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You are thinking of the Packard Merlin (vs RR Merlin), made under licence in the USA. The Allison was a completely different engine made by a subsidiary of GM. It gets confusing because they were contemporary engines which were often used on different marques of the same aircraft. Funny thing though, Allison got bought out by Rolls Royce around 25 years ago!
Quote:
Originally Posted by superquag
Ok then J2. [bigrolf] Rong is spelt with a W rong. Gettit?:Rolling: My name is not Ron.Quote:
Correct me if RRong,
No. The Allison, as well as the Merlin, copied the general layout of a V12 established by BMW, Renault and Rolls Royce (and later by the American Liberty) during WW1. But apart from this they had little in common except, unsurprisingly, being designed to meet similar specifications, they were about the same size.Quote:
Originally Posted by superquag
The Allison engine performed satisfactorily when introduced, but was not capable of the increase in power that the Merlin saw. In 1936, the Merlin produced 800HP, in 1945 some marks were up to 2,000HP (the most commonly used ones were around 1600HP). Merlins also outperformed the Allison at altitude, largely because of Rolls Royce's supercharger expertise. The exception perhaps was the Allisons fitted to a few aircraft with turbochargers - but inability to supply the high temperature materials needed for the turbines meant these were few in number.
Also completely unrelated to the Allison was the Packard built Merlins, that differed from the UK and Australian ones by using mass production methods and American threads etc. Performance of these was pretty comparable. (At least I am pretty certain that the Australian bult ones were RR spec not Packard)
Pretty sure the last of the Merlin Spitfires had counter rotating props up front to counter the torque reaction on the plane which was especially dangerous on take off.
DL
Just checking Jeffrey Quill's excellent Book "Spitfire" for that A/C as I had a feeling he mentioned that but i can't locate a reference for that even in the index.Quote:
Originally Posted by 350RRC
He was a Supermarine Test Pilot for many years & flew them in action during WW2, inc. The Battle of Britain.
Excellent read if you are Spittie inclined. A 300 page paperback published 1983. He died 20 Feb '96. ISBN 0 09937020 4 JQ was a test Pilot at Vickers & Supermarine. The story of the development of all Mks of Spitfire from 1936 up to WW2.
VINTAGE BOOK WAR WW2 PAPERBACK SPITFIRE RAF FIGHTER TEST PILOT QUILL 10 | eBay
DL they eventually went to a four Bladed Prop if that is what you may be thinking of?
Pretty sure I've read it and that's how I know. Just remembered the size of the rudders may have increased to try to deal with the problem as well.Quote:
Originally Posted by 4bee
cheers, DL
Quote:
Originally Posted by 350RRC
You may be correct. You Tube shows it in flight but the book doesn't mention it..IL2 Spitfire MK.XIV Contra-rotating propellers. - YouTube
Might have been a different book. Pretty sure they increased the size of the rudders before the counter rotating props.Quote:
Originally Posted by 4bee
Not a good look cork screwing into the airfield when just trying to get some elevation.
Thinking about it some more........... I'm pretty sure the diameter of the props went up as the Merlin hp rose and there was some other mod that was done as well.
You're mission, 4B, should you decide to accept it is to..............
cheers, DL
Stand-by, awaiting permission from Mrs B, to accept. [biggrin]Quote:
Originally Posted by 350RRC
From memory, I can't remember if any Spits had a RR Merlin with contra rotating props like the RR Griffon engined Spits. However, post-war the Short Sturgeon was fitted with 2x contra-propped RR Merlins - can't remember what model of Merlin though.