"Is the Blackburn engine as reliable as the Dripsy? In UK I'd say you'd have no chance of getting CAA approval for such a Major (pun intended!) change without some sort of massively ex'pensive re-certification excercise.
Reliability? Dunno. The Bombardier was the last development of the long line of Cirrus models. Memory is getting a bit dim now but I recall the Bombardier being used in the Auster AOP9 and I think a small helicopter of the mid-'fifties used it as well. In military form, the engine was rated at a bit over 200hp, about 25hp more than the "civilian" variant and therefore a useful increase of the Gipsy Major Mk10's 145hp for only a notional weight increase but it was never approved on the civil register. When I approached them, the bowler hats adopted their customarily negative and unhelpful attitude, the people at Brough weren't much better so in the face of this obduracy of officialdom, I gave up with proceeding with what was an entirely appropriate idea and, I still feel, would have been a very successful conversion. Apart from a brief period when Sir Sefton Brancker was in charge, the UK has never provided any real encouragement of light aviation and what was left after the War was finished off by Wedgwood Benn. Something akin to the US "Experimental" category would be allowing the plebs far too much autonomy.
I remember that having calculated the static centres of mass of the Blackburn and DH engines, there was room for the former forward of the standard bulkhead so minor modification of the engine braces and mounts should have proved sufficient. For a moment, I flirted with the notion of fitting a Regnier 4L.04 but felt that this would prove even more fraught with obstacles. I was sort of interested in Art Scholl's Ranger conversion and thought a Walter as used in a Zlin I occasionally flew might do but it was always back to the bureaucrats (who, in retrospect, saved me a ton of money!)
I never discovered the accepted TBO figures of the Bombardier but given its lineage, I suspect that with operational experience these might have bettered the DH powerplant. Actually, I have no real knowledge of Blackburn engines beyond having had a pair of Cirrus Minors (90hp) struggling to get me aloft in the Miles Gemini in which I took my multi rating.
But in looking back, I wonder if monkeying with the Chippie spec would have produced any real benefits. There have been so many occasions of a nicely-handling a/c being unacceptably compromised by the changing of some component. An example coming to mind is the 90hp Victa Airtourer which was a fun machine but the 150hp variant, whilst obviously benefiting from the power increase, was not so well balanced and not so nice to fly as a consequence.
Perhaps those lucky enough to own a DHC1 should accept the foibles of the engine, keep a good supply a rags handy, a short length of 4 X 2 in the after cockpit to thump the starboard mag impulse mechanism when gooed up with cold oil and just continue to enjoy a thoroughly delightful aeroplane. How I envy you . . .
GQ.
And to Dr Jekyll,
Some Moths were very nice to fly, the Puss and Leopard particularly so. I didn't care greatly for the Tiger and after having spent a couple of hours in a Stampe SV4, never bothered to fly one again.
Last edited by Gipsy Queen; 11th November 2011 at 22:33.