Beyond The Sprues

Modelling => Ideas & Inspiration => Engineering Dept. => Topic started by: simmie on December 23, 2011, 10:09:29 AM

Title: Twinned Engines
Post by: simmie on December 23, 2011, 10:09:29 AM
OK, here's another mad idea.

Germany twinned the DB-603 as the DB-606, and the DB-605 as the DB-610.

America twinned the V-1710 as the V-3420.

How about a twinned Rolls Royce Merlin/Griffon???

A Twinned Bristol Centaurus???

Or if that isn't mad enough, a twinned Napier Sabre??

Once again, ideas and comments are always welcome.
Title: Re: Twinned Engines
Post by: GTX_Admin on December 23, 2011, 01:07:10 PM
 :slow:
Title: Re: Twinned Engines
Post by: Frank3k on December 23, 2011, 03:13:15 PM
Or if that isn't mad enough, a twinned Napier Sabre??

So the plane can stand still and use the twin Napier Sabre to rotate the Earth around it?
Title: Re: Twinned Engines
Post by: simmie on December 23, 2011, 07:33:42 PM
Well I did say that Sabre was "edge of madness" stuff!!

And I was suffering from Sleep Deprivation at the time.

After some more thought I have also considered this idea:-

As Rolls Royce Peregrine is to Rolls Royce Vulture

Then Rolls Royce Merlin/Griffon is to Merlin/Griffon X???

As for Sabre, turn them on their side and mount them sump to sump!!!

Title: Re: Twinned Engines
Post by: Empty Handed on December 23, 2011, 07:49:23 PM
Not that mad!

Quote
A Twinned Bristol Centaurus???


http://www.flightglobal.com/airspace/media/civilaviation1949-2006cutaways/images/7871/bristol-brabazon-cutaway.jpg
Title: Re: Twinned Engines
Post by: simmie on December 23, 2011, 07:52:28 PM
Ah yes I know what you mean there Empty old boy (as this is a forum for gentlemen!),  but I think I was looking at it from a BMW 803 point of view.  Again a case of "Late Night-itous".
Title: Re: Twinned Engines
Post by: Empty Handed on December 23, 2011, 07:59:03 PM
You would probably have severe difficulty cooling the aft-most cylinders (hence the Brabazon's somewhat bizarre installation) but you could always go for liquid-cooling like the Jumo 222 or Lycoming R-7755.

I've always liked the idea of a bypass duct (like modern turbofans) to get cooling air to the back rows.
Title: Re: Twinned Engines
Post by: simmie on December 25, 2011, 08:52:55 AM
A thought occurs......

A De Havilland Mosquito with twinned Merlin in the fuselage driving a contra-prop on the nose!! a la He-119

I have a funny feeling that the centre engine bit is familiar, has someone done that already??

Or

A Spitifire with tandem Merlins for an attempt on the World Air Speed record
Title: Re: Twinned Engines
Post by: GTX_Admin on December 25, 2011, 01:01:15 PM
Bah!  Let's get serious:  twinned Pratt & Whitney R-4360s...cooled with a fine mist of fire retardant...
Title: Re: Twinned Engines
Post by: jcf on December 25, 2011, 03:20:53 PM
The Vega Starliner had a coupled powerplant - two Menasco air-cooled inline 6 cylinders driving
a single prop.

(http://1000aircraftphotos.com/Contributions/Larkins/10417L.jpg)

The MC72 used the FIAT AS-6.
(http://upload.wikimedia.org/wikipedia/commons/thumb/7/72/Macchi-Castoldi_M.C.72_engine_Fiat_AS.6_2009-06-06.jpg/783px-Macchi-Castoldi_M.C.72_engine_Fiat_AS.6_2009-06-06.jpg)

The Fairey Prince and Monarch were also true twinned engines.
(http://img.photobucket.com/albums/v734/Aeroplanepix/Yeovilton%202007/_MG_9584.jpg)

The Napier-Halford Rapier, Dagger and Sabre were basically two flat engines mounted to a common gearcase, all three types had a separate crankshaft for each 'engine'. Ditto the R-R Eagle.

As to improving the cooling of the aft cylinders.

After problems with the original installation the cooling air for the Armstrong-Siddeley Deerhound radial was taken in at the front by an under engine scoop and was then conducted across the cylinders from back to front. The engine was test flown on an A S Whitley.

The D-H Gipsy 12/Gipsy King inverted V-12 air-cooled engines of the DH.92 Albatross were cooled by air
taken in at the leading edge of he wing that was then ducted forward over the cylinders to exit out the bottom of the cowling behind the propeller.
Title: Re: Twinned Engines
Post by: kitnut617 on December 26, 2011, 12:34:33 AM
Not that mad!

Quote
A Twinned Bristol Centaurus???


[url]http://www.flightglobal.com/airspace/media/civilaviation1949-2006cutaways/images/7871/bristol-brabazon-cutaway.jpg[/url] ([url]http://www.flightglobal.com/airspace/media/civilaviation1949-2006cutaways/images/7871/bristol-brabazon-cutaway.jpg[/url])


Keep in mind that with this arrangement each engine only powered one propeller, same as the Double Mamba installed in the Gannet
Title: Re: Twinned Engines
Post by: simmie on January 03, 2012, 09:49:55 AM
Well, due to a shortage of half-decent TV in the middle of the holiday period, insanity took hold and a started to work out the sizes for a variety of potential X engines.

I was forced to make some assumptions about heights of V-1710, Merlin, Griffon and Peregrine.

The last one was used to get a possible block height for Vulture (if some has the real numbers for that, let me know so I can make any corrections required.).  All of the numbers are highly sceptical as I haven't had the set squres out for quite a few years.

Height/width
Vulture - 958.33mm
Merlin X - 1123.33mm
Griffon X - 1095mm
X-3420 - 1065.83mm

I tried to work out sizes for a twinned Merlin and Griffon, but it just won't work out right.

All opinions welcome.