Bristol Hercules 14 Cylinder Sleeve Valve Radial
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- เผยแพร่เมื่อ 13 มิ.ย. 2008
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Bristol Hercules 14 Cylinder Sleeve Valve Radial Engine Run
In 1986 the Bristol Freighter ZK-CPT ('Merchant Courier') was flown into Omaka Aerodrome (Blenheim, New Zealand) and retired. The aircraft engines were subsequently run on several occasions, but this has not occurred for over 20 years.
Enter Alastair Marshall - ex RNZAF Engine Technician, now commercial pilot, and a piston engine enthusiast. Over the past few months, Al has been working on the two Bristol Hercules engines on the aircraft, with the goal of getting the old girl to come to life once more.
On 13th June 2008, Stage 1 of the project was completed - the port engine was successfully run for the first time in over two decades. Well, done that man!
We look forward to Stages Two (starboard engine run) and Three (a full aircraft taxi) soon!
A high quality downloadable version of this movie is available on the Historical Aviation Film Unit website:
www.aviationfilm.com/bristol/e...
If anyone wants to read more about this project, see this website:
rnzaf.proboards43.com/?board=A...
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This video material may not be reproduced in any form (except as an embedded video on any other website), without the written permission of the Historical Aviation Film Unit. - ยานยนต์และพาหนะ
During my 5-year engineering apprenticeship in the late 1950s with the Bristol Aeroplane Co. at Filton, England, we had to take apart and rebuild a Hercules engine and a Proteus turboprop (the latter used on the Britannia aircraft). We were trained to operate every machine in the factories and make all our own tools from raw material, plus night school after the day's work and then college. I don't think lads have such training these days, with the ease of computers to do much of the theoretical work and calculations.
It took me about three months of spare time work to get both engines to the point where they could be run. They didn't need a great deal of repair/rectification, but needed quite a lot of system inspecting and/or testing to make sure everything worked.
I watched from the tower as Captain Bob Guard short three point land one of these with a 15_20 kt quartering tailwind in about 1986. Impressive doesn't describe what I saw, it was amazing.
Found the video by accident. It brought back memories of the early part of my apprenticeship with Air NZ (69-74) We overhauled those complex engines at the old Mechanics Bay base on the Auckland waterfront. Once the stock of Herc engines ran out we did some conversions of the Hastings variant to keep the Freighters flying. All good training for my future career as a pilot of turbine powered aircraft.
These used to fly over my school in Wadestown after leaving Rongatai (1950s). Freaking noisy they were. Last one I saw (2018) was at Wetaskiwin, AB, Canada.
She can run on the prime alone but was in fact running on her carb albeit very rich (hence the dark smoke). She was running at about 900 rpm on the 1st two attempts but the slow running jet needs a tweak to lean her off a bit. At 1300-1400 rpm, she sweetens up beautifully. It sounds quite glorious from up in the cockpit with all the windows open.
I've since run both engines together. They run beautifully and I'm now in the process of reactivating the pneumatic system. Hopefully she can be taxiied shortly.
I lived under the western approach to Mangere for a few years in the mid 70's to early 80's and saw one of these on a regular basis. Maybe it was this Bristol.
Thanks for preserving this piece of history.
I love watching the old radials start up. ... counting the chambers as they come to life.
I like how he says mind the prop instead of clear prop. =)
@TestECull yeah I did consider that and we tried opening her up a few times. Nothing happened! This carb has an eccentric input to give the pilot control of the throttle butterflies up to 10-15%. Oil pressure operates the carb beyond this. As much as I wanted to open the throttle, 20 years of stodgy, sludgy old oil had to move thru the carb before she would respond. I had SAFE Air's former chief pilot, the late Bill Ashley, Reg Taylor and Lester Hope along with me for the very first run.
Well done Gents, you can imagine all those gears and cams revolving and lifting the sleeves. Makes poppet valves seem like a simple technology. Best of british luck. However an R 4360 coming to life is pure magic. How much work was involved to free up the "valve train" and caburettors. Top Job....
It's amazing that in those 20 years of sitting still it wasn't robbed out.One of the luxuries of living in NZ I suppose.Anything left standing unattended in the UK for more than a week disappears or gets stripped.
silver760 The Kiwis are proud of their history, something the British are the total opposite of. One of my uncles is British, and he too agrees.
