Round Engines
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Round Engines
DEDICATED TO ALL THOSE WHO FLEW BEHIND ROUND ENGINES, better known as piston pounders, recips, oil leakers, etc.
We have to get rid of those turbines, they're ruining aviation and our hearing...
A turbine is too simple minded, it has no mystery. The air travels through it in a straight line and doesn't pick up any of the pungent fragrance of engine oil or pilot sweat.
Anybody can start a turbine. You just need to move a switch from "OFF" to "START" and then remember to move it back to "ON" after a while. My PC is harder to start. (The first No Brainer)
Cranking a round engine requires skill, finesse and style. You have to seduce it into starting. It's like waking up a horny mistress. On some planes, the pilots aren't even allowed to do it... (and for good reason).
Turbines start by whining for a while, then give a lady-like poof and start whining a little louder.
Round engines give a satisfying rattle-rattle, click-click, BANG, more rattles, another BANG, a big macho FART or two, more clicks, a lot more smoke and finally a serious low pitched roar. We like that. It's a GUY thing...
When you start a round engine, your mind is engaged and you can concentrate on the flight ahead. Starting a turbine is like flicking on a ceiling fan: Useful, but, hardly exciting.
When you have started his round engine successfully your Crew Chief looks up at you like he'd let you kiss his girl, too!
Turbines don't break or catch fire often enough, which leads to aircrew boredom, complacency and inattention. A round engine at speed looks and sounds like it's going to blow any minute. They sometimes do. This helps concentrate the mind! It also contributes to the illusion of DAP, or Dirty Airplane Parts, quite fondly revered by some.
Turbines don't have enough control levers or gauges to keep a pilot's attention. There's nothing to fiddle with during long flights. We usta tell the newbies "we'll let you sit up here, but dont' touch anything".
Turbines smell like a Boy Scout camp full of Coleman Lamps. Round engines smell like God intended machines to smell.
Anonymous
We have to get rid of those turbines, they're ruining aviation and our hearing...
A turbine is too simple minded, it has no mystery. The air travels through it in a straight line and doesn't pick up any of the pungent fragrance of engine oil or pilot sweat.
Anybody can start a turbine. You just need to move a switch from "OFF" to "START" and then remember to move it back to "ON" after a while. My PC is harder to start. (The first No Brainer)
Cranking a round engine requires skill, finesse and style. You have to seduce it into starting. It's like waking up a horny mistress. On some planes, the pilots aren't even allowed to do it... (and for good reason).
Turbines start by whining for a while, then give a lady-like poof and start whining a little louder.
Round engines give a satisfying rattle-rattle, click-click, BANG, more rattles, another BANG, a big macho FART or two, more clicks, a lot more smoke and finally a serious low pitched roar. We like that. It's a GUY thing...
When you start a round engine, your mind is engaged and you can concentrate on the flight ahead. Starting a turbine is like flicking on a ceiling fan: Useful, but, hardly exciting.
When you have started his round engine successfully your Crew Chief looks up at you like he'd let you kiss his girl, too!
Turbines don't break or catch fire often enough, which leads to aircrew boredom, complacency and inattention. A round engine at speed looks and sounds like it's going to blow any minute. They sometimes do. This helps concentrate the mind! It also contributes to the illusion of DAP, or Dirty Airplane Parts, quite fondly revered by some.
Turbines don't have enough control levers or gauges to keep a pilot's attention. There's nothing to fiddle with during long flights. We usta tell the newbies "we'll let you sit up here, but dont' touch anything".
Turbines smell like a Boy Scout camp full of Coleman Lamps. Round engines smell like God intended machines to smell.
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Amen to that!
Oh for the sleeve valve engine; watching a Varsity wet start; those flames belching from the exhaust - ah De Hav er sorry wrong company, but you get my meaning.
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Radial engine starting
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Well written Evileyes.
You brought back some fond memories of my early days in flying. The DC-3, Convair 300 (That was a 220 with 440 engines), Howard 350, LearStar Mk. II and the good DHC-2 Beaver. I flew 6 trips as a co-pilot in DC-6s, lost the oil cap on number 3 one night. (Talk about a mess.)
Pigboat needs to read this thread.
