Engine technology free-for-all

[wuzak]

Nice images W, but if you put a Nomad diagram up, you will see its a uniflow 2T, & sans S-V.

I apologise. You are indeed correct - no sleeve valves.

http://www.flightglobal.com/pdfarchive/ ... 01219.html

http://inter.action.free.fr/images/affi ... made-1.jpg

[gruntguru]

Halford's Sabre design for Napier was for Diesel, initially.. ..& then went as far as projected 2-stroke SI function.. Napier, oddly enough did not utilize sleeve valves in either Nomad or Deltic 2T Diesel mills though....yet NASA - in that high efficiency 2T Diesel turbo-compound study - still sees merit in the S-V..

Of course one of the main advantages of the SV - knock resistance - is no benefit in a diesel.

[J.A.W.]

& here: http://www.enginehistory.org/members/ar ... Sleeve.pdf
..is a fairly recent ( if academic thesis-like & somewhat superficial in certain aspects) aero-mill sleeve-valve re-appraisal..

[uniflow]

Where is all the information on the open ended sleeve system? Crecy.

[J.A.W.]

Where is all the information on the open ended sleeve system? Crecy.

Wuzak here has a fair old R-R data base, could try him..
.. or R-R Heritage Trust, AFAIR, they have a booklet pertaining to Crecy..

& also AFAIR, Ricardo in the UK - still have a Crecy - V-twin test unit - in their collection..

[wuzak]

http://www.amazon.com/Rolls-Royce-Crecy ... oyce+crecy

It's out of print.
http://www.rolls-royce.com/about/oursto ... lications/

[gruntguru]

"The High Speed Internal Combustion Engine" by Harry Ricardo discusses much of his sleeve valve research. Most good libraries have a copy.

http://www.amazon.com/High-Speed-Intern ... 0216890268

[J.A.W.]

Uniflow, both the books - listed above by W & G-G - are (likely) available via interloan from the NZ National library.
& - a bit too bloody pricey on Amazon..

[uniflow]

I have both those books, but want more. There must be some in depth literature on the subject somewhere. Both books cover the open ended sleeve valve but more detail would be nice. I am impressed at how some people can find all sorts of obscure engine material on this forum, or am I just lazy.

[wuzak]

At the National Archives in the UK.

http://discovery.nationalarchives.gov.u ... r/C2429367

[uniflow]

Thank you

[Tommy Cookers]

The Germans ran different ign' timings between plug sets ( & even comp' ratios per bank) on their V12s..

Not sure on the ignition timing for German IV-12s, but the compression ratio differentiation (on DBs - not sure on Jumos) was due to oil consumption. Jumos and DBs used fork and blade rods.

FWIW I thought that timing difference was used on such (DB) engines that had different banks at different meps due to an asymmetric effects in the induction system (from a cramped supercharger positioning ?)

regarding overboosting .....
the Munich/Manchester United crash in 1958 was somewhat bound up with boost control issues
a few years ago a TV drama/reconstruction showed the pilot pushing the power levers forward and the auto system opposing this by pushing the levers back against the pilot's efforts
authentic reconstruction or dramatic fiction ?

and a technical bit ....
if with a conventional 2 stroke we eg increase the B:S ratio with 10% more bore and a corresponding 21% reduced stroke
ie to enable about 10% mpre rpm and power
for a given port timing we have ports tending to 10% wider (ie diameter) but 21% squatter .... so smaller when we needed bigger
this was a limiting factor eg with GP 2 strokes

[wuzak]

regarding overboosting .....
the Munich/Manchester United crash in 1958 was somewhat bound up with boost control issues
a few years ago a TV drama/reconstruction showed the pilot pushing the power levers forward and the auto system opposing this by pushing the levers back against the pilot's efforts
authentic reconstruction or dramatic fiction ?

Saw an Air Crash Investigations episode in which that crash was the subject.

Apparently it was slush, which prevented the aircraft from reaching its required take-off speed before the end of the runway. Apparnetly the pilots had twice before aborted the takeoff.

[Tommy Cookers]

yes, but the 2 aborts were due to the auto indicating overboosting on 1 engine (and resisting it ??)
each takeoff attempt was made with ever-slower pilot advance of the power levers in an attempt to get pacify the autoboost
on the last attempt they were halfway along the runway before the power levers were even asking for normal permitted power
not the time to find that the hitherto unvisited far end of the runway was slushy

but real overboosting was less likely at Munich's altitude than at most other places
Centaurus ? - not famously reliable
also the wing section was more affected by snow etc than older planes eg the DC-3 ?

btw a former co-worker ex-Napier said that of compressor tests eg critical to N's failed engine design that killed the Rotodyne
the compressor was driven by a naval steam turbine controlled by viewing an oscilloscope and manually turning the steam valve

[J.A.W.]

Here is a 'Flight' article giving civil Centaurus power-curves, & AFAIR, the big Bristol mill had a '3000hr TBO'..

http://www.flightglobal.com/pdfarchive/ ... 01484.html