Oh the memories. Worked on RNZAF Bristol Freighters in '60s & 70's. At one time in about 1966/67 I had to adjust the vacuum relief valves mounted right behind the engine. I was sat in the nacelle a foot behind the engine at full power. Awesome.
Lovely to see and hear the Bristol. Flew in one to the Chatham Islands in 1975, sitting in the passenger pod. 3 hours at 180 knots and 8000 feet. They used to fly over my house in Khandallah Wellington - difficult sound and I said
Oops - I sent that unfinished! Whenever I heard the distinctive sound I always looked out to see her go over.
We live on an old WW2 bomber station.
It must have been amazing to hear all the Hercules motors on a Squadron of Blenheims at full throttle at the start of a raid.
Fantastic job guys.👍
Hi Jon. Just to put you in the picture the engines in the Blenheims were Bristol Mercurys . A much smaller engine with about a third of the power. Crikey , with two Hercules the Blenheim would have been capable of 550+mph ! I think the Halifax and Short Stirlings were Hercules powered.
@@johndavey72 of course, you are right. I had a bit of a brain fart when I posted that comment.🙂
@@johndavey72 yes you're right about the short sterlings because my nan told me a lot about them has she helped to build the wings for them in the war
I flew in several RNZAF Freighters from Changi to Malacca back in the 60s. Still one of the most memorable things I have ever done.
Is it very noisy inside the fuselage or cockpit? Seems like it would be. I love the Hercules engine. It was ahead of its time and very innovative
Great stuff from a Bristol born and bred lad and seeing them flying
Also as fitted to the Vickers Varsity, 5 FTS Oakington. Fondest memories. Fuel cooled, oil burning!
It's like the flight of the Phoenix!
Once the blokeage have cleared any blockage in the cylinders the engine is ready to be started. The manual suggests that the starter is first used to turn the engine through 4 blades. The starter is left running and the primer circuit is energised for a further four blades. The engine swallows a fairly sizeable amount of fuel before the magnetos are flicked on. This connects the booster coil and crank plus fuel plus spark equals what you see on video. Enjoy. I did!!!!
Congratulations, Alistair!
Was great to hear them "in the flesh"
I worked on these aircraft when I was an apprentice for channel airways in the uk
Sleeve valve was a great design, but once used a bit, - especially in desert conditions, they drank oil like a thirsty sailor hitting port ! I remember them well !
Well cool! Would love to see it flying!! Thanks for posting
Great to see the old girl reving up! GR8! 😁
We had 3 at Mallala SA 1953, they were new and worked a charm. The beasts were not as clumsy as they looked. Good load for those days.
In about 1987 at the wind-up of Safeair all flying BR170's, around 6 or 7 from memory, took off from Woodbourne Airfield, formed up and did a flyover of Blenheim. The whole event was filmed by someone from the balcony of the control tower. Who was that man? Where is the video capture of that historic event? I would love to see it. I was in the tower at the time and wore a sports coat and tie as a mark of respect.
Sounded great by the end! Would love to see her fly again!. Beautiful sounding engine!
You and me both!
Great work, lovely to see one of these running again!
Long may she run and live on.
8 Blades by hand to clear oil from bottom cylinders. Stops hydraulic lock and engine damage.
This type starred in the movie "Man in the sky" with Jack Hawkins in 1957
job well done to the people who got her going again!i hope she flys again one day! that would be cool!!!!
thats what i call a REAL engine!
Nice to just sit back and watch that....very nice ...Sort of reminded me of'' flight of the Phoenix'' with Jimmy Stewart ....
Amazing! Have never seen an aircraft sleeve valve engine before. I know about only by an old technical book printed 1940.
What 1940? the last Hercules engine type 739 (2040hp) was built under license in France by SNECMA up to 1964, to fit the Nord 2501 Noratlas military transport aircraft who was use in the french airforce up to 1998.This aircrafts was use in many countries, inclusive Germany and Israël...One is maintained airworty in France and is visible in many airshows...
Look up Napier Sabre, interesting engine sleeve valve twin crank H24 layout.
Great work!!! Fantastic!! REALLY!
Very nice sound. Cool aircraft. Thumbs up! :)
Greetings
Mega
Last live ones of this breed I saw were G-BISU and G-AMLK. Great work and keep it up! I can't wait to see it taxi on youtube!!
First hear that sound about 53 years ago when posted to 2ATU at RAAF Edinburgh as an Engine Fitter. Good reliable engine, but always leaked plenty of oil.
