Valance and Air Dam

The finished product

This is going to be mostly about the valance construction with just a bit about the air dam. Unfortunately a number of the pictures of the construction of both of these pieces have been lost but I will do my best to make up for it with accurate descriptions.

To begin with, the valance reconstruction was necessary for two reasons: 1) the installation of Dave Craddock’s (Preform Resources) widened the car by some 9″ and 2) I wanted to achieve a look closer to the original LeMans cars (I have no idea why it’s called a Sebring valance given it’s origins in the French classic), that meant a rectangular oil cooler opening and buckets for the driving lamps.

I started with a front valance from MGOC (in the U.K.) which is, to be fair, a so-so part to begin with, lacking any real contours at the outside of the fenders and with acceptable, but not spectacular, glass work. It provided a good starting point and it’s marginal quality meant I wasn’t too concerned about botching it up. Very liberating.

First fitting with temporary backers in place and lamp openings cut

Recreating the Valance
The first cut is the deepest and so it was as I started by widening the valance to fit the new stance of the wings. I measured to the exact center (exact int his case turned out to be a bit dodgy as the valance turned out to be not symmetrical), made a vertical line, then carefully cut the valance in half using a saber saw fitted with a sheet metal blade. I find this set up works particularly well on glass parts as it limits the edge chipping and ragged cut. Even though I wasn’t concerned about lowering the quality of the valance, it was still heart stopping to see it in two pieces, but I was committed now.

I needed something to help set the shape of the new glass, so I hand formed a new center section using a piece of sheet tin. It turned out to be a bit more involved than I thought it would be as the piece curves in both directions so my shot bag and teardrop hammer got a good workout. Fortunately, the finish didn’t need to be all the great as it would just serve as a temporary backing for the glass work. Good thing, I’d probably still be out in the garage hammering away at it if it had needed to be a final surface. Once I was satisfied with the shape, I installed it using some countersunk rivets knowing that the heads would stay embedded under the new work once I ground of the backs after the glass had set. Before riveting my temporary patches in place, I covered them in waxed paper so the glass wouldn’t stick when during removal. I’ve also used Saran Wrap for this but either will work (so does mold release if you have it on hand). Same process for the two vents holes.

Once the forms were affixed, I carefully laid 4-5 layers of glass into each of the openings to build up the surface to the surrounding area, being careful to trim it for a tight fit. Once I’d built up the surface, I glassed over the repair area about 2″ in either direction. After the front had set  up, I flipped the valance over, ground off the backs of the rivets, and removed my temporary tin. A couple of more layers of glass finished up the transformation. Next came cutting the new openings.

There aren’t any measurements available for this kind of thing (that I’m aware of) so I did my best to estimate sizes, shapes, and locations of the openings (oil cooler and lamps) using the images I had available from the original cars. To my eye, it looks real close but I’m sure there’s some MGBophile out there who will roll back his eyes at my effort. Ah, well, can’t please them all. I marked the openings with a Sharpie, drilled starter holes for my saber saw, and cut the new openings.  A bit of sanding around the edges and I was ready for the next steps…fabricating the cooler screen and the driving lamp mounts.

Test fitting the lamps, brake duct horns and cooler screen installed

Oil Cooler Opening and Lamp Mounts
The original oil cooler opening was a simple rectangle that was finished with apiece of square cloth and a tin edge so out came the forming hammer again. The cloth was easy, just cut the rectangle to the size, the edge was another story. I started by cutting out a simple plywood buck the same size as my screen then clamped a long piece of tin about twice the width I need to its perimeter, carefully beating down each corner as I went around the form. I wasn’t concerned about bending the back side as it would be hidden. Only the front needed to be formed. Once I had completed the perimeter, I carefully scribed my final cut lines about 1/2″ from each edge, then snipped off the excess (deformed from making the corners) with a pair of hand shears. Some quick hand filing completed the task. Next I trimmed the back edge about 5/8″ from the edge, set the screen into my frame, notched each corner and then bent the remainder over.

The result was not perfect in the sense of the craftsmanship but then, the original part was fit for a race car and so I felt it was appropriately authentic. If you ever seen old race cars up close, they aren’t exactly works of art from a fabrication point of view. Last thing to do was to test fit it and then fab up some lamp mounting brackets for my original equipment Lucas center-post 542s that I was lucky enough to source from a fellow MGer.

Not much to say about the lamp mounts. Basically just a piece of aluminum flat stock bent to suit and then riveted to the valance.

Painted valance installed

A closer look. Lamps have not been adjusted.

