[Bigmike]

[asheshouse]

Can you give a reference for the source of the image?

I am particularly interested in being able to see more detail of the engine and cowling. Any chance of an enlarged copy of this area?

[Vpmedia]

http://www.umt.fme.vutbr.cz/~ruja/modely/podklady.htm

[Username]

Can you give a reference for the source of the image?

I am particularly interested in being able to see more detail of the engine and cowling. Any chance of an enlarged copy of this area?

Hi Asheshouse - aren't you the Hampden modeller? That image is scanned from Bill Gunston's 'Classic World War II Cutaways' [ISBN 1-85532-526-8]. All the drawings in the book are taken from old copies of Aeroplane magazine. There is one of the Hampden too, but it doesn't show the fronts of the engines.

To quote Gunston:
"(The artist shows)... the twin ram inlets which fed air to the oil cooler behind each engine. He also showed how the exhaust from the nine cylinders was piped to the steel collector ring round the front of the cowling and expelled through a pipe on the right side."



Nearly all British radial engine installations used collector rings mounted at the front. If you see a British aircraft with a coppery-bronze cowl ring it means the engine is fitted with a front collector ring and that all the exhaust tubes are being fed forward into it. You can see this on Hampdens, Wellingtons, Blenheims, Beaufighters, Halifaxes, Stirlings and Lancasters. German BMW installations always arranged the exhausts to exit at the rear of the cowl apron and I believe American radials rarely used front collector rings because they were usually designed to feed exhaust gases into a rear mounted turbosupercharger. As far as the Brits were concerned, a front mounted collector suited their purposes well because it acted partially as a flame damper (better for night ops).



You can see the exhaust tubes entering the ring here:



and here:



and here (though this is a Hercules in a Beaufighter VI:



Here's the rear of a Blenheim Mercury engine. The tubes you can see entering the rear of the cylinder heads are the induction pipes feeding fuel/air from the centrifugal compressor at the back of the engine:



And in the hope that you are still going to make a Hampden, here's a picture of a Bristol Mercury, as mounted in the Blenheim. You can see the baffle plates between the cylinders and the pushrod tubes and rocker covers for the valve gear. This could be used as reference for the Hampden as the Pegasus fitted to that aircraft was just a long stroke version of the Mercury (they looked virtually identical):

[asheshouse]

Superb stuff. Thanks for posting it.

Yes, it is me thats working on a Hampden model -- though proper work has been getting in the way of progress lately.

I'm hoping to get back to it very soon. These images are great. A lot of the details of undercarriage and engine mountings are very similar to the Hampden so it helps me to fill in some of the hidden details.