P212 Camshaft Sprocket Lockpin

[Jesse16]

Does anyone know off hand what the thread size is inside this pin? Looks like neighborhood of 3 or 4 mm x ____. Rather not buy another tool if I can pull it out using a simple screw and pair of pliers. I don't have a large collection of small metric screws so may have to pick up something at the store.

[cgarr]

I don't know what size it is but a spark plug tip screws right in it.

[Jesse16]

Great tip, if I'd had a clue, would have saved an old plug to use as a puller. That thread is a 4.0 x .7mm so will look for one at the store this afternoon. Can attach that to my slide hammer/puller. Need to get cam bolt and washer off first with that "special" tool which arrives today.

[KTL]

You won't need a slide hammer. When you pull the pin you'll think to yourself, man, it doesn't seem tight enough that it would stay in place all the time.

[burgermeister]

Seems like it gets tight when the cam bolt is torqued - I imagine that's what keeps it in place. Otherwise, I can move it with my pinky on my engine.

[john walker's workshop]

the edge of the big washer keeps it from going anywhere. there is also a bit of timing adjustment available just from rocking the pin in it's hole.

[Jesse16]

Yes, they fall/slide right out. Didn't occur to me they'd be that loose when a "tool" is mentioned. Thanks

[burgermeister]

Originally Posted by john walker's workshop

the edge of the big washer keeps it from going anywhere. there is also a bit of timing adjustment available just from rocking the pin in it's hole.

Makes sense for the early mega-nut cams.

But on late engines with the cam bolt? The cam holding tool holds the sprocket. The only thing connecting the sprocket to the cam is that little pin, via a hole-disc keyed to the cam - and the bolt is threaded into the cam, so wouldn't tightening the cam bolt always rock the pin in the same direction? I ask because I recently did this, and I could not get finer adjustment than the offset pin holes allowed.

If the pin were loose after torque-ing the cam bolt, couldn't it go forward? The only thing stopping it would be the cam thrust plate & its 3 bolts if I remember correctly.

[cgarr]

It cant go forward because of the lip on the back side:

[burgermeister]

Ah-hah!! Thanks Craig. I missed that feature - I sure was careful not to insert it beyond flush for fear of causing later engine mayhem, but it happily looks like I was just extra paranoid

[cgarr]

Now if you want to adjust your cam timing on the fly you need to build a tensioner that operates both top and bottom of the chain so what you are doing is shorting the chain thus rotating the timing while running but you have to also keep proper tension while doing it. Something we are working on.....

[TibetanT]

You question John Walker's advise?

Bad, bad decision...he is a master at this.

[burgermeister]

Originally Posted by cgarr

Now if you want to adjust your cam timing on the fly you need to build a tensioner that operates both top and bottom of the chain so what you are doing is shorting the chain thus rotating the timing while running but you have to also keep proper tension while doing it. Something we are working on.....

Sort of like what Porsche did with their early variable cam timing?

If you have enough travel in your tensioner, you could accomplish it with just an additional adjuster on the drive side of the chain. The tensioner on the slack side would just to move to keep the tension adjusted. Adds a whole new dimension to valve clearance checks, too... still, sounds really neat!