Gentlemen Power Rangers,
Kindly note the engineering exercises of engine design where one quickly learns that TORQUE is proportional to displacement and POWER is proportional to Piston area. Thus the best combination for best power configuration for a given displacement will always be the largest bore and the shortest stroke. The stroke does not produce torque nor is it a torque multiplier unless it increases displacement.
That should stir up an amount of comments that are in opposition to the factual statement above.
Regards to All and a Happy New Year as well. Stay safe.
HB2
PS - May a pox fall upon the Bureau of Land Mismanagement and may they feel the heat of my Congressman who will contact them happily in 2016.
. . . the best combination for best power configuration for a given displacement will always be the largest bore and the shortest stroke. . . . That should stir up an amount of comments that are in opposition to the factual statement above.
Who would be so bold as to speak in opposition to you? What are some of the most extreme bore/stroke ratios in successful racing engines?
It would indeed be foolish to disagree with those who concur with the likes of C.F. Taylor, A.R. Rogowski, D.B. Kittelson, T.E. Murphy and HB2. I consider myself a disciple.
Since the time I have first embraced the disciplines of logic, data and analysis, my results have been better, with less expenditure and less time lost to "side-tracking".
FB, others and I share a common mantra: "Compared to what?"
http://www.epi-eng.com/piston_engine_technology/comparison_of_cup_to_f1.htm
Be sure to read down to the EPC definition. Most everyone is gonna be somewhere in between most of the criteria!
More than one way to skin a water buffalo and the water buffalo is not happy with any of them!
Here is some analysis I regularly use that supports both HB2's & Woody's positions. Put on your beanie-copter caps, or engage other brain cooling methods . . . . . .
Readers will want to use their screen zoom feature to examine these spreadsheet segments more closely. 250% makes the spreadsheet readable for my eyes. YMMV.
Does anybody know an easy way to enlarge a posted image from Photobucket so that screen zoom in not necessary? I tried manipulating the image's pixel width and height, but it inserts in @ the default values. Slim, maybe you can ask Bob the web elf?
The following image is the copyrighted intellectual property of Mark Balinski, dba as Dymaxion Design & Engineering, permission granted for individual usage only. (You can thank my lawyer for the previous statement.)
OK, as you examine the first 3, "RPM Segments" readers will notice that the Bhp/Liter (& Bhp/cu. in.) vary because of the Bhp/Tq/Rpm formula. Ie, Bhp/Liter, at any given Bmep development level, is directly proportional to rpm. Confirming Sir Harry Ricardo's statement that: He who can modify his engine to take advantage of rpm, can benefit thereby. Not sure that quote is exact, but close enough for demonstration purposes.
The 4th segment addresses my buddy Woody's statement: "Compared to what?" These are some comparisons of professionally developed engines, competing in World Class racing, where every development trick is used, and no expense is spared. We are talking tens of millions of R&D dollars (or Euros, as the case may be) every year, and in many instances, parts fabricated from Space Shuttle materials. The "average" professional with an "average" facility is not going to achieve those levels of development, let alone the average "enthusiast", the money just is not there. BUT, there should always be development goals that achieve a level of "respectability" for a project. Everybody gets to decide what level of "respectability" that they might embrace, and afford. One of the considerations here should be: component reliability for a given stress level . . . . . . . At not very elevated rpm levels, think: metal valve spring limitations. . . . . .
In the 4th segment, the columns I find interesting are:
A/ The calculated Bmep, both at peak Tq and peak Bhp, by itself, and compared to other engine types . . . . .
2/ The relative Bhp/liter . . . . . .
d/ Most interesting to me, Bmep % loss, from peak Tq to peak Bhp, over the operating rpm band . . . . . . . indicating the aspect ratio of the curves . . . . . .
Readers might find other derivatives of interest . . . . in all segments.
And, a deserved "Thank You!" to all of my mentors, but especially HB2. Grátiás maximás tibí agó.
Fordboy