Todays Welsh MT Dyno Day

[Minter]

A 665 cam? That begs the question, what was the MZ engine equipped with originally? Is there a cam for the 500 engine that is even more mild than the 665? Or did you strategically choose the 665 for qualities it has over a hotter cam?

My Armstrong has a 665 which is standard. The MZ motor standard cam is a 660 which is a very 'mellow' touring type cam.

[MT Pocket]

Mine is a 670

[jungleMTbiker]

Yeah, but yours is a 560, too. I wonder if it would be safe to say that 75cc + 670 cam will add 10+ hp? That'd be a pretty healthy increase.

[Minter]

Yeah, but yours is a 560, too. I wonder if it would be safe to say that 75cc + 670 cam will add 10+ hp? That'd be a pretty healthy increase.

It also has an 81mm stroke more compression and bigger inlet valves!