I only wish I had written it Con. Was sent to me by a mate from my T-28 days. No idea of the true author but I'd buy him a beer. Cheers, Evileyes
You brought back some fond memories of my early days in flying. The DC-3, Convair 300 (That was a 220 with 440 engines), Howard 350, LearStar Mk. II and the good DHC-2 Beaver. I flew 6 trips as a co-pilot in DC-6s, lost the oil cap on number 3 one night. (Talk about a mess.)
Pigboat needs to read this thread.
I only wish I had written it Con. Was sent to me by a mate from my T-28 days. No idea of the true author but I'd buy him a beer. Cheers, Evileyes
http://i114.photobucket.com/albums/n...s/P1000546.jpg
All the more impressive for the fact it was designed at home and built from 2 scrap VW car engines and a homemade crankshaft and case.
Search for "Webster Whirlwind"
http://www.youtube.com/watch?v=drw7kFC_teU
...and running at....
http://s82.photobucket.com/albums/j2...RunFFF06-1.flv
I'm the poor sod on the starter motor (DAF Variomatic car engine with the pistons removed). That yellow jacket ain't schrapnel proof!
All the more impressive for the fact it was designed at home and built from 2 scrap VW car engines and a homemade crankshaft and case.
Search for "Webster Whirlwind"
http://www.youtube.com/watch?v=drw7kFC_teU
...and running at....
http://s82.photobucket.com/albums/j2...RunFFF06-1.flv
I'm the poor sod on the starter motor (DAF Variomatic car engine with the pistons removed). That yellow jacket ain't schrapnel proof!
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But to be fair, in-lines, Vs flats and Xs (I'm thinking Napier Sabre here) are all God's wonders. Oh, and the H - Lycoming was it? They don't have to be round, just not turbine... right?
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Hands up all of you who've started one of HM's Chipmunks! No namby-pamby electric starter motor, no Sir - a fine round of .303.
Nothing like the smell of cordite in the morning
Nothing like the smell of cordite in the morning
treadigraph
I thought that the Napier Sabre was an "H" engine. My old man flew Typhoons(the tail dragger) and he called the Napier Sabre an "H" engine.
I stand to be corrected though.
CC
I thought that the Napier Sabre was an "H" engine. My old man flew Typhoons(the tail dragger) and he called the Napier Sabre an "H" engine.
I stand to be corrected though.
CC
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Compass, you are correct and I am drifting... just a bit... 'Ere I'm dropping me aitches... XXXX that! What was the X engine, was that the Big Lycoming jobbie?
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A friend (who inhabits here, sometimes) on watching one of my yak start-ups described it as 'biblical'.
Lots of smoke. Lots of noise. And the smiting of lesser objects if you're not careful (spamcans parked too close behind
).
It was much as described at the start of the thread. Press the 'start' button. There’s a loud ‘pop’ followed by an asthmatic wheezing as compressed air is admitted to the cylinders via a pneumatic distributor to turn the engine. The prop jerks slowly round a revolution and one cylinder fires. Pump the throttle to keep the prop turning. More cylinders join in with a sudden roar, and clouds of smoke stream from the exhausts. The prop dissolves into an invisible disc, blowing the smoke instantly backwards – but it’s not sustained and the engine dies, clattering round slower and slower, the prop becoming visible once more. Pump the throttle again, right hand going to the primer. But before I can decide whether to prime or not, several cylinders fire up raggedly accompanied by more grey smoke which is blasted under the wing by the propwash. The engine dies again, the prop slowing, but only for a second or so. With a glorious throaty roar all the cylinders report for duty, and this time as though they mean it. The engine clears its throat with a cough or two, becomes self-sustaining, and settles into smooth regular song. The battle is won and I snap the starter button cover down.
These days (and indeed, for many years prior to the Yak), it's a Chippy I fly. Electric start, no cartridges for us civvies. But still a nice art to bounce the prop over compression with judiciously-timed stabs of the starter button. If you've primed it correctly, and the impulse mag isn't sticking, she'll fire up with that lovely dH blatter.
