Why did the Ju-87 Stuka dive bomber use an inline engine rather than a radial engine?

[historygeek2021]

Most dive bombers and ground attack aircraft in WW2 used radial engines rather than inline engines because the radial engine stood up better to ground fire, whereas even minor damage to the radiator on the underside of a plane with an inline engine could prove fatal.

The two other major users of dive bombers (the USA and Japan) both used radial engines for their dive bombers. But as far as I can tell, the Luftwaffe never switched over to radial engines for the Stuka.

I've done some searching but can't find any explanation. Anyone know more about this?

[Carl Schwamberger]

Short answer is that was all that was available for the designers and builder of the Ju87. German engine manufacture did not have a lot to offer the aircraft industry in the 1930s & some tough choices had to be made in allocating items. Politics and a degree of mediocre leadership played their roles as well. By 1940 the over all design of the Ju87 was recognized as obsolete & a replacement was seen as making more economic sense than trying to upgrade the Ju87 in any large way.

Note the Curtiss BFC-1 Hawk had a radial engine. This was the US aircraft Udet purchased in the US to test its notable diving capability against ideas for a dive bomber then circulating in Germany. So its not as if the Germans were unfamiliar with radial engines on aircraft with a extreme dive capability.

[Ironmachine]

So its not as if the Germans were unfamiliar with radial engines on aircraft with a extreme dive capability.

And in fact both the Heinkel He-50 and the Henschel Hs-123 used radial engines and were designed as dive-bombers, and the Junkers K.47, which also had a radial engine, was used in dive-bombing trials.

[ConradM]

Hi
I think its because Junkers made good inline engines as part of their business (Junkers Motorenwerke/JUMO), and put it in their product.

[Denniss]

for near vertical dives it was probabyly not good to have a fat radial in the nose, hindering both sight and bomb release.
Plus the then-available radials were not realy powerful but V12 engines of the 1000PS class were in development.

[Thumpalumpacus]

for near vertical dives it was probabyly not good to have a fat radial in the nose, hindering both sight and bomb release.
Plus the then-available radials were not realy powerful but V12 engines of the 1000PS class were in development.

Radial engines didn't seem to hamper the naval dive-bombers used by several countries. I'd imagine they'd help keep diving speed a little lower, which would aid accuracy, as well as (noted by the OP) be more robust dealing with small-arms AA.

[Denniss]

None of them was capable of near vertical dives

[Grzesio]

Dauntless, for example, was.

[Denniss]

Dauntless at best 80 degrees if I remember right

[Thumpalumpacus]

None of them was capable of near vertical dives

Didn't see anyone saying they were.

[Grzesio]

Dauntless at best 80 degrees if I remember right

I think, 80 degrees is a nearly vertical dive.
A funny thing, the greatest diving angle included in the aiming tables of Ju 87 bombing manuals is 80 degrees.

[danebrog]

The prototype of the Ju-87 had a Rolls-Royce Kestrel in-line engine. The simple reason for this was that, because of the Treaty of Versailles, Germany did not yet have its own modern "high-performance" engines ready for production in 1935.
One remained then with the in-line engine for various reasons: Junkers had its own brand of engines, wich saved money, and it also saved time in terms of design/re-design – as the company was competing for a contract to build a dive bomber for the Luftwaffe