German V-8's

[R Pope]

How did the Germans, with all their technical bent, miss out on the V-8 configuration? They tried it ( 190 Benz, for one) but had no luck, vibration and crankshaft failure being common problems. Sounds like they were using a single- plane crankshaft to me. This sounds like a good deal on paper, but lots of the hot-rod guys have tried it on Hemis and small-block Chevvies and had the same problems. Was that the reason? Looking forward to your replies.

[jumpinjan]

I'm not that familiar with the V8 Benz, I know the V8 was tried in the Junkers J9 at one point because of the scarcity of the big inline 6s in 1918. The flat plane V8 could be visualized as using a 4-cylinder crankshaft with two 4-cylinder engines (set at 90degrees) sharing each crankpin. There are some secondary vibration problems. The cross-plane V8 uses additional counterweights to reduce all vibrations to almost zero. Check out this link:
http://autozine.kyul.net/technical_s...ne/smooth4.htm
Pretty interesting stuff. Thanks for bringing this up. I didn't realize that there could be a difference in V8 configurations.

[fltmech]

I know ford was late in getting a V-8 out due to crankshaft failure. the flat plane V-8 sounds similar to some of the early 12 cylinder engines, 6 cylinder crank, with two cylinders sharing. 30 degree V though.

[Dan_San_Abbott]

R Pope:
The impetous to develope a V-8 engine came after capture of an intact S.E.5a, B507 in October 1917. Idflieg took serious interest, in the 200 hp Hispano Suiza geared engine that weighed 440 lbs and put out 200 hp versus the 180 hp Mercedes D.IIIaü that weighed 627 lbs. several were approached to develope a comparable V-8 engine. Argus cam,e up with the As IV, 225 Ps, Mercedes D.IIIb, 195 Ps, Benz Bz.IIIb 195 Ps,and the 500 Ps V-12 Bz.VI engines, Körting, Kg.III 180 Ps and the V-12 KgIV 245 Ps engine, and Oberusel U.IV 230 Ps V-8 engine. The Benz V-8, both geared Bz.III bm and direct drive Bz.IIIbo engines appeared at the second Fighter Competion May-June 1918 in the Alb.D.X, Av.D.III, Fok.V.27, Pfalz D.XIIa and the LFG Roland D.VII.
In the fighter evaluation in July 1918, The Benz Bz.IIIb and the Bz.IIIbm engines were used in the same machines, LFG brought two Rol.D.VII, one with the geared Bz.IIIbm and Rol.D.VII with the ungeared Bz.IIIbo engine.
In the third Competion, October 1918, the V-8 engines were excluded from the competion. The V-8 were not ready and required further developement.
Blue skies,
Dan-San