Chain Case Seal to Rocker Tower leak.
 

I am cleaning up my engine while waiting for my transmission overhaul to finish.

I stripped the CIS, all the tin, and the exhaust system. While spinning the engine around and cylinder plane vertical, I noticed oil dripping from the case to my drip pan. Is this common?

The plan is to upgrade to hydraulic tensioners, sprocket supports, guides and check chains, and sprockets.http://forums.pelicanparts.com/uploa...1690309406.jpg

Yours may be from another cause, but when I rebuilt my engine I had a small leak there due to the 930-105-197-03 gasket.
I didn't enjoy replacing it, but no issues after the second time.

Ok, I just machined a plug to go into the distributor hole. I have a small regulator and i’m going to pressurize the case. I have had o-rings get so hard they seemed like plastic. That was on my ‘72 911. Just wondering if this is common.

Here is my pressure plug for the distributor.
http://forums.pelicanparts.com/uploa...1690321044.jpg
http://forums.pelicanparts.com/uploa...1690321044.jpg

I don't understand why you are pressurizing the case? To look for leaks?? Seems like you might cause one this way, depending on the amount of pressure.

To look for leaks. Leaks happen because of pressure differential. Higher pressure inside, the leak (Oil) goes out. Lower pressure inside, the air goes inside. A 1/2 pound of air pressure is not going to CAUSE LEAKS OR DAMAGE the engine. Physics is a strong point.

The o-rings and gaskets that seal the chain housings are a leak point. Since you're going to be in there anyway, it only makes sense to replace them and it's way easier with the engine out of the car. You have to re-time the cams but it's a very doable DIY with the right tools.

With a minimal amount of inlet, it felt like an air conditioning vent and noisy.

You have 3 paper gaskets and one o ring on the chain boxes. It could be this o ring, but the leak on mine was the paper gasket I mentioned, between this plate and the cam carrier. No reason not to change them all with the work your doing. Watch the shims for sprocket alignment.
http://forums.pelicanparts.com/uploa...1690488522.JPG

http://forums.pelicanparts.com/uploa...1690488099.JPG

Hi Ed, I got it apart and the o-rings are real flat. Gaskets were good to the tower. You say three gaskets? Mine each had the a single gasket between the three bolt hockey puck and the tower.

Ahh, three counting the cover to chain case, triangle gasket to tower, and chain case to crankcase.