54 Cadillac V-8 Finish Assembly
With our 54 Cadillac 331 cid V-8 engine rebuilt, along with accessories and engine compartment detailed, we are test-fitting all engine parts before assembly. As we have covered in pre-vious articles, the Cadillac s 331 overhead valve V-8 premiered in 1949, replacing the long-lived 346 cid flathead V-8. The new V-8 was nearly 200 lbs. lighter, had 10% more horsepower, more torque, and delivered 14% better gas mileage. Owners were divided over the merits of the new 331s, saying that the flatheads were quieter, smoother-running engines. But by 1949, the V-8s were here to stay, had more power growth potential, and were able to handle all of the new power steering, air conditioning, and accessories that were starting to be added to the cars. The early 49s were tough engines, but not without their faults. Hard starting was a problem, due to a voltage drop upon starting, caused by a problem in the wiring harness. This was corrected in the late 49s, along with new, thicker heads and new piston design. Improvements continued being made each year, making this one of Cadillac s most reliable engines. In 1953, Cadillac introduced air conditioning. This was a large R-12 unit with a large, thick condenser in front of the radiator, lines running to the evaporator in the trunk and two blowers directing air into the car via ports in either side of the rear deck. There were no vents in the front, so on the four door models, there were green plastic distri-bution tubes which ran from the rear air ports forward along the headliner that dropped cold air onto the appreciative driver and his front passenger. The overall system worked ok , but since the condenser was blocking airflow through the radiator, and there was very limited airflow in the en-gine compartment with its wall-to-wall accessories, the engine could heat up in traffic with the a/c on. In1955, Cadillac came out with a new water pump which had 1 water ports, compared with the 49- 54 which had 1 ports. The head and block ports were increased to match the larger water pump ports, and a new plastic 6-blade impeller with thicker and rear-angled blades were added to the water pump. Our 54 is an original air car , and we experienced the overheating in traffic. Our solution was to change to a 55 water pump, but to use a cast iron impeller (the plastic ones are known to fail and start slipping on the bushing), and to increase the size of the 4 water ports: 1 in each head and 2 in the block. We used a die grinder with a carbide-cutting bur, putting a gasket over each port with bots to hold them in place. This formed a template showing us how much ma-terial to cut away. With their new pump, Cadillac s 55 Shop Manual Update indicated a 15% in-crease in water flow at an idle. To further increase water flow at an idle, we added a smaller pulley on the water pump (6 instead of 7 original size). This pulley came off of an 82 Buick V-6. The only modification was to press the fan bolt hub in about 1/8 . This allowed all belts to align up.
Another problem was hot starts caused by the starter and solenoid being right below the exhaust manifold, a common problem also found in small block Chevys. To remedy this, a starter heat shield was made using 16-gauge steel. First we measured the starter front to back, using the rear starter bolt for one tab and adding a threaded stud bolt to the front of the starter to lock down the other heat shield tab. The shield was made by drawing out a rectangle of the exact size, then drawing a series of horizontal lines front to back about 2 apart. Using a metal brake and slightly bending on these lines, a gentle roll was given to the shield, then the front and back bolt tabs were welded in place and test-fitted to the starter. The piece was then metal prepped, acryli-cleaned, primed and painted semi-gloss black with high-temp paint.
In these engines, the oil pump/vacuum pump is in the oil pan. The vacuum part rums the windshield wipers, so once the engine is in the car, you can t remove the oil pan without lifting up the engine. So with the engine on the worktable, now is the time to test the pump. We closed and plugged all oil lines except for the manual gauge, and hooked a vacuum gauge to the vacuum line coming from the pump to the windshield wiper motor. Restorer Charles Butts made an adapter to fit the distributor shaft and fit it into our drill. The distributor turns counter-clockwise, so he turned the drill to run in reverse. The oil pressure cane up and the vacuum pegged at a30 lbs.+. There should be no surprises when we hook it up in the car.
We also test-fitted the carburetor and generator, and replaced all thread worn bolts. Upon deciding to replace the motor mounts, we discovered that our engine had the wrong mounts! The 49- 56s had the thin-type mounts and the 57s had the wider type mounts. Somewhere through the years, 57s had been put onto our car. You can never assume anything is right when working on any car. Factory manuals and parts books are a must! We will soon be putting the engine back in the car.
Concerning our door project from last month, we have put the newly painted passenger door on, and will feature it next month, showing rubbing out the paint, and window and rubber in-stallation. Keep em driving!