Unusual engine cowling for German inline engines …

[Volker_Nemsch]

Unusual engine cowling for German inline engines …
… why were they produced ?

Hello!

While looking through my little library I noticed a special device on some German 2-seaters (as far as I know only on L.V.G. aircraft).

The L.V.G. C.V on the old retouched photo has a streamlined engine cowling.

Most pictures of German 2-seaters show, that the upper part of the engine is normally not covered, exposing the cylinder heads and the push rods to the slipstream. Even Albatros, well known for very streamlined fuselages, did it like this.

Did the hood improve the performance of the aircraft or had it an additional function (maybe collecting blown away oil of the engine for further use - there was such a device existing for rotary engines)? Was it ever used on other German aircraft?

Some profiles with this type of engine cowling can be seen here:

http://www.wingstrut.com/

[R Pope]

Perhaps the increased fire hazard combined with the difficulty of access offset any streamlining gains. At the speeds involved, and given the drag of the rest of the airframe, it would be more trouble than it was worth.

[greenknight]

Originally posted by Volker_Nemsch@Jul 27 2004, 07:50 AM
[b] Unusual engine cowling for German inline engine.....

Was it ever used on other German aircraft?

I can think of at least one other example. Some DFW C.V airplanes used a cowling of this type. Here are links to pictures on Rosebud's site showing 2 examples cowled cylinders:

http://204.83.160.230/archive/images1/DFW.jpg
http://204.83.160.230/archive/images5/DFW_sanke435.jpg

and one without:

http://204.83.160.230/archive/a/images/dfwcv.jpg

The C.V was built by a few factories in various production runs, so I don't know offhand how many would have had the cowl installed when built, or to what extent they might have been removed in service. (Dan-San Abbott has published articles on the production variants of the DFW C.V.)

The Austro-Hungarian builders seemed more fond of the cowled-in cylinder arrangement. A couple of examples that can be seen easily on-line are:

http://204.83.160.230/archive/a/images/wkf_drei.jpg
http://www.rodenplant.com/HTML/026.htm

I would think that field removal such cowlings, or deletion in production would be for servicability reasons similar to those R. Pope has given in the above post. Better cooling in warmer weather is perhaps another:

http://www.rodenplant.com/HTML/018.htm

Regards,

GK

[wingstrutdotcom]

I believe these were removed in the field. The cowl was often removed and left off by ground crews for maintenence reasons. I am reminded of the cowls placed over steam trains in the late 1930's for streamlined looks but were not well liked by maintenence crews and later removed.

I have read that removal provided better cooling of the engine much like many overheat concerns with many aircraft.

I have seen this on DFW CV and LVG CV. I think perhaps some others?

[Volker_Nemsch]

Hello!

Thank you all for your prompt reply.

So the theory is, that the L.V.G. C.V as well as the D.F.W. C.V had these engine cowlings when leaving the factory.

But were the new aircraft still delivered with this device even after it was known that the cowlings were removed at the frontline units? That sounds a bit unusual, especially when you know about the problems concerning all kind of raw materials in Germany after approximately mid-1917.

Who knows more about that?

[SteveS]

Could it have anything to do with protecting the engine and machine guns during colder months? I've noticed Albatros DIII's (Oeffag built that I've seen), Hansa-Brandenburg DI's and Aviatik D.1's with these cowlings or "hoods". Of all the photos and profiles I've seen, I think all if not most were used by the Austro-Hungarians. Surely they must have had some harsh conditions.

Salute,
Steve

[Dan_San_Abbott]

Volker:
All DFW C.V (all mfrs) and LVG C.V were delivered with the aluminum hood over the engine. Both aircraft were designed by the same engineer.
The hood would of had a lower drag factor than the exposed cylinders with all the parasitic drag producing rocker arms push rods, valve springs air pumps bolt heads intake manifolds, etc. The hood was designed to maintain a specific operational engine temperature. I seems that some units removed the hood to possibly improve the view in front.
The louvers on the hood both injected air to aid in cooling and to exhaust the hot air.
Blue skies,
Dan-San