3.6 cam tower mod for earlier style oil feed

[Harveymushman82]

Not sure if this goes here or the tech forum but wanted to show my way of modifying the 3.6 cam towers to work with earlier style oil feed. I am building a 3.2 currently. Couldn’t get my hands on 3.0 or 3.2 cam towers for a decent price but found a nice set of 3.6 ones. Besides the drilling and tapping to the valve cover studs to work with my earlier valve covers I needed to make the oil feed work. I know some people may have other ways of doing this. Such as a bushing to insert. However I went about this another way that I hadn’t seen yet.
The hole in the cam tower which is untapped is roughly .495-.498. Perfect start for m14x1.25. I started the threads and then inverted the tower to reduce the risk of getting chips in the feed line as well as plugged the bottom of the hole with a cut and folded piece of masking tape. Then I went about making a fitting on the lathe. Essentially the same thing as the factory updated with the restricted hole but with a m14x1.25 male end instead of the m12x1. Other wise it’s the same.



I made the fitting a little bit long and cut it down after to the appropriate length.

[gled49]

What’s on the other end of the housing. The plug end has pin that indexes the spray bar to keep it from rotating?

[Harveymushman82]

The pressed in plug has a point on it just like the threaded one on the earlier towers.

[Walt Fricke]

Hmm - pressed in plug with locator. So you have to pull it when removing the aluminum spray bar for cleaning? Then press it back in?
Saved manufacturing costs vs repair costs much later? But the pressed in part is threaded too.

[Harveymushman82]

I may be confused here.
The factory plug on the opposite end of the tower on the 3.6 is a pressed in aluminum plug with a locator.
The end that I modified does not have a plug. It is a threaded hole with the fitting in it. It is in stock form an unthreaded hole.
The spray bar is still being located with the plug on the other end.
I believe when people remove it to clean the spray bar they either replace it with a factory plug or potentially tap it and install the threaded plug from the earlier towers? However I believe hole size would come into to play again as that hole is larger than the earlier towers threaded hole.
If I were to remove that plug I would most likely make a bolt with a locator much like the earlier ones, but except I would make a m14 bolt and tap the hole.

[Walt Fricke]

I don't think Porsche confuses us on purpose, but we can get confused. Up through the 3.2s the cam carriers can be used on either side, as the castings are the same. The big cam journal size plug can be pressed in at either end. The spray bar can be installed from either end. Using a pointed bolt at one end and the banjo on the other, both holes threaded the same, etc.

With the switch to the different oiling system affect this sort of symmetry in the raw castings?

Me, I have always dreamed of using 993 cam carriers, so the rockers can just be bolted on. But I didn't research how I'd deal with oiling. Apparently, that isn't much of a problem?

[PeteKz]

Ditto what Walt wants. Having just gone through the frustrating and time consuming process of installing RSR seals on the rocker shafts in my engine, I rhetorically asked myself many times why Porsche drilled those bores from one end of the cam housing to the other. Mounting the rockers inside the 993 housing make so much more sense, and has a dozen fewer places to leak.

[Harveymushman82]

Wish I had the money to buy 993 towers to experiment or at the least find a customer interested in the idea.