What do you want? Power? millege? reliability?

You will not find a more powerful .21 engine then my clockwork modded jpx. It's crazy fast and powerful, but it is TOTALLY not necessary. I have several vspecs and ninja's and they are great engines with great runtimes. However from what i have seen personally, and i had to buy another engine it would be the werks b5. It's only 200$ and if you were to take ninja's, vspec, plus 4 four and ran them side by side you would not tell the difference. It's a great engine and my buddy is getting 13+ minutes per tank. DOn't know how long they last or how hard they are to tune though. TYe alphas are screaming too, but i know little about them except they run really well.

A little more pricey but the ninja has everything you could want in a motor long lasting, easy tune, powerful and killer mileage. But if i were you i would at least go to clockworks home page and see what might be best for you. The clocked jl is a monster and is only 250