Find a radial that doesn't leak it's share, only way to know there's an oil problem seems to be when it's not leaking anymore!
NO: engine in good conditions burn the Hercules not more oil as a common US radial: i known this engine on the Noratlas, as mecanic...(hercules engines built under license in France by SNECMA)
You can see that on the last flying Noratlas...
Uma obra de Arte. Deve preservar para as futuras gerações.
She sounded pretty good even for youtube lol, keep up the good work mate!
Just a note about the starting sequence. It appears that the starter when first energized, winds up a manual spring. As the spring winds up it increases the tension on the engine pinion gear and as its torque increases it increases the load on the starter motor which causes it to slow down until it overcomes the resistance of engine friction. As engine turns over and first cylinder fires, the spring tension helps to increase engine speed, thus increasing potential startup of engine. My Thoughts.
Bravo!
Give it some bloody stick man !
if you had heard a beverly ticking over wow it had four of these engines !!
Awesome.
Love it.
i love the smell of av-gas in the morning
Whilst in the RAF, I loved the possession of Avgas in the morning!
woow amazing... are they going to fly it ??? would love to see it !!!
What a din! a lovely din
that was painful . . .
Mind the prop!
did the engines have to be de-sludged before running them?? i is well known aparently that these engines sludge up and block up oilways especally when they sit for a long time?
These engines don't have an inertia starter. They are a direct drive electric starter that drives through a clutch. The clutch is set to ensure the engine won't be forced to rotate if there is a hydraulic lock in the lower cylinders. It is a multiplate clutch that is gradually engaged. If the engine turns before the torque threshold is reached all is good. If not, it will continue to slip and protect the engine. I haven't yet got my head around the nitty gritty of it all! Too British....
Great to see these engines running again but no good in a emergency to get up in the air as you wouldn't of had the engines started 😀 😉
Very true
As an old RNZAF Freighter pilot - 1960 vintage - it was great to see the old girl taxying again! When are you going to have her ready for a takeoff? One point though - why were you taxying it with the nose door hatch open??
Bloody Marvellous!
Makes me happy. Typical good NZ humour too.
Is this one of the old IPEC aircraft from Essendon in Australia?
No, this is a ex-SAFE Air machine, in New Zealand.
LOL yep we like to drive on the wrong side of the road too, it is actually turning in the right direction for that engine, if you look at the blades you'll see the leading edge is reverse to most props you're used to seeing.
Was she just running on the prime the 1st 2 attempts?
Chitty Chitty Bang Bang!
this engine sounds like when i recycle empty beercans :P
That's oil you're seeing, common for radial engines to smoke.
The saying for radial engines goes " if it aint leaking oil, it doesnt have any"
Great. You used the multicam modus. I did too for Handproping and landing in my Video about the Aeronca Champion. One Question: " Are the Ancestors of this famous Engines from the Beaufighter?"
Yes Beaufighter was powered with Bristol Hercules or some types with Roll-Royce Merlins
Could stand the idle mixture a little weaker?
Any updates on this wonderful old machine... Is it flying??
Unfortunately not. Still taxis about now and again, though more often just doe an engine run. The cost to get this old bird flying again would be simply enormous, and it's unlikely anyone has the resources or desire to do that. :-(
@@historicalmachines thanks for the update.. Wonderful sounding engines.. At least they are running and giving people the gift of hearing the sounds of the past in person... Would love to see and hear them but a ticket to NZ from Ireland is out of the question..
At least those crazy Brits has the adventurous spirit to keep something like sleeve valves alive long after poppets became dominant. Besides, it just sounds awesome.
Why do modern people always battle to get old engines started? Not enough electronic systems to think for them?
When this video was shot, these two engines had NOT been run for many, many years -- this was the culmination of a significant restoration of the engines.
How do you go getting parts for these engines?
Aircraft graveyards have lots of parts. Also you can source similar parts and for some things like exhaust manifold you can probably machine yourself. But as long as it isn’t overly damaged you don’t need many new parts to get and engine to start just the patience.
I suppose cylinder sleives have good oil supply advantage over poppet valves which are dry and can easily seize after short time
Much easier to pull it through if the lower cylinders have had plugs pulled & accumulated oil drained out first. I am assuming that had been done already.
Nice Herc :-)
Check out my little baby lawnmower sleeve valve, and see if you can figure out where I got the head design from!
Yep it was the Herc & Centaurus.
The sleeve drive is off the Napier Sabre.
