The thing is, you comparing a 4 stroke nitro to a 4 stroke gas, this isn't a good indicator, I'm comparing all factors from cheapest glow to multi cylinder petrol 4 stroke engine Prices increase dramatically when you talk four stroke petrol/gas you are looking at $600 where as 4 stroke petrol/gas radial 4s would set you back $4000. Clearly we must not loose our sanity.

Having spent sometime on choosing my engine I decided to buy another brand new Force .46cu,in nitro glow engine, as a spare because a new piston and sleeve would set you back £60, a complete brand new engine is costing £90, so I've ordered two engines, one to use/fly and the other for spare parts