tomorrow and post here. I think the width might ultimately be the critical thing - Weale suggests that over the years width was increased to increase the capacity, though I think that pre-dated S3. I know that earlier cars had a notably shallower boot, but whether that was solely due the allowance for movement of the live-axle diff, or whether a taller and slimmer tank was required too - I cannot remember... oh, and inlet neck on a current tank would be on the right, is that ok? Did you solve the conundrum of whether or not later Caterham sidescreens would or wouldn't fit? Nobody offered as reason as why they wouldn't, and anecdotal evidence offered here suggested they probably would. The later 'increased visibility' ones had taller window sections - which has implications for the hood - but it's hard to see what else would be different. Unless someone can tell us...

I made much use of large Q-Max punches, which give nice, clean, distortion free curved (well, circular obviously) cuts -- but I can't remember how I determined the shape of the cut-out to begin with! I'm thinking I must have taken a template from another car and repositioned it to suit my engine installation.

… despite the 'bespoke' service of which Thundersport’s website boasts. jb - where are you based? As Jonathan suggested earlier, you ideally need to try a later hood from another owner since, as yet, no one has suggested why it wouldn’t fit.

I’m puzzled (nothing new…): According to Weale (and other reputable sources) the first Caterham chassis was based on that of the Twin-Cam and other model Lotus Sevens, with early revisions thereafter largely confined to altered triangulation of the spaceframe, especially around the rear beyond the cockpit sides. All the ballyhoo about the long-cockpit chassis when it was released was of increased internal dimensions, without changing the appearance or external dimensions of the car; this achieved, in the main, by relocation of the cockpit’s rear bulkhead within the frame. I don’t think the shape or size of the cockpit side opening changed at all? (witness the change of position of the seat back against the curved cockpit side). I have a recollection of, years ago, the now late-owner of a Lotus Seven Twin-Cam (by definition an S3-size, short-cockpit, live axle car) trying out my sidescreen’s (from an early 90s, S3, long-cockpit de Dion) -‘increased viz’ versions with the ‘arm bulges - on his car (which had the original flat sidescreens) and I’m pretty sure I remember them fitting. What has changed since then, or what have I missed, that means that a later hood or doors cannot fit jb’s earlier Seven?

Do you have the ignition key in the 'fully on' position? (It's something that's tripped me up in the past.)

I had wondered about the hole - but since I'd had no issues whatsoever re. grease seepage, then wondered if it was there simply to hang the components on a wire frame when they were plated (as happens for lots of very basic, not overly critical components). Interesting point...

Ah - that's an even neater solution (if adding yet more imperceptible amounts of unsprung weight!).

I put a small rivnut in the centre of the dustcap, so that it can be driven out with a bolt or setscrew. The rivnut has to be short enough to allow the cap to be driven fully home. Overkill? Yes, probably, but a satisfying solution (and I have an ingrained aversion to self-tapping screws). If the larger hole this creates in the cap is a concern, then a blob of an 'adhesive' grease (such as Castrol CL or some other marine-use grease) fills it adequately.

I’ve been relatively lucky, I think: only had a couple of alternator failures (Valeo on a XFlow) in donkey’s years. Had altogether more trouble with the mountings though, several broken or worked loose or had a bolt break in the block. The standard mounting bracket, whilst looking substantial, never seemed to be much good at resisiting vibration; whether design, application or welding being not up to snuff I don’t know, but several other XFlow/BD users had the same experience I went the full Wilcox route - nylon strap (as Michael, above) ‘floating’ on a blank-one-end spindle through the water pump (to lessen the chance of any vibration loosening and snapping that bolt off in the block - that breaking on a trip or a track day is a real nuisance) - and the alternator mounted on a wide metalastic bush inside a bracket (like a suspension bush but longer - just have to remember to earth the alternator separately). That solved everything - one of the most worthwhile ‘upgrades’ I’ve found. (Also, keep spares of the UNC bolts - finding those in hurry whilst away will only get harder.) Some Escort rally cars, using a XFlow or a BDA, had the diode pack (?? is that what it’s called?) mounted remotely and so better isolated from the heat of the exhaust - but means more wiring to be insulated.

Hello Ralph. That "missing bodywork" is just a cover plate for that triangular box, into which the inertia reel seatbelts would be mounted. Unless you have an uncovered slot in the bulkhead behind the seats (which might let in road dirt - but gaffer tape could seal that up!), the cover not exactly essential - you just have two more awkward corners to keep clean. Yes, fairly easy to make if they cannot be supplied by Caterham. If you fit them with riv-nuts, you'd have a couple of secret hidey-holes! :-)