DID YOU TRY DUSTING IT WITH CORN STARCH...

Trying to keep a radial engine free of oil leaks is a never ending chore.  It might stay nice and dry for a couple of months, then bingo!  Another bolt has worked the tiniest amount loose.  Still, the P&W R-985 450 Wasp is quite a reliable engine.  Just keep a metal pan on the hangar floor to collect the ounce of oil.

There's not enough cornstarch, besides, it's not a good idea to treat an aircraft engine like that.  Aside from the mess the cornstarch would make, it's not that easy identifying from which cylinder the leak is emanating with all the finned cylinders and heads.

Just something to put up with as long as it's not serious.


Courtesy Pima Air And Space Museum  ↔

Model: R-987-AN-14B
Type: 9-cylinder, air-cooled, supercharged radial
Displacement: 985 cu.in.
Maximum rpm: 2,300
Maximum hp: 450

That is just like the Macks and Detroits, they mark their territory same as any good dog does!

Old saying about Dakota - " If it doesn't leak, there is no oil in that engine"

Corn starch only sticks to the oil, and changes color.
It will dust off the rest of the engine and leave a trail showing the path the oil is taking, back track it to the location it is coming from.
NOT a hard trick and not that dusty..

Dusting it off, is the developer stage for the Dye Penetrant Method in Non Destructive Testing or Inspection. The first steps are to wash the part thoroughly in a clean solvent, dry it, apply a dye penetrant, after a specified time wipe and dab the part {machine} clean, then apply a developer dust for the penetrant to be absorbed into the developer to highlight the discontinuity, ie. non conformance. Technicians are not allowed to call it a crack, only a graduate P Eng. or a Third Level Tech. with a visual ticket has that authority.
On occasion when not working as a paid technician but in another trade, I have seen cracked wheels where a little road dust high lighted the wheel bearing oil weeping out of what you and everybody else knows damn well is a crack in a hub! If the surface configuration has a crack like jagged edge and is not a smooth line it probably is a crack. If the workpiece in question has several component parts bolted or secured together and the "developer" powder shows an "indication" at the junction of the mating surfaces, then there is a leaking seal or loose bolt(s), etc. The operator / inspector / user, has to use intelligent judgment as to the meaning of the visual indication(s). The first and most important step is to clean the part properly followed by using a written known method and clean, fresh reagents, before making a sound rational judgment about any and all indications. Until the proper steps are followed, all comments are just guesses. Depending on the true nature of the leak source, lives can and do hang in the balance especially if it is aeronautical.