When you're approaching the end of a project, the anticipation runs high and you can't wait to see it all come together. Although we had some assembly left on our straight 8 engine, we were getting close to starting!
ASSEMBLY: To install our pistons, we applied oil to the cylinders, rings and upper bearing shields, then compressed the rings with a ring compressor, tapping #1 and #8 pistons into the block together (becasue the crank journals are up at the same time). We made sure the journals were up, because the rods were wider than the space between the counterweights. To protect the rod bolts, we slipped rubber hose over them as we tapped them down, then rotated the crankshaft a little, tapping the pistons as we turned, until they were all the way down. At this time, we oiled the other half of the bearing, screwed on the uts, torqued them, and put in the cotter pins. We repeated putting in the pistons, two at a time, until we had all 8 of them in. With the short block assembled, we installed the pickup tube assembly with our NOS pickup tube from John Ulrich Packard Parts, and bolted up our freshly-cleaned-and-painted oil pan, using a new reproduction cork anda rubber gasket with Permatex 2-B on the pan side, so if it needs to come off later, the gasket will come off with the pan and not stick to the block. We always use a quarter-inch socket set, in order to not over-tighten and distort the pan. Joe Rabelskie did the machine and head work at his shop "Motorvation", resurfacing and cc-ing the chambers on the head, taking off ten thousandths from the surface and bringing all chambers to 116cc (there had been a .007" difference between the largest and smallest chamber). CC-ing will enable the engine to run smoother with a more balanced idle.
At last it was time to put the head on. With the studs already in and the block checked with a straight edge, we cleaned the block and head with solvent, dried it off, positioned our NORS steel gasket and put on the head. Following the proper torque sequence listed in the Packard manual, we torqued the brand-new chrome acorn nuts and washers to 42 foot-pounds, then to its final 62 foot pounds. Later, we will do it again after the engine runs at operating temperature for a while and then again at 500 miles.
With the engine still jacked up from putting on the pan, now was a good time to replace the rubber front mount. We lowered the engien and bolted the bottom of the mount to the frame and bolted the nOS water pump on using copper washers on the bolts that have water behind them to prevent leaks. When we put the side covers on, we decided to make our own gaskets out of a quarter-inch sheet of finely ground cork/rubber combination, available from Napa AUto Parts. This thick material allows the covers to be tightened down without worrying about them bottoming out on the block and causing leakes later on. (Some gaskets are made from coarsely ground cork, which can cause the gasket to break apart easily under pressure). We bolted the covers down using rubber coated washers and the original style copper washers over them. They don't leak and they look great.
Next, we put on the intake and exhaust manifolds, which had been shot-peened for rust removal, leaving a smooth finish for painting with our hi-temp cast paint. Of the many types of gaskets available, we decided to use a gasket sandwiched in steel. We have had better luck with that type not burning out. They also have sleeves built into them to hold them into position while lifting the manifold on. The '41 356 still retained a drip tube (a carry-over from the '30s). We decided to cap ours off. When the engine is shut off, excess fuel would drain onto the garage floor, creating a dangerous situation. In later years, Packard did away with them. We'll keep it capped for now and see if any starting problems develop later on.
Next, we hooked up the radiator, hoses, generato and fan belt, bolted on the new fuel pump and carburetor, bent new lines and installed the heat shields, starter and exhaust pipe.
Upon going through the distributor, we tested our vacuum advance and found it needed to be replaced. We had a NOS one, but they can be rebuilt. We installed new points and condenser, distributor cap (we like the ones with brass contacts) and rotor button. When we unscrewed the distributor's grease cap, we discovered that 60+ years of use had not been kind to the threads. Several were flattened. Using a thread gauge, we determined the thread count, re paired them with a thread file, then filled the cap with grease and easily rotated it inward to grease the distributor shaft. At this point, we put the harmonic balancer on 4 1/2 degrees before TDC compression, installed and wired the distributor, rotated the distributor until #1 wire sparked, and primed the carburetor.
The engine was really looking great and we were close to starting it up. All that was left was to hook up an auxiliary gas tank and a hot battery. Using our remote switch, we cranked it over a few times, then it started. Sweet! We heard an intermittent clacking sound and knew immediately that it was the hydraulic valve lifters. Checking the oil pressure using a remote gauge, we found it showed slightly low pressure. We shut the engine off, pulled the oil pressure spring out of the oil pump and checked its length and resistance, finding it a little weak. We inserted 2 flat spacer washers into the spring cup that holds the spring into the oil pump. That gave us the right tension and the right length in the spring, which we reinstalled into the pump. (We will replace it with a NOS one later on.) Our oil was 10W30 detergent. The book calls for straight 30 weight, so we went back to straight 30 weight detergent oil. When we re-started the engine, the oil pressure came up to 55 pounds at driving speed, and about 24 pounds at idle (hot). All of the lifter noise was gone, but we heard a squealing noise coming from the rear of the engine. WHAT???? We got under the car adn quickly round that the problem was the throw out bearing, dry from sitting. When we pushed the clutch down, the noise went away and the engine sounded smooth and quiet, running at 180 degrees. We were really happy with the results. It was worth the wait! See you next month when we start on the suspension. Keep 'em driving!