Those that have been following along should be close to having an intake manifold top that closely parallels this one's state-of-finish. The top half will now be taped off with 2" masking tape to prevent dirt, dust and other contamination from getting inside. It will stay that way until I'm ready to bolt it back to the lower manifold.

There's some special areas of concern during re-assembly that I've circled in red/yellow so they aren't overlooked.

The red area refers to the butterfly shaft o-rings that are hidden within the aluminum bushings that linkage assembly protrudes from and that the actuator valve rotates during manifold switch-over. They are "directional" o-rings and MUST be installed the same way they were removed. Install them backwards and you'll be chasing a small vacuum leak and subsequent erratic idle and off-idle hesitation problem forever. They can only do their job and prevent a vacuum leak if installed with the sealing lip that exists on one side of the o-ring facing outwards (away from the intake manifold. Internal vacuum then pulls (sucks) this lip flat against the switchover rods bearing material and seals it.

The second area of note is marked by the yellow circles in the above pic. We all pulled little plastic spacers out of there upon disassembly that were so fragile and heat-fatigued that most cracked and crumbled upon removal. While those spacers, in and of themselves, are expendable/unnecessary the job they accomplish on re-assembly is imperative, They align the butterfly shafts to the bores. An easy work-around is to push a pair of needle nose pliers between the machined flat on both bore O.D.'s. The idea is to center the slight protrusion of bearing material so that you can then re-install the butterfly plates and have them centered within their bores and the same amount of axial (in/out) play of the butterfly shafts. If this method is not used one shaft can have more axial play than the other and cause a "binding" of the linkage when pushed/pulled by the actuator vacuum diaphram ball-socket.

First pic shows butterflies open so you can see degree and depth of finish underneath them.

In this pic you can see the top half with butterflies closed. This also shows the new 3mm stainless buttress screws I used for re-attachment. Suffice it to say I've never had a more difficult time locating screws for a specific application. I ended up ordering from Germany. I have plenty to go around and we'll do the SASE thing again but this time it will require a small "padded" envelope instead of the standard paper "business" envelope. No charge to any Abnormally Aspirated customer. Small charge to cover costs for non-customers. But trust they ARE expensive as they are ISO spec stainless and from Germany. If the cost is too much for some I encourage you to find your own. Plan on 85 cents each+ the SASE padded envelope. ."Membership has it's privelages."

And everyone using these screws MUST have a #1 Phillips screwdriver. Don't even attempt install with a #2 Phillips. There is no more direct method to failure than the wrong tool in this case. I also recommend Loctite 272 high temp/high strength thread locker as the "ONLY" thread locker to be used on these screws. Little spendy (ok, LOT spendy for some) and little hard to find. But these are not screws you want vibrating loose down the road.

Total man-hours spent on IM Top: 32.5

This concludes the IM Workshop as it relates to the IM top half. There is one remaining post w/pic pending for the lower half that I'll get to when it's at the same level of completion.