dgmattingley

I'm wondering if someone out in Rennlist land knows why Porsche changed the design for the 993 of the cam lid that covers the end of the camshaft for cyl 1-3. Previously Porsche just used what looked like a flat cap that fit more or less flush to the cam housing, but the 993 design sticks out about 2 inches and has 3 bolts that secure it and a large o ring. The problem with the 993 design is that it allows for VERY LITTLE clearance to the suspension behind it, to the point where I scraped mine up pretty good reinstalling the engine. Why does it need to stick out so far?

Mike J

Yeah, it looks a bit like some sort of farm power takeoff - but there is nothing behind it so it also looks like some sort of aborted engineering. You are right, it gives a very tight spot when installing the engine. If they just had to cover it up, you figure a flat cover would have worked out just as well.

I have no clue on what its for .. nothing to do with cam timing since you take them off, I doubt if its involved with any oiling. Lets see if someone has an answer.

Cheers,

Mike

MarkD

My only guess is so that some poor soul can actually get it out while the engine is in the car (to install cam lock tool)
Gives you something to grab hold of so you can wrestle with the over-sized o-ring.
At least it is shaped so it can be removed with engine in. They seem to have designed it to allow relief for the rear sub-frame.

Speaking from recent experience... my forearm is still sore

Still, I completely agree with you guys... awfully complicated little piece to accomplish such a simple task.

dgmattingley

Great theory, and makes sense. I guess it's good to know that it's possible to time the cams with the engine in the car, although here's to hoping I never have to do that.

MB965

Based on the horizontal, flat surface it looks like they intended to mount something there.
After determining the extension had no function, I cut off the extension when I rebuilt my engine just to provide extra clearance for the engine R&R.
I also cut off some of the un-needed engine sheetmetal at the No. 3 spark plug for the same reason.
Mike

bobt993

You can cut it down so it does not hit the suspension. I think it may have use on the 993 turbo. You can also order block off plates from Patrick Motorsports (there are other shops that have them). I purchased a set from Ebay, but had to mill the one side on a lathe to fit the 993 cams. Work just fine and no leaks. (I have electric power steering so both sides were done).

dgmattingley

Here are the parts Bob is referring to: http://www.patrickmotorsports.com/part/pmp-36camblock/