RMC Type-B Engine Build

[Jasonb]

I have liked the look of the engines from RMC designed by Nick Rowland for a long time but they went through a period of being hard to get. About 18 months ago I managed to pick up a Type-A from a collector who was reducing his stash, then earlier this year I saw a link to an e-bay listing where Nick was selling a small batch of the Type-B castings. Unfortunately they were all gone but I decided to e-mail him and luckily some more were available so i snapped one up as they are on my small list of Casting sets that I would like to make.

Nick's Website could probably do with an update but I'll post a link to his various designs for those interested http://rowland24.20megsfree.com/

A couple of weeks later the box arrived and as well as the castings and individual numbered name plate it contained one of the most comprehensive drawing/construction packages you are likely to get together with a CD with several hundred images ranging from some of the original hand drawn sketches, through CAD models to patterns and mould making then machining and finally finished engines. Nick has said it is OK to share a few here, this one gives a good mix of whats on the CD





As you can't have quality castings without quality patterns these bode well for good parts. Although Nick does use traditional patterns this one looks to be done with CNC cut PU board.



A rubber mould is then taken



Then from that resin copies are cast and mounted onto the boards to go to the foundry



You then say the magic words and hand over some cash and come away with a few castings! Jo, best cover Surus' eyes now so he does not get over excited.



Though this is all you get when buying teh quite reasonably priced set of castings, in next post I'll make a start on them and see how that very generous chucking spigot is used to hold the casting for machining

[Vixen]

Hi Jason,

Well , what can I say?     The RMC is certainly different and unlike any engine I have built. It reminds me of a futuristic space ship or perhaps one of those fancy iced cream cakes you see in a confectioners window.

That said, the patterns and the castings look to be extremely well executed. It should be a fun build and an interesting engine to display and run at one of our shows. It should attract a lot of attention.

Mike

[tghs]

I've looked at them as "steam punk gone organic"  a modern take on Victorian embellishment.. it's something is just made to watch running, might as well look cool..

[Jo]

It looks better in the metal than in the photos 

Surus is still of the opinion it looks like a Mr Whippy Ice Cream and unless it comes with nuts he says he will stick with his box of Snickers and more traditional model engine casting sets

Jo

[Roger B]

That's a very elegant engine      Very much form and function 

[Jasonb]

Yes Nick's engines have an almost unique look along the Art Nouveau style, the only other engine that I can think of along similar lines is the hot air fan from Myers

I often seem to start an engine by working on the silencer (muffler) and this was no exception, I think it is because they are reasonably simple parts and can be fitted in while the previous engine is being test run or painted.

I started with the half that goes towards the engine first holding by the edge of the flange to true up the chucking spigot, in fact it ran amazingly true maybe a thou or two run out but still needed skimming to remove the draft angle. I then had a parallel surface to hold in the 3-jaw chuck to skim the flange which even though it's not much more than 1/8" think machined easily - no chilled thin sections here. 



The casting was then turned around and held by the flange again, I had added the Sharpie marks when doing the spigot so it could be replaced in the same position. The spigot was cut off and a hole drilled and then bored to a firm fit on some 1/2" steel rod.



The other half was then skimmed across the flange before reducing the thickness to leave the three bosses full depth which act to space the two halves apart unlike a lot of silencers that have simple turned spacers. I cut until the edge was just breaking through as any more would have risked cutting into the chuck jaws, what little remained was easily files off.



The small stub pipe is simply a piece of 1/2" steel drilled out and then cross drilled for some additional holes, I just used a square ER collet block to index the 4 holes with the back of the nut against the vice jaws to locate the block in the X-axis.



All that is left is to drill clearance holes in one half and tap the other, I opted to use BA fixings on this engine rather than UN so in this case 4BA rather than #6-32, the hex head fixings are temporary and I will turn up some fillister heads screws for the finished engine. The pipe is retained with high temp Loctite 648.

[Art K]

Jason,
I've seen Nick's stuff at the names show. I do like the steam punk look to them. I will be following along.
Art

[Alyn Foundry]

Good morning Jason.

As yet you haven't mentioned the engines working principle.

My own assumption is that it's based on the Southall patent,  a two stroke/cycle that doesn't have a charging piston or crankcase transfer arrangement?

Attached is a picture of an early Hardy and Padmore that employs the same principle.

Cheers Graham.

[Jasonb]

Morning Graham, I was going to come to that when I got to the piston but it is a modified Loyal Cycle.

That's an interesting flywheel/crankshaft arrangement with the single bearing and a flywheel either side or has the far one been added?

[Alyn Foundry]

Morning Graham, I was going to come to that when I got to the piston but it is a modified Loyal Cycle.

That's an interesting flywheel/crankshaft arrangement with the single bearing and a flywheel either side or has the far one been added?

Ah, thanks, I thought as much.

No, that's the standard engine design. Rather nifty and elegant with the crankpin extended to be the starting handle!

Under that domed casting on the cylinder top is a weighted flap that is blown open as the piston passes the port, exhausting the cylinder.  The remaining down stroke pulls in a fresh charge of gas and air to be compressed for the next cycle.

Cheers Graham.

[Alyn Foundry]

Here's my own example of the Loyal patent.

A modified " A.L.F. " engine with water cooled hopper and the 1/8" BSP nipple fixed half way down the stroke. A non return valve was fitted to the nipple so that induction could occur directly after the exhaust event.

This engine ran beautifully and would go in either direction depending on a simple change of the ignition timing.

I'll be following with interest Jason, I like IC with a twist....

Cheers Graham.

[Jasonb]

Graham, if you like things with a twist then sit down and watch this video all the way through with your afternoon cuppa, it has got plenty of twists 4-stroke, duel stroke, 2-stroke, throttled or governor and a glass cylinder head all in the same engine which is a modified version of the same Type=B.

I do like the look of the fan and may just add one for interest as the bosses are already there on the casting, engine runs quite cool so not really needed.

<a href="https://www.youtube.com/watch?v=rz17bBpR0xM" target="_blank">http://www.youtube.com/watch?v=rz17bBpR0xM</a>

[Alyn Foundry]

Thanks for the video Jason.

Pretty straightforward until about two thirds the way in. Without a commentary I started to get a bit lost on what was happening.

I don't get the " dual " bit, if the engine fires once per revolution it's a two stroke. I'm assuming we watched a " ported " exhaust followed by a " mechanised " exhaust?

Perhaps someone could explain please?

Cheers Graham.

[Alyn Foundry]

Hi Jason.

My apologies if I appear to have shifted the focus of your thread topic. Having spent most of my adult life both restoring and researching the early IC engine it's refreshing to see something a little different.

Despite this being the " information " era I can find very little on either the Loyal or Southall patents. It's obvious that they differ because they were both patented. The employment of the " weighted " exhaust valve on the Hardy and Padmore might just be the subtle difference for a patent application? However....

I'll just sit back and enjoy the rest of the journey.

Cheers Graham.

[Jasonb]

No apologies needed Graham, I can always learn something from your posts and you do tell a good storey so happy for you to chip in whenever you fancy.

Nick has directed me to this page on his website which may go some way to explaining the cycles (about half way down) or it may equally leave you with more questions

http://www.rmccyclestrokes.20megsfree.com/rich_text.html

He also included a nice shot of the spark through the glass cylinder head

J

PS did you get my second e-mail yesterday?