Expansion Engine Progress

typak

Subscriber
A little progress on the Dreadnought double expansion cycle engine, starting the turning and boring of the new cylinders, cylinders each weigh 231lbs with a displacement of 622ci, engine has been freed up and other than being dirty and needing a good clean the bearings, crank, cams and so fourth are in remarkably good condition, a good friend and tool maker is at present doing the turning and tooling to begin boring, will add images and updates as it all progresses.
 

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typak

Subscriber
Taking a proof cut down the bore, a good half inch of material to come out, cylinder walls were cast heavy for good density with little chance of flaws or porosity.
 

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typak

Subscriber
Parting off one eighth at the base end for a datum and holding point for the turn around, getting down near the finishing cuts now and then the honing for final size / piston clearance, also bore step still to go in for the head location bosses, the last of the main patterns nearing completion for the water jacketed exhaust manifold.
 

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Nathan K.

Subscriber
Hi Typac,
Always enjoy seeing parts made and machined. Very interesting engine, how long till we see a video of it running?:D.
Nathan.
 

typak

Subscriber
Machining from the top end now completed and cylinder removed and second cylinder now in and same process begins then they will go back in for the turn around for the profiling of the mounting flange and base end, cylinder sitting next to a 20l oil drum for indication of the actual scale and size, pcd grooves set out and bore step identical as the originals, second cylinder set up and some proof cuts etc, a picture taken decades ago when the engine was taken out of service showing the valve arrangement and volume chambers that governs the volume differential for the induction, compression and working strokes.
 

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Wirebrush

New member
Now that is what I call a restoration project. I makes my hit and miss engines restoration look like matchbox toy resto. Can not wait for the running. Great work.
 

typak

Subscriber
How long did the castings cure before you commenced machining?
Ian
Hi Ian, five cylinders were cast and the last two six months ago when the patterns and castings were proven, both cylinders were shot peened so stresses aren't a issue.... image of Dreadnought oil engine plate and one of the original cylinder heads.
 

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typak

Subscriber
Down to the finishing cuts boring the second cylinder, this was a easier operation than the first as its now established the absolute rigidity of the jack bolts/tooling holding the job, cuts of an eighth of a inch pushed through with accuracy then after the finishing cuts less than a thou fall/taper from top to base, a view showing the right hand side of the engine, another view at the Dreadnought engineering works from a set of pictures, other image in reply 3, that appeared in an article in 'The Sun' July 1922.
 

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isandian

New member
I rather think I saw one of these engines under a tarpaulin at White bay in the late 70's. It was rather unloved at the time. I am pretty sure it was green in colour.
I had gone down with neighbours who were volunteers restoring a vessel that was of special significance (I forget the details), and they were celebrating a special milestone.
I did ask other volunteers at the Maritime Museum about it some years later without response.
Ian
 
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