Talk:Napier Deltic

message: Hmmmm... Everything2 articles are copyrighted isn'it ?
Ericd 15:03, 20 Aug 2003 (UTC)
thread_title: ?=

message: Great article.  I'm still confused on the basic design concept, though.  A diagram would be a great help.  Rossami 16:04, 24 Oct 2003 (UTC)
replies: text: As always, a diagram would be a great help (when it comes to how things look, words can be cumbersome).  Unfortunately all will be copyrighted and thus unusable here.  I'm going to see what I can do to draw one. --Morven 16:27, 24 Oct 2003 (UTC)
thread_title: .

message: I worked the cylinder timings out on paper, i hope this animation helps, ive managed to include the lag between exhaust valve and inlet valve and get everything running in phase. If anyone notices a fault i havent twigged to, please let me know, i had to remove the inside inlet manifolds for space reasons, but everything else is actually to scale.
Emoscopes 22:21, 28 December 2005 (UTC)
replies: text: The text quotes "in/out/in/out/in/out" tubing and rotaion symetry. And just common knowledge tells that symmetric engine would be more easy to handle. But alas the diagram shows non-symmetric engine with left bottom piston pair flipped against proper position. Alas original artist is no more active and i dunno if someone would be able to re-create the diagram. 85.90.120.180 (talk) 11:01, 30 August 2012 (UTC)
replies: text:  The engine isn't quite rotationally symmetric. Although the cylinder blocks and ports are, remember that the bottom crankshaft rotates in the opposite direction. Andy Dingley (talk) 11:51, 30 August 2012 (UTC)
replies: text:  I just added a more accurate animation. Doesn't show combustion process, but the phasing is now correct based on the Deltic Manual http://pigeonsnest.co.uk/stuff/deltic/deltic.html and a diagram in 'The Napier Way' http://www.ptfnasty.com/images/jpg/delticway/napier134.jpg. Shape and arrangement of parts based on this section http://www.craftsmanshipmuseum.com/images/ClenSection.jpg . This animation shows the engine as viewed from the FRONT (blower end). MigMigXII (talk) 08:04, 30 January 2013 (UTC)
thread_title: Animation Added (but wrong :-( )

message: It's a 2-stroke Diesel, however I have no idea how to introduce it the article. Ericd 22:38, 1 April 2006 (UTC)
thread_title: 2-stroke Diesel

message: Fantastic article, especially the animation. I've got a few questions about the Deltic design which I'm chucking around in the direction of anyone who might be able to answer, however:
* Is a Deltic-type engine inherently inferior in power output to a four-stroke engine of the same displacement?
* Just how unreliable are Deltics? I've heard accounts saying they proved highly reliable and accounts saying they were constantly breaking down.
* Would a Boxer, or an X- H- or W-block engine of the same displacement be superior in performance?
Any help with these would really be appreciated!
:My thoughts are not to think of the Deltic in terms of displacement, but in power to weight ratio. As a uniflow, 2-stroke, opposed piston engine, it lacks heavy cylinder heads and valve gear, and comparable 4-stroke arrangements are likely to be of a lower power to weight ratio.  Emoscopes Talk 00:53, 27 April 2006 (UTC)
replies: text: Some brief thoughts on this; the Deltic 25 was a rail deltic, and therefore was (as far as I know) derated for rail use and designed to produce 1,650hp continuously. The Vector 40 does not state a continuous rating, and fairs far more favourably with the Deltic 37 (marine deltic) in terms of peak power and weight. This place is a bit of a goldmine anyway; http://www.ptfnasty.com/ptfTechnical.html Emoscopes Talk 07:36, 28 April 2006 (UTC)
thread_title: What happened to the Deltic?

message: A question re diagram in Napier Deltic/History.  As I read the description all 3 cranks should each have an inlet and an exhaust piston.  In that diagram, one crank has this, one has two inlets and one has two exhausts? —Preceding unsigned comment added by Dunheved1 (talk • contribs) 
* Reply: Yes, you're right. I have added a note to the caption about it. The ports and timing of the left-hand cylinder are reversed.
http://www.ptfnasty.com/ptfDeltic.html states: "each crankpin carries one inlet and one exhaust piston".
This of course follows from the fact that the bottom crankshaft's -60 degree phase difference cancels one of the others, leaving the remaining shaft's +60 degrees to be cancelled by the -20 degrees in each of the 3 cylinders in sequence.
Thus the port order should be "ex, in, ex, in, ex, in", giving "lead, lag, lead, lag, lead, lag" going round the engine anti-clockwise from the bottom. 195.92.168.164 00:51, 22 August 2007 (UTC)
replies: text:  No, I believe that the ports & timing of the left hand cylinder are correct, based on that the bottom crank turns the opposite direction, as described in the text. The animation would seem to bear this out. --71.214.237.152 (talk) 19:42, 26 August 2010 (UTC)
replies: text:  No, it's incorrect. Read the refs, look at the photos on the linked Deltic gallery site. Andy Dingley (talk) 21:16, 26 August 2010 (UTC)
thread_title: Is this accurate

message: Since there seems to be some confusion, maybe this will be of some help.  TREKphiler hit me ♠  14:09, 11 December 2008 (UTC)
thread_title: FYI

