After a very long night last night and all of today, the bus is running again. There is a very specific order of assembly, and if this order is violated the engine has to come back out to start over. Although this seems obvious, several of the key early assembly parts are not so obvious. Because of this the engine was in and out a few times.

Today I was assembling the cylinders and pistons onto the engine when a piston ring broke. Normally I would be able to go to the local auto parts place and get a replacement ring set, but since the bus had 88mm over-sized cylinders the rings cannot be sourced locally. The 88mm cylinder set is known to cause alot of problems since the cylinder wall is so thin; so I’m taking this opportunity to replace the cylinders/pistons/rings with the standard 85.5mm size. This makes the engine a ‘1600’ (1584cc) again, with the 88mm cylinders it was a ‘1700’ (1679). No changes had been made to the stock cylinder heads, so the ‘1700’ configuration would have needed racing fuel to run with any longevity. The ‘1600’ will be able to run on regular, or at-worst mid-grade.

Today the crank was installed and engine case reassembled.

The new crankshaft arrived today and tonight I began prepping it for installation. The cam gear and distributor gear both were pressed onto the new crankshaft.

Since the engine is out and I’m waiting on parts, tonight was a good opportunity to double-check the cooling system. I found a few problems:

#1 – Cooling air could leak out of the fan shroud near the base of the oil cooler, before going through it. The gap is normally bridged by a piece that’s enigmatically called the “Hoover bit”; I fabricated the missing part of the “Hoover bit” and the gap is now closed.

#2 – Air could leak past the cooler on the sides. To fix this I added foam rubber weatherstripping between the cooler and fan shroud as it would have been done originally.

#3 – Even with everything sealed, the hot oil cooler exhaust would exit a few inches away from the fan inlet. With the extreme lengths that VW went through to keep hot/cold air separated this didn’t make any sense. So I did some research and found that a few pieces were missing that move the oil cooler exhaust air over to the hot side of the engine cooling tins; these pieces are now on order.

Tonight was my first chance to evaluate the bus after the “meltdown” event of last Thursday. I found a few things of interest:
#1 – Loose linkage on cooling flaps
#2 – Incorrectly adjusted valves

When these were corrected it ran perfectly, and I was finally able to correctly tune it to idle slowly, proving that there was some leakage past the valves. It ran very well and had plenty of power, but unfortunately it also had plenty of loud internal knocking, proving that major damage had been done during the meltdown event. So I pulled the engine, disassembled, and found the culprit:

Remarkably, the melted bearings did not damage the block or rod journals and only lightly scuffed the crank. I think the crank is reusable, but since I have to replace all of the bearings anyways this is a good opportunity to replace it with a counterweighted crank. Unlike every modern vehicle, the bus’s original crank was not counterweighted. A counterweighted crank will allow it to run much smoother & quieter, and the new bearing will last much longer than they would with the un-counterweighted crank.

I’m not 100% convinced that the meltdown event was the entire cause of the bearing problems, I found some major pitting in many of the bearings shells that was deeper than the gouging, indicating there was corrosion present. Since the bus has sat with unknown quantities of oil since 1981 this seems logical in retrospect. Also, along with the bearing material there was a lot of sludge clogging the oil screen. This screen had been cleaned prior to running but I think all of the dried oily goop that was throughout the engine case was washed off by the new oil.