Technical Croma 1.9 jtd 16v

[offibc]

Hi all :worship:
Someone knows if the engine of the Croma 1.9 jtd 150hp has a specific geometry where in case of cambelt failure the valves are safe? Or in case of failure all valves are "dead"??

 

[s130]

This engine does not use the more traditional Fiat direct overhead cam direct to follower setup. Instead the overhead cam drives a rocker arm which has by design fracture points so that if the cam belt/timing were to fail then the piston hitting the valve would break the rocker arm and thus in theory protect the valve, guides and pistons from damage.

That is the theory/design intent. As to whether this is 100%, 90% or less reliable is to my knowledge not known/proven.

My gut feeling is that with a little bit of luck there should be no issues were interference to happen other than broken rocker arms. On the other hand it could all go 100% in the opposite direction and damage to valves, pistons, guies etc. could occur.

 

[offibc]

Hi, thanks for your reply. Before to dismantle everything I'll try to replace only the belt and I will see it it starts......
The belt was in good condition, all teets OK, it had a sharp crack only and I've not seen any bad noise. In the past I had same experience with a BMW and I remember very well the noise of all valves.... Completely damaged.

Thanks.