Coupling two model engines together.

[Steamchick]

For Tornado - read Typhoon. (Picked the wrong wind!).
https://en.wikipedia.org/wiki/Hawker_TyphoonInteresting to note the Napier H24 was so powerful, and successful but the complexity was superceded by the relative simplicity of Jet engines....
I think the final note on the Napier H24 is this:
The final test engines delivered 5,500 hp [13](4,100 kW) at 45 lb/in2 boost. By the end of World War II, there were several engines in the same power class. The Pratt & Whitney R-4360 Wasp Major four-row, 28-cylinder radial produced 3,000 hp (2,280 kW) at first and later types produced 3,800 hp (2,834 kW), but these required almost twice the displacement in order to do so, 4,360 cubic inches (71 litres).

 

[Steamchick]

A mate suggested Alan Millyard is an expert - see this link - if it works for you.
https://uk.images.search.yahoo.com/...sted_003&hspart=iry&hsimp=yhs-fullyhosted_003Ken

 

[Steamchick]

Also:
https://www.youtube.com/user/millyardviper
Incredible!

 

[L98fiero]

No-one in their right mind - which means a lot of modellers will have a go , now...

But I have never seen a model of one of those, so maybe there is a point of complexity that modellers won't pass?

I had to do a search as I had seen an article on it years ago, but it has been done, all without CNC, Napier Dagger H-24
https://modelengineeringwebsite.com/Napier_aero_engine.html

 

[Steamchick]

Love it...
The modellers who attempt this sort of thing are world class. "Olympian" best describes their efforts.
I once owned a "family heirloom" coal truck that was used as a sales model to explain why colliery owners should buy hundreds of this design from my ancestor's business. Fantastic detail, but when the family down-sized (jobs and life necessity) I passed it to the Newport model Engineering/railway group and have never heard of it since. that probably got me into modelling, as well as the models of liners and ships in Cardiff museum.
Nostagia ain't what it used to be!
K

 

[Steamchick]

Or "Nostalgia"...

 

[Steamchick]

Did you ever hear of the Arial square four moyorcycle? I guess it's long-levity and reliability was due to the slow engine speed and low stressing of the engine - single carb and not tuned for power. Not sure of the phasing, but I think it had contrarotating cranks geared together?
K

 

[Peter Twissell]

Yes, we are using gears from the Ariel four to couple our Triumph engines together.

 

[Tim Wescott]

But Tim, that should not stop you making an A57.... !

First I need to manage a running single cylinder, or at least one that's broken in before it's worn out.

I think if I were going to start down the "complicated aero engines" road, I'd start with a Junkers Jumo or similar opposed-piston engine. Why? It gives me more of a nerdy "zing" than an H engine. Why more of a zing? I dunno!

 

[Peter Twissell]

I completely understand the attraction to 'odd' engines, like the Jumo.
If anything, I would have thought the Jumo would be less challenging to build in miniature than a conventional OHV 4 stroke. No fiddly valves and seats/guides.
Reproducing the direct injection system might be a struggle, but I can imagine ways to simplify it for a model.

 

[Tim Wescott]

Maybe a Jumo-esqe engine with fewer cylinders, and a carburetor? Still need to make a blower, though.

 

[Steamchick]

Maybe there is a carbon-vane blower readily available from a small motor scooter? - Then you can adapt it until you make your own? - I think they are pretty small?
K

 

[Steamchick]

Also,. most blower engines (and turbos) start and run with virtually no boost.
K

 

[Tim Wescott]

Four stroke engines with supercharging -- yes.

The original "modern" two-stroke engine, by Dugald Clerk, used a pumping piston separate from the power piston, and did not use the crankcase for primary compression. There's a whole family of two-stroke, usually Diesel, engines that use a positive-displacement blower instead of crankcase compression to force air into the cylinder for scavenging. The Jumo (and Detroit Diesel, and most Diesel ship engines) use this method. These engines need the blower to get air into the cylinder.

The two-stroke design that most people are familiar with, that uses crankcase compression to pump air into the cylinder, was invented by Joseph Day later on.

 

[earlwb]

Way back circa 1979, Webra took two of their 10cc glow engines and made a mount for them and used a gear drive to couple them together. That was when the large size pattern planes were coming into play for the Las Vegas Tournament of Champions pattern contests. Later Webra made a single cylinder 20cc glow engine that replaced the twin.

A number of different fellows over the years have ganged together various numbers of Cox .049 engines together to make twins and radial engines out of them. Hear are some of the engines I have seen.

 

[earlwb]

Oh yeah speaking of little superchargers. RB Innovations make and sell superchargers for small RC car glow engines:

https://rbinnovations.com/collections/super-chargers-to-fit-associated-brand-chassis
There is something like a scale effect that takes place with small engines and superchargers that tends to affect performance quite a bit though.

 

[earlwb]

A company in California made a supercharger for a Saito glow Rc engine years ago. They did it to showcase their machining skills for customers. But it works and it does look really cool too.