Needs advice & help on cam gear

[leonl]

Right side of my 1991 964 3.6 cam has no movement. Took it apart and found the bolt on the cam gear is loose. Cam gear is loose. Pin is no where to be found. Smaller gear set behind cam gear is completely grind. My question is I definitely needs the smaller gear set, may be right side cam. Next is will I need to replace all right side intake & exhaust valves? Anything else I need to keep an eye while I am at it?

Thank you.

Leon

[Flat6pac]

Yes, you probably have some spare metal on the magnet.
Once the pin started to tear up the inner drive, the valves began to bend when touching the pistons.
Another thing I have seen is the cam binding in the housing and causing the pin to shear the the lobes on the inner drive of the cam
Bruce

[leonl]

Bruce. Thank you very much for the reply and advice. Is the cam still usable? Can you describe what is cam binding?

Thanks again for the input.

Leon

[Flat6pac]

Cam binding, the cam wont turn in the carrier because of lack of oil or twist in the carrier to bind turning. Once it binds, it tears up the cam drive and lock pin.
Bruce

[Lapkritis]

If it's bound then you'll likely need to address the cam tower and cam. Webcam in riverside welds and re-grinds cams in pairs. The cam housing may be a doorstop now but inspection would tell.

Any idea on cause? Oil starvation perhaps?

[leonl]

Originally Posted by Flat6pac

Cam binding, the cam wont turn in the carrier because of lack of oil or twist in the carrier to bind turning. Once it binds, it tears up the cam drive and lock pin.
Bruce

Wow. That sounds pretty serious. Any visual I can tell that the cam is binding?

Originally Posted by Lapkritis

If it's bound then you'll likely need to address the cam tower and cam. Webcam in riverside welds and re-grinds cams in pairs. The cam housing may be a doorstop now but inspection would tell.

Any idea on cause? Oil starvation perhaps?

So, looks like cam, cam tower, valves, at least. That will be an expensive but pretty door stop. Not sure what the cause is, probably oil starvation but there were oil when I took the valve cover off. You know, it makes sense if the cam is binding since the inner gear is completely grind off and cam gear bolt was loose. So cam seized while the chain is still spining, somehow loosen the bolt and the lock pin spin free and grind off the inner gear.

Thanks again for all the info. I will continue to take it apart to see what other damage done.

[Flat6pac]

I have a C2 cam carrier if you were to need one.
Canyou put the bolt into the cam and turn it the cam?
The cam in reality turns against the thread direction so the bolt shouldnt loosen.
Bruce

[leonl]

Originally Posted by Flat6pac

I have a C2 cam carrier if you were to need one.
Canyou put the bolt into the cam and turn it the cam?
The cam in reality turns against the thread direction so the bolt shouldnt loosen.
Bruce

I will let you know if I need one. Thanks. I was thinking about turning it to see, in theory if turing the cam when crank is not in TDC will bent the valves right? I don't think it matters in my case.

[docrodg]

I could be wrong, but it seems to me that if the bolt loosened up that would allow space between the gears and thus a large shear force on the pin, causing the pin to fail and the cam to stop turning due to lack of connection. The cam tower may be fine if this was the chain of events.

[leonl]

Originally Posted by docrodg

I could be wrong, but it seems to me that if the bolt loosened up that would allow space between the gears and thus a large shear force on the pin, causing the pin to fail and the cam to stop turning due to lack of connection. The cam tower may be fine if this was the chain of events.

That will be a good thing for me I am just preparing for the worst case scenerio. Maybe I will luck out. We will see.

[leonl]

How do you remove the inner gear?

Thanks.

[KTL]

You have to coax the inner hub/gear off the snout of the cam by pulling on it. The inner gear is keyed to the cam snout via a woodruff key. It's a half-moon shaped chunk of steel that sits in a female half-moon shape machined into the cam snout.

Since your inner gear got sheared, it leaned on the woodruff key quite hard and may make removal of the gear a bit hard. A small two jaw gear puller would work to draw the gear off the cam.

[leonl]

Originally Posted by KTL

You have to coax the inner hub/gear off the snout of the cam by pulling on it. The inner gear is keyed to the cam snout via a woodruff key. It's a half-moon shaped chunk of steel that sits in a female half-moon shape machined into the cam snout.

Since your inner gear got sheared, it leaned on the woodruff key quite hard and may make removal of the gear a bit hard. A small two jaw gear puller would work to draw the gear off the cam.

Thank you very much. Those are great info. I have puller that I can use to pull it off. Thank you again. I think I will replace the inner gear and set the timing. Then try to turn it to see if the cam is ok. Once that is set, I will run another leak down test.

[Flat6pac]

I have both gears and the pin, woodruff key
Bruce

[jtsilverfox]

Lapkritis (Andrew): Do you have any address, or whatever for 'Webcam in Riverside'? I've got a couple of 69 911E cams with some pitting on a few of the lobes that might need fixing...

[Ronnie's.930]

Originally Posted by jtsilverfox

Lapkritis (Andrew): Do you have any address, or whatever for 'Webcam in Riverside'? I've got a couple of 69 911E cams with some pitting on a few of the lobes that might need fixing...

First hit on a Google search for "webcam" -

Web Cam Inc. - Performance and Racing Camshafts

[jtsilverfox]

@Ronnie's.930: Damn! I knew that'd happen as soon as I hit the 'reply' button! Thanks.

[Lapkritis]

Originally Posted by Ronnie's.930

First hit on a Google search for "webcam" -

Web Cam Inc. - Performance and Racing Camshafts

You must have "safe search" on. I saw more accidental porn looking up their phone number than I would like to admit.