Buzzing in and around Stewart Island, and Invercargill









Olderndirt wrote:QUOTE (Olderndirt @ Jul 28 2011,3:13 AM) <{POST_SNAPBACK}>Okay - a question for the Spitfire experts. Why am I seeing so few exhaust stacks on the Spit compared to six a side on the P51 - different manifolds? I was under the impression they both used the same 12 cylinder Merlin.
Almost totally different engine in respect to power by almost double , Stanley Hooker who design many aspects to increase power found independent stacks increase trust by a couple MPH course this chap also designed the blower and two stage supercharger increasing the engine length , this Mk1 and the Mark2 powered by Merlin 1/2/3 were the Mustang was a Merlin 61/68 series, as Connor mentioned licence built by Packard - Packard Merlin 68/69 .
Ian Warren wrote:QUOTE (Ian Warren @ Jul 27 2011,5:44 PM) <{POST_SNAPBACK}>Almost totally different engine in respect to power by almost double , Stanley Hooker who design many aspects to increase power found independent stacks increase trust by a couple MPH course this chap also designed the blower and two stage supercharger increasing the engine length , this Mk1 and the Mark2 powered by Merlin 1/2/3 were the Mustang was a Merlin 61/68 series, as Connor mentioned licence built by Packard - Packard Merlin 68/69 .Remember reading something about Packard remarking about the unusually close tolerances on the Merlin but they should have been used to that - their auto engines were liquid cooled and some of the finest.
Olderndirt wrote:QUOTE (Olderndirt @ Jul 28 2011,1:59 PM) <{POST_SNAPBACK}>Remember reading something about Packard remarking about the unusually close tolerances on the Merlin
That is true and reason for example the Brits had 3/8 BSW (British Standard Witworth ) and the US counterpart was UNC (Unified Nation Course) only difference was the thread pitch by 5 Deg.s , they re-engineered many parts for manufacturing speed and production .