Cam belt line

[lukasdeopalenica]

I noticed recently that my cam belt runs close to the outer edges of pulleys, and looks almost like the cover stops it from falling down. Is that correct or at least safe? What should maintain the proper belt line? The tensioner is brand new and tightened correctly.

[peteracs]

Hi

I thought it was the lip on the cambelt pulley which provides a guide?

Peter

[rossocorsa]

not all have a lip

[Thotos]

Not all twincam pulleys have lips. Not in Fiat applications anyway which can be a lot older than Lancia Betas. Early Fiat applications had plastic pulleys while I think Lancia always had metal pulleys. Some engines have lips at the front, some at the back, some one at the front and one at the back with or without lip on the auxiliary shaft pulley. The lips (if there) are for safety and the belt should not be in constant contact with them as it will quickly wear on the edge. The position of the belt is determined by the tensioner bearing which has a slightly convex profile. As you say your tensioner bearing is new I'd suggest that you check its mounting to see if it's at an angle due to a bent carrier. Where did you get the tensioner bearing from? Could it be that it's not the right one for the purpose?

[lukasdeopalenica]

It is a genuine SKF VKM12004. There was no markings on the pulley about the outer or inner side. Another thing I remember, the old pulley also worked at the outer edge what was proven by the belt that left a track on the pulleys.

[peteracs]

Not all twincam pulleys have lips. Not in Fiat applications anyway which can be a lot older than Lancia Betas. Early Fiat applications had plastic pulleys while I think Lancia always had metal pulleys. Some engines have lips at the front, some at the back, some one at the front and one at the back with or without lip on the auxiliary shaft pulley. The lips (if there) are for safety and the belt should not be in constant contact with them as it will quickly wear on the edge. The position of the belt is determined by the tensioner bearing which has a slightly convex profile. As you say your tensioner bearing is new I'd suggest that you check its mounting to see if it's at an angle due to a bent carrier. Where did you get the tensioner bearing from? Could it be that it's not the right one for the purpose?

Hi Thotos

My 1600 is early S2 and has plastic cam pulleys and one has flange one side, the other also has one on the other side.

Peter

[rossocorsa]

It is a genuine SKF VKM12004. There was no markings on the pulley about the outer or inner side. Another thing I remember, the old pulley also worked at the outer edge what was proven by the belt that left a track on the pulleys.

is that on a 2 litre? if so I think you will find the outer diameter is too small. That pulley size, 67mm, is for the smaller engines 2.0 uses (from memory) 70.5 mm. best solution on a 2.0 is to replace the bearing only keeping the original outer casing, the actual bearing is readily available.
not sure if this would cause the issue you are experiencing though

[lukasdeopalenica]

The pulley diameter can only influence on a belt tension I think. The smaller diameter can be easily compensate by additional pulley strain, but how strong the belt may be tensioned to not badly impact on the bearing...?

[75coupe]

It does not look too bad to me. In your setup the crank pulley stops the belt coming too far forward and the auxiliary drive pulley has a lip on the rear to stop it moving too far backwards..

I have found after many Km's the crank drive pulley can wear to.

If the belt is too tight it will make a loud whirring noise. You should just be able to turn it 90 degrees in the middle of the longest run between inlet cam and auxiliary driveshaft with 2 fingers.

[lukasdeopalenica]

Thanks, I will check it.