Westland Lysander to Whirlwind

[yulzari]

I was looking at a photograph of Westland's production factory in 1940 (which I cannot find again!) and it showed useless Lysanders being built with Bristol Perseus engines on one side and Rolls Royce Peregrine engined Whirlwinds on the other.

How might one alter things such that the Perseus engines (equivalent to the Peregrine) and Lysander production line were given over to making Perseus engined Whirlwinds instead? Possibly more in the low level strike role?

 

[tomo pauk]

The hi-alt Perseus X was good for 880 HP at 15500 ft (on +3 psig), or just a bit better than Peregrine. On 100 oct, max boost was IIRC +5 psig - we might get up to 950 HP, at a perhaps 12000 ft. Much more drag than Peregrine, low amount of exhaust thrust - net 320 mph?
For low level work, the numerous Perseus variats gave 900-950 HP at 3000-5000, pushing with 100 oct perhaps up to 1000 at SL.

There is also the unloved Dagger VIII around. Almost 1200 HP at 7200 ft, 850 at 15000 ft all for 4400 rpm operation, or 800 HP at 15000 at 4200 rpm. The installation on the Hereford, while on paper affording more power than Pegasus, was an unfortunate one. The cooling would be a problem on a slow Hereford, and lack of second speed of the SC will either kill the performance, or force the pilots to use more aggresive power setting for cruising - not good for reliability. The Dagger might allow for easier use of exhaust thrust.

All of the proposed engines block the visibility for the pilot, more than it was the case for the Peregrine. Benefit is that there are no radiators (bar for engine oil) in the wing, so there is much more space for fuel. Stick two automatic 2-pdr guns for AT work, plus 4 Brownings, bombs & rockets and we're set. More costly proposal than Hurricane IID for AT work, but it can do both AT work and bombing/rocketing during a single mission.

 

[yulzari]

Westland were trialling a single Vickers S gun (as well as the standard 4x20mm drum Hispanos, trial belt fed 4x20mm Hispanos and Martin Bakers' 12x.303 nose) which are about as much as the airframe might stand. Yes what you lose in speed you gain in fuel and the fuel system needed reworking anyway.

However the biggest change would be the RAF acknowledging that the Army might quite like some close support and that they were not going to get it from Westland Lysanders. In the defence of Dunkirk it was FAA Farirey Albacores that gave the troops close support dive bombing. Not that I am suggesting making the Westland Whirlwind a dive bomber.