C-97 Still Losing Engines!

[Jase Pence]

Reams; Thanks! I had missed that article, some very good info there, and also verified how we are operating as being how ANG ran their birds. Based on that article, that lends credence to my "gut diagnosis" that we lost a scavenge pump. In about 90 seconds or so, the engine swallowed ~23 gallons of oil... then puked it out the breather. :/ When I drained the sumps, probly 5 gallons came out the scavenge sump ..... a gallon or so ended up on me. Even my socks were oily!!

Randy, email is moparzAT hotmailDOT com. Are you still using the NDPER email address?

Best
Jase

[Randy Sohn]

As for the ignition analyzer, i.

Chuckle, we always called it the "Chinese TV".

best, randy

[Randy Sohn]

[QUOTE lost a scavenge pump. In about 90 seconds or so, the engine swallowed ~23 gallons of oil...............Randy, email is moparzAT hotmailDOT com. Are you still using the NDPER email address?[/QUOTE]

Chuckle, THAT was the exact reason I had to shut down that #3 just past ETP that day, coming back from VN. IIRC, we called it the "G rotor pump".

best, randy

[Randy Sohn]

how ANG ran their birds

When we first got the 97s, we got 10 of them from Travis AFB, C-97A models, along with the MATS mission. Now they refer to it as MAC. The 109th had previously been a F-89 Scorpion unit wirh an ADC mission. Several years later we got the C-97Gs and took out all the tanker stuff (boomer station, tanks, etc.) and dumped all of it out back (but kept those squealing brakes <g>).

best, randy

[Russell Holton]

Based on that article, that lends credence to my "gut diagnosis" that we lost a scavenge pump. In about 90 seconds or so, the engine swallowed ~23 gallons of oil... then puked it out the breather. :

Sounds like something that should easily be detectable with a pressure sensor (or would it be a level sensor) in the right spot. Some of the modern liquid sensors are interesting. Ultrasonic, capacitance, etc. Lots of stuff not available to the original engine builders now as close as a Grainger catalog.

[Russell Holton]

Edit: After looking up radial engine oil systems (Great googly moogly!) I suspect what's desired is to know if a scavenge pump is falling behind. Oil pressure may not be a good indicator, but scavenge oil level might be. I suppose you could monitor the main oil tank and have an alert if the level falls too quickly. (23 gallons lost in 90 seconds - it doesn't matter why, I can't see engine continuing to operate.) At least that would be one sensor well away from various engine parts flying around in all directions.

Perhaps a simple way to implement is 3 levels sensors: Yellow, yellow, red. If a yellow one comes on, you need to keep an eye on it. Second one, you've got a problem. Red, shutdown. I'm sure there's always a bit of hesitancy if a single light comes one - especially if it's a new system. But if two are on and while you're wrapping your head around it, the 3rd comes on - there's no doubt.

I wonder if this results in something like what happens when you really overfill a V-8 and the crankshaft hits the oil. That's going to be ugly. By the time it shows up on the ignition monitor, I'd think the engine would already be hurting.

[Randy Sohn]

(23 gallons lost in 90 seconds

Try'na recall now what we had in each oil tank on the 97s - 35 gals.? Anyone remember/know?

best, randy

[Bruce Gorrell]

Try'na recall now what we had in each oil tank on the 97s - 35 gals.? Anyone remember/know?

best, randy

I suspect it was more than that. We have 40 a side with only 2/3 of the cylinders. And MUCH less range.

[Randy Sohn]

suspect it was more

Just can't recall for sure now, tho I did forget to mention the spare oil tank we had down in the "hellhole" beneath the cockpit's floor. IIRC, it had an 80/90/135/?? gallon capacity that the F/E could tranfer/pump to any engine via a selector switch on his panel.

Longest leg I ever flew was one from London to Goose via Stephenville (Harmon), 15+45 IIRC, deadheaded over to Mildenhall, England to get and return one that Bobby had left over there for an engine change. IIRC again, it was 48-0607 ("Sick-ole-seven" we always called it).

best, randy

[Jase Pence]

Try'na recall now what we had in each oil tank on the 97s - 35 gals.? Anyone remember/know?

best, randy

Randy, my -1 for ours sez 32.5 gallon capacity, with 7 gallon expansion room for the nacelle tanks. We have 2 fuselage tanks, each holds 56 gallons with 2 gallon expansion room. There's a 7gpm pump that transfers oil from each fuselage tank (one pump per tank) to any of the nacelle tanks in flight. So, total tank age capacity is 242 gallons if everything is full to the scuppers. I'm told that on long trips, they used to carry an extra barrel or two to replenish the fuse tanks. According to Pratt's engine manual, *accepted consumption* is 1.5 to 4 gallons of oil per hour per engine.

best
jase

[Jase Pence]

Randy, could your G rotor pump be "gerotor pump"?

http://www.pumpschool.com/principles/gerotor.asp

Getting into the engine manuals here, there's 2 oil pumps, front and rear. The front has 1 pressure compartment and 2 scavenge compartments. Rear pump has 2 pressure compartments and 3 scavenge compartments. Still looking for a picture of one of these creatures, but good grief!! Well hell, everything *else* on the engine is huge....why shouldn't the oil pumps (!!) be proportional?!??

Best
Jase

[Randy Sohn]

my -1 for ours sez........per hour per engine

Ho-boy, mucho gracias, all my -1s for the As, Ds, Fs and Gs have "gone west" somewhere, used to have them and now I know why! Anyhow, guess that I never had seen it written down so I really dunno, only heard it pronouned. 56 gallons rings a bell with me. Our Gs had been tankers somewhere before we got them at the MN ANG and while on active duty during the Berlin crisus I'd been sent down to the ANG unit at Savannah once for several months to instruct and that's where I flew the Fs. Spent a lotta time flying and instructing and examining in them but just never thought any more about it.

best, randy

[Terry Carraway]

What is/was the failure mode of the scavenge pump?

Maybe a chip detector down stream of each one to see the bits starting to come off.

[Jase Pence]

What is/was the failure mode of the scavenge pump?

Maybe a chip detector down stream of each one to see the bits starting to come off.

Terry, other than the engine swallowing great quantities of oil quickly, and EOP going down (EOP stair stepping down happened first, quickly followed by oil quantity dropping, fairly linearly. Feathering was iniatiated shortly thereafter) I have no idea what broke/let go first.

I told Tim that when we swap engines, I'm taking the shelled out one home for some "forensic investigation " . Luckily I have wreckers, to get 5,000 lbs of engine into my basement

I'm also contemplating a "Reno style fundraiser". So much for a piston, so much for an empty cylinder.... but I *really* want to know what shelled first and how to prevent it going forward.

Best
Jase

[Jase Pence]

Saw this at Reno last year....

As soon as we get the rocker covers on we'll be ready to run. (remember the IO-720 lycoming was 2 1O-360s so why not 2 4360s)

I want you to know, Jeff, that this picture has given me nightmares... cold sweats.... and possibly a plague of locusts in the garden!! Geeezo Pete. "If 28 cylinders are good, 56 must be great!!"

Did it actually run or was it an empty mockup for giggles?

Best
Jase