Finishing Touches
I’ve always thought the one of the more unique features of these valances were the “horns” for the brake duct openings, although you rarely (if ever) see them on the aftermarket glass pieces. These turned out to be some of the more challenging tin work because of the compound bends involved. I started with some pieces of sheet stock that I rough cute to approximate size, forming the round shape around a piece of heavy PVC that just happened to be the correct diameter. To make the mounting flange, I cut a second piece of my PVC about 5″ long then slit it length-wise so I could snap it around the first piece with the tin in the middle. A sort of tin sandwich, if you will. I positioned the tin over the inside form about 3/4″ past the edge of the form then snapped the outside piece on the same distance from the edge of the tin. I used some 200-mile-an-hour tape (racer’s tape) to hold everything together then sat down on my work stool and began to carefully bend over the flange using a light forming hammer. Once the edge was formed, I removed the work from my forms, marked for the final trim and used snips to take off the excess. Some minor clean up with a set of files finished up the first one.

As any who has done tin work knows, making a matched set of anything can be particularly challenging, especially when you’re working with small parts and compound shapes. This proved no exception but I was able to get an acceptable mate on the first try. Mounting them was straight forward. I drilled out the old rivets that held the duct in place, marked where the holes would go in the new ‘horns’, drilled, then riveted them in place.

The last thing to do was to test mount the widened valance, then paint everything International orange similar to the color used on many of the factory race cars. To determine where the mounting screws wen, I again referenced a couple photos of the originals I had on hand. No one shot really gave a good look at exactly how many panel screws were used but I used visual references (parking lamps, etc.) to approximate their location and number. Market the holes, drilled them and mounted the valance using #6 x 3/4″ stainless trim screws (though I doubt the racers were extravagant enough to use stainless on the originals). To finish the look, I removed the oil cooler, unmounted the valance, sanded it, primed it with two coats of urethane filler primer, and finished it off using several steps of fine paper. The valance was then remounted, the surrounding areas masked off and two coats of industrial orange applied followed by two coats of urethane clear.

Why paint the valance on the car? Simply because that’s how it would have been done back in the day. Most factory race cars started off as regular production models that were shunted to one side for conversion to track duty. The race fabricators would have taken apart as little as possible to facilitate getting the cars completed. It’s one of the reasons that, if you open the bonnet of a team car, you’re likely to see an engine bay one color and and exterior another color. Race cars were painted as completed units. In keeping with that, the valances were nearly always painted after the car was fully assembled.

Splitter fitted to valance with adjustment rods in place

The Splitter
This has been one of the more controversial additions to the ‘B’east but something I’ve always wanted take a crack at but hadn’t yet primarily due to the expense of the carbon fiber sheet stock. Not for the faint of heart, to be sure.

In the interest of full disclosure, I know how a splitter is supposed to work but I have absolutely no idea if it will work. So this is pretty much just a crap shoot as far as shape and size are concerned. A couple of things are pretty simple though: 1) it needs to be adjustable so you can (hopefully) play with the down force and 2) it need to be removable in the event I want to trailer the car (low over hang) or it gets munched from some spirited driving or outright blunder.

The shape and size were determined by esthetics as well as by the rules of a number of racing organizations that stated the device (if allowed) could not extend beyond the farthest point of the car. Hence, I drew an imaginary line from the point of the bonnet and that became the “farthest” point. After that, I just tried to match the curve of the valance. As far as depth goes, the deeper I could go, the more I could influence the airflow under the car (for good or bad). This version is about 12″ deep at it’s deepest point. I have several other patterns, some deeper, some not. I used some bond board to cut a pattern and make sure it would fit before hacking into a $400 piece of carbon fiber. You only get one chance at this or you end up with some very expensive scrap so the old adage of “measure twice (even three or four times), cut once”  is appropriate. Again, I use my saber saw and several (carbon is tough on cutting implements) very high quality, fine tough blades. A mask, gloves, and long sleeves are must when you’re working with carbon as the dust is not particularly good for you and shards are sharp as all get out.

The splitter was mounted to the frame rails using a custom bracket that bolts to the old tow flanges and rivets to the splitter. The bolts are easy to get to so the splitter can be quickly removed or adjusted. Front adjusters were sourced fro one of the web-based race car suppliers and riveted to the splitter deck and valance. A bitof racer’s tape on the leading edge will help prevent it from minor scuffs and dings.

The finished product

The hardest thing on this piece was not the splitter itself but the tin that blends it in to the body. Like the horns on the brake ducts, these were bent from flat stock in a matched (or pretty close) pair then riveted to the splitter floor.

As I mentioned earlier, I took some grief for this piece when I first posted up on BV8 but I like it and think it fits the car’s personality. I bet if the Brits had though of it back in the day, it would have been part of the original race package. Anyway, that’s my story and I’m sticking with it. One of my trips out to the garage, I’ll make it a point to take some detail shots of the bracketry and various other details.

That’s all for now…

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