Spitfire/Merlin supercharger whine (or lack of).

[Boatbuoy]

I was just watching a video of a spitfire display that I took last year (Lee Proudfoot in MH434), and I realised that almost every Spitfire I've seen in recent times has not really featured much, if any, supercharger whine. I'm sure as a kid/teen at airshows in the 80's & 90's I recall the whine as the aircraft dived and approached, followed by the clatter and rasp as it passed and climbed away. Is it just the case that the aircraft are more nursed during dispalys these days, or have I imagined something from the past that never actually was?

[anonymous-user]

The Merlin uses a centrifugal supercharger oil bath gear driven from the crankshaft, so there would never be a lot of whine surely?

[Boatbuoy]

Like I said, I may well have imagined it, but I'm pretty sure there used to be more noise.

[FourWheelDrift]

Possibly thinking of a Mustang? They do it a lot more and louder, although the Spitfire here does a little.

https://www.youtube.com/watch?v=BhiNBVPdH5k

[rich83]

FourWheelDrift said:

Possibly thinking of a Mustang? They do it a lot more and louder, although the Spitfire here does a little.

https://www.youtube.com/watch?v=BhiNBVPdH5k

Such a great noise (spitfire, i mean)

[Boatbuoy]

FourWheelDrift said:

Possibly thinking of a Mustang? They do it a lot more and louder, although the Spitfire here does a little.

https://www.youtube.com/watch?v=BhiNBVPdH5k

I'm definitely, and specifically talking Spits here. The one in that video features more whine than many a display I've seen recently, and that is the noise I recall.

Perhaps I've just been watching the wrong shows!

[Eric Mc]

I don't ever recall hearing significant supercharger whine from the Merlin (or Griffon either - for that matter). I've heard much whinier superchargers on things like Austin 7 racing specials or even some Continental/Lycoming light aircraft engines..

[Yertis]

Boatbuoy said:

I'm definitely, and specifically talking Spits here. The one in that video features more whine than many a display I've seen recently, and that is the noise I recall.

Perhaps I've just been watching the wrong shows!

I've noticed that too. I assumed they weren't opening the taps as much as they used to do. The Spit supercharger whine is quite different to the Mustang.

[Boatbuoy]

Eric Mc said:

I don't ever recall hearing significant supercharger whine from the Merlin (or Griffon either - for that matter). I've heard much whinier superchargers on things like Austin 7 racing specials or even some Continental/Lycoming light aircraft engines..

I think significant is too stronger description to what I was alluding, but certainly notable. Recently I would describe the whine as absent or minimal.

[davepoth]

Is the OP sure he didn't see a Griffon engined variant? They make a different (and IMO less exciting) noise.

[Boatbuoy]

MH434 is most definitely a Merlin equipped machine, and yes, it was definitely MH434.

[Storer]

I live near Duxford and we are treated to many free displays of the various Merlin engined aircraft.
There is usually very little supercharger whine from the Spits and Hurricanes. The Mustangs do whine more.

There may be a reason for the lack of whine these days (can't remember if there was more years ago). These engines are now getting rather scarce in airworthy form so I suspect they are detuned a bit to avoid stressing the engine. To do a display the need for every mph of speed is not necessary compared with dogfighting in WWII.

[Simpo Two]

Just running lower/no boost surely?

Or maybe all the superchargeers have been reconditioned/changed/improved?

[Eric Mc]

The whineist Merlin powered aircraft is the Buchon. Although I'm not altogether sure if the whine is anything to do with the supercharger.

[lufbramatt]

I thought that the whine you get from mustangs is the air rushing through the gun bays in the wings rather than the supercharger.

[Buzz84]

I was always under the impression that the whine from a mustang was due to the air intake