vroom wrote:
I have an interference engine (Yaris) and when I took it in for a new timing belt my mechanic told me it has a chain. Interesting. I suspect it is because the Yaris is a world car (sold everywhere) and outside the first world an expensive disposable timing belt is a no go. Once again locost rules!
Interference valves can be found in any engine no matter which system is actuating valves, belt, chain, gear. It is a design choice. The issue is that when the system closing-opening the valves (in the interference type) fails valves end up colliding with the pistons. This is the problem. Years ago I had a 6 cylinder Volvo and the gear running valves self destroyed. The engine was not of the interference type and all I had to repair was the gear in question (about 2 hour labour and $150 part).