P-39q vs. Cannon

[PJ_Godzilla]

You are splitting hairs because I responded to you.....

No. I suspect many have not considered the ingenuity of the motor kanone properly. I'm sure many people, without much thought, think that the bore and the crank Cl are shared. Of course, such a thing is impossible unless you could somehow allow a connecting rod to pass through the bore. The Merlin, of course, has no such problem. But that's why you have to offset the output shaft from the crank centerline in the DB.

For you, though, this does imply a question: what defines the engine centerline you cite? Typically, I think of that as the crank axis, which, as stated before and for reasons above, is not the same as the output shaft axis. That may seem like splitting hairs, but, past life before leadership, I was an engineer. This detail is relevant, and, it's an interesting discussion and one in which you've provided useful input.

[bustr]

I had to translate the manuals to create the presentation. I suppose the dead engineers and writers of the manuals are wrong since they are dead and you are alive splitting hairs.

[Zoney]

I had to translate the manuals to create the presentation. I suppose the dead engineers and writers of the manuals are wrong since they are dead and you are alive splitting hairs.

Roflmao   

[icepac]

P39 gun setup.




Me109 hub gun setup.

Breech.



Hub

[PJ_Godzilla]

Look at either engine pic, bustr. Very clearly, the crank is offset to the bore, both cases.

Thanks for the probative pics, Ice.

I'll try again: there's this thing called a geared hub. In the db, the bore rests in between the cylinder banks. In the Allison, the output is aligned to crank but drives a geared hub. In the case of the DB, the gearing is integral to the engine.

I don't know what presentation you're talking about, but if it's for the convergence, then it's okay, since the offset is irrelevant to the convergence point.. However, if it implies or states that the crank is aligned to the bore, it's just wrong.



But, maybe you're right. This kind of crankshaft this, output shaft that is just so much hairsplitting. You wrote the presentation... anybody home in there, McFly?