Talk:Radial engine

Inventor of the radial engine?
"The radial engine is a particular engine configuration, in which the cylinders are arranged pointing out from a central crankshaft like the spokes on a wheel. " - I think a direct link to rotary engines would be useful here - not just indirectly through engine configuration

Who invented the radial engine? Was it an evolution of the rotary piston engine, or a seperate invention?

"The other disadvantage is that the frontal area of the radial is always much larger than the same displacement inline, meaning that the radial will always have greater drag. For a low-speed plane this is not very important, but for fighter aircraft and other high-speed needs, this is often a "killer problem". "  -  This statement is too general and does not take into account other important factors: 1) the frontal area is not much larger, in fact with a double bank it can be the same size or smaller, 2) as a percentage of overall drag, the increase is not significant, 3) a radial engine does not require a "radiator", which can offset any increase in drag, 4) a radial engine is lighter than an in-line engine, and 5) the cylinders in a radial engine receive even cooling, a problem with in-line air cooled engines. Plus, the lack of cooling system that's vulnerable to enemy fire is a big "plus" for a fighter aircraft. For proof of the viability of radial engines in fighter aircraft, compare the performance of fighter aircraft with in-line engines to the British Hawker Tempest II and Hawker Sea Fury, both of which were powered by the double row 18cyl. Bristol Centaurus radial engine, housed in a very aerodynamic cowling.

I agree. There are direct contradictions between paragraphs five and seven.

Animation
I think the animation should be moved to the bottom of the page, so people can read the article without distraction. Really, try concentrating and reading the entire article with the animation in view.

I've done this before and thought the article looked a lot better. Duk 06:38, 23 Jan 2005 (UTC) Hey the current animation has got the cam gear train running opposite to its geared drive direction. Watch it for yourself. The 1st original animation from 10 years earlier in the animation history has it right. Take your time--compare & see. — Preceding unsigned comment added by Avfanguy (talk • contribs) 06:04, 28 February 2024 (UTC)


 * Also, the firing sequence should be 1-3-5-2-4, not the 1-2-3-4-5 shown. Toolnut (talk) 00:03, 22 April 2024 (UTC)

'Zvezda' 42-cylinder diesel boat engines
Wow! As a diesel enthusiast, I find the idea of a radial diesel engine quite peculiar, much more so a 42-cylinder one! Can anyone add any more info? Phasmatisnox 07:06, 20 May 2007 (UTC)

Rotating mass
Someone gave me some comments on that I'm passing on;

The statement  Another mixed blessing is the greater rotating mass of the radial engine. might be wrong, I thing it was meant for Rotary piston engine. I'm no expert on these engines, but Radials have a lower rotating mass than inlines (because there is no crankshaft) while rotaries have a greater rotating mass because it's the cylinders and housing that rotates (I think). --Duk 17:07, 21 August 2005 (UTC)

-- Good catch. The "greater rotating mass" comment was alrady there; I just expanded on it - but I think you're right - it belongs with the rotaries, not the radials. I know pilots in both wars used torque and gyroscopic effects, but only the WWI pilots had rotaries - the 2nd War pilots just had huge propellers and gobs of power. Knotnic 17:25, 21 August 2005 (UTC)

Clarifying Statement
"The Radial Engine is a type of [Reciprocating engine]".
 * Guys, I added this line to the first paragraph:

I added this because people seem to be getting confused between this and this. --Pavithran 22:55, 27 September 2006 (UTC)

Profanity in description
someone had put profanity in the first sentence. I deleted it. Check to see if it's worded correctly and if not feel free to correct it. Thanks.

Odd number of cylinders?
The article says, Four-stroke radials almost always have an odd number of cylinders. Isn't that an understatement? Are there any examples of a radial design which didn't have an odd number of cylinders? -- RoySmith (talk) 21:15, 20 November 2006 (UTC)
 * Oh, never mind, I read further and saw the bit about the even-numbered ones. -- RoySmith (talk) 22:18, 20 November 2006 (UTC)

Totally obscene
Well, personnaly I find the animation totally obscene !

