Heat the oil in a large soup pot over a medium-high heat. Add the Canadian bacon, onions and celery. Cook, stirring occasionally, until the vegetables begin to soften, about 6 minutes. Add the potatoes, clams, clam juice, thyme and water, to cover. Bring to a boil, and simmer until potatoes are soft, about 30 minutes. Season with salt and pepper.
* Can use clams and clam juice from 2 (1-pound) containers of frozen chopped clams in natural juice, thawed.