Snapped timing belt - RS4 B5

[hsf]

Well....

After fully building the engine, with forged rods, JE pistons, upgraded valvetrain , bigger turbos etc , i have made around 1400 km of a break in period.

When finished, corrected some minor bits , such as oil leaks and installed the tfsi coils (thetuner conversion) and bosch ev14 950cc injectors.

Went for mapping and in the middle of a mapping session the engine shut down.

Result : Broken timing belt. ( brand new gates blue rpm installed with rebuilding ).

Already dismantled engine and conclusions:

- Most of the engine valves are bent ( ferrea competition )

- Not a single problem found on pulleys , waterpump etc ( all of them are new )

- Slight marks on pistons that won´t cause any problem later.

Other than that, the chamber gives me the idea of a very lean mixture, also the exhaust valves were "rought" on the surface, indicating too much heat.

Did the belt snap because of overtension ? It seems that the supposed 15nm of tension wasn´t applied.

[Nige_RS4]

That's not good - was the belt new? I guess it could be a lot works i.e. bent rods or a hole in the block.

Why did you chose to use an aftermarket belt rather an OEM Audi one?

[hsf]

Well,

Don´t have an explanation for that.

Always knew Gates as timing belts company, and saw a vast amount of tuners using these gates rpm belts

There are many tuned S4´s and RS4´s using this exact belt..

Brand new when i bought it, it has the break in quilometers

[ViktorP]

I will listen too. A similar situation