Talk:Scuderi engine

Restoring page

I brought this page back due to the creation of the new category, "proposed engine designs." The page had been redirecting to the "split cycle engine" page, which had erroneously been categorized under "proposed engine designs." As the split cycle engine article indicates, the first split cycle engine was built in the 1890's. (Tallik (talk) 16:48, 10 October 2008 (UTC))

The previous discussion page referenced the completion of the prototype as a marker for bringing back the in-depth article. The prototype has apparently been completed and is undergoing testing and is scheduled to be unveiled to the public in Detroit on April 20.--CSvBibra (talk) 19:29, 24 February 2009 (UTC)

My recollection was after a long and spirted discussion on the discussion page was that the article should be removed but go back up whenever a working prototype was completed. Now that the prototype has been declared completed, it appears that the goal posts may be moved. I don't think it should be deleted. If it is deleted then it should go back up when it is publicly exhibited now scheduled for April 20, 2009.--CSvBibra (talk) 01:21, 25 February 2009 (UTC)

Lack of RS

Frankly I'm less than convinced that they'll unveil anything meaningful at Detroit, but exactly what WP:RS do we have that says " a working prototype was completed" ? The company itself is not an RS, Wired is no authority at all on internal combustion engines. This article should go, it is basically an ad. There are very fundamental reasons why this rather old architecture for an engine cannot be made to be very efficient, their main claim for promoting it. Greglocock (talk) 00:07, 1 March 2009 (UTC)

OK, the SAE have taken the company's word for it. http://www.sae.org/mags/aei/5873, quid pro quo for them exhibiting at the SAE show I guess. Can't wait to see those independent test results. Greglocock (talk) 00:19, 1 March 2009 (UTC)

Well, to no one's surprise, they just showed yet another model. http://jalopnik.com/5219985/scuderi-split+cycle-engine-could-make-140-hp-per-liter Greglocock (talk) 12:13, 12 May 2009 (UTC)

AfD

Here's the original AfD Wikipedia:Articles_for_deletion/Scuderi_Split_Cycle_Engine. I've also got the old text stored locally, it was far more ridiculous than the current article. Greglocock (talk) 00:59, 1 March 2009 (UTC)

KEEP IT

I don't believe that fear of free advertising or the lack of a commercially viable product should prevent an entry regarding pluasible or semi-plausible inventions. Obviously, crackpot ideas will be ridiculed and die of either a slow death or a spectacular demise. This idea has some promise though the additional mass going up and down at the same time will present significant balance challenges and the severe compression ratios will demand diesel-heavy components. The ability to burn many kinds of fuel without regard for octane rating is a huge plus. Keep this as well as the Crower six-cycle engine entry. Wiki has adequate ratings for incomplete or LTCE (less than completely encyclopedic) articles. I want school kids to be able to find all kinds of things that don't exist in published encylopedias and I realize that such a preference has some limits, too. Thanks, guys —Preceding unsigned comment added by Homebuilding (talk • contribs) 23:14, 30 March 2010 (UTC)

Only runs on extremely high-octane fuel?

When I first saw a description of this engine I thought "It's designed to produce extremely high compression, so it has to require extremely high-octane fuel." However, I saw no reference to the fuel requirements anywhere in the PR or newspaper articles.

I've finally found a reference on their website at http://www.scuderigroup.com/assets/Patents/United%20States/Pending%20Published%20Applications/US20090038597A1.pdf (I was also able to find it on the USPTO site at http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=%22knock+resistant+split-cycle%22.TTL.&OS=TTL/%22knock+resistant+split-cycle%22&RS=TTL/%22knock+resistant+split-cycle%22 , although I don't know if the link is durable).

The document is a patent application, titled "Knock resistant split-cycle engine and method", numbered "US 2009/0038597 AI", filed June 11, 2008 and published February 12, 2009. On Page 4 (page 17 of the PDF), paragraph 0071, it mentions that the study whose results were included in the application used 100 octane fuel. You can't currently get anything close to that at a gas station.

Requiring 100 octane fuel would be a major flaw in the engine design, and if true would be important to include in the article. However, this is the only reference I have been able to find, and certainly does not state "This engine must be supplied with high-octane fuel." On the other hand, if true then the company would have a large incentive to downplay this information.

What would be the appropriate path to take on this? -- Dan Griscom (talk) 11:29, 26 September 2011 (UTC)

Issues about the Scuderi Engine

Here are excerpts from a set of comments I just wrote for engineering friends who got excited about the Scuderi Engine (SE). Web searches today turn up mostly journalistic puff pieces based on promotional materials, which are much like ‘infomercials’ targeting investors using file footage of vehicular traffic scenes overlaid with animations of engineering isometrics. Caution is advised: Modern design automation tools, much like Photoshop, can be effective or deceptive in representing visual information to viewers about proposed realities.

For a remarkably relevant case in that point, see http://bourke-engine.com/ani.htm produced back to 1999 – twenty years after my in-person review of The Bourke Engine (BE) as reported at http://niquette.com/books/sophmag/bourke.htm, a narration which continues year after year to be challenged from all over the worldwide web mostly by BE partisans, not always in a collegial way. The fallacy in the BE resulted from a fatal error in the bench-test data (measuring specific fuel consumption). So far the SE has not reported its SFC data, but I expect a similar fallacy. Here’s why. In the simplified drawing of the SE in the present article, we see the connecting pipe between the companion cylinders in dark blue. Actually, there must be two pipes, each separately valved into the combustion cylinder and the the transfer pipes must be as large as practicable to accommodate rapid relocation of compressed air parcels into the combustion chamber where each receives injected fuel and ignition. Nota bene, the internal volumes of those pipes must be added to the total volume being managed by both cylinders atop their respective pistons. The so-called hybrid compressed air configuration of the SE will require more valves to contain the volume of compressed air between cylinders.

