Peak Pressure Inside the Internal Combustion Engine
Peak Pressure Inside the Internal Combustion Engine
(OP)
I have to design a connecting rod with minimum weight. For this I selected the Honda GX25 engine. I want to know the peak gas pressure on the piston so that I can calculate force on the piston and hence maximum force on the connecting rod. Does anybody know how I calculate the peak pressure or how pressure varies between TDC and BDC.





RE: Peak Pressure Inside the Internal Combustion Engine
je suis charlie
RE: Peak Pressure Inside the Internal Combustion Engine
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Peak Pressure Inside the Internal Combustion Engine
RE: Peak Pressure Inside the Internal Combustion Engine
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Peak Pressure Inside the Internal Combustion Engine
RE: Peak Pressure Inside the Internal Combustion Engine
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Peak Pressure Inside the Internal Combustion Engine
RE: Peak Pressure Inside the Internal Combustion Engine
https://www.google.com/search?q=cylinder+pressure+...
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Peak Pressure Inside the Internal Combustion Engine
Point is, at peak engine speed on any modern gasoline engine, inertial forces on the connecting rod far exceed forces due to cylinder pressure.
RE: Peak Pressure Inside the Internal Combustion Engine
As many said, inertial forces are most important in conn rod design. Conn rod forces are largest when the piston reaches tdc on exhaust stroke (all masses are going up, and then come to an abrupt stop, causing extreme tensile forces).
RE: Peak Pressure Inside the Internal Combustion Engine
RE: Peak Pressure Inside the Internal Combustion Engine
RE: Peak Pressure Inside the Internal Combustion Engine
I wrote the above without looking at what a GX25 is.. Soon to find out that it is a lawnmower or weedeater engine. So considering that, I don't think there are many lawnmower engines that make these kinds of peak pressures, if so I want one...
RE: Peak Pressure Inside the Internal Combustion Engine
"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz
RE: Peak Pressure Inside the Internal Combustion Engine
https://www.epa.gov/regulations-emissions-vehicles....
Here you can see the F-150 2.3L EcoBoost making ~23 bar bmep
https://www.epa.gov/sites/production/files/2016-10...
There is also some raw test data in the "Test Data" section of the first link.
Of course these may not be the highest on the market nowadays, but you can form your own conclusions about how turbocharged and naturally aspirated engines are running in terms of peak torque, bsfc, bte in today's world. In addition to the vehicles in the articles in the links, calculting bmep from GM's Cadillac ATS rated at 295 lb-ft torque equates to bmep of 25 bar; Ford Focus RS rated at 350 ft-lb equates to nearly 26 bar.
RE: Peak Pressure Inside the Internal Combustion Engine
http://mb-soft.com/public2/engine.html
Best of luck reducing your rotating mass on those connecting rods.