chuck540z3 Posted January 24, 2020 Share Posted January 24, 2020 Thierry, This is fun and really gets me inspired to build another (older) Spitfire! Thanks to your query, I have looked at at least a hundred pics like the ones below. 90% of them show that there is a slight but very real angle downwards, like others have said above. Hope this helps. Cheers, Chuck LSP_K2, RBrown, Anthony in NZ and 1 other 4 Link to comment Share on other sites More sharing options...
thierry laurent Posted January 25, 2020 Author Share Posted January 25, 2020 Hi Jennings. From inboard to outboard. By the way, the last picture posted by Chuck shows clearly that -as you wrote- they are fully parallel with the engine axis. So, we are OK with that dimension. The other one is far more difficult to measure as nearly always the pictures are taken from the bottom (very rarely from a point at the same level than the exhausts and never from the front at that level)! I think we are agreeing on some slope. I have know to assess how many degrees (I will not care about a limited discreapancy!) as I do not think we have one that is comparable of the engine banks one! LSP_K2 1 Link to comment Share on other sites More sharing options...
MikeMaben Posted January 26, 2020 Share Posted January 26, 2020 Straight ... Down ... Alain Gadbois and thierry laurent 1 1 Link to comment Share on other sites More sharing options...
geedubelyer Posted January 26, 2020 Share Posted January 26, 2020 Fascinating topic. Hi Mike, the top photo you shared is a very tight crop. Is it possible that the photo itself might not be plumb? Could it have been tilted a degree or two to the left by the photographer to make the exhausts look level? Sometimes things just appear weird when they're cropped in tight and a little manipulation is needed for balance. FWIW, I'd go with a slight downward droop but perhaps it depends on who manufactured the manifold? Looking forward to seeing more input on this topic. Cheers. MikeMaben 1 Link to comment Share on other sites More sharing options...
jenshb Posted January 26, 2020 Share Posted January 26, 2020 Regarding tight tolerances... A CAD designer I used to work with had previously worked for BAE Systems designing the flap for the Nimrod MR.4. This update of the venerable Comet family got an entirely new wing and new engines. He told me that the attachment points for the wing to the fuselage could vary as much as four inches between the fuselages, so a set of wings would literally be tailor made to fit one specific fuselage... Link to comment Share on other sites More sharing options...
airscale Posted January 26, 2020 Share Posted January 26, 2020 the Monforton book has drawings that I think are common to all Marks.. That is to say the exhaust meets the cylinder block at the angle of the 'Vee' of the V12 Merlin. There is then some curvature in the stubs - for the Griffon XIV I did, the ports were virtually straight like a P51, the book is about the IX and XVI so these drawings relate to those versions - posted under fair use... Peter MikeMaben 1 Link to comment Share on other sites More sharing options...
thierry laurent Posted January 26, 2020 Author Share Posted January 26, 2020 Thanks Peter. This confirms the exhausts were twisted. Stupidly I did not think about checking the Monforton book! LSP_K2 1 Link to comment Share on other sites More sharing options...
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