You need to get out more. Kingernie (talk) 07:00, 3 October 2011 (UTC)kingernie

Very Basic Question
I'm almost embarrassed to ask this question, but I haven't been able to find the answer up til now. I've heard that the radial engine itself rotates with the propeller, i. e. the propeller is fixed to the engine and they both rotate at incredible RPMs. Can this be possible? Wouldn't that make it extremely complicated to operate properly ( fuel flow, centrifugal force, etc) ? Could someone clear this up, please? Thank you 67.72.98.45 18:45, 2 December 2006 (UTC)
 * What you are referring to is one type of a radial engine called a rotary engine --rogerd 18:56, 2 December 2006 (UTC)

Overhead camring?
for high rpm? Arnero 21:45, 21 April 2007 (UTC)

Non-combustion radials
I'm considering the prospect of a radial stirling engine. The basic engineering considerations here come down to the core needing cooling; heated working fluid runs past the outside, while coolant runs through the inside. This then leaves the question of how the engine will maintain firing order. I am thinking that, with proper design using Beta stirlings for cylinders, once it starts moving it will naturally occur that the position of the piston determines how the gas inside heats or cools and thus the whole engine will self-regulate. I don't have a lot of ideas on what problems I'll see though.. any takers?


 * You're considering writing about such an engine, or inventing it? This page is for talking about the article itself, not a forum for discussing new ideas. That said, it does sound intriguing. - BillCJ 02:39, 17 July 2007 (UTC)

Clarification + Valve configuration/cam & valve operation?
Hi Guys,

I like what's in the the article so far. Can someone clarify this: They differed from the norm of radial design by using two opposite cylinders as a double master instead of single master rod usually found, and managed to run perfectly circular.

Why is/was it required that radial engines have an odd number of cylinders? What about this engine permitted an even number of cylinders in a single row? These engines could have a consecutive firing order. What was the typical firing order if it wasn't consecutive?

If it could be expanded, I'd like to see info about how valves are configured and used. I assume early radials had "side valve" configuration, or flat heads, like early in-line engines did. And, just guessing here, the two stroke Diesel radials had exhaust valves (either side valves or overhead valves), and intake ports near the bottom of the cylinder. But how were the valves operated? A single cam shaft positioned between two jugs and driven by the crank? Or, perhaps a cam concentric to the crank driven by planetary gear set? Do any radials have over head cams?42toyoutoo (talk) 23:34, 2 April 2008 (UTC)

The obvious has been passed-over
The fastest piston plane is radial: 3 km World Speed Record of 528.33 mph (850.26 km/h). . The NACA cowling accelerator could be what levels the playing field. This should be at the head of the "pros."John Bessa (talk) 20:26, 4 March 2013 (UTC)

Why would you not want to use a radial engine for a particular application? Kwertii (talk) 08:38, 20 August 2008 (UTC)
 * Radial engines have a large frontal area, and that creates more drag than an opposed or inline engine. The top cylinders sticking up far above the propeller shaft also make pilot visibility poor. With the invention of the gas turbine engine, the need for very large piston engines disappeared, and small piston engines almost always are opposed designs. Shreditor (talk) 09:56, 20 August 2008 (UTC)
 * I rewrote the "Radial vs inline debate" section to include more advantages of inline engines and removed the NPOV tag. I included a few citation-needed tags; some are strong claims that were there but lack sources, while some are on my additions where I'm going from memory and don't have any relevant sources handy to reference.Vykk (talk) 17:49, 8 April 2009 (UTC)


 * On an air-cooled radial (most radials are air-cooled) the engine can only be run as hot as the hottest cylinder. In these A/C engines there is usually one cylinder that, due to it's location, gets slightly less cooling air than the others. This cylinder is where the engine temperature sensor is then located. As you attempt to get more power out of the engine design - say by increased boost pressure, better fuel, etc. - there comes a point where the maximum power is limited by the engine maximum operating temperature, and disposal of any increased heat cannot be achieved without a change in the cylinder head design.


 * Because an air-cooled engine is therefore limited in the ultimate amount of waste heat it can dispose-of, the engine cannot be run as efficiently (i.e. at higher temperatures) as an equivalent liquid-cooled engine. To run a liquid-cooled engine at higher temperatures one only needs to increase the radiator capacity and/or the rate of coolant flow. To do the same with an air-cooled radial requires re-finning and redesign of the cylinder heads.


 * This is one of the reasons why Formula One and similar high performance racing cars have liquid-cooled inline engines. — Preceding unsigned comment added by 80.4.57.101 (talk) 12:37, 23 August 2011 (UTC)

Soviet Diesel Radials
I may be counting wrong, but there is a sentence in the article saying that a 56 cylinder diesel had "7 banks of cylinders and 16 rows." Wouldn't that give you 112 cylinders? Shouldn't it be 8 rows of 7 cylinders each? —Preceding unsigned comment added by 98.170.193.11 (talk) 00:37, 8 December 2008 (UTC)

Ok, I just re-read that sentence, and it does mention the 112 cylinders. So sorry! —Preceding unsigned comment added by 98.170.193.11 (talk) 00:40, 8 December 2008 (UTC)

Radial engine valve system
the 2-stroke five-cylinder radial engine: this appears to be "crankshaft ported" with a pair of five-way small-diameter rotary valves. The crankshaft is hollow and has a hole in the side. It runs through a bearing block with five hole in it. When holes line up between block and crank, that valve is "open". The holes are probably machine rectangular and very carefully spaced & sized, to give the best timing and valve opening. This technique is well known for small single-cylinder two strokes, but it tends to give very small ports. With five cylinders these would be very short, especially as it's hard to arrange overlap between them. It might work for a high pressure air engine, but it doesn't work for petrol engines as these breathe at quite low pressures, so need long valve open times.

