"...did it with his own hands."

"The engine, for one thing. It's going to be an eight cylinder
V engine, as you probably know. For everybody
else, for the Cadillac, it's good enough to cast a
V engine block in two pieces and bolt them together.
That's not good enough for Mr. Ford. He says it has
to be cast all in one piece. Our foundry men kept telling
him it couldn't be done. He said they had to do it.
I think at first he didn't know himself how it could be
done, else he would have told them. That went on for
weeks. Then one day he went into the foundry and did
it with his own hands. Now we've got an eight-cylinder
V engine block in one piece, which is something nobody
else ever had, but what will happen next we don't
know."

-page 71-72