My brother ran across an 8V-71T for sale and mentioned it to me. Not knowing much of anything about them I thought I need an education before I go any further.
What does one look for or at in one of these?
What to make sure it has or does not have?
What are the real world specs on a factory 8v-71T with unknown injector size?
How large of injectors can be put in and what would they yield?
Can the turbo be changed or modified without compromising longevity? Does it make sense to do so?
Can a marine engine be used?
Can a mil engine be used?
What are the differences in these?
Lastly, what real world prices to pay for strong running engine?
Read my writeup on the Project page on installing a military 8V71T into an MCI bus. http://www.busconversions.com/bbs/index.php?topic=21836.0 If you have a line on a military engine, it will help you. The very first thing to check is the basic configuration of the engine - left hand vs right hand, where is the starter motor, etc. Regardless, you will need to probably change the flex-plate or flywheel to match what you have, you may need to change the bell housing so that the MCI cradle mounts bolt up, you will probably want to change the front cover so the MCI engine mount will work. You may need to change the thermostat housings so the MCI cooling system works, ditto the oil cooler. You need to look to see if the left hand most accessory drive position has a power steering pump drive mount, just under the air compressor. If it doesn't you will need to take the rear engine plate off to install the drive. You will probably have to swap over your 75 degree mount air compressor. But - it's all doable - I did it!
Here are the engine spec's on an automotive (truck/bus) 8V71T: http://www.powerlinecomponents.com/literature/detroit_diesel/brochures/8v71t_automotive.pdf (http://www.powerlinecomponents.com/literature/detroit_diesel/brochures/8v71t_automotive.pdf) The injector size sets the power level, but a turbo engine is always a bit more powerful than the equivalent natural engine with the same injectors and a bit more fuel efficient.
My military engine has N80 injectors and is rated at 400 hp gross at 2300 rpm. Don Fairchild suggest a different turbo for mine, so there are definitely options there. I would shy away from a marine engine, if only because they are often set up for about 50% more hp than an automotive engine (helps to have an ocean to use for cooling) and they may have other differences. I paid $2K for a never-run factory rebuild that had been setting on racks in barns for probably 20 years and I think that was a screaming deal - guys wife wanted her garden shed back in the worst way! I think a strong running take-out might be worth between that and $3500, more than that and I would be wanting a guarantee...