Perkins 4.108M: The Teardown
Disclaimer: Not too many pics here -- greasy, grimy hands and digital cameras are a bad combo.
I took my time disassembling the engine, giving all of the parts a first-pass cleaning as they came off to get the majority of the grime off. I kind of used a wide variety of cleaners, together with brass, stainless and regular tooth brushes. Spray Nine did a god job on light dirt. Purple Power was a little better, but plain old mineral spirits was probably the most effective and gives the best bang for the buck. For cleaning non-threaded fastener openings, I bought a cheap gun cleaning set from Wal-Mart; the bore brushes included work well for holes up to 3/8". For the larger holes I laid on a set of pipe cleaning brushes from the plumbing section of Lowes. For the nooks and crannies I broke out the dental tools.
I hit all threaded openings (and fasteners that were still in good shape) with thread chasers.
Each assembly went into its own ziplock bag, complete with fasteners. Those assemblies that were too big for bags were wrapped in packing stretch film. I gave all the iron parts a quick wipe down with ATF or WD-40 first to keep rust at bay until the engine goes back together.
Getting the cylinder head off was a bit of a struggle. I had to use some wooden door shims between the block and the head to get them to come apart. Once the head was off, I saw why. Several of the studs had developed a decent layer of rust, which kind of jammed things up.
All in all, I only had to hit a half-dozen or so fasteners with heat to get them out. The cheapo propane torch definitely came in handy. A couple put up real fights, but they eventually came loose. Repeated applications of PB Blaster, heat, and perseverance eventually won the day.
Several of the head studs are getting a little pitted...
Some of the fasteners are just not worth saving. Here's what most of the bell housing studs looked like. It'll be much better/easier to just replace them.
Getting gasket residue off is time consuming. For small parts that came off the block, I chucked a brass brush into the drill press and let the machine do the hard work. For the bigger parts, it was a combination of tools: a putty knife I put a chisel point on; utility knife blades; safety razor blades; and an old putty knife blade I had sharpened like a card scraper.
Clean mating surfaces:
The broken damper plate bolt eventually came out. Initially I drilled a hole for the easy out only deep enough to get the threads to bite, then let it soak with PBB. No joy... Heat, then more PBB and soak a couple of days; still no joy. Eventually I drilled completely through the length of the bolt so that the torch flame would get heat to the whole part -- JOY!
Next Chapter: Measurements