Is this a cam tower to head leak?

[jchatfield]

I posted this on the main 911 board earlier today, but got only one response, so I thought I'd try over here, as I might have to drop the engine.


I have oil leaks on both sides of the engine that appear to be coming right where the cam tower meets the head. I have not done a dye test, but I'm quite certain it's not the oil return tubes and I've already replaced the valve cover gaskets with the silicone beaded ones.

Also, I think I'll rule out the rocker shafts as I looked at them when I did the last valve adjust and al the dry areas were in fact dry.

Now some facts:
1. The car has been leaking since the day I bought it over 3 years ago.

2. It had a rebuild in Aprill 2000 by motormeister (hey, I did not know about their reputation back then) where they fly cut the heads, put in Solex cams & rebuilt the Webers.

3. Last winter, after it had been in storage 3 weeks or so, it suddenly leaked a large amount of oil on my garage floor. It was probably overfilled at the time.

4. The leak is worse when I have more oil (past the half way mark on the dip stick) in the engine.

Does this sound like a cam tower to head leak or not?
It looks like one, but I find it odd that it is on both sides and the mid winter in storage leak seems strange as well.

If it is a cam tower to head leak, how many hours will I end up paying my mechanic to fix? I know you all will say DIY, but I'd have to buy an engine stand, adapter, proper floor jack & cam removal tool for about a $750 outlay before I even start the project.

Any answers or insight is greatly appreciated.

Jim Chatfield
72 911T
Royal Oak, MI

[snowman]

Sorry to hear this dude. It dosen't look good. Thats probably why no one has responded. You have one of the most expensive possible leaks, next to the case itself. I would at least try and see if moter shyster would look at doing it under warrenty.

If you are not up to doing it yourself, at least go to a highly reputable Porsche shop and have them confirm your diagnosis and give you an estimate for repair. If you are correct it ain't going to be cheap. They will have to drop the motor, remove the valve towers and heads, clean everything, investigate why it leaked to begin with, fix that and put it back togather, ie almost the cost of a full rebuild, less parts, except for gaskets. My WAG $1500 to $3000.

[Wayne 962]

Which engine is it?

-Wayne

[jchatfield]

Wayne:

It's a 2.4L T engine that Motormeister fly cut the heads to raise compression and installed Solex cams.

Snowman: Thanks for your input. I have been working on the engine since day one to get it to run correctly. The rebuilt carbs were way overcarbed for this engine - 34 venturi. 180 mains 60 idles, etc. Took me 1.5 years to learn about carbs and correct this with PMO's help and float level guage & synchrometer and proper jetting (32 venturis 155 mains and 45 idles). I then added the MSD and it runs great and has good power. BUT, the leak has been there since I bought it. The car was in Arkansas (I'm in Michigan) and I bought it based on a detailed video the seller sent me and the rebulid sheet from Motormeister for $6,500. The car was still in the break in mode, so I thought I could not go wrong. If necessary, I do know of a very reputable shop in Ann Arbor named Eurotech that I used when my old 944S chain tensioner failed and chewed up up the cams but somehow did not jump timing.

Thanks,

Jim Chatfield

[dtw]

Jim,
How's that engine run? I obtained a 2.4T with flat top pistons and solex-like cams installed, but the motor was in boxes. What I couldn't figure out, was how they got those cams to clear those pistons, without retarding the hell out of the cam timing. (The motor was torn down due to rod knock).

Good luck solving the leak problems. Maybe you can borrow some tools and take a shot at fixing it yourself?

[jchatfield]

DTW:

I've never heard of T pistons having a problem, but certainly domed E's or S' . However, maybe the Solex are too aggressive even for T pistons. My understanding is that there are different thickness shims that go between the base of the cylinder and the case to make room for the valves. The correct way is to get one shim the right thickness rather than multiple, thinner shims stacked on top of each other. I have never looked to see if mine were done correctly. However, if I have to get the engine apart to fix the leaks, I will upgrade to 2.2 E pistons (or new JE's) and fix the shims.

I'd like to take a shot at fixing it myself and if the estimates are above $2,000, I definately will. I am worried that the leak is due to head surfaces that are not level and need to be machined before cleaning and resealing - I just don't know what to do to assure the surfaces are"okay" before resealing.

[Wayne 962]

Originally posted by jchatfield
I am worried that the leak is due to head surfaces that are not level and need to be machined before cleaning and resealing - I just don't know what to do to assure the surfaces are"okay" before resealing.

The problem with these surfaces leaking is almost always a cleanliness problem - not a surface/level problem. You're mounting aluminum heads against aluminum cam towers - they don't really warp, and they mesh very tightly. Usually when they leak, it means they weren't cleaned properly, or the sealant wasn't applied properly.

If this is definitely where they are leaking from, then you should be able to tear it down, reseal and reassemble with no machine work...

-Wayne

[snowman]

If you do it your self get WAYNES book first. IT shows the steps necessary to check the parts. All you need is a good steel rule or straight edge and a feeler guage.