Got the air cleaner assembly all cleaned up, put together, and mounted back on the plate that also holds the Air Flow Meter ("AFM"), along with the now spotless rubber air coupling. This particular coupling, being several feet away from the engine, and located behind the grill, was extremely dirty with "road dirt", but in excellent condition once I spent about 20 minutes in the kitchen sink scrubbing it with hot, soapy water and various small brushes. Finished it up with some of the 'no scratch' Scoth-Brite and a good rinse, and it looked great . And I used some silicone grease on the slip connection to the air cleaner. This helps preserve the rubber, helps seal it from air leaks, and makes it much easier to rotate for alignment during assembly.
This is the side you can't see when it's mounted in the car. Besides the one main 'snorkel' air intake, there's also a smaller one below it, and turned 90* into the airstream coming in from the grille. "Ram Air"? Not a chance...ram air only adds significant power at very high (>>100MPH) speed. No, it's for cold air into the air cleaner. Cold air makes more power than hot under hood air, so although the 60's and 70's muscle cars offered "Ram Air", almost all the benefit of those systems was to feed cold outside air to the carburettor.
In some cases, the temperature difference was 100* or more, resulting in an increase in the air density, and a resultant increase in the amount of Oxygen available for combustion. More Oxygen means you can add more fuel, and get more power.
This is the side the AFM connects to. It's an 80mm flow path all the way from the outlet of the air cleaner, through the AFM, and into the new air intake pipe, which feeds a 75mm Throttle Body via a reducing silicone hose coupling.
OK, turn to your right, please....
My wife sees me scrubbing these parts down, and at first just shook her head and said "Nobody's going to see it. Why clean it so well?". It's a valid question if you look at cars like toasters, and yes, I know, there are people who collect old and "vintage" or "classic" toasters. Those guys look at their toasters like I do my project car and my radio gear. I'LL know it's dirty there, and as long as it's apart, I'll at least wipe the grunge off it. It actually looks a notch or two nicer now, as after I took the pix, I noticed a couple of spots on it I missed, so they got the windex-and-scotch-brite treatment, and now the entire metal bracket looks pretty spiffy.
The AFM also cleaned up nicely. Not sure why I didn't take any pix. All the dirt on the alloy casting was "road dirt", and not greasy at all. It came right off with the previously mentioned method, and the stains on the housing came off with some green Scotch-Brite, Windex, and elbow grease.
One thing that troubled me when I took these assemblies off to clean was the corrosion I found in the rubber air coupling between the AFM and air cleaner. See all that "white stuff"? It's residue of the corrosion on the inlet to the AFM. Looking through the air coupling you can see a shinky area at the other end of the house. That's where the hose clamps to the air cleaner, which is plastic.
I buffed both the inlet and outlet of the AFM with the green Scotch-Brite, and it cut the white oxide/chloride/whateveride right off the metal, and it looks much better ow. The connections these make to their air couplings will also get some silicone grease for the same reasons, but it's curious that this surface, NOT in "electrical" contact with anything, could have that kind of corrosion. I don't know what alloy this casting is. It might be aluminum, or it might be zinc, but it sure got attacked a noticeable amount.
And the timing belt cover is a real PITA to clean. 30+ years of belt dust, oil vapor, and engine heat combined to cook a layer of "stuff" on the backside of the cover that requires Good Old Gunk and a stiff brush to get loose, and then everything has to be wiped down again, and put back together.
I took a break from the outside paint because I was getting "dazzled" by staring at dirty white paint being scrubbed to clean white paint under bright LED lighting.
And I'll be equally glad to take a break from scrubbing under the hood! At least I've been wearing the 5 mil nitrile "Two By Two Hands Of Blue" gloves from Harbor Freight. Keeps the solvents and cleaners off my dainty hands, makes clean-up easier, and my hands don't smell like Gunk....