Spinner

[gottschs]

Anyone know why some aircraft in WWII had spinners on their propeller hub yet some didn't. The P-51/P-40/P-39/BF-109/FW-190/Japanese aircraft did yet the P-47,P-36 & none of the Navy aircraft did? Was it simply the radial vs. inline engines sizes that provided the streamlining and efficiency?

Thanks in advance for any insights.

 

[warbird51]

Anyone know why some aircraft in WWII had spinners on their propeller hub yet some didn't. The P-51/P-40/P-36/P-39/BF-109/FW-190/Japanese aircraft did yet the P-47 & none of the Navy aircraft did? Was it simply the radial vs. inline engines sizes that provided the streamlining and efficiency?

Thanks in advance for any insights.

The Navy didn't use spinners as in their opinion, the maintenance required outweighed the improved drag performance that was obtained.

 

[PFVA63]

Hi,
I believe that Warbirds is correct. In addition to maintenance issues there is also the fact that they were added weight as well.

To help complete the picture though, it should be noted that not all USN Radial engine planes did not have spinners, as the early F2A-1 and F2A-2 planes did have spinners as well as some SB2C variants. Additionally in the UK while the merlin inline engine Hurricane and Spitfire fighters had spinners, the Merlin engined Fairy Battle did not for example.

F2A-1, F2A-2, & F2A-3

SB2C

Hurricane, Spitfire, & Battle

 

[warbird51]

Hi,
I believe that Warbirds is correct. In addition to maintenance issues there is also the fact that they were added weight as well.

To help complete the picture though, it should be noted that not all USN Radial engine planes did not have spinners, as the early F2A-1 and F2A-2 planes did have spinners as well as some SB2C variants. Additionally in the UK while the merlin inline engine Hurricane and Spitfire fighters had spinners, the Merlin engined Fairy Battle did not for example.

F2A-1, F2A-2, & F2A-3
View attachment 602251View attachment 602252View attachment 602253

SB2C

View attachment 602254View attachment 602255

Hurricane, Spitfire, & Battle

View attachment 602257 View attachment 602258View attachment 602259

Most Navy prototypes had spinners, but when they entered fleet use, they were deleted. There may be an exception out there, but everything I've read, the Navy decided against them

 

[pbehn]

The spinner is there to smooth airflow over the hub, not all props worked the same way and some had more "gubbins" in the hub than others. For water cooled designs there is an obvious advantage for having the hub/spinner blend as smoothly as possible with the cowling. For air cooled designs this isn't as clear a choice because any spinner just changes the airflow into the engine. Later designs like the Sea Fury have a big spinner and a tight cowling such that I thought for years as a kid it was water cooled. It obviously worked although I don't know how long it could be kept on deck with the engine running without over heating.

 

[PFVA63]

Most Navy prototypes had spinners, but when they entered fleet use, they were deleted. There may be an exception out there, but everything I've read, the Navy decided against them

Hi,

Although I do believe that they were eventually removed from the F2A-3's I believe that there are many photos of operational F2A-1 & 2's with spinners as well as SB2C's.

Regards

Pat


Curtiss SB2C-5 Helldiver

 

[chuter]

Spinners on full cowled radials only really work if the entire engine compartment is reasonably streamlined with a gearbox cover behind the spinner and minimal exposed structure inside the cowling. The cowl flaps control the amount of air that enters the cowling (duh) and with them closed (not actually "closed" as in sealed but the normal flight position) a lot of air pressure builds up in front of the engine forming a "pressure dome" that forces a lot of the air around the cowling, so, around the spinner. So on a radial, a spinner is basically just part of the overall cooling drag reduction solution that doesn't really accomplish much without the rest of the drag reduction measures inside the cowling (like what you might see on a racer). That extra sheetmetal can be a maintenance nightmare and was likely deemed not worth it in service.

 

[Admiral Beez]

Hi,

Although I do believe that they were eventually removed from the F2A-3's I believe that there are many photos of operational F2A-1 & 2's with spinners as well as SB2C's.

Regards

Pat

View attachment 602339View attachment 602338View attachment 602337View attachment 602336
Curtiss SB2C-5 Helldiver

This Wildcat just doesn't look right.

 

[BiffF15]

This Wildcat just doesn't look right.

View attachment 602567

I like it. I looked around for a picture of an F8F with a spinner but couldn't find one (someone used to fly one around). Also, La Patronis, and F7F has spinners on it and I think it looks good.

Cheers,
Biff

 

[PFVA63]

Hi,
I think these might be some.
Pat

 

[GregP]

The spinner on Rare Bear (below):

Came off of a Bristol freighter.

 

[GrumpyOldCrewChief]

The efforts that went into RareBear for its racing career would have been impossible to support in an operational Naval environment. Not even going into the engine alterations / substitutions area...
... an R-3350? In 1945? On a carrier?

 

[GregP]

I didn't and don't recommend any Reno racer as a military aircraft. They have no armament, no range, and have VERY temperamental systems and powerplants.

Rare Bear, for instance, has a compressed air system for the gear, and it only works maybe twice before needing to be charged up. But ... it DOES have a neat spinner.

 

[jgreiner]

As Pbehn stated above, I believe it was mostly air cooled vs. water/liquid cooled engines. Prime example: P-47 vs. P-51. Huge air cooled radial on the '47 and the water cooled Merlin on the Mustang. Of course the Mustang had a cold air duct below the fuselage (and small one in front, below the spinner, but for an air cooled engine, smack dab in front and getting air on that big radial was very important. Note the bottom 1/4 or so of the P-47 had a separate air duct running to the supercharger.

 

[MiTasol]

The spinner is there to smooth airflow over the hub, not all props worked the same way and some had more "gubbins" in the hub than others. For water cooled designs there is an obvious advantage for having the hub/spinner blend as smoothly as possible with the cowling. For air cooled designs this isn't as clear a choice because any spinner just changes the airflow into the engine. Later designs like the Sea Fury have a big spinner and a tight cowling such that I thought for years as a kid it was water cooled. It obviously worked although I don't know how long it could be kept on deck with the engine running without over heating.

The Sea Fury and many others had great big fans incorporated in the rear of the spinner to force airflow through the engine.

 

[jgreiner]

The Sea Fury and many others had great big fans incorporated in the rear of the spinner to force airflow through the engine.

Yup. So did the Fw-190, Ju-88, etc. I was just saying I believe it was *mostly* because of air vs. water cooled engines. Not exclusively.