Week 2 Air standard Cycle

i tried but i was not able to get the desired curve.

import math
import matplotlib.pyplot as plt

p1=101325
t1=400
gamma=1.5
t3=2000

bore=0.1
stroke=0.1
con_rod=0.5
cr=8

def engine_kinematics(bore,stroke,con_rod,cr,start_crank,end_crank):

	a=stroke/2
	R=con_rod/a
	v_s=(math.pi/4)*pow(bore,2)*stroke
	v_c=v_s/(cr-1)

	sc=math.radians(start_crank)
	ec=math.radians(end_crank)

	n=10

	dtheta=(ec-sc)/(n-1)
	v=[]

	for i in range(0,n):
		theta=sc+i*dtheta
		term1=0.5*(cr-1)
		term2=R+1-math.cos(theta)
		term3=pow(R,2)-pow(math.sin(theta),2)
		term3=pow(term3,0.5)

		v.append(1+(term1*(term2-term3))*v_c)

	return v
		



v_s=(math.pi/4)*pow(bore,2)*stroke
v_c=v_s/(cr-1)
v1=v_c+v_s

v2=v_c
p2=p1*pow(v1,gamma)/pow(v2,gamma)

rhs=p1*v1/t1
t2=p2*v2/rhs
v_compression=engine_kinematics(bore,stroke,con_rod,cr,180,0)
constant=p1*pow(v1,gamma)

p_compression=[]

for v in v_compression:
	p_compression.append(constant/pow(v,gamma))

v3=v2
rhs=p2*v2/t2
p3=rhs*t3/v3
v_expansion=engine_kinematics(bore,stroke,con_rod,cr,0,180)
constant=p3*pow(v3,gamma)

p_expansion=[]

for v in v_expansion:
	p_expansion.append(constant/pow(v,gamma))




v4=v1
p4=p3*pow(v3,gamma)/pow(v4,gamma)
t4=p4*v4/rhs

plt.plot([v2,v3],[p2,p3])
plt.plot(v_compression,p_compression)
plt.plot(v_expansion,p_expansion)
plt.plot([v4,v1],[p4,p1])
plt.savefig('otto cycle')
plt.show()