Restoration of a Lowne atmospheric engine.

[Alyn Foundry]

Restoration of a Lowne atmospheric engine.

A few weeks ago a member of my FB group was in contact about an R.L.E. engine that he’d recently acquired. After several messages I decided that it was enough typing and I called him instead. Needless to say I was able to help him get the engine running. A few moments later he sent me a link to eBay about the engine in question. Luckily for me the listing wasn’t placed anywhere near where you’d expect it to be like under engines or not live steam so there was minimal interest. I put one bid against it at £2.00 above the last, quite early into the auction and then watched and waited until the last hour before closing. I was expecting the bids to skyrocket, it being such a rare engine, but no one was biting. I had put a maximum bid amount that I was comfortable with and watched the closing stages with great interest. In the last minute the amount went up from the tens to the hundreds but suddenly stopped, I had won the auction. I was over the moon.

The engine is a late 1880’s RM Lowne patent atmospheric engine. A flame gulper in today’s parlance. This model was built by the company that RM Lowne founded and shouldn’t be confused with the engines, built under license by messers Hardy and Padmore Ltd of Worcester.

The engine arrived this morning in very good shape and over the coming weeks I’ll be posting the restoration progress.

   Graham.

[Dave Otto]

Looks like an interesting project!

Dave

[Alyn Foundry]

Thanks Dave.

I was aware that the Lowne was incomplete from the photos that the seller posted. However, from my point of view the missing pushrod and flame port flap were of minor importance.

My son and I have been looking at the piston and bore assembly this afternoon. We discovered that the Brass ring carried a pair of thin Steel seals, one of which had snapped. This is the actual main seal against the vacuum and is held in place by a pair of tension springs. The piston is almost a slack fit in the majority of the cylinder.

   Graham.

PS. The last photo is courtesy of a good friend who owns a beautifully restored twin cylinder version.

[Admiral_dk]

Congratulations on wining the Auction 

Looking forward to see more 

Per

[Alyn Foundry]

Thank you Per.   

Members may recall a recent topic about soft soldering Piano wire? I suggested to Allen that a good old “ Copper “ was the answer. Well I needed mine today. In the picture of the repaired seal you can see my “ one pounder “ this made short work of the job.

The Blue Steel ring had broken and had jammed the piston. Another problem was that one of the Brass wire tabs was missing and also needed replacement. The wire measured 1.2 mm diameter and is readily available on eBay, however I only needed 1/4” not 5 Meters. I ended up beating out a sliver of Brass sheet into a short wire.  The Blue Steel ring was tinned and re anchored to the collar.

I’m now ready to move onto the next stage and hope that the cracked ring won’t spoil the vacuum too much.

   Graham.

[RayW]

What a great find Graham. Watching progress with interest.

[Alyn Foundry]

Thanks Ray.    I’m really looking forward to to finishing the restoration.

The next item on the list was the shutter and cross arm. Again the rod diameter is 1/8” and drops into a slot on the pushrod side and slips into a clearance hole on the far side. I’m guessing it was done like this to aid periodic cleaning of the shutter and port face. Two Brass washers locate the arm in the slotted support bracket. The end of the arm carries a crank and hole that picks up the pin on the pushrod. A very crudely made arm made from 1/4”-1/8” flat bar is soldered at one end to the cross arm and carries the pivoted port shutter at the other. The flap is made from thick Brass sheet but I opted to turn down a piece of Brass and form the flap and spigot in one. This was then lapped on an oilstone before being fitted to the arm. From a mechanical point of view I assumed that this item was also able to pivot, or perhaps a better description, float within the arm.   My assumption being based upon the fact that a fixed flap would only touch at the top due to it moving through an arc. My friends engine was so heavily painted which he didn’t want to disturb left me with no option but to contact Nick Rowland of RMC fame who also has one of these motors for an answer. A short video was received from Nick via the FB group chat which showed it did indeed float about the pivot.

The two pictures are pretty much self explanatory.

   Graham.

[Alyn Foundry]

As a footnote the engine is really quite small. The flame port flap measures 1” or 25 mm in diameter.

I’ve just learned from Nick that the piston is sealed, not by the two Blue Steel rings but the whole assembly is a kind of Stuffing gland that pushes against some packing between it and a slightly larger opening in the front end of the cylinder. The gland is secured by a couple of small tension springs.  I have just ordered some 1 mm section, high temperature “ O “ rings because luckily the piston diameter is dead on 37 mm and the opening is 39 mm. The stroke is enormous…. A whopping 3,250 thousandths of an inch. 

   Graham.

[Zephyrin]

Lucky man, what an awesome bid you win !
atmospheric engines are fascinating, and I will watch the progress in the overhaul !

[Alyn Foundry]

More to come but I couldn’t wait to share the current situation.

<a href="https://www.youtube.com/watch?v=dGC7NqhCKgU" target="_blank">http://www.youtube.com/watch?v=dGC7NqhCKgU</a>

   Graham.

[Chipmaster]

That's running well Graham 

Andy

[Alyn Foundry]

Thanks Andy, it’s taken several hours of serious tinkering to get it dialled in.

Viewers will notice that the pushrod has a couple of 13 amp plug top terminals slid on to retain the springs. This was done because the only other engine available for any reference was a larger size. With this method I could adjust the stops to get the correct bias between the two springs for operation. I have to admit to a serious “ senior moment “ regarding the spring. Having ordered a stainless Steel spring of 300 mm in length from China I came to fit it and to my horror, it didn’t.
I had only forgotten to multiply the wire diameter by two! 

Luckily my workshop contains a massive selection of retained $#,t parts and a suitable 100 mm long spring was found. The remains of an old “ Proops pack “ of miscellaneous compression springs furnished the bias end.

Whilst the 37 mm O rings were still in transit I made a crude piston packing from some PTFE tape, twisted to form a thin rope. This enabled me to give the Lowne its first run in many decades.

A temporary gas line was rigged up to provide a pilot light for the main Bunsen Blue flame and the video above says it all.

Obviously there’s still quite a lot of work to do but to see it running properly for the first time gave me immense pleasure.

   Graham

[Admiral_dk]

Thanks for showing - helps the the Olde Two Bits upstairs ....   

Per

[Roger B]

Looks good to me     

How much power would this deliver, 10s of Watts?

[Alyn Foundry]

Hi Roger.

Probably a few Watts yes. So little is known about this particular engine whether they were used for work or just a toy. At this moment it’s pure conjecture.

Attached is a picture of another twin cylinder version that’s recently surfaced you can see a chain drive sprocket fitted to the crankshaft. The twins have a slightly larger bore diameter than the one I have.

   Graham.