[Six Nifty .50s]

In May 1943 (long before Packard-powered Spitfire XVIs were in service), RAF Fighter Command informed the USAAF that on average the Allison engine lasted about three times longer than Merlins in-between bearing failures.

Originally Posted by Nash

Do you have a source for this?

BRITISH ARMY CO-OPERATION TACTICAL EMPLOYMENT
OF THE MUSTANG I (P-51)
26th August 1943

HEADQUARTERS
NORTHWEST AFRICAN STRATEGIC AIR FORCE
CHARLES F. HORN
Brigadier General, GSC,
Asst Chief of Staff, A-3

The Introduction of the report says it was filed as a result of contact with RAF Wing Commander Peter Dudjeen on 31st May 1943.

Originally Posted by Nash

AIR 2/7498 - 95A (British archives reference) has correspondence from Air Marshall Tedder, commander RAF forces in the Middle East, asking for more P-40Fs (Packard Merlin engined) rather than P-40Ks (Allison engined), both because of the better performance of the Merlin engined variant, and because they suffered less bearing failures than the Allison engined aircraft

The records also show lower serviceability rates for the Allison engined P-40 variants in North Africa than for the Hurricanes serving there.

That is very unlikely, unless the Allisons were elderly with high hours and there was a much greater supply of replacement Merlins.

Originally Posted by Nash

Have they? I've never seen that claimed, could you please provide a source?

You overestimate my willingness to spend hours reminiscing in the Usenet archives just so we can recount endless technobabble about the (alleged) dive speed of one Spitfire. Do it yourself.

Originally Posted by Nash

You forced me to look up the production numbers, which tell an interesting story. So if in 9 Spitfires was a XVI, you'd expect in 9 engine failures to be as well. In fact, if there were 9 engine failures in Mk XVIs, you'd expect 180 in all Spits, and yet Six Nifty .50s says there were only 162, which gives the XVI a slightly higher failure rate than average.

That doesn't make sense because I never said there was 'only' 162 Merlin engine failures. Those are just the ones I know about, because there is no basic reference source with a compiled list. What I posted was pieced together using several sources.

For the Battle of Britain period, I looked at FIGHTER COMMAND LOSSES by Norman Franks and he listed just a few RAF fighters lost to engine problems between July 1940 and October 1940. But then I checked the BATTLE of BRITAIN: THEN and NOW and found 35 RAF fighters reported lost to engine failure or some type of motor trouble -- not including a few cases that I discounted because they involved glycol leaks or pilot error in handling the fuel switches.

I do not live in the UK so I cannot visit their archives whenever I please. I own a few of the published RAF squadron histories. The ones that have an appendix showing a list of airframes is very helpful, but it will take time to find more of these at the local libraries.