Well there are several foundries in the USA but they make only small parts & limited batch runs .
The largest for information is Fritz Winter Foundry which is German and the USA it is merely a subsidiary and commercial office base.
The next closest are located in Mexico and provide the majority of the Ford production cylinder blocks. Nemak & Tupy come to mind.
The next closest in the American continent is either Brazil or Argentina!
As to Chinese production of cylinder blocks etc, Cummins opened a Chinese subsidiary in 2015, I suppose as a way of containing base cost and a supply chain logistics issue for their Columbus plant .
Of course this was before we had Trump and his wrecking ball policies starting will tariffs.
This was probably the plant our Mr Pencieboy was referring to in the article!
https://www.cummins.com/news/2015/01/29/cummins-breaks-ground-new-plant-china
As to your idea opening a US based foundry of the Chinese magnitude to make engine blocks for Cummins on shore production would be colossal and I couldn't see any merchant bank backing that venture!
As with GM and Ford these policies are clearly having a negative effect sending new production work out to be off shored at the cost of the American worker.
As a tail piece GM's supply chain logistic company in Warrensville shut down this week with a loss of 170 employees jobs .
Plus this policy & outlook the future looks increasingly bleak for many US auto workers.
http://knowledge.wharton.upenn.edu/article/general-motors-closings/
Dennis