Management of the transfer is influenced by the relative cylinder bores and strokes (compression volumetrically larger than combustion) and by the phasing of the two pistons by the crank-shaft (the compression piston reaching top-dead-center after the combustion piston has reached top-dead-center and has started its downward motion).

The timing of the valves along with the shape of their cam lobes must be designed to optimize the transfer management. Ideally, both transfer valves should open instantly and close instantly with some appropriate interval in between. But when? And how long? Although ignition timing can be adjusted dynamically for various speeds and loads, the shape of cam lobes cannot. Bench-test videos shows the SE running, but most fundamental question about any engine is, “What is its specific fuel consumption?” Compression Ratio determines thermodynamic efficiency according to the Second Law of Thermodynamics. The designs of engine parameters are necessarily optimized for performance over a wide range of operating conditions in motor vehicle applications.

Before reaching its own top-dead-center, the compression piston must begin over-compressing the air in order to assure delivery of its charge already in the transfer pipes thence through the open transfer valve to the combustion chamber – always at the highest possible compression ratio. At that instant, the combustion piston itself has gone beyond its-top-dead center and is thereby opening up space, imposing an upper boundary on compression ratio.

Moreover, neither fuel injection nor spark ignition can begin until the transfer valve has closed (ruling out compression-ignition applications). Igniting by spark the fuel-air mixture after top-dead-center might seem to be preferable, but a hundred years of industry experience have proven otherwise. Reminder: With all valves closed, the charge in the combustion chamber acts almost like a perfect gas – a mechanical spring – with full thermodynamic reversibility, so that compression with or without simultaneous combustion does not waste energy.

Commensurate Flame Front Velocity is one of the most important features mandated for the internal combustion engine in its vehicular applications. My informal essay on this subject at http://niquette.com/certainb/chapt05/5text.htm#EfficiencyChampion introduces the concept as the mystery that few non-experts understand, then tries to explain it to a general audience using this treatment http://niquette.com/certainb/chapt05/5text.htm#DynamicRange which can be summarized in something of a mouthful: “Flame speed adjusts itself to the engine speed as a result of compression enhancement of inlet induced charge turbulence.” The issue arises in the Scuderi Engine as a result of the fact that compression enhancement must be accomplished in an entirely different place from where inlet induced charge turbulence is produced! That architecture may relinquish a feature essential for the practical application of SE ‘Dynamic Range’.Paul Niquette (talk) 13:56, 23 April 2012 (UTC)

Hi Paul, the above is good stuff but unfortunately unless it has been published in a Reliable Source then we can't use it in the article. Cheers Greglocock (talk) 23:48, 23 April 2012 (UTC)

I have two issues with the animation in this article. First, it shows a compression cylinder that is larger than the expansion cylinder. Actually the expansion cylinder will have a larger displacement (larger diameter and/or stroke length) in order to get over-expansion and therefore higher efficiency. (Miller and Atkinson cycle engines also use over-expansion to improve efficiency.) The use of "miller over expansion" is discussed at http://www.scuderigroup.com/engine-development/. The animation also shows only one valve between the two cylinders. Although that could work, and some figures at the Scuderi Group site show only one valve, I believe practical engines will have two valves, a "crossover compression valve" and a "crossover expansion valve". The crossover compression valve should open whenever the pressure in the compression cylinder is higher than in the crossover passage, so it could be a simple one-way valve closed by a spring. The crossover expansion valve must remain closed during the exhaust stroke, so it would presumably be a conventional cam-operated poppet valve. It would open at about the time the expansion piston reaches TDC, and close soon enough to prevent any flow backward into the crossover port (and certainly before the flame front arrives at the valve).

I have not attempted to change the animation. Apparently it was adapted from US Patent 6952923. Maybe the two-valve concept and over expansion are covered by other patents. See: Vanzandtj (talk) 19:13, 27 June 2014 (UTC)

References

NDA puffery peacocking

" Various manufacturers, including Honda, Daimler AG, Fiat, and PSA Peugeot Citroën, were said to have signed non-disclosure agreements with Scuderi Group" This of course means nothing. many companies will not talk to you about an invention until NDAs have been signed. It is the very first step. Is this a case of WP:UNDUE? Greglocock (talk) 20:09, 2 March 2023 (UTC)

Different cylinder bore sizes?

I saw an article on something like this years ago, probably similar timescale to this engine, but maybe much earlier. As far as I remember, it used almost identical principles, but would have different size cylinders. The claimed advantage was that by using a larger compression cylinder, a turbocharger or other precharger was unnecessary.

I see nothing about this in the article. Maybe it was a completely different engine, but seemed like a nice idea at the time, particularly for Diesels.

I think these engines come under the general heading split cycle engines.

Split single engines are not split cycle, similar name easily confused.

Lkingscott (talk) 12:06, 21 April 2023 (UTC)

References