Discussion and questions related to the course Engine Building Fundamentals
What is the difference between the materials used in valve guide? Why do performance engines use bronze or Manganese ? Pros cons?
OE valve guides are typically a cast iron material which work well with stock valves. In a race engine we more often end up running stainless or even titanium valve material and these technically aren't compatible with a cast iron guide which is why bronze is the guide material of choice in a competition engine. Cast iron guides in some engines also have a reputation for cracking and falling to pieces which can destroy your engine very quickly - The Nissan RB26 is just one example where this is common.