[Contadino]

Decided to do a cam tensioner pad inspection today ('93 968). The pads look good as far I can tell but the exhaust cam shaft has two broken teeth. They are adjacent teeth. I couldn't see any pieces of metal or plastic anywhere. And I have no idea how long it has been that way. I bought the car last year and just use it for DEs.



So now what should I do?

Does anyone think it is ok to run it like that?

RSBarn has refurbed cams but they are $650 exchange. Would I need new lifters if I swap cams?

I think Webcam will fix my cams - not sure of the cost.

Wasn't really in my budget for this year....

but if I have to spend that much maybe I should go to a race cam. Any recommendations?

Car has the airbox mod, lightweight flywheel, cat delete, some sort of lightweight exhaust.

Partial Post: Please Login or Register to read the full post.

[MB968]

Although the chain has almost 180 degrees of wrap, it's pretty risky to use it as is. It could run for a long time, or you could loose more teeth or the chain tomorrow and end up with a complete engine overhaul/replacement. Best not to run it, and find some (used?) replacements. There probably are some out there if you afford the time to wait.

Partial Post: Please Login or Register to read the full post.

[vliegwielolaf1234]

i would't not run it , replace with new or refurbed ones .

Used ones , you need to make sure they are a couple otherwise you run into uneven wear and it will destroy the chain and theeth on the cam's in no time .

Replace/refurbish both they are a couple .

No need to replace lifters if they where ok before .

Replace the slider pads and chain .



Race cam , ask RS Barn Pete he will now all about them , i have only driven a 968 with race cam´s one time , was not my cup of thee , if you drive the car on the street would be no no for me .

Partial Post: Please Login or Register to read the full post.

[tamathumper]

I would not drive it that way, for fear the $650 would turn into $6,500.

Partial Post: Please Login or Register to read the full post.

[Darryl]

I still have the cams (matched pair) from the parts car. PM if interested.



- Darryl

Partial Post: Please Login or Register to read the full post.

[astroede]

Just curious...what's the likely cause of this kind of tooth breakage? Sorry about your situation, but glad you caught it before more serious damage was done.

Partial Post: Please Login or Register to read the full post.

[MB968]

Too many potential reasons like: mat'l &/or heat treat not to spec., one chain link too long (unlikey to be the cause by itself, as I assume the chain precesses with each rotation), excessive loading (like from a valve into a piston), excessive wear although it doesn't look to be significant in the picture, eratic actions of the vvt system, stretching of the chain causing the links to no longer be in a rolling motion mode causing unexpected tip loading, etc.



Curious what the companies that support the race crowd might say.

Partial Post: Please Login or Register to read the full post.

[flash]

when not due to a foreign object, typically tooth breakage is due to a worn or stretched chain. these chains are pretty done at 100k, and high revving engines show wear much much earlier.

Partial Post: Please Login or Register to read the full post.

[Contadino]

FYI, the car had 74,000 miles but has seen a lot of DE time.

Partial Post: Please Login or Register to read the full post.