Why doesn't anyone build an engine out of titanium?

Question

Why doesn't anyone build vehicles with engines built out of titanium if titanium is such a good metal? Other than being more expensive.

Answer 1

Some parts are made of Titanium, jet engines have a good amount of Ti, but you are asking about internal combustion reciprocating engines. Bolts exhaust systems, connecting rods, valves, and valve retainers are about it. Way too expensive and hard to cast or machine for the block and heads. No real advantage since Aluminum are lighter.