It has been remarked before in more than one Hackaday post, that here are many communities like our own that exist in isolation and contain within them an astonishing level of hardware and engineering ability. We simply don’t see all the work done by the more engineering-driven and less accessory-driven end of the car modification scene, for example, because by and large we do not move in the same circles as them.
One such community in which projects displaying incredible levels of skill are the norm is the model making world. We may all have glued together a plastic kit of a Spitfire or a Mustang in our youth, but at the opposite end of the dial when it comes to models you will find craftsmanship that goes well beyond that you’d find in many high-end machine shops.
A project that demonstrates this in spades is [mayhugh1]’s quarter-scale model of a vintage Rolls-Royce Merlin V12 piston aero engine. This was the power plant that you would have found in many iconic Allied aircraft of the WW2 era, including the real-life Spitfires and all but the earliest of those Mustangs. And what makes the quarter-scale Merlin just that little bit more special, is that it runs. Just add fuel.
The build took place over a few years and many pages of a forum thread, and includes multiple blow-by-blow accounts, photos, and videos. It started with a set of commercial castings for the engine block, but their finishing and the manufacture of all other engine parts is done in the shop. In the final page or so we see the video we’ve placed below the break, of the finished engine in a test frame being run up on the bench, with a somewhat frightening unguarded airscrew attached to its front and waiting to decapitate an unwary cameraman. Sit down with a cup of your favourite beverage, and read the build from start to finish. We don’t think you’ll be disappointed.
If this Merlin has whetted your appetite, you’ll be pleased to hear that the HMEM site it’s hosted on has been going for quite a while.
Thanks [nfk] for the tip.
Now to build the P-51 Mustang to go with it.
Or a Spitfire, or a Hurricane. I believe most of the P-51s wore US made engines.
Original design was for an Allison V12, but the British put a Rolls Merlin V12 in it to get high-altitude performance. Later ones were powered by Packard’s version of the Merlin with two-speed supercharger.
The P-51 was developed as a plane for the RAF,it wasn’t until they put the merlin in it that the USAAF took any interest in it.
50,000 + Merlins were made in the US by Packard beginning in 1941.
Hardcore drone, or toddler’s toy, your choice!
Nah, make a second Merlin and build a Mosquito.
Make 4 and build a Lancaster…
First thoughts. 1/4 scale Lancaster.
Maybe mount two on wheels and have a really fun, [read dangerous] pod racer style chariot.
I think I want to build a merlin. How do I get started?
Go to the Bank?
Over-engineered, noisy and dangerous table fan…
At 1/4 scale of a Merlin, you also forgot to add “overpowered” ;-)
Just wonderful, innit?
And fumes makes you dizzy, that’s a plus !
We have a war weekend (long story, look it up if you must) in Uppermill and there is a fair. This guy occasionally shows up. Contra-rotating propellers scare the crap out of me.
https://www.youtube.com/watch?v=9GhS0p2eJo0
Yeah, that’s going to pummel you into a really fine mist if you get too close.
Someone with the skill to build that has the skill to build a shroud and grill.
Question: Why, at exactly 1:00, does the operator apparently go full throttle for a split second, just before powering off the engine?
Presumably for the exhaust effect….or because he can…..
Quote from somewhere on the web:
“I still do it, it’s habit from driving over-carbed V8s when I was young. If you didn’t pop the motor after idling for a while, the plugs would load up and make it hard to start the next time.”
Sounds about right. I habitually do the same thing with an old motorcycle. It’s called “clearing the engine” if I recall.
“clearing the engine” @TGT “blow out the carbon”
Car Talk on the subject.
Tom: In the ’70s, cars had carburetors. Carburetors let gasoline slosh into the cylinders. And with all that excess gasoline, a buildup of carbon was a much commoner problem.
Ray: There was a school of thought that suggested that running the car at high speed would help clean the caked-on carbon off the valves and pistons.
Tom: But by “running the car at high speed,” they meant taking it on the highway for a long, high-speed drive – not stomping on the gas at a stoplight and leaving a lime-green AMC Pacer in the dust.
http://www.dispatch.com/content/stories/business/2011/07/16/flooring-it-wont-blow-out-the-carbon.html
When I was working on Griffons, I was told that it was to leave some fuel in the system to aid starting.
Love the guy with the E-stop switch. That would do some serious damage if it ever got loose.
The guys and gals that pull this stuff off blow my mind.
The attention to detail and patience is awe inspiring, not to mention the physics of making a scale engine just run. It’s not just the challenge of copying a scale but then making the adjustments to compensate for the flow of fuel and air,
Truly a labo(u)r of love!
Awesome that it runs so well, and look at the quality of the test stand. This guy is a serious craftsman.
beautiful piece of work, but i think he has too much spare time on his hands. what a go kart engine
Airscrew? Sounds like something to do with the mile high club…
British engine => British terminology.
:)
Wouldn’t be surprised if it was a drink.
Cool drugs mules Microlight motor
Roughly how much power does a one quarter size v12 Merlin produce?
“Normal” production Merlins (not racing engines) came in a lot of variants, ranging from about 1000 to 2000 horsepower. Assuming the same power/displacement ratio, a quarter-scale engine with 1/64 the displacement would be in the 15-30 hp range. (I would assume this naive scaling is an overestimate, because an optimal design at one scale would not be optimized for a different scale, but I really don’t have any experience with model engines.)
It’s possible that it could make more than 30hp since at 1/4th scale you can rev a lot higher than a full-size Merlin. I think stock they redline at 3000rpm. An engine of that size can easily handle 10k rpm.
This would make a really cool motorcycle engine. WW2 themed chopper…
You have heard of the motorcycle that used a slice of two cylinders from a Merlin V-12?
http://thekneeslider.com/5000cc-v-twin-motorcycle-engine-for-sale/
Yup. I read about that some 20 or more years ago.
Holy hell. 500 horses at 330 pounds. That’s not a bad thrust to weight ratio, is it? I bet merely touching the throttle on that bike launches it to the moon, dropping the rider off at a police station or hospital along the way. I want it.
Now it needs a 1/4 scale pulling tractor to mount it in. :)