MASCOT March 1992

YET MORE TALES OF A 4AD

Dave True

Last Issue I rambled on about getting ready to assemble the front end, and now we come to the actual putting together, starting with bolting the flitch assemblies (which ideally should already have been painted) to the chassis. Only tighten the nuts and bolts enough to hold the assemblies in position. This applies to all fixings to start with.

Next fix the front wing supports to the chassis in conjunction with fixing the front bumper brackets. The bumper brackets at their rear ends fit between the flitch assembly and the side of the chassis. Packing is required where the rear bumper bracket fixing bolt goes through, i.e. you need some thick washers between the bumper bracket and the flitch.

Then the bonnet sides can be bolted on their bottom edges to the flitch and the rear edges of the bonnet sides screwed to the wooden framing of the scuttle through the aluminium cladding which is rebated to give a flush fit. A look at other Roadsters will show various size screws at these points. Original screws will have rusted and woodwork rotted leading to larger and larger screws being used. One of the advantages of RKC 394 (it's not all bad) is that the wood frame has been repaired and there was no problem in fitting some neat 1" screws with slotted flattened round heads and small washers. Not too critical a detail I think - they're going to get sprayed over anyway.

The bonnet side supports can then be fixed. These run from the bracket welded to the inside face of the bonnet sides down to the main chassis member side.

You then need to set up the radiator bolted to the chassis cross member including the circular rubber pads, together with the two long thin straps running diagonally from the top of the radiator back down to the chassis.

This is now followed by the radiator surround, bolted to the chassis ensuring that it can be sloped slightly to fit neatly up to the sloping front edges of the bonnet sides. I will describe in another article how I repaired the slats to the radiator grille, otherwise I shall be here forever. The bonnet sides can then be bolted to the radiator surround (captive nuts) with slotted flattened round headed bolts and washers. I did find in my stock some bolts that I believe are quite close to the originals.

Later production cars were fitted with radiator surrounds that had an adjustable criss-cross rod bracing - useless in my opinion in that the brackets through which the rods pass are not substantial enough for any serious tightening. I don't know when these cross bracings were introduced but they certainly weren't on the original cars in 1951. I decided to do without it on RKC 394 - after all, I've run my other 4AD without this cross bracing for 15 years with no untoward effects.

The front wings can now be fitted to the bonnet sides (captive nuts on the bonnet sides), having inserted the wing piping in between. I think the original piping was 5/16" diameter, but the piping I used was 1/4" diameter and looked neater. You have to make cut-outs to fit the flange of the piping over the fixing bolts - make sure you've got a reasonable clearance round the bolts to allow for adjustment. I found it wasn't a good idea to make neat holes for the bolts - it's impossible to get them in the right place. No doubt the original piping was actual rubber, but plastic has to be acceptable nowadays and you'd be hard put to tell the difference by just looking. Where taking the piping round curves vee cuts have to be made in the piping flange and it follows, of course, that the tighter the curve, the closer these vee cuts need to be.

The wing piping needs to run in a continuous length at least from the front of the front wing (including the length where the valance abuts) back to the front edge of the rear wing. I suppose it could be stopped off at the end of the running boards some 21/2" short of the rear wing (this measurement varies a bit from car to car), but I thought it looked neater continued to meet the piping round the rear wing. I had to make small steel supporting plates for each side to hold the piping in position over this 21/2" length. These were screwed up to the underside of the body framing through the flange of the piping. It would be possible, I suppose, to run the piping in one continuous length on each side of the car, over the rear wings as well, but I think it would get rather unmanageable.

Now comes a real push and pull exercise - the fitting of the front valance. This has to be slid up under the somewhat delicate pointed front ends of the bonnet sides and onto the flitch assembly (temporarily fixed bolts to be taken out and re-fixed when the valance is in position). The outer flanges of the valance need to be aligned with the front wings where these abut at an angle, and then bolted up with the wing piping in between, i.e. the continuous wing piping diverts from running between wing and bonnet side to running between wing and valance. This leaves about 6" of joint between bonnet side and valance without piping. The valance that came with the car was a somewhat homemade looking effort made out of steel about three times as thick as the original. It proved to be unfittable as it simply did not have the required flexibility. I had to search around in the loft for an original type valance, but even this was by no means easy to fit.

The next thing to do is to run round all nuts and bolts and tighten everything fully, pushing the components into their final positions as you go. You can also fit now the small brackets that fit from the top rear edges of the bonnet sides onto the bulkhead.

One or two of the bolts adjacent to the steering box are very difficult of access to tighten and I cut an old spanner to reduce the width of the land on one side of the spanner jaw.

You're going to say what happens if some or all of these captive nuts have got stripped threads? In a lot of cases you could get away with running bolts right through the captive nuts and fitting ordinary nuts, filing or drilling out the holes if necessary. In certain areas, where the front ends of the bonnet sides are fixed to the radiator surround for example, it would be very difficult to fit a nut on as there is no access. If you haven't got any taps and dies, now is the time to invest in a set but stick to BSF if at all possible. You can then cut a new thread in the captive nut after drilling out as necessary. Elsewhere on the car some captive nuts are held by welded tabs and these are a pain when they rust away and break off. More of that particular problem another time. More also about my problem with one of the running boards.