I have a 1969 911T with an '82 SC 3.0 case and an '87 3.2 top end. I do not know the exact pistons and rods, but it was claimed to be a 3.2SS. The cam towers and cams appear to be stock 3.2 (unless the cams were reground -- I have no reason to think that).
The engine runs terrific. I went from PMOs to a Motec ITB setup. It's a great street car, plenty of power for me, excellent all-around driver.
Issues:
1. Both sides I have small but constant oil leaks between the cam towers and the heads. I have investigated this over and over, and it's definitely NOT rocker arms, valve covers, nor oil return tubes. Several times I have carefully cleaned everything, checked with fluorescent dye in the oil. Leaks appear near cylinders #3 and #6. Only drips while running, but over the course of a couple of months, it starts to bake oil on my SSIs, and flings back onto the muffler and bakes on there.
2. I occasionally get a "mosquito fog" of blue smoke when idling. Not on start up, not often, but if the rear end is parked lower than the front, after starting I get a giant cloud of smoke at the first stoplight or two. Or if working on a warm idle in the driveway. Doesn't happen often. Suspect worn valve guides, though I don't get any smoke on a downhill decel test. Pictures of #4 oil fouled plug (about 1,000 miles on it) and exhaust valve #4. Exhaust valves are showing seepage around the valve guides, #4 particularly bad. At least one intake valve looking oily (can't recall which one). See pics below
3. I do have some oil leaking from the case parting line. Not a lot, but a few drops overnight. Annoying.
Leakdown:
1: 3%
2: 2%
3: 2%
4: 3%
5: 2%
6: 2%
Compression:
1: 175
2: 175
3: 180
4: 175
5: 180
6: 175
Oil consumption: have not been carefully tracking. Estimate about 1qt / 1,000 miles.
I would love to clean up the oil leaks. At some point, the heads look like they need to be rebuilt, with new valve guides, etc.
I know splitting the case is a lot more work, but feels like sooner or later I will want to fix the leaks at the case line.
Just in the planning phase, but trying to think ahead to the fall and winter. I will do most of the (non-machining) work myself, with help from a friend who has built a number of Porsche engines, from 356s to 2.2s to 3.0s to 3.2s.
So my questions are:
Valve guides appear to be a problem, yes?
Do it all at once (top and bottom end), or am I asking for trouble splitting the case?
Constructive advice welcome.