Keep them sleeve valves running!!! :-)
Motores dificiles, facilmente con fallas, el sistema de valvulas distinto de las habituales no era confiable, creo que ya no deben quedar estos aviones Bristol con aquellos motores.
Uncommon maybe, unreliable no Napier had problems with their early engines until Bristol started providing them with sleeves. More efficient and powerful than in period poppet valve engines
It almost sounds like they are directly turning the engine over with the inertial starter motor.
Is it back in the air?
Unfortunately not, and not really ever likely to be as it would cost way too much.
Historical Machines TV sounds kinda cheesy I know but if you started a go fund me, I bet you could get close with the right advertising
@crushingvanessa There are none left in taxiable condition except this one.
I'm not sure, but I think the electric starter motor spins up a flywheel. Once it's up to speed a clutch connects it to the engine. I could be wrong though.
That's correct
Bristol freighter?
Indeed it is a Bristol Freighter!
@@historicalmachines had a friend who used to pilot them many years ago. The story was ! if he or the co pilot had too stretch their legs they used a small bike in the cargo hold. if the pilot in command wanted a laugh he would nose up or down depending on which way the bike was handing. Cheers
wasnt firing on all cylinders for a while there
Was commonly known as the “Bristol Frightener” in the RAF.....much hated by mechanics and crew alike !
@schlusselmensch ....wondered the same thing.
Besides do you know why I even said wrong plane ? It's because the gentleman I was replying to was quoting a line from the movie "Flight of the Phoenix" This type of plane was not in that movie.
Sure sounds different from a P & W radial....I think we have one of these in our Aerospace Museum - Aerospace Museum of California - interesting design.
Sleeve valves as opposed to conventional poppet valves. Larger airflow in and exhaust out as ports are bigger in sleeve than conventional poppet type valve I suppose that makes a good bit of difference to sound.
I Really dont know how Could a Single Sleeve Valve System operate but I do know how the Willys Knight Dual Sleeve Valve Engine work. Essentialy as what bazwabat the Piston moves up and down within the Sleeve's wich uncover the intake and Exaust ports. A sleeve valve eging has every advantage possible (including reliability) over a Poppet valve engine except it has poorer sealing because of the sleeves.
@larrylewislarry Ahh, I see. Strange design, but I suppose it puts a bit of a fail-safe in should it lose oil pressure.
I would have cracked the throttle open about 15-20% the moment it fired off the first time instead of letting it choke and sputter on whatever nastiness it was choking and sputtering on. But that's just me.
Great engines but used large volumes of oil.
Too much complication/gear sets
finally put paid to the sleeve valve..
No way would I fly anywhere in that contraption. What a tub 😂
They were pretty rock solid!
Sleeve valve engines use a lot of oil. They have no piston rings to control oil burn, so they use a lot of oil, and smoke a lot!
all false, as rings, and , if warmed up in normal t° did the Bristol NOT smoke, and the oil consumption is comparable to common radial engines...the different Knight engines, they did smoke and burn lot of oil, and was far less reliable as Bristols who use a totaly different system with a single silicon nitride steel sleeve...
@@leneanderthalien Later Knight engines with a properly operating oil rectifier used far less oil than earlier engines and did not smoke excessively. Knights were dead reliable actually and would routinely rack up high mileages when it was common for engines to need valve jobs at 15,000 or less. A Knight Light Six lasting 70,000 miles or more was not considered remarkable. I don't know where you heard of poor reliability, they could last to ridiculously high mileages with regular oil changes.And yes, I am familiar with them, there is one in my garage. They were also, like the Bristols, mechanically extremely quiet.
All big radials use sizeable quantities of oil, 18 pistons the size of paint cans are bound to go through a bit. In my experience, they leak more oil than they use though.
👍👍👍 🇧🇷
Radial piston engine much more economical than a jet or turbine engine.
NNNNice !!!
Depends on what you mean by economical. Time is money, remember.
its a shame they never flew this plane.
IM GONNA USE ONE CARTRIDGE IGNITION OFF CLEAN OUT THE CYLINDERS
Open up the fuel quicker once fired making the old girl hunt and struggle knobs
Still preferable to Ryanair
NOt sure I understand that starter. It sounds as if it's being 'clutched'.....
It’s a inertia starter, it uses centrifugal force to spin the engines fly wheel over
bloody engines turn the wrong way...lol
for scientists it's the right way: the "trigonometric" way