SSD
Lots of smoke. Lots of noise. And the smiting of lesser objects if you're not careful (spamcans parked too close behind
).It was much as described at the start of the thread. Press the 'start' button. There’s a loud ‘pop’ followed by an asthmatic wheezing as compressed air is admitted to the cylinders via a pneumatic distributor to turn the engine. The prop jerks slowly round a revolution and one cylinder fires. Pump the throttle to keep the prop turning. More cylinders join in with a sudden roar, and clouds of smoke stream from the exhausts. The prop dissolves into an invisible disc, blowing the smoke instantly backwards – but it’s not sustained and the engine dies, clattering round slower and slower, the prop becoming visible once more. Pump the throttle again, right hand going to the primer. But before I can decide whether to prime or not, several cylinders fire up raggedly accompanied by more grey smoke which is blasted under the wing by the propwash. The engine dies again, the prop slowing, but only for a second or so. With a glorious throaty roar all the cylinders report for duty, and this time as though they mean it. The engine clears its throat with a cough or two, becomes self-sustaining, and settles into smooth regular song. The battle is won and I snap the starter button cover down.
These days (and indeed, for many years prior to the Yak), it's a Chippy I fly. Electric start, no cartridges for us civvies. But still a nice art to bounce the prop over compression with judiciously-timed stabs of the starter button. If you've primed it correctly, and the impulse mag isn't sticking, she'll fire up with that lovely dH blatter.
SSD
Here's another example of the big round sound, courtesy of the Pratt R2800.
When the weather turns cold, before you get a chance to experience all the fun of a radial, there are certain preparations involved. Depending on the expected temperature on the following am, on the last flight of the day you may be called upon to perform a procedure called 'oil dilution.' Oil dilution is where the engine oil is diluted by introducing fuel into the engine oil system, via a solenoid, at a pre-determined rate, typically - on the small Pratts anyway - of one quart of gas per minute for each minute the dilution solenoid is held open. Depending on your company procedures, you may have to do both a hot dilution and a cold dilution. A hot dilution is done before shutdown and before the oil temperature has dropped below 50*C, and serves principally to dilute the oil in the oil cooler and prop domes. Typically, this would be one minute if the expected temperature for the next am was forecasted to be -20*F. A cold dilution was done with the oil temperature below 50*C, and at the expected -20, would be for two minutes. After your hot dilution, you restart the engine and stabilize at 1000 RPM, then hold the oil dilution switch down for the required time. At the end of two minutes, close the throttle, and mixture, but hold the dilution switch open until the propeller has stopped. The oil temp should not have risen above 50* during that two minute run because the fuel would evaporate out of the oil, rendering your dilution null and void and causing great blasphemies early on the morrow when you attempted to start the beast. After the various ablutions with the oil system, it is time to install the engine tent, a bulky contrivance not unlike a circus tent. One propeller blade is moved to a horizontal position, and a special sleeve sewn onto the tent is slipped over the blade, which is then raised to the vertical, dragging your tent up over the cowling. You then proceed to the other side of the aircraft, grab the skirt of your tent and pull it down over the cowling, attaching the two skirts of the tent together with the handy-dandy little cords supplied for that very job. There's more slack to the tent skirts, so you gather that part up and wind it around the other blade(s) of the prop, tying the whole thing up with lengths of rope. You have, of course, already installed your wing covers while you were waiting for the oil temperature to drop for your cold dilution. The above procedures have, in all probability, been carried out in the dark. If you are lucky, the wind is calm.
On the morrow, you arrive at the strip. In the dark. And cold. If you are lucky a Herman Nelson is available, so if the gas engine on that apparatus will start, heat is at hand. You slacken off the ropes on your engine tent, and stuff one of Mr. Nelson's ducts into the engine accessories cowling and the other into the front of the engine. Retire to the company shack and embrace the oil stove. When you've stopped shaking from the cold, go out and remove the wing covers and check that the cylinder head temperature guage has moved from where it was huddling on the far left. Give the prop a few experimental wags to see if the cement it seemed to be stuck in has relinquished it's grip. If so, you are go. Pull the Herman Nelson out of range of the prop, whip off your engine tent via the reverse of how you installed it, and begin your start procedure. Pull the prop through a few times, six or nine blades, mount to the cockpit and hit the master. Throttle cracked, prop full fine, mixture idle cut-off, mags off. Six shots of prime, hit the starter, wait six blades and hit the mags. If you have done everything properly, it will be as Evileyes hath writ. Keep it running on the primer until a majority of the cylinders have joined the chorus, cast a glance at the oil pressure to verify its' health then advance the mixture to auto rich. Dead easy. But wait, for every action there is a consequence. You have to burn off the gas you diluted your oil with the previous pm. If you diluted for two minutes cold, then it will require ten minutes - five minutes per minute - to burn off the gas you added to the oil system. This at an oil temperature greater than 50*C.
