Bristol Hercules 14 Cylinder Sleeve Valve Radial

[sbentjies]

What a din! a lovely din

[alteisenfahrer]

Amazing! Have never seen an aircraft sleeve valve engine before. I know about only by an old technical book printed 1940.

[matthius13]

Very rich running there?



[steamgeezer]

IM GONNA USE ONE CARTRIDGE IGNITION OFF CLEAN OUT THE CYLINDERS

[johnpetermalcolm]

@steamgeezer

Hardy Kruger says "Du verdammter arshficker".

Dickies too pissed to care.

I appreciate your humour :)

[Kitcatcoat]

this engine sounds like when i recycle empty beercans :P

[BlackWiiOwner2010]

Very cool! Keep an eye out for a poof at 4:08.

[plummy1952]

if you had heard a beverly ticking over wow it had four of these engines !!

[wlb50]

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.

[fixitdude74]

For gawd sake, give it the gas pedal, rev it a bit!

[TestECull]

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.

[larrylewislarry]

@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.

[TestECull]

@larrylewislarry Ahh, I see. Strange design, but I suppose it puts a bit of a fail-safe in should it lose oil pressure.

[genmaxpain]

its great to be a kiwi

[nawindsor]

Most excellent latin lady **busizz4me.info**

[kirkconway]

It took a bit of doing,,,

But they took off and they run good now,

[schlusselmensch]

Could stand the idle mixture a little weaker?

[Dav123xyz]

@schlusselmensch ....wondered the same thing.

[rangersmustang]

The saying for radial engines goes " if it aint leaking oil, it doesnt have any"

[ccc771]

woow amazing... are they going to fly it ??? would love to see it !!!

[crushingvanessa]

There are at least two flyable ones in British Columbia and one here in Winnipeg Manitoba in the museum that is on static display, but was flown there in 1986.

[luke96241]

@crushingvanessa There are none left in taxiable condition except this one.

[fjbutch]

Nice to just sit back and watch that....very nice ...Sort of reminded me of'' flight of the Phoenix'' with Jimmy Stewart ....

[kyberforce]

bit more choke lol

[kilzwes]

It is the only one left in the world? He can not fly? I'm from Brazil!

[StopMotionNAnimation]

Bloody Marvellous!

Makes me happy. Typical good NZ humour too.

[fjbutch]

NNNNice !!!

[dogsbody710]

Great work, lovely to see one of these running again!

[1339LARS]

I say bloody good show!

[Shalinar45]

If these engines are in tune and well pampered, they are a joy to start and run...if they have been neglected and are handled roughly, big piston engines are tempermental beasts that will bite back.

[MCCXK120]

Awesome.

[camp69]

Well done!

[johnmc58]

Congratulations, Alistair!

Was great to hear them "in the flesh"

[atomage2006]

Great stuff from a Bristol born and bred lad and seeing them flying

[ChargerMiles007]

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!!! :-)

[hoggdawn]

Radial engines might be pieces of junk in economic terms but they sure are beautiful. Is there any sound as sweet? I think not! Keep 'em running!

[TheSteamLocomotive]

Radial piston engine much more economical than a jet or turbine engine.

[blue46gt]

Depends on what you mean by economical. Time is money, remember.

[oiseautempete]

@TheSteamLocomotive

Economical as fuel consumption yes, but not in maintenance: he need 10 or 15x more as a turboprop, and the high rate aircraft gazoline is 3x expansiver as kerozene...

[moxx064]

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.

[wrxguynz]

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?

[GerbilEssences]

I think you get a nasty bang if you don't de-sludge :)

[bazwabat]

The starter on the port engine had a problem but she is fixed now I believe

[larrylewislarry]

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!!!!

[larrylewislarry]

This is big round engine theory 101. There is an exam at the end. The radial engine can soak itself in oil if left stationary for a period. If the amount of oil in the lower cylinders exceeds the space left over between the piston and the cylinder you are in big trouble. If there is blokeage available, they are a good indication of any hydraulic lock that may occur. The Bristol manual suggests that groundcrew pull the engine through '8 blades' before start. PTO next....

[luke2reeve]

can sum 1 tell me wats the point in turning the properelor ova nd ova again

[larrylewislarry]

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....

[Nateb123]

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.

[joness105639]

Radials always sound awesome, but this one is especially nice

[Bamchucknorris]

you want to hear an awesome radial...

search on youtube "Wright 3350 Radial Engine"

its the first vid. You wont be dissapointed.

[flexyco]

Ah, thank you, that's the answer I was looking for. It seems this system has been used on various types in the past.

[gowron277]

If she can run and taxi then......what about flying? She belongs in the air...

[countrycanid]

Excellent work gentlemen! I look forward to seeing her move under her own power!

[oisiaa]

It almost sounds like they are directly turning the engine over with the inertial starter motor.

[afghanpilot]

Superb job gentlemen. Best of luck getting the rest of her flowing with life.

[MandolinHymns]

Wish I knew just how the "sleeve valve" system operated. That engine sure sounds sweet!

[bazwabat]

Basically the individual cylinders have a sleeve which goes up and down and the piston goes up and down within this sleeve. Instead of valves for exhaust and intake it has openings in the sleeve which align with the intake and exhaust manifold. Must be an interesting exercise making sure all the timing is right! Does make for a smooth sounding engine!!

[Detoyato]

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.

[Robkat3751]

Yes the sleeve moves up and down with the piston aligning intake and exhaust ports, I saw this on an animation. But what makes the sleeve move up and down if pushrods are not involved? I couldn't see any type of mechanical linkage.

[bazwabat]

In the front section of the crankcase is the sleeve valve operating mechanism. 14 small cranks(for each sleeve) driven by a series of gears(7) running off a single gear (the rear row of cylinders needing long spindles to reach them)

If you message me with your email address I can send you a diagram from a Bristol Hercules operating manual I have on loan.

Merry Christmas!

Barry

[larrylewislarry]

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.

[afconcorde]

I love the SAFE Air paint job we have one painted the same in Nelson

[bazwabat]

That takes me back. I was one of the lucky few to ground run the RNZAF museum's TBF Avenger in 1980 (and occasionally the Dakota and Devon before the plug was pulled on running them. Well done getting the Freighter running, very very interested in what was involved in getting her going again. (Also green with envy!)

[cjrudge]

Congratulations guys! What fun! What a great sound! I look forward to seeing the aircraft taxiing at Omaka during Easter 2009! Now I wonder if the pilot will do a "Spencer-Bower" and inadvertently get airborne . . . !

[wrxguynz]

job well done to the people who got her going again!i hope she flys again one day! that would be cool!!!!

[grogadile225]

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....

[larrylewislarry]

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.

[darrylfx]

Well done boys !! Lets see her fly one day.

i grew up in south wellington in the 70s-80s

and fell in love with the sound thay made.

In the 80s i had the thrill of flying ZK-CPT

from Blenhamto wellington. (with pilot)

110 knots at 1000ft A THRILL I WILL NEVER FORGET!!!

Keep up the good work i will keep in contact

Darryl Richards AKL

[Bergstaller01]

Was she just running on the prime the 1st 2 attempts?

[larrylewislarry]

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.

[Bergstaller01]

She sounded pretty good even for youtube lol, keep up the good work mate!

[newbonne]

What a unique exhaust sound. Can these engines still be rebuilt?

[delatbtah]

Great to see the sight of the old Freighter coming alive - I am just finishing an Air-Britain book on the history of the Bristol Freighter and that fact will be included - Well done to everyone concerned.

[Tillerman56]

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!!

[sjion]

Great work!!! Fantastic!! REALLY!

[xKmotx]

Bravo!