Engine ponderings

[MB LeMirage]

Hey guys, has anybody ever thought about or know of/heard of anyone who has used one of the high horse marine engines in their bus? If so is it a matter of swapping out the marine cooling and the rear cover or are there other limiting factors. I know a guy who has a 760 hp 8v92 in a boat and was just curious. Might have to do a midnight, candlelight um erm .....removal shall we say.
Ryan.

[brmax]

I think the biggest factor is they can use the coolant source to keep engine temp down, at levels a radiator x 20 couldn't do. So putting the fuel to it can be pretty easy but still limiting durability. Sure sounds fun though
Floyd

[TomC]

Marine engines are unique compared to vehicle engines. One-marine engines produce their maximum at top near governor rpm-say 2,300rpm. Back it down to 2,000rpm, and you're nearly 50% less propeller load. Plus a marine engine has all of the ocean to cool it. The biggest injector I'd go in a 71 series (with turbo) is 90 and in a 92 series, an 100 injector. 90 Injector will give a 450hp in a 8V-71. 100 injectors will give 500hp in an 8V-92. Good Luck, TomC

[bobofthenorth]

The biggest difference between a marine and OTR application, aside from the cooling, is the nature of the load.  When I push the throttles up in the morning I may literally never touch them again until we enter a harbour 10 hours later.  Compare that with the up and down load the governor sees as you go over hills or vary speed in traffic and through the gears.  I'm not sure whether that is easier or harder on the engine but its definitely a lot different.

[luvrbus]

Big difference is the engines are rated in hours not miles like TomC posted you run a 800 hp 8v92 at full bore 2450 rpm it quickly becomes a 2000 hr engine and will use some fuel 

[MB LeMirage]

I had been wondering about the life span and assumed the fuel bill would skyrocket, but by golly that could be fun while it lasts. I have a buddy trying to convince me to take a 12v71 and a b500 tranny. I doubt the combo would fit without sticking out the rear doors. I like my old 8v71, it's reliable and just goes forever, but it's fun to dream, and I do have a power bug issue sometimes. When that bug bites I get baaaad ideas.
Ryan.

[bevans6]

Power is relative, I think.  I had 405 hp in my MC-5C at 26,000 lbs for a while, and after I got used to the fun of going up the hills without downshifting it was just like driving a bus.  I wasn't keeping up with the cars at the stop lights, and I drove with a light foot to save fuel.  It was kind of startling to go up the hills in fourth gear, the engine speed stayed pretty constant but you could really feel the engine come on the injectors and start to grunt louder and harder, and the black smoke started flowing out.  I went down to 350 hp with N75's from N80's but I saved the N80's in case I want to go up again.

Brian

[c-coop]

had a yacht with 8v92's  with all the water you could give them utilizing v12 water pumps you still had to watch the temps very close. these had 140mm injectors with 735hp never got more than 800 hours between overhauls. average was around 600

[HB of CJ]

Things have certainly changed.  Back before the dawn of time, or around 1972-1975, our new to us then American LaFrance Fire apparatus had 71 series Detroit Diesels with N90 injectors, no turbos, and a governed speed of 2700 rpm with a mear 2500 being deemed the maximum for a short while.  2100 rpm for long trips.  The black smoke flowed.

Now all the new apparatus today has some sort of Detroit with all the needed smog gear and no smoke.  They are now talking seriously about natural gas fire apparatus.  We will see how that works out.  But the new apparatus will run circles around the old apparatus.  Progress I assume.  But the old stuff was fun to drive.  Fuller T905M manual trannies.

[TomC]

I know that Caterpillar basses it's oil change on how much fuel is burned in the engine. Along those lines is the life of the engine is determined how much fuel you burn.
6-71's were pumped as high as 485hp @ 2500rpm from the factory for marine use. But ask any fisherman how long a 6-71 will last rated at continuous rating at 165hp at 1800, but then running it down around 1400. Will last for years of continuous use before overhaul Good Luck, TomC

[Detroitenginespecialist]

Ryan,
Brian here from American Fleet in Springfield Missouri.  We specialize in the re-manufacturing of Detroit Diesel bus engines.  We use genuine parts, and all of our engines come with a warranty.  If you have any questions please give me a call, and at the minimum, we can point you in the right direction.

[Don Fairchild]

coop, if that is all you got out of your engine then they had the wrong parts in them. Detroit used ceramic coated parts in  the high hp marine engines they usually go around 7500 hrs between rebuilds. I have several 525 hp 8V71TI's out there with over 21,000 hrs on them just coming in for rebuild.some of my 12V71TI's set 735 hp and running strong. these engines are in work/crew boats. There are several 3 and 4-71T's on barges that have been out there over (10) ten years. I have seen 12.7L 60's set at 600 hp used up at 6000 hrs.

you can go to cctskit.com and look at the web site to seen some of what we did.

Don