This is how you fabricate no-longer-available parts

Our Elva project needed some crucial components to mate its engine to the transmission, and in two years of looking, we never saw them for sale. So, we’d have to make our own.

Those parts? Something called an adapter ring and an adapter plate. They sit between the engine and transmission and, among other duties, also mount the starter.

Sounds hopeless and expensive? Not entirely. We were able to build those pieces–plus the other missing parts required to mount the driveline–at our home shop. We duplicated those vintage parts using some modern machinery, but high-tech doesn’t always have to mean high-dollar.

1. Our Elva’s Coventry Climax engine and a Hewland Mk III transaxle fit together via an adapter ring and an adapter plate. Our car didn’t come with these parts, so we gave up searching and decided to make our own. Thankfully, a reader with Elva’s other 1962 Sebring entry was nice enough to loan us the necessary parts for use as templates.

2. We started with the adapter plate. Using transfer punches and a drill, master machinist Steve Eckerich duplicated the necessary holes on a 1/8-inch-thick piece of aluminum. Before cutting the outer contours, we ensured that the holes properly lined up. And they did!

3. Now on to the adapter ring. We needed to duplicate a piece of aluminum more than an inch thick. Since this piece was complicated and contained more features than the simple plate, we decided to create a digital file and build our copy using computer-controlled machinery. First step: Publisher Tom Suddard digitized the original. We placed the original on our vertical mill and zeroed the tool’s digital readout display. Now we had a starting reference point for the other necessary measurements.

4. We then fired up Autodesk Fusion, the popular CAD software, and designed a digital version of that ring on our MacBook. Our machine control computer is fairly modest: a 10-year-old PC running Windows 7.

5. To actually cut the spacer, we used our CNC router table. We have a simple, overseas unit that retails for about $1000. Don’t want to make that investment? Companies like Xometry can turn a digital file into a one-off part.

6. The aluminum stock needed for this spacer cost us more than $300. To make sure that our file was accurate, we first cut a ring from a piece of plywood. It also fit!

7. We don’t have the world’s most powerful router table, but we do have patience. Cutting the aluminum spacer kept our little router table busy overnight. And, like the wood test piece, the aluminum one fit as well.

8. After the machine work, we just had to clean up our edges and thread some holes for the mounting studs.

10. Now we had a place to mount the starter, a high-torque Wosp unit from Michael’s Vintage Racing, an Elva prep shop. While the starter comes from an Isuzu, the folks at Michael’s Vintage Racing swore that it would fit a Coventry Climax FWA engine–and it did.

11. It’s looking like a complete driveline: engine ready for the transaxle plus the starter, Tilton clutch and custom Fidanza flywheel all in place.

12. After also duplicating the engine and transmission mounts–find those details on our site–our driveline snugly fit into our Elva’s frame for the first time in a very long time. Happily, a bit of modern, high-tech work allowed everything to slide
into place perfectly.