Update: many things. Camshafts failed and deposited a lot of metal into the motor in very short order, and I was not happy with the engine compartment detailing or level of finish. I decided to pull the motor and take opportunity to detail the engine compartment, fully rebuild the 3.0 with help of @fourmotioneer, and make some other updates.
March 2019, pulled into garage for engine extraction:
I had already dealt with the heads a couple of times separately, and it was a lot of work and wouldn't allow me to do the other things I wanted to do. After discovering the issues initially, I swapped out the failed cams for new stock Alfa ones and put in all new followers and drove the car for a few hundred miles. But, after thinking about how much material had ruptured from the lobes in such a short period of time, and how damaged the lifters I removed were, I was having doubts about the rest of the engine and thought it was best to just pull the whole thing and address everything at once. With the engine out, it was an opportune time to strip, repaint, and detail the rest of the compartment. Luckily I had some excellent help locally to help proceed on this project.
The engine had other issues from the first build, including undersized bearings (not needed). So who knows how long it would have lasted anyway. This effort would receive more careful attention. I started gathering parts during the teardown.
With engine out, car was towed to a body shop and the engine compartment media blasted to bare metal. There were a couple layers of paint in there of differing types and I wanted to start with a perfectly clean slate. Nice clean metal, only one spot of surface rust and "pocking" that was addressed.
I don't recommend doing this unless you spend a lot of time sealing the holes in the firewall, and everywhere else. I had to clean media out of crevices for a while. The good news is the blasting was affordable in the scheme of things and made surfaces perfect.
I totally understand why, Rob. Given the amount of steel shed, which could be all over the innards of the engine, oil passages, etc. I would have pulled the motor too. This way, you'll know for certain you got everything cleaned up to your standards.
I lost all photos of the prep and first painted bay photos. This is the only one I have, before touching up local areas - just after painting. The bay was done in base/clear to be a bit more durable than original. Now the real work begins...
Steering rack to come out, bad insulation to be removed, new hoses to be installed, etc.
Meanwhile, engine parts ordered and received included NOS Alfa crankshaft and rod bearings, Reinz gaskets, Elring or Reinz seals, etc.
I sent off all my hardware meant for final assembly for blasting and plating including duplicate fasteners needed for engine compartment items to replace ones painted over.
Engine starting to go back together... @fourmotioneer laid in OE Alfa bearings for bottom end assembly.
Blueprinting the bottom end revealed that the lightweight flywheel was not properly machined or balanced, so I discarded it and sourced another 3.0 stock unit for rebalancing with the existing crank (polished), H-beam rods (balanced and re-sized), and other rotating assembly parts. The shop made a number of adjustments and said they were pleased with the results.
Cylinder heads were disassembled and checked for good measure.
Assembled bottom end back to undisclosed location for final assembly. Thermostat assembly to be removed for refurbishment.
Cylinder heads being prepped for cams. The heads were prepared beautifully.
Cylinder heads re mounted with proper Reinz gaskets.
I replaced studs for the timing belt tensioner to prepare for the Zat "2.0" Centerline unit; one was damaged. I also had to grind down the allen grub screw because whoever had done the TSB in the past didn't tap the threads straight and said screw sat proud of the block surface, preventing the tensioner from proper mounting. There was also some raised area from poor workmanship in the past so I filed it flat. After this it was OK. I think this is a common issue actually, and something to check when installing a Zat or Centerline tensioner.
Thermostat housings were media blasted and coated. All sensors were cleaned and polished...a little OCD. New studs, gaskets, and NOS housing bolts. Zinc plated the TTS boss and wiring harness bracket as well. I will be ditching the timing "retard" sensor, to be seen in a later photo.
Cam timing set with gauge (hubs modded to allow slight adjustment), belt installed and initial tension set. I set the cam timing to be a bit earlier than stock 3.0 to get the intake valve closed a touch earlier for snappier bottom end and midrange, as this is a street car with a Verde final drive. This same setup works quite well on another car of mine so I decided to replicate it.
Getting to about December '19:
Next was matching the mating surface of heads, gaskets, phenolic spacers, and intake runners. Witness marks on one side of the spacers made the first pass easy. Quite a bit of overlap but not sure how much this will really matter in terms of power output.
Onto the wiring for a bit. This was a lot of work.
The original loom wrap was damaged in many places, had red overspray on it from the first repaint, and didn't look too good. So I decided to completely strip the entire harness forward of the firewall of all the original wrap and left only the solid plastic shrink tubing in certain sections of the Jetronic harness.
I used cloth type Tesa harness wrap, which should be a big improvement over the aged original stuff. Exposing the original wiring also exposed a few issues which were easy to remedy once visible.