Armstrong Siddeley engined specials

[Max Tone]

Does anybody have info on Bristol's experiments using 3990 cc AS Star Sapphire engine in prototype 407s? BOC website estimates four such engines supplied to Bristol, one of which was tried in the "240 project mule", but found to be too heavy.

I'm also looking for info on said 240 project; might this have been the 'Bullet' that spawned Blenheim Speedster?

These were not the only 'special' uses of the AS lump; Frazer-Nash ordered two out of eight high-performance engines built by AS using earlier 3435 cc Sapphire 346 engine for their 550F Le Mans prototype, entered 1953/4, but not apparently run.

One is said to have had a special alloy head & triple Webers, producing c. 230 bhp, but ran its mains in testing, the other (still in 550F), has iron head & triple single-choke sidedraughts, said to produce 180-190 bhp. Standard 3.4 got 125 bhp with single carb, 150 with twins.

Another alloy headed example was fitted in the "Sphinx Allard", successfully campaigned by Tommy Sopwith.

These were advanced efficient hemi-headed short stroke lumps (97 x 90 for Star, 90 x 90 for 346), but block strenghthening for Star made it very heavy.

AS did, however, develop a lighter short-block version of the engine at 82.55 x 82.55 for 2651cc and 87.3 x 82.55 for 2965 cc, fitted in Series Humber Super-Snipes & Imperials.

Unlike Sapphire & Bristol lumps which are like hens teeth, this smaller AS Hemi is fairly readily available worldwide, long-lived, easily tuneable & CHEAP. I saw an engine (with plugs out!) & box sell on fleabay for £2.50, & rebuilt twin-carb 3-litre lump sell for £250, complete with the car!

With about six known examples of 'official' use of AS engine in place of usual Bristol lump, there is surely an opportunity to experiment further in the hope of finding a historically acceptable replacement for engine-less basket case 400-406 cars or even bare rolling chassis, that might otherwise be broken up or scrapped, not to mention saving such advanced engines from being weighed in with rotten Snipes.

Comments & any info on Bristol's experiments, state of tune of Star engine, comparative weights of the lumps they tried, inc. W.O Bentley Lagonda twin-cam, two of which I gather were fitted in Bristols, will be most welcome.

Happy New Year,

Rob

[RGSchmitt]

Rob -

There are two sections, 4 pages total about the
AS engined Frazer Nash in James Trigwell's
recent book on the postwar Frazer Nash cars,
including 2 color photos of the chassis, as
discovered a few years ago. I would imagine
there is much more information in the Frazer Nash archives.

And a Happy & Prosperous New Year to all correspondents!

Bob

[Max Tone]

Thanks Bob,
Cannae quite afford £300 for James' book!............but I e-mailed him
re any info in FN archives. No reply as yet.
Rob

[geo]

I nearly purchased a surviving one in the late 1970s that was owned by a friend's father, Julian Lugrin. He used it as daily transport when he worked at AP Films doing the 'supermarionation' of the likes of Lady Penelope!

When I was about to purchase the car, it was finished in that silvery-green (R-R?) colour and in excellent condition. Lugrin was a fairly eccentric fellow and, whilst he was happy for me to spend ages viewing and playing with the car, the one thing I was most interested in I was not allowed to see at that stage — the engine!! Eventually (after about a year), our negotiations did not progress beyond admiring the car and I acquired a 408 and gave up trying to persuade Lugrin that he really did want to sell it.

This was not the end of the tale, however, when I was looking for another Bristol in the mid-90s, his daughter again told me that he was really intending to sell it this time as it had spent the last fifteen or so years sitting in a lock-up garage in Acton, West London.

This time I did not see the car as Lugrin reported that when he went to tart it up a bit he allegedly discovered that parts had been removed and it was in a terrible state. His daughter suspected that although he claimed to have been too attached to the car to part with it in the 70s, she thought he had not seen it since he had mothballed it in one of his lock-up garages, some miles from where he lived in Isleworth.

I was never entirely confident of the authenticity of the tales that Lugrin told about the car, but his version of events was that it had not been scrapped by the company when the Star Sapphire project came to nought as it had been rescued and used by the White family (with whom he was acquainted). The engine and automatic gearbox was supposedly identical to its use in the final Armstrongs — I can testify that it was very smooth in operation and the unrevealed engine certainly sounded like a smooth 6-cylinder.

I tried Lugrin's tale out on LJKS at the time when I thought I was purchasing the car and he confirmed that as far as he knew, the essentials of the story sounded correct.

George

[Max Tone]

Thanks George,

With standard Star tuning of 165 bhp & 230 lb ft of torque & auto box,
it would have been super-smooth & effortless. You never know when it might
turn up again!............or news of the other three 407Ps.

Of eight earlier tuned 346 engines, two went to FN, one to Allard, but
any knowledge of the rest? One likely used in Sapphire rally car, but that
leaves 4 unaccounted for. It would be interesting to find out if any were
used in other cars normally using Bristol lumps.

Rob