911 Fitting woodruff key to camshaft

[Higsy]

I'm in process of assembling 911 3.2L engine. Have installed 993 cams and am at the point where I need to fit the woodruff keys. Problem is that the woodruff keys I have (from the original 3.2L cams) won't push into the slots on the 993 cams - they only engage with the slot but won't bed down. Is there any difference in the keys used between the two types of camshaft? Is there any way to press them in?

Grateful for any ideas!
Thanks

[Higsy]

I've just checked both 3.2 & 993 parts catalogues and the woodruff key has the same part no so the old ones should fit the 993 cams. How can I press them in?

[Emery G.]

get yourself a very small hammer and tap them into place.

[Higsy]

ok thanks - wasn't sure if they should need that sort of "persuasion"!!!!

[tom1394racing]

You may need to smooth over any burrs with a light sanding and then tap them into place with a brass hammer or hammer and punch. Just light tapping should bed them.

[Flat6pac]

What is the over lap setting for the 993 cam?
Bruce

[Walt Fricke]

After you smooth their sides, waterpump pliers should do the trick.

[LeakProof]

I just lightly set the keys in there, with the rear of the key facing downward, lubricated it and torqued (used) the sprocket flange, to guide it in there and get it home.

Then removed the nut and washer to install the cam sprocket.

Everything seemed to lock in properly.

Just assumed that was the only way.

Leakproof.

[Walt Fricke]

That is one way, to be sure, if the fit is loose enough for the key to equalize, so to speak. Worked for you, which is what counts.

Sometimes, when I have tried to use the flange's keyway to guide it home, it has just rocked up in the rear (or something - the flange wouldn't seat, and on removal the key was katywampus). But, bold as I am, I've not tried torquing.

Once the key is fully seated in its slot, all is well (assuming you don't need to fiddle with the shims again, that is).

I have learned to have the engine at least level, and maybe it would be better to rotate the engine to have the cam you are working on down, the better to prevent that slippery devil from falling into the bowels of the case if it gets away from you. On the right side I tend to stuff a rag into the case opening just in case if the engine is level. The left side at least has a sort of dip before the chainbox bottom can guide your parts in and out of sight.

[LeakProof]

Walt,

In-fact I did have a problem with one of the flanges not seating, Didn't realize it until about the fourth hour of trying to time it, then I torqued it a little more and it went.
I suspected, the whole time that the cam nut didn't look quite right, but wasn't really sure.

Needless to say the cam timing took me way to long, because of that.

Everything seems perfect now. (I hope)

Do you think the woodruff key's seated OK?

Leakproof.

[Walt Fricke]

I assume you put the shims back in the way you found them. Unless the flange is fully seated, you would notice the chain not running right. It would be like having too many shims.

One engine builder told me that if you are off by more than two shims (maybe he said one), you can't help but notice, as the chain won't run right while you are turning the engine over timing things. I've not tried doing that on purpose to see for myself, though, but it makes sense.

Furthermore, where could the Woodruf key go? If you pushed it out the back side, it would prevent the flange from seating, as it would act like a very thick shim. I don't think there is room back in there for the key to fall out of the way.

I suspect the key wasn't all the way seated, but four hours of fiddling, with the nut on, then off, some torque, more torque, less torque, etc. wiggled it down into its seat and allowed the flange to move all the way in.

If a guy was worried early on, the simple thing to do is put the flange on, tighten things some without worrying about setting anything, then take the stuff off and pull the flange out and look. It should slide out easily, and the key should look properly snuggled into its hole, with its top nicely parallel to the shaft.

If it is any consolation, you should have seen me fussing with chain wheel parallelism the first time I put the top end back on a motor. I cut off the short arm of a carpenter's square to use as a straight edge (it actually is quite straight), and took readings with nice depth micrometers I had borrowed. But I got dozens of inconsistent readings, and even made a graph to see what figure I could deduce as being the most likely before deciding to call one shim combination good. Thereafter I made sure I had someone to help me and hold the straight edge sort of straight, and used my dial caliper. When I finally purchased the nice Stomski tool, and the depth gauges I had purchased, I found that what I had was spot on.

[john walker's workshop]

i get the key started and then use large channel-locks to squeeze it in all the way. better than beating on it.

[LeakProof]

Thanks Walt,

I totally agree, It would have been simple to pull off the sprocket flanges and check the woodruff key's after seating them.

Perhaps next time I'll use #430 or #440 Channel Locks, with a rag for protection to install, or a small hammer as mentioned above.

Just assumed, I was doing it the correct way and didn't give it a second thought.

Everything seems fine in there.

Also, yes I put the shims back exactly how I found them. Four on the left and four on the right. I'm not planning on checking the alignment.

What you say makes perfect sense, about my trouble with dialing in, because of the sprocket's and key not being set. Then it went and the timing method started to work on the left side.

Man, was I sore the next day, from all the torquing and cranking. And I work wrenches for a living! Go figure.

Leakproof.

[BoxxerSix]

hmmmm. I'd still check the alignment with new cams. Wouldn't want premature wear on the sprockets, especially on the intermediate

Just my opinion

[LeakProof]

Adam,

Not new cam's. Only right cam sent out for repair of, two pitted lobes, and then heat treated.

I also believe the engine has never been torn apart.

Service Manual states:
If new camshafts or sprockets are installed, camshaft sprocket parallelism must be checked.

I did not do any of this.

With that being said, many on this site are recommending that I should check the sprocket parallelism anyhow.

Perhaps the four and four spacer shims, is suspect enough and has curiosity going.

Thanks,

Leakproof.

[Alan Goettel]

I am trying to get parellelism squared away on my 3.6 rebuild. I have the Stomski tool. The 4-6 depth is fine, but the outer sprocket face is flat so it's cut and dry where to measure from. On 1-3 the face is concave. If I measure from the outer edge it is below spec, and if I measure from the inner face it is above spec. What is the proper point to measure from on the concave face?

It is all original cams ect, and I'm 99% sure that the washers are the way they came from the factory. When counting washers does the larger beveled one just count as one? I think that I only had 2 on one side and 3 on the other.

Thanks,

[Walt Fricke]

Unless something changed in the conversion to the 3.6 motor which affects this, you measure to the rearmost part of the chain sprocket.

The concavity you notice is a result of the left bank being set forward relative to the right side. Porsche needed to move the right side chain plane in, and the left side out, in order to line up with the placement of the gears on the intermediate shaft. Otherwise, with sprockets which had no "side," the IS gears would have had to be farther away from the crank gear, which no doubt would have caused other dimensional issues somewhere.

The thick, beveled ring is not a shim. It is a thrust surface, and the bevel is there to allow it to clear a radius.

Because the adjustment shims don't come in an infinite number of thicknesses, you will seldom hit exactly on the spec. Best you can do is compare the one which is over to the one which is under, and pick the one closest to spec. That will be close enough and work fine.

And if you don't have extra shims, get out your micrometer and measure what you have. They have a nominal thickness, but can vary some, especially after use and wearing in. If you are under by less than half a shim, no sense going farther.

[Alan Goettel]

I got it squared away!