Author Topic: Radial or Inline?  (Read 851 times)

Offline mora

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Radial or Inline?
« Reply #15 on: May 21, 2002, 03:41:56 PM »
Another interesting engine. The Allison V-3420 24-cylinder double-v or W. Much like the Sabre but a little different cylinder arrangement.

Offline Mikepb42

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Radial or Inline?
« Reply #16 on: May 21, 2002, 08:25:00 PM »
In general terms:

radial engine advantages:

-Lighter weight per HP- no heavy cooling systems

-relative simplicity and durability

Disadvantages:

-Large frontal area to give every cylinder equal airflow

-Large cooling drag penalty from moving a large volume of air through the cowl or nacelle.

In-line,  or vee advantages: (liquid cooled only)

-Higher combustion temps possible,  so more power per cubic inch

-narrow,  low-drag profile

disadvantages:

-Heavy,  complex cooling system that has radiatiors,  which impart their own large drag penalty unless the designer is very clever.

by the end of the war,  I think it was agreed that neither configuration was totally superior.  Both engines were developed to high levels,  and placed on highly developed fighters.

Just my own thoughts,  though.

-Vspeed

Offline M.C.202

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Radial or Inline?
« Reply #17 on: May 21, 2002, 08:26:56 PM »
"BTW, Erik passed away several weeks ago after a long term fight with cancer. He is greatly missed.

My regards,

Widewing"


Damm!:(
If you ever had the chance to exchange messages with him, you know we lost one of the few people "who were there" that was willing to talk with the public at large.
He was nice enough to answer some questions I had on the C.W. Demon. In his writings to me he was every bit the gentleman. If your last name was the same as a certain American car company, it was a different thing.

Now I know what markings I want on the A.V.G. Hawk.

Rest in peace, and thanks from me for your service...

Offline Staga

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Radial or Inline?
« Reply #18 on: May 22, 2002, 12:40:41 AM »
Some old Ferrari 12-cyl boxers (Flat-12s) can be described as a V-engines because engine's crankshaft's "knees" (for connecting rods) and ignition timing were arranged similar way like in V-engines and not like they usually are in flat engines.

Offline Xjazz

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Radial or Inline?
« Reply #19 on: May 22, 2002, 03:26:36 AM »
Quote
Originally posted by Naudet
i think stage means that aircooled hat odd numbers in a row like 5,7,9,11 and so on, while inlines had even numbers like 8,10,12 and so on.


BTW
Audi had (have?) inline 5 car engine which runs very smoothly.

Offline Staga

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Radial or Inline?
« Reply #20 on: May 22, 2002, 03:41:11 AM »
Yeah, and Suzuki and Daihatsu had 3cyl engines too which btw had a very nice sounds. I believe first 5cyl engine was used in old Mercedes-Benz 300 diesel in late seventies AFAIR.

Offline Staga

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« Reply #21 on: May 22, 2002, 03:46:18 AM »
Yep, Mercedes OM617.912 used in early 300D's, came in Feb.1976.
I'm not sure if there were some earlier car engines with odd numbers of cyls.

Offline Naudet

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« Reply #22 on: May 22, 2002, 05:38:31 AM »
Yes i know that 5 cylinder inlines too.

My dad had such a good old 300 TD, very reliable.

The numbers i gave are for WW2 plane engines, yet did not hear that they used odd numbers for inlines.

Offline Wilbus

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Radial or Inline?
« Reply #23 on: May 22, 2002, 05:47:27 AM »
Sorry for my lack of knowledge but was Erik a WW2 pilot?
Rasmus "Wilbus" Mattsson

Liberating Livestock since 1998, recently returned from a 5 year Sheep-care training camp.

Offline Staga

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« Reply #24 on: May 22, 2002, 06:24:56 AM »
Something Google found: http://www.danford.net/erikrip.htm

Offline Duedel

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Radial or Inline?
« Reply #25 on: May 22, 2002, 06:45:14 AM »
Quote
Originally posted by Xjazz


BTW
Audi had (have?) inline 5 car engine which runs very smoothly.


Inline 5 cylinder engines are common engines. Volvo has one in many cars, Audi too.

