Timing chain tensioner

[2seater]

I was pulling down my spare engine that I rebuilt some years ago. At that time it received the "new style" chain tensioner. It now has about 35k miles on it and I found the tensioner to be completely worn away on the lower third, just short of metal to metal contact. The shoe of the new tensioner has void areas on the back and once it wears into the void, it looks like it will wear very quickly. The photo shows the original style tensioner from my '90 engine with 92k miles on the left and the new style with apprx. 35k miles on the right. My unscientific test with a spring loaded center punch indicates the new style is softer material. I tried the old tensioner back in place and it looks like it would go another 92k miles with no problem. Has anyone else seen this sort of wear?

[2seater]

Update on the chain tensioner issue: The wear on the new style tensioner has allowed the chain to run at an angle which appear to have worn the front cam bearing to an unacceptable level. The engine was torn down to check for any issues arising from the turbocharger installation and to find the cause of reduced oil pressure. All engine internals look just fine except for this tensioner and the front cam bearing. The front cam bearing is where the oiling system crosses over from one oil gallery to the opposite side. One other related item is the chain itself. The chain that was installed during the original rebulid was a Cloyes brand. It appears to be worn considerably more than the O.E. chain (Morse on the side links), with 1/3 the miles, probably from the twist. Examining the chains closely reveals the side connecting links are .040" below the level of the main links on the Cloyes brand and .012"-.014" low on the O.E. Morse chain. Since the chain is only six links wide, including the side links, the Cloyes chain would tend to wear the tensioner more quickly, at least initially.

[Jim]

I don't know anything about the tensioner but I am sure impressed with what you have done under the hood.

Jim