Bristol Perseus survivors?

Not sure about that one, but a complete example was auctioned about 6 years ago and was bought by a restoration company here in the UK.

Pete

There is a nicely sectioned Perseus on Wiki but where is it? Does anyone know? It isn’t Bristol.

Wez1

Perseus
Layout: nine-cylinder, one-row, radial
Bore by stroke: 5.75 by 6.5 in (146 by 165 mm)
Displacement: 1520 cu in (24.9 L)
Compression ratio: (unknown)
Power: 540 hp (400 kW) at 2400 rpm
Weight: 1026 lb (466 kg)

According to this Finnish Bristol advertisement (Aero 2/1939) all Pegasus engines had the same diameter of 1,32 meters so the weight could not vary much between the versions?

Perseus X:
Max hp = 880 at 4730 meters with 2750 RPM

Perseus XII:
Max hp = 905 at 1985 meters with 2750 RPM

Perseus XIIc
Max hp = 890 at take-off with 2700 RPM

Martti

From Wikipedia: http://en.wikipedia.org a rather telling power-weight ratio. The version of Perseus isn’t specified, and the website says:
“The first production versions of the Perseus were rated at 580 horsepower 433 kW), the same as the same-year model Mercury, which shows that the sleeve system was being underutilized. However this was quickly uprated as improvements were introduced, and by 1936 the Perseus was delivering 810 hp (604 kW), eventually topping out at 930 hp (690 kW) in 1939.” – assuming the weight stayed about the same isn’t so bad.

Perseus
Layout: nine-cylinder, one-row, radial
Bore by stroke: 5.75 by 6.5 in (146 by 165 mm)
Displacement: 1520 cu in (24.9 L)
Compression ratio: (unknown)
Power: 540 hp (400 kW) at 2400 rpm
Weight: 1026 lb (466 kg)

Pegasus X:
Layout: nine-cylinder, one-row, radial
Bore by stroke: 5.75 by 7.5 in (146 by 191 mm)
Displacement: 1753 in3 (28.7 L)
Compression ratio: (unknown)
Maximum continuous power: 915 hp (682 kW) at 2600 rpm
Take-off power: 960 hp (720 kW) at 2475 rpm
Weight: 1005 lb (456 kg)

Mercury VIII:
Layout: nine-cylinder, one-row, radial
Bore and stroke: 5.75 by 6.5 in (146 by 165 mm)
Displacement: 1519 in3 (24.9 L)
Compression ratio: 7:1
Power (max continuous): 840 hp (630 kW) at 2750 rpm
Power (take off):730 hp (540 kW) at 2650 rpm
Weight: 980 lb (440 kg)

Thanks Andy.

It’s a bit clearer. one of those engines that seems to have been unfortunate in the airframes it was in not surviving. Not a great selection, but the Lysander Mk.II seems to have been popular enough.

I’d missed the Flamingo as a user – nice plane, shame about the war! Was used for the Kings Flight IIRC, and shared a layout similarity with the DC-5 – also a case of bad timing…

Thats what I thought, but thats what was included in a document which was the basis for the list (an interesting out-of-date document on the internet at www.crossandcockade.com/files/UK%20ENGINES.doc ) . I thought I’d leave it in (with a question mark) to see if it raised any eyebrows.

A quick check shows that NF370 is a Mk.III, so should have a Pegasus Mk.30 in it. Presumably this was a typo in the original document, unless anyone at IWM can confirm if they have a Perseus?

Another quick check shows that Perseus marks only went up to XII, so we can definately scratch that one from the list. It may have been underpowered, but it was the first sleeve-valved engine in the world to go into production (the first to enter service in the Vildebeest of RAF No.42 Squadron in 1937), so deserves some credit. Another type to use it (apart from the Bristol Bulldog testbed) was the de Havilland Flamingo – not a type I’ve come across before.

Andy

Thanks Andy,
But the Swordfish only ever had the Pegasus – not Perseus… Are you sure the two haven’t got muddled in the listing?
Thanks

Perseus in the UK

I believe the following UK organisations have a Perseus in some state. This list may be out of date though:

RAF Museum (a Mk IA and a Mk.XII)
RRHT Bristol (Mk.XA)
FAA Museum, Yeovilton (Mk.XII, probably the one in the Skua)
Imperial War Museum, Duxford (Mk.30, in Swordfish NF370?)
Bristol Industrial Museum
Scence Museum

The Irish Aviation Museum which used to be in Dublin had a Mk.XII.

cheers,
Andy Appleton

Thanks for that Nick.

DHFan – The Botha was a great disaster, but I’d not forget it – just to remember the poor blokes who had to try and fly it. Yes, it was Perseus driven – underpowered it says.

It was an early successful production sleeve valve design.

Some interesting info out there on the web – Henry Ricardo has a tribute website at Cambridge that’s fascinating.

Perseus Lost by RAF Museum

In 1974 Bolton Sub Aqua Club successfully recovered the Perseus engine from Blackburn Skua II L2892 of 776 Squadron from a flooded disused quarry near Bolton and following cleaning and conservation at the Bolton Institute of Technology it was passed on to the RAF Museum & placed in store at Cardington. Sadly its subsequent fate is not clear and enquiries to date have not managed to track it down.

Brief details of the crash and photos of the site today are on my website at:

http://web.ukonline.co.uk/lait/site/Skua L2892.htm

Botha twice James? I’m fairly confident nobody would think it merits that. 🙂

Certainly they appear thin on the ground.
I don’t remember consciously ever hearing of them before, although with the years I’ve spent poring over books I must have done. I thought the Botha had Taurus (Tauriii?), it doesn’t seem enough grunt for the Empires and the rest I wouldn’t have a clue.

JDK,

The Norwegian Aviation Museum at Bodoe has a Perseus XII.

And a photo of the ultra rare FAA museum Skua, with Perseus attached to its mount.

Septic.