Guidance on tensioning a cam belt on H reg Clio

generally a firm twist on the middle of the longest run of the belt should be able to twist it by about 90 degrees, in your case there isn't a long enough run easily available, so between the cam and the water pump a twist of about 45 degrees would be about right. if it is too tight it will whine , too loose and it will flap about, I would tend toward slightly tight and let it settle in.

Mrcheerful

we use the Gates electronic timing belt tensior, you enter the part number of the belt into the unit via a keypad, as it has all the tension details of all the gates programmed into it,put the pick up on the belt and then flick the belt, the resonance is picked up by the machine and then it tells you + or - if it needs to be adjusted or de-adjusted ect, good bit of kit, but tends to only get used for the more eleborate belts, v6 ect.

Thanks for that. Good info that I can work towards.

reg

Would love that sort of kit but might have to wait for it. But I suppose a small price to pay compared to being able to replace cam belts for the rest of my life.

/Heds

reg laid this down on his screen :

Surely the resonant frequency depend both upon the distance between the pulleys as well as how tight the belt is?

From the gates site

The force and deflection method used to be the only reliable way to test belt tension. Of course, it required a spring tester, plenty of muscle, a piece of string and unfortunately, at least three hands.

Belts, like strings, vibrate at a particular natural frequency based on mass and span length. Gates unique Sonic Tension Meter simply converts this frequency into a measurement of tension. Here's how it works:First, enter belt mass constant, belt width and span length into meter using built-in keypad. Next, hold meter sensor to belt span, then lightly strum belt to make it vibrate. Press "measure" button to obtain reading and the meter quickly converts vibrations into belt tension. Readings are displayed on a liquid-crystal screen.

• Belt mass constants are listed on a data card that comes with the Sonic Tension Meter.

Mrcheerful was thinking very hard :

Thanks, that explains it.

Yep. The cheap version