message: The single set of three cylinders looks like it will have overall vibrations (twisting vibrations as well)
Can someone expand on how sets of cylinders were arranged to get rid (assuming they did) of these overall vibrations (as per 4 cylinder engines)
I don't see it in the article. Thanks213.249.232.187 (talk) 14:58, 6 April 2009 (UTC)
thread_title: Vibrations

message: For a complete description the article needs:
*Accurate diagram (very desirable)
*Description of the direction of rotation of camshafts crankshafts relative to the position of the input ports needs to be explained.
*Vibrations of set of three cylinders
*How the vibrations of a planar three cylinder set are balanced out by grouping in multiples of three sets (if true)
**and by extension phase difference between "crankpins" on camshaft. crankshaft
*Where the output stage - ie main driver or whatever it is called is located and how it is connected to camshafts. crankshafts
*also paragraph 5 and last paragraph of section "History and design" see http://en.wikipedia.org/w/index.php?title=Napier_Deltic&oldid=282249299 duplicate the same concept in part - so that could be combined.
*Any further information would be good, (but not essential) eg
**Weights general
**Build materials (steel?)
**More info on how a high power to weight ratio is obtained - I understand that the absence of cylinder heads helps - but device requires 3 camshafts because of the lack of the heads - more details of how this fits together.
**More info on expected time between failure/repair - this (alledgely) is an issue when used in diesel locomotives - figures for comparison with contemporary "normal diesel engine" would be helpful to prove/dispell this.
**If above point is an issue - does the service life vary between marine/(air)/rail applications - ie do less 'forgiving' loads cause higher failure as found in (alledgely again) gas turbines.
**rpm
**emissions - comparison
And anything else. Only the intial points (singly indented) are necessary to make the "design" section acceptable.FengRail (talk) 01:34, 7 April 2009 (UTC)
replies: text: You've got to stop talking about "crankpins on camshafts". Why is this article pulling _GOOD_ (albeit not perfect) animations that really did illustrate the key operating principles of a delta-layout uniflow engine, then using crass howlers like this? How are you expecting to have a serious discussion about vibration modes when you can't even tell a crankshaft from a camshaft? 8-(  Andy Dingley (talk) 01:44, 7 April 2009 (UTC)
replies: text: Sorry, corrected those. I'm not the expert..FengRail (talk) 01:52, 7 April 2009 (UTC)
thread_title: Expert attention

message: This entry should be linked to the Junkers Jumo 205 entry.  Napier licensed the Jumo 205 opposed piston design and their only original contributon was the Delta configuration. The key to the original Jumo design was the 11 degree crankshaft offset to provide the vital scavenging timing. 
The problem with the Jumo design is although at the point of ignition there is a potentially high thermal efficiency, harvesting the power needs 2 crankshafts etc. per combustion chamber. Napier's deltic design was an attempt to increase efficiency by having one crankshaft per combustion chamber.  However, since all the crankshaft were linked, it was impossible to maintain the crucial 11 deg crankshaft offset that delivered the original Jumo power output per cylinder.Sageofabbott (talk) 13:41, 14 June 2009 (UTC)
thread_title:  Jumo 205 

message: Here's some proper un-ambiguous info 
*this image  via http://www.modelenginenews.org/etw/deltec.html
*also this image 
Both clearly show the location of the inlet and outlet ports (manifolds).87.102.78.86 (talk) 16:46, 17 November 2009 (UTC)
replies: text: I can't figure it out either :-)  I used to strip these things down at Ruston's at Vulcan Foundry, and it was definitely in-ex:in-ex:in-ex as you went around the delta, but I can watch the animation for hours and it still works with one bank's ports reversed... The phasing works, the scavenge works...everything.  We used to dread these things coming in, along with when we had to fit new cast bedplates to all BR's Paxman Valentas.  Fortunately we just stripped them and put the spares order together...they screwed them back together again somewhere else (Colchester I think :-). I think that the diagram is still good enough for explaining the general 'idea' of a Deltic, and I could not even approach the cleverness needed to create it, let alone correct it 86.148.252.237 (talk) 00:10, 7 September 2010 (UTC)
replies: text: Sussed it! (I think).  You have to watch for a long time, but it's the crank timing.  If you leave the Top-Left crank as it is, then the Top-Right crank should only lead it by 20 deg.  In fact its somewhere nearer 60 in front (because the animation has 12 frames).  Same with the Top-Right and Bottom crank...the bottom crank also needs retarding so that it only leads the Top-Right crank by 20 deg. The combined effect of these two 'extra' leads is to put the bottom piston in the lead in the left cylinder, whereas it should lag behind the top piston.  Once the Top-Right and Bottom cranks have been adjusted 'back' two and four frames respectively, the ports can be reversed in the left cylinder, and the scavenge will work the other way. Phew! 86.148.252.237 (talk) 13:22, 7 September 2010 (UTC)
thread_title: Diagrams

message: http://pigeonsnest.co.uk/stuff/deltic/deltic.html
A possibly useful reference - reproduction of the original? multiple pages.Sf5xeplus (talk) 18:46, 6 February 2011 (UTC)
thread_title: Manual

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thread_title:  External links modified (February 2018) 

message: If anybody knows that would be good to add to the description. Gjxj (talk) 15:49, 26 March 2023 (UTC)
thread_title:  how are the cranks lubricated?