Engines & Turbo System
Welcome to the engine and turbo systems section, a complex and intriguing topic. Everyone who hears the roar of the big turbo prop engines can not mistake the sound, the B-17 power plant incorporated with the 1200 HP engine built by Studebaker and designed from Wright Cyclone. The depth of the engines and back ground deserves its own entire section, therefore we will stay with what was recovered from the site, with reference to the assembly involved. In this section I will cover the engine parts found, turbo chargers, Tubo coolers, filter, air ducting, amplifier for the regulators, and engine covers.
So what have we found, first to mention was the key piece in identifying the wreck as Bull Session for 100%. In the Missing Air Crew Report (MACR), all engines are listed by serial number. It is very important to identify the wreck as the correct aircraft, the engine data plate is one way to help. The engine tags or data plates were a priority in the initial search of the wreck zone to identify the wreck positively without doubt. I knew the serial numbers of each engine, and only hoped to find proof. In the first days of searching the fields I never dreamed it be possible to find the engine ID plate right off, but it happened, I had found a very mangled data plate belonging to one of the engines, but the entire number was not present, within two weeks I had the other half of the data plate and the complete number, that indeed match the serial number on the MACR. The site was therefore proven to be Bull Session. There is always the possibility that the engines had been swapped out and not recorded correctly, but when you find three out of four with the recorded numbers, its pretty good odds you have the right aircraft.
A
B
This is the original engine data plate in the condition found. Great care was taken to open the tag to read the complete number. The left side was slightly bent as compared to the right side that was completely folded, but contained the rest of the number and had to be unfolded carefully. This is done with slowly heating and slowly bending, Aluminum will break easily when bent cold, but this does not mean it still wont break when warm. In the right photo, (A) points to a sliver of shrapnel from the flak, (B) points to the SW-0.
Left photo shows the data plate after flattening, photos below show the detail of the numbers and lettering that proved it to be the engines SW-030481 from Bull Session, which were then compared to the MACR.
A second data plate later found in the deposited dig, was from another engine and was still attached to the engine sump face. It too was compared to the MACR and was a number match. Now there were two seperat engine ID numbers to positively identify the wreck, but there would be more evidence in and around the engine.
The only cylinder found of the engine also exhibits the serial number of the engine on the intake valve box chamber, Serial # SW 030457. That makes three confirmed engines serial numbers, and pretty much confirms the wreck as Bull Session.
The only engine, or lack of, that was found, was the engine-back plane. The back-plane is where all the engine system components are located, that is the left/right magnetos, starter, generator, fuel pump, vacuum, oil pump and filter, the mechanical tacheometer and ignition wiring harness leads. The comparison here is what was found and what is the norm. Also shown and found is the Stromberg carburetor. Two out of four carburetors were recovered.
