Wikipedia:Reference desk/Archives/Science/2019 December 12

= December 12 =

What was the first ICE >1797 cc displacement ever made that could reach 10,000 rpm?
Redline rpm if it had one. Sagittarian Milky Way (talk) 02:58, 12 December 2019 (UTC)
 * What does the Immigration service have to do with Revolutions Per Minute? ←Baseball Bugs What's up, Doc? carrots→ 04:14, 12 December 2019 (UTC)
 * Internal combustion engine. Sagittarian Milky Way (talk) 04:21, 12 December 2019 (UTC)


 * No idea, but I bet it was a 1950s, maybe 1960s, Formula One engine. 10,000 is pretty fast for an engine that size, even now.  BRM built a number of engines which revved that high, although the formula limit was 1,500cc, so under your limit. However they also built at least a few (the H-16 for one) which followed a rule change one year and allowed up to 3,000 for non-supercharged engines. They pretty much doubled the previous engine and used that, and as it was the same size (they coupled two flat-8s into a H-16), they still revved beyond 10,000 rpm. Andy Dingley (talk) 15:44, 12 December 2019 (UTC)
 * Rotary Wankel engines have highest r.p.m. capability, for example in 1957 a prototype NSU DKM=Drehkolbenmotor was tested to 17000 rpm. Small displacement Wankels then appeared in vehicles from Citroen, Hercules, Norton and Van Veen (see Comotor), and Mercedes-Benz C111 concept cars with M950F engines had up to 2.4 L four-rotor Wankels by 1970. Among reciprocating engines, 2 stroke engines don't have the camshaft, timing chains, valves, or rocker arms that limit the speed of 4-stroke engines. Small 2-strokes that reach 20 000 rpm have appeared in extreme motorcycles such as Suzuki RP68. Among Formula One 4-stroke engines the Cosworth DFV 2,993 cc exceeded 10,000 rpm during the 1980s. Engines at the time were limited to around 12,000 rpm due to the traditional metal valve springs used to close the valves. DroneB (talk) 16:18, 12 December 2019 (UTC)

Non helical models of DNA structures, sub-title Experimental studies of circular DNA structure
I have made some edit on the Non helical models of DNA structures, sub-title Experimental studies of circular DNA structure. I tried to add a reference［37］ to it but failed. Can you help me? — Preceding unsigned comment added by Ycxu2019 (talk • contribs) 23:00, 12 December 2019 (UTC)
 * Shouldn't you leave that on the talk page for that article? --OuroborosCobra (talk) 23:20, 12 December 2019 (UTC)
 * (Non-helical models of DNA structure). The opening &lt;ref> tag was missing; I have fixed it. Please note WP:SELFCITE. catslash (talk) 00:51, 13 December 2019 (UTC)


 * I have made some edits to the references and also opened a discussion at Talk:Non-helical models of DNA structure about some concerns. Any and all comments etc welcome.  Thanks, EdChem (talk) 04:10, 13 December 2019 (UTC)