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I have a number of aircraft fitted with the Jumo 205 opposed piston diesel engine.      The thing has six cylinders and twelve pistons.      From the standpoint of computing the cubic capacity per cylinder, is this engine regarded as a six cylinder or a twelve cylinder design?      I feel that it ought to be twelve cylinder but I'd like some confirmation before I get the sums wrong.

I have a number of aircraft fitted with the Jumo 205 opposed piston diesel engine.      The thing has six cylinders and twelve pistons.      From the standpoint of computing the cubic capacity per cylinder, is this engine regarded as a six cylinder or a twelve cylinder design?      I feel that it ought to be twelve cylinder but I'd like some confirmation before I get the sums wrong.

How is that possible? You must have 1 piston per cylinder surely?

Zaphod.

Good-old Wikipedia...;)...>>>

http://en.wikipedia.org/wiki/Junkers_Jumo_205

The pistons meet in the middle......!

Paul....with a 180 degree crankshaft twin motorcycle engine 8-)...!

I have a number of aircraft fitted with the Jumo 205 opposed piston diesel engine.      The thing has six cylinders and twelve pistons.      From the standpoint of computing the cubic capacity per cylinder, is this engine regarded as a six cylinder or a twelve cylinder design?      I feel that it ought to be twelve cylinder but I'd like some confirmation before I get the sums wrong.

How is that possible? You must have 1 piston per cylinder surely?

Zaphod.

Good-old Wikipedia...;)...>>>

http://en.wikipedia.org/wiki/Junkers_Jumo_205

The pistons meet in the middle......!

Paul....with a 180 degree crankshaft twin motorcycle engine 8-)...!

LOL.  I deleted my post after doing exactely that! It's amazing the things you find out on this forum.

Zaphod.

Proud owner of a V-twin motorcyle.
Any more cylinders is just plain greedy

I have a number of aircraft fitted with the Jumo 205 opposed piston diesel engine.      The thing has six cylinders and twelve pistons.      From the standpoint of computing the cubic capacity per cylinder, is this engine regarded as a six cylinder or a twelve cylinder design?      I feel that it ought to be twelve cylinder but I'd like some confirmation before I get the sums wrong.

How is that possible? You must have 1 piston per cylinder surely?

Zaphod.

Good-old Wikipedia...;)...>>>

http://en.wikipedia.org/wiki/Junkers_Jumo_205

The pistons meet in the middle......!

Paul....with a 180 degree crankshaft twin motorcycle engine 8-)...!

LOL.  I deleted my post after doing exactely that! It's amazing the things you find out on this forum.

Zaphod.

Proud owner of a V-twin motorcyle.
Any more cylinders is just plain greedy

..we motorcyclists have a natural fascination with our engines... ...!

My first Wife was more than happy with my "engine" for a while, until someone came along with a bigger "engine"....

...apparently... ...!

Paul.... ...!

LOL Paul.

Never heard of a 6 cilinder, 12 piston engine. Learned something today. Thanks for that. And I think it still is a six cilinder design.

Crash (with a V-Twin Honda motorbike)

By nature of it being diesel, and hence ignition by compression (very simply), both pistons in each cylinder would need to be synchronized at TDC and B/LDC - if they weren't you have some very strange effects.

With this in mind, I think you need to effectively "divide" each cylinder in two, effectively making the calculation as if it was for 12 cylinders (well, calculating the capacity of one cylinder with the piston at B/LDC, and multiplying it by 12! )

Thanks Charlie.        Since you and I agree, everyone else MUST be wrong.

I can't gaurantee I'm right though! I've just been logical...

Wow - thank goodness my Pan European's engine is so logical & what about the new Wankel for 'planes ?!!

Wow - thank goodness my Pan European's engine is so logical & what about the new Wankel for 'planes ?!!

..I've been told-off before, for using "naughty words" on the Forum... ...!

Paul... .... ...!

"That" engine has always been a problem calculating the cylinder capacity of the engine....especially for racing purposes... ...!