Two Flash Steam engines

[Graham Meek]

I have just completed these two engines, this was my Winter project. They are based on a design by Edgar T Westbury, "The Gemini High Speed Engine for Flash Steam". My units are actually smaller than ETW's original with 12 mm bore and 14 mm stroke. Overall the engines work out at about 8/10 th's the size of the original. I followed the 2 cylinder design but also added a 3 cylinder version for self starting. Both engines tick over at about 30 PSI and are extremely smooth running as the revs rise. I have had them running at 100 PSI and the noise produced is comparable to a two-stroke Diesel engine.

My best regards
Gray,

[Perry]

Graham, that is beautiful work 
Would love to see work in progres photos too..

Will those power some speedboat?
Thanks for showing your work

Peter

[Roger B]

Magnificent work Gray     I do like the 'splitpin' dipstick  It reminds me of the style used on my fathers Austin Cambridge.

[Ramon Wilson]

Very nice work Gray, and something quite, quite 'different'. Beautifully made parts - is that brass finish bead blasted?

You don't say but is that 100 psi on air or S/H steam?

Yes sir, very nice work indeed

Hope you and Jean are well - looks like you are at last being able to enjoy your retirement

Kind regards - Ramon

[Perry]

That gorgeous 3cyl crankshaft with interesting Counterbalances got my attention.. More photos please

[b.lindsey]

Gray those are both beautiful. Yes please, more pictures if you have them.

Bill

[Graham Meek]

Thank you all for your compliments. Unfortunately these are the only photographs I was able to take. A problem with my camera which has now been sorted, did mean I was unable to take individual photographs of the parts before the build. I have limited the running to air only at the moment, I am currently building two oil pumps to keep the rotary valve lubricated when the engines are used on steam. The pumps attach to the rear of the cylinder head and are driven by the rotary valve. The blanking plug currently in each steam manifold is for the oil pipe union.

The crankshaft for the 3 cylinder did pose some head scratching as regards balancing. Most 3 cylinder engines use a balancer shaft, but I did not want this complication. Whilst reading a book on Experimental Flash Steam by J H Benson & A A Rayman I came across a 3 cylinder design which was done by Ricardo of Shoreham, as a design study for General Motors. The cross sectional view shows the displacement of the counter balance weights. With tongue in cheek I decided to give it a try, and to my surprise it worked out to be just about right.

The brass fabricated blocks are sand blasted using "Builders Sand" and an attachment I made to fit on the end of my air line. The result came out better than I expected and I shall use this technique again.

I have a design for a vehicle which uses the 3 cylinder engine, both the engines are probably too heavy to go in a boat. If I had intended to fit them into a boat I would have machine the blocks from aluminium, but I think they would not have have been so pleasing to look at. 

ETW did have a design for a V4 version and this is currently being drawn up using many of the standard parts from these engines. This design is also shown in the above book.

My best regards
Gray,

[ths]

Magnificent Gray. Perhaps a video might be available at some stage? I'm intrigued by the 'attachment' you made to blow builders sand around!

Cheers, Hugh.

[Jasonb]

Very nice indeed. Two questions if I may.

1. Is the curved piece next to the sump a baffle to stop too much oil being flung about?

2. What are the pistons made from, they have the pinkish look of freshly pickled copper?

J

[Graham Meek]

Hi Jason,

The curved item is what ETW calls the lubrication trough. There is one hole in the centre of the 2 cylinder trough and 2 holes in the 3 cylinder trough, (between the big ends). ETW uses the same item on the Seagull engine that I built some time ago. It prevents the contents of the sump being thrown around the inside of the crankcase and the big-ends becoming starved of oil. As oil is displaced from the trough the level is replenished via the holes in the bottom of the trough.

The pistons are brass fabrications, I toyed for sometime in making the pistons out of cast iron, but in the end I settled for brass with one piston ring. Because of the holes in the cylinder liner the ring needs to be pegged to stop it rotating. This peg and the gudgeon, or wrist pin bosses are silver soldered into position before final machining. There is no chance of silver solder entering the pre-machined ring groove as all solder is applied from the inside of the piston and the peg is a press fit with a portion protruding inside the piston for the silver solder to adhere to.

My best regards
Gray,

[Don1966]

Wow! Those are some awesome looking engines Grey. Would of loved to see the built log. Every piece is a work of art. 

Don

[Niels Abildgaard]

The pistons are brass fabrications, I toyed for sometime in making the pistons out of cast iron, but in the end I settled for brass with one piston ring. Because of the holes in the cylinder liner the ring needs to be pegged to stop it rotating. This peg and the gudgeon, or wrist pin bosses are silver soldered into position before final machining. There is no chance of silver solder entering the pre-machined ring groove as all solder is applied from the inside of the piston and the peg is a press fit with a portion protruding inside the piston for the silver solder to adhere to.

My best regards
Gray,

The two stroke professor Blair from Belfast said somewhere that for ports less than 30 degree of  cirkumference no ring fixing is needed.Is Your ring locking based on personal expirience of mishaps?
I am asking as all my two stroke doodlings revolve around this fact,ie at least 8 ports.

[Graham Meek]

I freely admit I am not familiar with the writings of Professor Blair. However based on his findings my engines are just border line, so it seems un-knowingly I was right to fit the peg. This is the first time I have had the need to peg a piston ring, all my other engines that have required piston rings have been 4-stroke petrol/gas or diesel. Making and fitting the rings was a lot easier than I thought it was going to be, the ring sizes are 12 mm O/D by 11 mm I/D and 1.15 mm wide. These are made to Professor Dennis Chaddocks recommendations which he published some time back in Model Engineer. I did however reduce the gap piece to 3 times the thickness of the ring during heat treatment, (Dennis recommended 4T), this gives more than enough ring pressure on such a small bore.

My best regards
Gray,

[cfellows]

Really pretty engines.  Very nice work.

Chuck

[Zephyrin]

impressive workmanship, beautiful.
are they designed with an uniport only or with also an additional exhaust on top ?