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Spitfire engine test bed - DONE!

Started by PR19_Kit, June 24, 2025, 03:06:40 PM

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PR19_Kit

Checking on an actual Merlin/prop setup at Tangmere Museum today, I noted that there's only one gear train between the crankshaft and the prop on a Merlin, so that means the engine rotates anti-clockwise viewed from the cockpit and the prop rotates clockwise.

But which has the most torque effect on the airframe?
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

Old Wombat

Quote from: PR19_Kit on Yesterday at 08:20:40 AMChecking on an actual Merlin/prop setup at Tangmere Museum today, I noted that there's only one gear train between the crankshaft and the prop on a Merlin, so that means the engine rotates anti-clockwise viewed from the cockpit and the prop rotates clockwise.

But which has the most torque effect on the airframe?

In the case of a piston engine - the prop.

The engine is mostly comprised of heavy bits going up-&-down, rather than round-&-round.

The round-&-round bits consist of the crankshaft, driveshaft & gear cogs, none of which are particularly well aligned for combining their forces into a cumulative torque effect. Of these the crankshaft produces almost no effective torque because its forces are fairly diffuse & unbalanced. The driveshaft produces very little because it's relatively small, light & narrow. This leaves the gear cogs to produce the most effective torque, which is significantly less than that of the prop (but which would reduce the overall torque at least a bit).

By the way, in which direction does the supercharger spin? :unsure:
Has a life outside of What-If & wishes it would stop interfering!

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Charlie_c67

Quote from: Old Wombat on Yesterday at 09:21:03 AMBy the way, in which direction does the supercharger spin? :unsure:

Round and round  :wacko:

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The Rat

You want torque? YOU WANT TORQUE?!

Pratt & Whitney R-4360 Wasp Major 28-cylinder four-row radial, reconfigured as a rotary.

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Old Wombat

Quote from: Charlie_c67 on Yesterday at 10:11:47 AM
Quote from: Old Wombat on Yesterday at 09:21:03 AMBy the way, in which direction does the supercharger spin? :unsure:

Round and round  :wacko:

[Facetious Pedant mode off]

Wally!  :rolleyes:
Has a life outside of What-If & wishes it would stop interfering!

"The purpose of all War is Peace" - St. Augustine

veritas ad mortus veritas est

zenrat

Quote from: Old Wombat on Yesterday at 09:21:03 AM...By the way, in which direction does the supercharger spin? :unsure:

In the case of this Merlin XX, if I read the drawing correctly the same direction as the crankshaft...
Fred

- Can't be bothered to do the proper research and get it right.

Another ill conceived, lazily thought out, crudely executed and badly painted piece of half arsed what-if modelling muppetry from zenrat industries.

zenrat industries:  We're everywhere...for your convenience..