as stated on the main page this engine was overhauled by Pete Fleming, not me, so i don't have my usual array of excessive photography. however, nothing truly mysterious and exotic was done -- it was "simply" treated as it it was a real engine, and received top-notch attention and care, and difficult problems weren't glossed over. i know that doesn't sound sexy but that's where power and reliability come from.
in the months it took for this 2017 build we were able to fairly solidly identify these likely or certain causes of the previous build's demise:
the last two items above were worked out while the build was underway. i bought a stupidly expensive NOS oil pump pressure relief valve spring from which i got exact dimensions so that non-NOS parts can be found or fabricated. NOS tappets were installed in the 2017 motor.
immediately below are some "before" pictures, after the rally and before the engine went to Pete's.
my brief diagnostic partial teardown to see what went wrong. the main visible damage is the bearings, pretty much all of them ruined. crank was scored only moderately. plugs looked OK if a bit lean. plugs are a couple years old here.
this lovely chrome valve cover i believe to be factory, and installed only on 1965 engines, it's final year. it is not vented, unlike all previous years back to 1958. this matters; this is not a PCV engine, decent ventilation was slightly tricky to achieve. (condensation accumulates in the valve cover, since it's sticking up away from engine heat. the faint ventilation of the vented cover controls this.) and as it turns out this shiny thing leaked terribly in the rear.
back in 2010 i had requested, in writing, the previous shop to flycut the deck and head, because i knew there were sealing issues. they belt sanded it. Pete took one .005" pass off the top of the block that revealed the ripple pattern in the deck surface.
partial assembly here. the bottom end. the crankshaft was dynamically balanced. crank and rods are forged parts.
the biggest single change and improvement was modern forged pistons and rings. a decade ago i bought a set of NOS Silv-O-Lite .060" over pistons on eBay, shown here for comparison. those will go back for sale on ePay shortly. the rings are 81mm steel rings for some Honda turbo application i believe. Pistons are Arias.
you'd think the stock valve setup would at least be a no-brainer here, but it wasn't. the previous machine shop botched this, including resurfacing new valves i had bought in 2010, and cut the exhaust seats too deep. pete had to use a larger exhaust valve, which didn't exist, so a Chevy valve was turned down.
you might think that stock-replacement valve springs and retainers would be easy, but no: there are different springs for the OHV and flathead versions of this engine, reasonably enough; the flathead spring is 40lbs closed, the OHV is 80lbs. they look identical. Kanters shipped me 40 lb springs back in 2010. (my receipt shows i ordered the correct part). Pete measures every spring he installs, which was a good thing. they were also binding with what appeared to be the stock retainers. new springs and retainers were found (i dont know what the source is) to solve this. after 50 years nothing can be "assumed".
needless to say there are no (and never were) aftermarket performance cams for this engine. a used cam was reground, but because the base circle is only .010" or so larger than the rough casting increasing lift or duration is not possible. but Pete's cam genius crammed 110 degrees lobe separation into it. it no longer sounds like a lawnmower, idle vacuum runs about 10 In Hg and it pulls like mad.
back in 2010 i took a Foredom and a box of abrasive rolls to the head and cleaned up all of the chambers and ports. they were quite rough.
though this is more of a chassis thing than engine, the exhaust system, which uses the stock manifold, with the center siamese pair equalized (shown here is after disassembly; see the 2010 build for construction detail), had a wide-band oxygen sensor added and the entire thing wrapped in fiberglass tape. this keeps the heat in the exhaust, and not under the hood, in the floor pan, or cooking the brake master cylinder.