With four-stroke radials, they use a cam ring. This is a two-cam camshaft (inlet & exhaust) that is shared between all the cylinders in one row of a radial engine. Compared to a "normal" inline camshaft, it's very short and fat - the diameter of the crankcase, but only a few cm long. It is transformed from a shaft to a ring. Each cam "track" has two lobes on it, and it rotates at quarter engine speed (not half, as usual for four-strokes). Each cylinder valve thus sees a cam lobe pass by once every two crank revolutions, as for any four-stroke engine. The two lobes/quarter speed difference is to get the "interleaved" firing order, 1-3-5-2-4, of a four-stroke radial engine.

Schematics:
 * http://pergelator.blogspot.com/2010/03/radial-engine-cam-ring.html
 * http://www.nomeking.com/animations/radials/index.html

Info by Andy Dingley — Preceding unsigned comment added by 91.182.6.108 (talk) 07:28, 9 September 2011 (UTC)

Nordberg engines
that allowed the engine to be timed so the cylinders fired in consecutive order A 2-stroke MUST fire cylinders consecutively, or it wouldn't be a 2-stroke!!!--Petebutt (talk) 15:40, 28 February 2013 (UTC)

Animation
From the illustration in the animation it would appear that the uppermost cylinder's piston master rod is actually connected to the same ring to which the other pistons are connected, rather directly to the crankshaft itself as described in the text. Dave Chesterman (talk) 12:19, 16 March 2017 (UTC)


 * If you mean the connection between the "pentagon" and the master cylinder connecting rod should be solid, not jointed, I agree. Though it appears to behave that way in the animation, the connecting "point" on the pentagon between these two is misleading and should be removed. Toolnut (talk) 00:32, 22 April 2024 (UTC)

Bleroit
Bleroit's engine was a three cylinder air cooled car engine, with the three cylinders about 60 degrees apart, the pistons on three separate throws. Look at the pictures.It was not in a radial configuration (120 degrees apart.)97.115.227.9 (talk) 12:59, 15 June 2017 (UTC)
 * And who or what is Bleroit anyway? Jan olieslagers (talk) 16:22, 15 June 2017 (UTC)


 * See here: Louis Blériot — Preceding unsigned comment added by 95.149.172.141 (talk) 17:52, 12 November 2017 (UTC)

801
"The downside was a relatively large frontal area that had to be left open to provide enough airflow, which increased drag. This led to significant arguments in the industry in the late 1930s about the possibility of using radials for high-speed aircraft like modern fighters.[citation needed]

The solution was introduced with the BMW 801 14-cylinder twin-row radial. Kurt Tank designed a new cooling system for this engine that used a high-speed fan to blow compressed air into channels that carry air to the middle of the banks, where a series of baffles directed the air over all of the cylinders."

Actually, the Bristol Hercules was an earlier powerful and reliable twin radial. It was available for service two years earlier, with less teething problems. Twin radials had been known for roughly two decades by that time. The 801 was no breakthrough for being a twin radial - its engine control unit was a technological breakthrough Its fan was merely a necessity because Tank designed the BMW801 cover without appropriate variable cross section cooling air exhausts. That fan did cost 60 hp. — Preceding unsigned comment added by 62.117.24.34 (talk) 17:24, 8 May 2018 (UTC)

Patents and first publications are the only real sources in science and technology
Hello Bilcat! Patents and earliest publications of the inventors are the only original sources about inventions and science. In the case of priority in invention disputes at the legal courts, the earliest publication in a technical or scientific journal or the earliest patent is considered the primary source and immediately decides the case. They are also the strongest arguments in the history of technology and science for establishing the identity of the inventor. A book mentioning an inventor, on the other hand, is not an original source, it is just a mere reference, its probative value is incomparably lower and even more insignificant than primary sources (patent and first publication).

