Duratrax Torq (.21), 4/10, the only good this about this engine was that it held a tune.
O.S V-01-B (.21), 7/10, Held tune, good smooth power.
RB C4 (.21) 8/10, WWWWHHHOOOAAAA loads of power but all in one go.
RB S5 (.21) 7/10, very reliable engine, good power.
RB S7II (.21), 8/10, Great engine, very reliable, powerful but lacking a little bit down low.
Wasp .28, 8/10, Fast but hot. Good looking engine.
Collari XS3200 (.21), 10/10 my favourite engine ever. Very powerful and as smooth as a babies bottom. Holds a tune. I'd love another one.
Nitro Star S-25 (.25) 7/10, a better engine than people let you believe. Makes a savage fun.
Sirio XXL monster block (.27) 1/10, hated this engine from day one, powerful when running, but terrible pullstart/oneway, terrible to tune, rubbish aftersales not worth the effort. I will never-EVER buy a sirio again. utter rubbish. A $300 paperweight.