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I am looking for a diagram that shows the different diameters of various nozzle openings, including Rocketdyne's F1 (150 inches) SpaceX's Merlin (66 inches), the Air Force's Delta IV Heavy, and NPO Energomash's Proton-M (59 inches). Those ones are rather popular and easier to find, but I am wondering if anyone has a list of different engines and their different characteristics.

My theory is that engine size compared to launch vehicle weight is going to decrease over time, especially as efficiency rises. If I had some more data I might be able to show this to be true. Thanks for any help.

EDIT

Let me clarify a little bit. I want to see if, for a given launch vehicle weight, the diameter of the engine nozzle has decreased slowly over time, as engines become more efficient and use lighter materials. As such, if I have different nozzle diameters at different time periods of high engine usage, there may be a trend through time. Plus, it would just be cool to see this information, and see how different engine characteristics have changed through time. I want to see what sort of trends like this exist among other engine characteristics, to see how the technology evolves. I would also make this comparison against thrust.

Lastly, I am really interested in engine design, and understanding how technological advancements change the dimensions and components will help a lot.

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    $\begingroup$ What is your theory exactly? What are the dimensions of engine "size"? In general your theory sounds incorrect. The total nozzle exit area would like to be proportional to thrust, which is proportional to weight. However the area at the end of the rocket grows as about the 2/3 power of the weight. So nozzles end up being constrained by the vehicle, since they'd like to be bigger. Inefficiencies have to be accepted for under-expanded flow. $\endgroup$
    – Mark Adler
    Commented Dec 31, 2013 at 1:51
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    $\begingroup$ I wish some of the awesome infographic makers like at Space.com, might consider doing engines like you suggest. I would be really curious to see an F-1 vs an RD-170. $\endgroup$
    – geoffc
    Commented Dec 31, 2013 at 2:11
  • $\begingroup$ Let me clarify a little bit. I want to see if, for a given weight, the diameter of the engine nozzle has decreased slowly over time, as engines become more efficient and use lighter materials. As such, if I have different nozzle diameters at different time periods of high engine usage, there may be a trend through time. Plus, it would just be cool to see this information, and see how different engine characteristics have changed through time. $\endgroup$
    – Stu
    Commented Dec 31, 2013 at 2:32
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    $\begingroup$ I still don't see how this is any different that asking if performance over area ratio has increased as rocket engine design evolved. Which boils down to, have rocket engines evolved. Which in turn is the same as asking whether we've been burning all the R&D money for nothing during all these years. I agree, it would be interesting to see some graphs how they did tho. But if, I have no doubt. $\endgroup$
    – TildalWave
    Commented Dec 31, 2013 at 2:45
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    $\begingroup$ The nozzle size you have for the Merlin is way off, at 1m67 you can't fit 9 of them on a stage with a diameter of 3m66. The first stage Merlins are around 93 cm (no diameter has been published by SpaceX, so this has been measured from photos). The Merlin Vac may be 1m67, but again, no size info has been published that I'm aware of. $\endgroup$
    – Hobbes
    Commented Dec 31, 2013 at 8:31

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I could not find any diagram, but here is one:

enter image description here

Wikipedia's list of orbital rocket engines is a good place to start, just click the link to their main article. Most of them have their diameter in their fact box:

enter image description here

Be aware that determining the optimal nozzle diameter is complicated, especially for the first stage, due to atmospheric backpressure

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    $\begingroup$ The Merlin 1D has a diameter of about 90 cm. At 168 cm, you wouldn't be able to fit 9 of them under a stage that's 366 cm in diameter. 168 could be the diameter of the Merlin Vacuum version, but I've never seen good data for that. $\endgroup$
    – Hobbes
    Commented Jan 11, 2016 at 8:49
  • $\begingroup$ @Hobbes fixed it! $\endgroup$
    – SE - stop firing the good guys
    Commented Jan 11, 2016 at 9:03

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