Regarding the 180° V called Boxer. I thought the term "Boxer" for those engines is wrong cause in a "real" Boxer engine the cylinders are aranged in opposite direction (and working in opposite direction) while in a 180° V-engine the opposite cylinders aren't working in opposite direction.
(Wow bad english hope u can understand this) :)

Offline Staga

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Radial or Inline?
« Reply #26 on: May 22, 2002, 07:39:41 AM »
I know the engine type you're talking about but I cant remember it's english term (4 pistons "head to head" in two cylinders with two crankshafts in opposite sides of the cyl-block).
Anyway if Porsche is using word Boxer when talking about their engines I'm going to do the same when talking about flat engines :)

edit:Good link
« Last Edit: May 22, 2002, 07:44:18 AM by Staga »

Offline Duedel

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Radial or Inline?
« Reply #27 on: May 22, 2002, 08:34:24 AM »
Quote
Originally posted by Staga

Anyway if Porsche is using word Boxer when talking about their engines I'm going to do the same when talking about flat engines :)

edit:Good link


:D

Offline HFMudd

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« Reply #28 on: May 22, 2002, 09:26:44 AM »
Quote
AFAIK, radials use odd numbers of cylinders per circle as to under no circumstance have TWO cylinders pushing/pulling on the central rod in opposing directions (There is no 180 degree angle 'tween two cylinders, vector addition does the rest for u)


That is actually quite a good guess as to why they use an odd number of cylinders, but the truth is a little more subtle than that.

The reason a radial has an odd number of cylinders to make the firing sequence come out smooth.   These engines are all 4-stroke engines and so only fire once every *other* time that the piston reaches the top of the cylinder.  With an odd number of cylinders you never have two adjacent pistons firing on the same engine revolutions.

By way of example, if you have three cylinders, the following happens during two revolutions of the engine:
- Cyl 1 fires
- Cyl 2 exhausts
- Cyl 3 fires
- Cyl 1 exhausts
- Cyl 2 fires
- Cyl 3 exhausts
At this point we can start again with the next two revolutions.

Now let's try the same thing with a four cylinder radial:
- Cyl 1 fires
- Cyl 2 exhausts
- Cyl 3 fires
- Cyl 4 exhausts
- Cyl 1 exhausts
- Cyl 2 fires
- Cyl 3 exhausts
- Cyl 4 fires
See the two exhausts right next to each other?  That is why radials have an odd number of cylinders.

(BTW: BMW motorcycles and Subaru autos have 180 degree opposed boxer engines.  Both are know for their reliability.)

Offline Widewing

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« Reply #29 on: May 22, 2002, 09:27:24 AM »
Quote
Originally posted by Wilbus
Sorry for my lack of knowledge but was Erik a WW2 pilot?


He sure was. Erik began flying with the USAAC in the late 1930s. During an assignment to Langley Field, he tested such aircraft as the Curtiss YP-37 and the Bell YFM-1 Airacuda. He was qualified in virtually every fighter the USAAC had prior to WWII. When Chennault was granted permission to recruit American pilots for the AVG, Erik was quick to sign up for the adventure and the promise of high pay and bounties. Chennault would come to hold Erik as one of his favorite pilots, stating, "Shilling can fly anything better than anyone." Indeed, Chennault picked Erik to defend AVG honor in a mock combat between the RAF detachment at Rangoon and the AVG. Over the course of several engagements, Shilling easily defeated his British counterpart by "flying circles around the Brewster" Buffalo with his Curtiss Tomahawk. Shilling was chosen as the AVG's recon pilot. He stripped a Tomahawk of its guns and non-essential components. He then cut a hole in the bottom of the aft fuselage, where he installed an aerial camera. Mechanics worked to tune the already hand-built Allison to peak performance. Shilling would routinely fly deep into Japanese air space and photograph airfields and military installations. His lightweight, high powered Tomahawk was capable of speeds close to 390 mph, and Erik used this to race away from pursuing Japanese fighters. After the AVG was disbanded (7/4/42), Erik signed up with CNAC, and flew transport aircraft "over the Hump" for the remainder of the war.



Erik later flew for various organizations, being the last aircraft in and out of Dien Bien Phu. No other contract pilot was willing to fly into that dirt strip under heavy fire. He landed a C-119 under fire, bringing in medical supplies, food and ammunition. Likewise he took off under fire taking out the sick and wounded. His C-119 taking over 50 hits, and having to fly most of the way back on one engine, Erik would be decorated by the French government for his courage.

Later in his remarkable career, Erik was a contract pilot for Air America, flying covert missions deep into Laos and Cambodia. He is rumored to have actually landed in North Vietnam, bringing in CIA operatives.

Erik was the personafication of the Flying Tiger, right until his death, which he met with great dignity and an indomidable spirit, passing on with the great satisfaction of knowing that he had made a difference. I can't think of a single person I admire more.

To read more about Erik, click on the link.
Erik Shilling

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.