C-97 Still Losing Engines!

[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.

[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.

[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

[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]

As for the ignition analyzer, i.

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

best, randy

[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

[Jase Pence]

See, Russell, there you go again, making me think!! This is an example of something that had *never* even occurred to me. Hmmmmmm. This has some promise. Any software genius types hereabouts?

I want to clarify my "rant" about Keyboard Kommandos, earlier. That was certainly NOT aimed at anyone here on the 'sig.... it was a grumpy rant about some of the self-appointed experts on the Book of Faces. Apologies if anyone thought it was aimed their way, it definitely was not. And, as far as "spirit intended", absolutely. I wouldn't have posted, especially in detail, if I hadn't been seeking inputs and thoughts from folks whose experiences are in some ways similar to mine, but in other ways are far far greater than anything I'll ever be involved with. For the record, I value the heck out of *everyone's* comments and opinions here.

So, thanks, and keep up the questions comments and especially the prayers for our sanity (or demonstrated lack thereof!! )

Best
Jase

And thanks for taking the suggestions in the spirit intended.

As for the ignition analyzer, it seems with today's computing power, it should be possible to have a computer keep an eye on it for you. I'd think the technology exists, the trick is to find the people capable of it.

[Jeff Hartmann]

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)

[Reams Goodloe]

http://www.enginehistory.org/Operations/R-4360Ops/r-4360ops1.shtml

A bit if interesting operational history here....

Reams

[Russell Holton]

All good questions though, keep em coming. They make *me* think as well

And thanks for taking the suggestions in the spirit intended.

As for the ignition analyzer, it seems with today's computing power, it should be possible to have a computer keep an eye on it for you. I'd think the technology exists, the trick is to find the people capable of it.

[Randy Sohn]

Dunno what was special about *that* nose case versus any other T-34

Jase, dunno either, meb'be the "inverted" V/S "upright" deal? Still recall once on our merry way to V/N in our 97 and overheard on HF that C-133 not answer and disappear, never heard from again.

At any rate, Clay and I were both BS'n and wondering the last time I was out there in Van Nozzle about whatever happned to Jack's SG. Now we can remember, thanks. Clay was my upperclassman in cadets but he was Cal. ANG on active duty.

BTW, need your E-mail address.

best, randy

[Jase Pence]

Ah yes, the C-97J "Turbo-Stratocruiser". Think they built 2 of them, I know most of one (and the T-34 turbo props) ended up on Conroy's Super Guppy. Built as test beds for the C-133 engine. As an aside, I was told by one of the guys at Ellington that maintained the 377SG, the only reason NASA retired it to Pima was a lack of spares for the props and the nose case. Dunno what was special about *that* nose case versus any other T-34. I do know the inboard props were like 1 foot diametre smaller than outboard ones tho.

Randy, I feel honoured that you have that much faith in my mechanical abilities.... but I think a turboprop conversion is more than I'm comfortable undertaking!!

Best
Jase

[Randy Sohn]

there may well be something utterly simple that we've missed!!

Chuckle, 'fraid there is! They did it to one 97, saw it once down at Kelly or Reese or somehere else down around San Antone or LBB. Gen. Gerrity's airplane, converted to turboprops. Can't recall now, what were they? T-what's?

And re that 500 gph fuel factor, concur.

best, randy

[Jase Pence]

Yes indeed, we have definitely given this subject *much* thought. The first thing is what Ralph mentioned, it's a terribly complex thermal distribution. Different metals, multiple rows of cylinders, and so forth. The second thing is, "the nature of the beast". In Graham White's wonderful book on the R-4360, I believe he mentions just how many "moving parts" there are in a -4360. Taking into account bearings/bushings etc, I think the number is like NINE THOUSAND moving parts within a running R-4360. With that many parts flinging around, it doesn't take but ONE small issue to quickly cause other issues.

Another issue, that we have talked at length with people *much* smarter than me about; is the metallurgy of the time. Ray Anderson is convinced that some of the bearing metallurgy was *not* the best, or maybe was sub-standard from new (low-bid suppliers mebbe?). There is no doubt that today's metallurgy, aided by computer simulations of stresses etc, is orders of magnitude better than what was "state-of-the-art" in the late 40s and 50s.

Lastly, and this is something ALL of us vintage plane operators are faced with, is that at the newest, we are using stuff that's 50 years old. (Yea, I know, there are some new build engine parts for some specific popular engines but that's an exception). As well as it was designed when new, I can't help but think that the engineers at Boeing, or Pratt & Whitney, or Allison, would be blown away that we are still operating their stuff 50,60,70 years on...especially when their design parameters were probably a 5-10 year "useful life".

We are talking about chip detectors...the problem there is that once something makes metal, that metal is distributed thru the oil system damned rapidly. There is also the "Chinese TV", the Bendix Oscilloscope Ignition Analyser, that in the hands of a knowledgable engineer can see such problems.... My big issue with the analyser is that looking at the analyser takes my eyes off the panel, looking for other issues. Plus, we aren't doing "long hauls", most of our flights are going to be less than 2 hours in the air, we figure....except for special stuff like Osh, S&F and so on. The sad reality is that while airshows on the West Coast might want us, they tend to choke at the 500+GPH to get us there....

All good questions though, keep em coming. They make *me* think as well, and I'm sure not perfect, there may well be something utterly simple that we've missed!!

Best

Jase

I'm mildly curious about why that is. About the only activities I can think of that regularly goes though engines is drag racing, tractor pulls, etc. In their case, it's understandable. Why something that's being run within it's specs is doing it is curious.

To protect future engines, have you thought about how to detect problems and shutdown before the block goes? Perhaps chip detectors in the oil?

[Randy Sohn]

the Martin Mauler as well as the F2G "Super Corsair"

Wow1 Yup, you be 100% correctamundo! Twuz the Mauler, only ever saw one, it was down in Lubbock with Gerald Martin. And had forgotten about that Corsair that Steverino had come to grief with.

best, randy (sure happy to hear about Fuentes!)