Shortround6
Major General
Building an actual engine manufacturing plant could take a year, Some engine manufacturing plants also required the services of hundreds (in some cases 800) subcontractors. Not something that can be arranged in few weeks.
Canada did do an amazing job of producing war materials during WW II. But it's ability was not bottomless, Please read your own sources. The Machine gun plant they talk about cost over $1,000,000 for the building and $7,000,000 for the machinery and equipment. An engine plant that is capable of making several hundred engines a month will be at least that expensive if not more.
This argument is bit like a local garage or hot rodder ordering parts and assembling an engine in a garage compared to actually making the crankcase, the crankshaft, the heads, cylinders, pistons and so on. There is little point in setting up an assembly plant in Canada if the engines are to be made from parts kits supplied by P&W in America.
Please note that the Original Ford Plant to make R-2800s (a larger engine) was 889,717 sq ft. for 800 engines a month. If you plane a smaller number of engines per month the size can adjusted accordingly.
Up until 1937/38 P&W, like many other companies, was looking to increase their market share. Having a somewhat local service center made sense, especially considering some of the tariff or import duties that some products were subject to. However up until the French start ordering in 1938 and the British in 1938/39 P&W had all the production capacity it needed.
French orders allowed P&W to double the floor space of their East Hartford factory, The British orders allowed them to double it again. In the fall of 1940 P&W was so busy they could not help Ford out with new plant. Ford could send engineers to P&W and see how P&W was doing things and how the factory was laid out but P&W had no (or darn few) engineers or supervisors to send out to Ford to assist on site.
It might have been possible to squeeze in a Canadian facility but Canada was stretched to capacity too. And Canadian factories needed to be equiped with machine tools made in the US.
A lot of the tooling has to be new, You don't make aluminium aircraft engines on machinery that made cast iron 6 cylinder car engines (not to mention Canada was supplying a good amount of the British commonwealth with light trucks.)