Worlds first Otto Langen Engine
Otto Gasoline Engine (circa 1895) Owls Head Maine Transportation Museum
Gas engine,Crossley Otto, Otto slide valve.
physics problem: otto engine?
For an Otto engine with a compression ratio of 7.50, you have your choice of using an ideal monatomic or ideal diatomic gas.
1. Calculate the efficiency in the first case, when the ideal monatomic gas is used .
2. Calculate the efficiency
I don't know which formulas you've studied.
These sites derive (for an ideal engine): E = 1 - 1/(r^k - 1)
where k is the specific heat ratio (Cp / Cv)
http://web.mit.edu/16.unified/www/SPRING /propulsion/notes/node25.html