Large model radial engine project

[Wez1]

Some of you may know that I have been building a 1/3 scale model of a historic British radial aero engine dating from the 1920s, the Armstrong-Siddeley Lynx IV. It isn't quite finished but I am at the stage of preparing detailed drawings of it for others to use. My question is: would there be sufficient interest among you to justify the considerable work required to do this?
This is certainly an advanced project but can easily be built in the typical home workshop. It does however require a number of intricate alloy castings, some of the investment type. I have all the tooling for these and could assist UK builders in acquiring their castings but do not have the resources to produce more than a few waxes at a time.

Pictures of the engine can be seen on this site by following the Gnome Monosoupape link and scrolling down to the Armstrong-Siddeley Lynx photos. The Gnome is another of my engines, examples of which are being built around the world.

Note that this Lynx bears no relation to the other one of the same name by Nemett. It has 7 cylinders of 1.67" bore.

I would be happy to enter into discussion about any aspect of the build.

Wez1

 

[stevehuckss396]

Hard to say if there would be any interest. Sounds like an interesting build but much larger than most model builders would be used too.

 

[bobm985]

Yes! After all , one can always scale....

Regards,
Bob

 

[Wez1]

The problem with scaling down is the castings. The builder would have to start from scratch with new patterns etc. A horrendous job I can tell you!
I don't think this is all that big, certainly not compared to the steam locos being built these days. And there are plenty of 10BA screws on it if that makes you feel better.

Wez1

 

[bobm985]

Others might scale down, but I've always been a fan of the Lawrance R-75 (5 cyl, 75 cu. in., approx 2 ft. dia.)!
Regards,
Bob

 

[Wizard69]

The problem with scaling down is the castings. The builder would have to start from scratch with new patterns etc. A horrendous job I can tell you! I don't think this is all that big,

Some of us are more advanced than others and more so aren't as well equipped shop wise. Your castings and parts may be very good but for many of us a radial is a bridge to far at the moment.

certainly not compared to the steam locos being built these days.

I would think that a steam engine would be far easier.

And there are plenty of 10BA screws on it if that makes you feel better. Wez1

Well that settles it, BA screws are not exactly common world wide.


By the way I wish you the best of luck with this build and do hope that you get a few others to join in with you. Radials are fascinating and I'd love to see a few built. Just realize that this is more than many of us are prepared to dive into. I hope I didn't sound negative above but the perception is that radials require more time and skill than the majority of engines being built.

 

[Rivergypsy]

Lol, there's some seriously detailed locos out there, and a lot of BA screws in my experience, but surely finding a metric equivalent isn't too hard

Sounds like a nice project, Wez - can you post a link to your pics, please?

Good luck,
Dave

 

[Jasonb]

This should take yopu to the post with some shots of the Lynx.

Having also read the article in ME this is certainly not a project for the faint hearted and there are probably only a handfull of members here who would be able to build one.

http://www.homemodelenginemachinist.com/f26/gnome-monosoupape-rotary-engine-18713/#post193523

 

[Rivergypsy]

Oh thats lovely! It brings back fond memories of a stainless Bentley BR2 I built some years ago - unfortunately it had to be sold to fund a Dutch barge restoration though
I'm very interested in the plans and castings though , so count me in

 

[petertha]

What a beautiful engine & extraordinary effort Wez1. Consruction is definately above my skill level presently. I have a soft spot for radials & would consider drawings, just for interest sake, if not too spendy. Judging by the pics & finer details like roller tappets... looks very intriguing & well thought out.

I would like to see anything more you could share - build pictures or how you went about researching this engine, developed the plans, parts, casting molds... Is there another link or any more references you can provide?

Engine is intended to be a fairly exact copy of one in possession of RR Derby

 

[Wez1]

Thanks Petertha both for your comments and interest. I have published three articles in the UK model eng mags; one of them was all about pattern-making and casting, another about electroforming. Let me know if you would like me to email them to you.
I started off by studying the Derby engine plus the maker's Handbook which you can buy from RR. There are no surviving detail drawings so all of these I have done myself. They still require a huge effort to get into a form that others could use, hence my enquiry on this site and others. It seems there definitely is interest so I will get on and finish. We can worry about how to supply castings later!

I will try to get some more pics on to this site if I can remember how.

Wez

 

[kf2qd]

Some of you may know that I have been building a 1/3 scale model of a historic British radial aero engine dating from the 1920s, the Armstrong-Siddeley Lynx IV. It isn't quite finished but I am at the stage of preparing detailed drawings of it for others to use. My question is: would there be sufficient interest among you to justify the considerable work required to do this?

Probably the best reason for documenting this engine would be for posterity. There is probably not much opportunity to financially recover your time investment. And there are probably other like myself, who have collected some of these just to look at them and admire the creative minds that came up with them in the first place.

 

[Wez1]

The engine is now finished. It was started for the first time two days ago and goes OK. This was quite a surprise as I had expected all sorts of problems. I used a cordless drill engaged with the engine's Hucks starter claw. We gave it 2 shots of priming petrol then rotated it rapidly about 4 or 5 turns. Then it just started!

One pot remained cold due to a leaky exhaust valve. Despite that, it ran at a very constant speed with hardly any vibration giving out that lovely radial sound. I hope to fix the valve this week then we can try again. The drawings are also finished for anyone who may be interested.

Although I didn't dare open the throttle more than a crack this promises to be a mighty beast. Prop is 34" x 24".

Wez1

 

[Wez1]

Forgot to mention that the Lynx will be on show at MEX (UK) in a couple of weeks. I shall be there to answer questions etc. Hope to meet some of you.

Wez1