It'll take about twenty minutes or better from the time you get the engine started until you are ready to aviate. During that time you sit huddled in the cockpit, scraping your breath off the windshield and thinking warm thoughts. 
Tomorrow we'll explore the use of the "blow pot," a device that can be used for preheat and asphyxiation, should you find yourself without benefit of Herman Nelson.
When the weather turns cold, before you get a chance to experience all the fun of a radial, there are certain preparations involved. Depending on the expected temperature on the following am, on the last flight of the day you may be called upon to perform a procedure called 'oil dilution.' Oil dilution is where the engine oil is diluted by introducing fuel into the engine oil system, via a solenoid, at a pre-determined rate, typically - on the small Pratts anyway - of one quart of gas per minute for each minute the dilution solenoid is held open. Depending on your company procedures, you may have to do both a hot dilution and a cold dilution. A hot dilution is done before shutdown and before the oil temperature has dropped below 50*C, and serves principally to dilute the oil in the oil cooler and prop domes. Typically, this would be one minute if the expected temperature for the next am was forecasted to be -20*F. A cold dilution was done with the oil temperature below 50*C, and at the expected -20, would be for two minutes. After your hot dilution, you restart the engine and stabilize at 1000 RPM, then hold the oil dilution switch down for the required time. At the end of two minutes, close the throttle, and mixture, but hold the dilution switch open until the propeller has stopped. The oil temp should not have risen above 50* during that two minute run because the fuel would evaporate out of the oil, rendering your dilution null and void and causing great blasphemies early on the morrow when you attempted to start the beast. After the various ablutions with the oil system, it is time to install the engine tent, a bulky contrivance not unlike a circus tent. One propeller blade is moved to a horizontal position, and a special sleeve sewn onto the tent is slipped over the blade, which is then raised to the vertical, dragging your tent up over the cowling. You then proceed to the other side of the aircraft, grab the skirt of your tent and pull it down over the cowling, attaching the two skirts of the tent together with the handy-dandy little cords supplied for that very job. There's more slack to the tent skirts, so you gather that part up and wind it around the other blade(s) of the prop, tying the whole thing up with lengths of rope. You have, of course, already installed your wing covers while you were waiting for the oil temperature to drop for your cold dilution. The above procedures have, in all probability, been carried out in the dark. If you are lucky, the wind is calm.
On the morrow, you arrive at the strip. In the dark. And cold. If you are lucky a Herman Nelson is available, so if the gas engine on that apparatus will start, heat is at hand. You slacken off the ropes on your engine tent, and stuff one of Mr. Nelson's ducts into the engine accessories cowling and the other into the front of the engine. Retire to the company shack and embrace the oil stove. When you've stopped shaking from the cold, go out and remove the wing covers and check that the cylinder head temperature guage has moved from where it was huddling on the far left. Give the prop a few experimental wags to see if the cement it seemed to be stuck in has relinquished it's grip. If so, you are go. Pull the Herman Nelson out of range of the prop, whip off your engine tent via the reverse of how you installed it, and begin your start procedure. Pull the prop through a few times, six or nine blades, mount to the cockpit and hit the master. Throttle cracked, prop full fine, mixture idle cut-off, mags off. Six shots of prime, hit the starter, wait six blades and hit the mags. If you have done everything properly, it will be as Evileyes hath writ. Keep it running on the primer until a majority of the cylinders have joined the chorus, cast a glance at the oil pressure to verify its' health then advance the mixture to auto rich. Dead easy. But wait, for every action there is a consequence. You have to burn off the gas you diluted your oil with the previous pm. If you diluted for two minutes cold, then it will require ten minutes - five minutes per minute - to burn off the gas you added to the oil system. This at an oil temperature greater than 50*C.
It'll take about twenty minutes or better from the time you get the engine started until you are ready to aviate. During that time you sit huddled in the cockpit, scraping your breath off the windshield and thinking warm thoughts. Tomorrow we'll explore the use of the "blow pot," a device that can be used for preheat and asphyxiation, should you find yourself without benefit of Herman Nelson.
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[/quote Hands up all of you who've started one of HM's Chipmunks! Nothing like the smell of cordite in the morning ]
Or to begin the day with a bigger & better bang , try starting a Provost
] Or to begin the day with a bigger & better bang , try starting a Provost