For example, if, in a court hearing, the defendant wants to present a book which calling him an "inventor" as evidence of the priority of his invention, but the plaintiff client has a patent with this earliest date, the defendant who presenting the book will simply be laughed out of court. Okay, maybe the judge won't laugh out loud, but at least a smile would certainly come out in this case. After all, books do not have the same probative value as patents and earliest publications.

You can cite books written by scholars in a historical controversy, a philosophical or literary or political debate, because there is no patent office for these subjects. In these humanities and arts subjects, books written by scientists can decide everything by their references. However, as mentioned above, the role of books in invention discovery priority disputes is overshadowed by the greater importance of first publications and patents.--Peddigsten (talk) 07:30, 13 September 2022 (UTC)


 * I think all you need to know about citing patents is summed up in WP:PATENTS. The short version is that the existence of a patent is proof that a patent was filed and accepted, and nothing more. As that page points out it does not prove that the invention was ever built, that it runs or works, or that it was the "first" of anything. If it was truly a first and a successful, built design, it will have been reported in a reliable source, such as a history book written on the subject. It is also worth recalling that as Wikipedia editors we don't try to sort out things here like who was "first" from primary sources as that would be original research and also likely to produce incomplete and inaccurate results. We are also not here to WP:PROMOTE any one particular inventor or invention. We try to simply report what reliable sources say. - Ahunt (talk) 13:19, 13 September 2022 (UTC)
 * I don't think that the word "invention" had any relationship with constructing the invented thing. In that case there are no inventors in the field of nuclear science, because of the huge price the researcher can not build the concept as a prototype, maybe it will be relaized after the death of the inventor. How many inventions were relized as first prototype only after the death of the inventor due to financial problems? Please realize that the invention is not the same as prototype. Invention is a concept. My question was still not answered: Why is a patent more probative of an invention than a book in the legal courts?--Peddigsten (talk) 14:05, 13 September 2022 (UTC)
 * Peddigsten, I don't know why you're adding "in the legal courts". And we're not in the legal courts; we're on a website where we agreed that we are basing our content on reliable secondary sources. And besides WP:PATENTS, that's really all there is to it. Drmies (talk) 14:09, 13 September 2022 (UTC)

Patents
Bilcat despertely keeps repeating that official patents are "not reliable sources". He has no rational arguments and reasoning at all. He did not answer the previous section on the talk page, and he doesn't want to communicate. He confused the humanities history literature philosophy (where books written about various people and topics can be important references) with science and technology, where official patents and scientific first-hand publications matter in question of priority. The probative value or relevance of patents is greater than that of books written by some people about some other people or subjects. --Peddigsten (talk) 10:26, 13 September 2022 (UTC)
 * Please read WP:AGF and WP:NPA to learn how to interact properly on Wikipedia talk pages. - Ahunt (talk) 13:52, 13 September 2022 (UTC)
 * I suggest to read that article: Relevance_(law). Patents have more relevance, evidential value for legal courts than a book. What do you think, what is the cause of that phenomenon in all legal courts (in all legal systems) on this planet?--Peddigsten (talk) 14:11, 13 September 2022 (UTC)
 * And you read WP:THREAD, cause I'm getting tired of correcting the indentation after you. Once more, for the people in the back, phenomena in legal courts are completely irrelevant here. Drmies (talk) 14:23, 13 September 2022 (UTC) Ridiculous false statement: "Government patent authorities, however, do not fact-check, edit or endorse any material in the patent application" sometimes the checking and granting patents could last for years, especially in the old times.--Peddigsten (talk) 15:10, 13 September 2022 (UTC)
 * It is no coincidence that patents have evolved throughout the world's legal systems to be the strongest evidence for inventions. Mankind has created the judiciary as a professional institution for this task, and the laws themselves, the courts, to administer justice in disputes as perfectly as possible.

If Wikipedia's own community rules on an issue are imperfect (and they have bad faith) when viewed clearly and objectively, they can (and should) be changed. It would be worth starting a separate discussion on this.--Peddigsten (talk) 14:41, 13 September 2022 (UTC) Reliable sources/Noticeboard is probably the best place to discuss that. BilCat (talk) 15:19, 13 September 2022 (UTC)
 * The misinformaion: "Government patent authorities, however, do not fact-check, edit or endorse any material in the patent application. "FALSE. The priority (at least in the country of patent office) was fact checked, and after that the patent was granted. Sometimes a patent was granted by US. patent office only after long-long years passed.--Peddigsten (talk) 15:25, 13 September 2022 (UTC)
 * The patent is for a "Engines with star-shaped cylinder arrangements", I see no mention of "radial", thus this is wp:or to claim it is a radial engine. Slatersteven (talk) 15:58, 13 September 2022 (UTC)