Check out CVAP's website, he's got a mechanical tensioner up for sale. From what I've been told - much less likely to let go when compared to a hydraulic one. You'd never want to touch a second hand one IMO.
John Hill who's built a few engines for APC recommended I change to one when I was rebuilding my engine.
John Hill who's built a few engines for APC recommended I change to one when I was rebuilding my engine.