Re: whats the best engine for the job???
Mike, i hate to burst your bubble, but i figure who better than me?
You are NOT going to get 250hp at the wheels, shile acheiving 20 or more miles per gallon, unless you're running some kind of nuclear powered device for propulsion. A Diesel wont get you that much horsepower, and a gas wont make anywhere near that kind of mileage. Like i said, i hate to break it to you.
A more realistic goal would be to decide whice of those two numbers, the HP of the MPG is more important to you. And i dont see the need for 250 hp at the wheels in a Jeep. You will have a transfer case so you can get lower gearing for more torque. And with all that power and that NV4500, i sure hope you dont plan on running anything less than front and rear Dana 60s for axles. Anything less wont live under there for long.
I have never performed a fuel injected engine swap, so i cant speak from experience, but from what i read, i gathered that its not TOO much more difficult, providing you get ALL the wiring harnesses and ALL the computers and electronics from the donor vehicle, along with having a place to mount the various sensors. Be advised the cooling will be an issue unless you get a top of the line radiator.
Your project is ENTIRELY possible, except for the conflicting MPG/HP #s. Other than that, its going to take a LOT of time and a LOT of money to accomplish. Sure would be worth it all when its done. Good luck, and i hope i've helped you some!!
Give me Jeep or Give me Death!!!
(Will trade functioning organs for CJ-7 or flatfender)