[Grady Clay]

Brad,

I agree with Andy, that is usually not an issue with a 911 as the chains outlive most everything else in an allready long life engine. The chains are a standard item to replace at an overhaul. You can replace them with split link chains without splitting the case if the need arises.

On a 911 you can generally tell the condition of the chains by looking at the cam sprockets and idler arm position.

The only exception is an engine that has had solid tensioners. Those can over stress the chains if not kept in proper adjustment.

I have never seen a chain fail, even with all sorts of jumped cam timing carnage from other causes.

The critical issue is keeping proper functioning chain tensioners and replacing the chain ramps when opportune. Any engine older than the late ‘70s should have confirmed late plastic ramps.

Best,
Grady