Warbird Information Exchange

First of all, congrats to all of the participants in the FiFi project with the achievements so far. In my humble, layman, opinion, it is no less that impressive.

I think this must be the place to get the little knowledge I have about radials 'aligned'?

[ As tech English is not the easiest English to handle, please excuse me, if I use the wrong technical term ]

As I understand it, the crankshaft/connecting rod bearings in the bigger WWII radial engines were/are plain bearings?

And there is a lubrication duct in the crankshaft, so that the lubricant always will enter under the 'loaded zone' of the connecting rod?

Is it possible to say anything about the load on that bearing? Must be huge? Guess that no lubricant results in an almost instant seizing up?

Take care

J

[Edit: Rephrasing]

_________________
Laughter is the closest distance between two people. (Victor Borge) - To err is human, to forgive, divine (Alexander Pope)

My books: https://www.goodreads.com/user/show/14115381-jesper-jorgensen

Yes the bearings are plain with about .002 inches of clearance. The oil film is enough to cushion the load. When there is a negative torque on the engine, the oil hole is not in alignment with the load. That causes the bearing material to rapidly wear away. A negative load on the engine is caused by a low power setting and the propeller attempting to turn the engine.

The clearances run more like .004 to .008. Kinda why SAE 60 oil is used.

We use AeroShell 120

_________________
Those who possess real knowledge are rare.

Those who can set that knowledge into motion in the physical world are rarer still.

The few who possess real knowledge and can set it into motion of their own hands are the rarest of all.

which is SAE 60

_________________
Matt Gunsch, A&P, IA, Warbird maint and restorations
Jack, You have Debauched my sloth !!!!!!
We tried voting with the Ballot box, When do we start voting from the Ammo box, and am I allowed only one vote ?
Check out the Ercoupe Discussion Group on facebook

If it was actually 120, you'd have to chisel it out of the barrel

_________________
Those who possess real knowledge are rare.

Those who can set that knowledge into motion in the physical world are rarer still.

The few who possess real knowledge and can set it into motion of their own hands are the rarest of all.

Lube oil into any bearing is never into the loaded zone, its the no load area, and then it wedges into the loaded area. As pressure increases on the oil it increases viscosity, thus helping separate the surfaces better.