Timing Belt Tension

[Dave A.]

I've been thinking about the design of the timing belt tensioner and I'm trying to figure something out. Why in the heck does the tensioner have a spring if the spring isn't really used in the first place? :? Once the tensioner pulley bolt is torqued to spec., the spring sits there and does absolutely nothing to keep the belt tight. DSM cars are the same way with the 4G63 engines having a hydraulic "automatic timing belt tensioner", yet there's nothing automatic about the silly thing as long as the pulley is locked in place by the bolt. In fact, a lot of engines are this way! Just doesn't make sense is all! :roll: I wonder what would happen if you used a shoulder bolt torqued to spec. on the tensioner pulley to let the spring remain active and keep the belt tight at all times? Any thoughts on this :?: :idea:

[Dave A.]

I mean, blower belt tensioners don't use springs, but you can visually see the whole enchilada and adjust the tension if necessary. Not so on a 5M, 6M, 7M.

[DKJones96]

that's because the spring is used it tentioning the belt on installation. the reason you can visually tention a supercharger belt is because the supercharger freely rotates. not so with cams and crank. but your right once the bolt is torqued the spring can be taken completely out.

[Dave A.]

Well, part of my concern about the spring has to do with what a PITB it is to re-adjust the timing belt tension when necessary. New timing belts stretch a little after they break in and removing the timing belt covers just to loosen the bolt on the tensioner seems like a PITB that could possibly be avoided.

[SupraWes]

That spring doesnt seem strong enough to keep tension on the belt while it is rotating. I would be suiprised if the car ran at all, the cam timing would be very erratic I think. Whats the big deal about removing the timing cover, just dont use all the bolts, I think I have all but the center bolt on my plastic cover and its really easy to get off.

[Dave A.]

No big deal really! I was just tossing the idea around in my head on how to make the timing belt self adjusting. Thanks for the input!