could anyone explain the difference between direct-injection and indirect-injection engines, and which category the 6.5 falls into? i believe it is IDI but i want to be sure.
thanks!
Paul

IDI injects fuel into a precup, this is where ignition takes place and also where the glow plug protrudes into. DI injects fuel directly on top of the piston, hence the difference in piston designs. The 6.2,6.5, 6.9 and pre power stroke 7.3 are all IDI.:eek:

Indirect engines are not quite as robust as direct injection engines and are more suited for smooth running. Direct injection engines are quite a bit stronger as they have to take the full force of the combustion process.

Check out the opposed piston diesel engine.

http://www.fleetsubmarine.com/propulsion.html

Is it direct injection or opposed piston injection?

Maybe piston port IDI? Either way, that is pretty wild. Never seen that before. Thanks DP!

A lot of really large stuff has that type of drive configuration. Cruise ships and those giant strip mine dump trucks come to mind

Diesel locomotives.......

I am an engineer at a locomotive plant in Boise ID. The engines used in locomotives are standard v block configuration. I did get to see one of the oppossed cyinder engines up close. Sorry I didnt take more pics. The owner said they were 140 BHP and would run for 300,000 miles with just one new set of injectors, no other work!!!

I went on a tour of a a submarine and they had the engine where you could see some of the internals. I thought man it must be really tight in here having to turn the engine upside down to gain clearance. I did a little research and found out it was an opposed vertical piston engine with two cranks connected by chain drive. Seems they used these engines in submarines, locomotives and other odd applications. When I was trying to figure it out I assumed they turned the engine upside down so you could service the engine in the sub without pulling the engine. What a laugh!

Do a search on Fairbanks-Morse & submarines to find more articles on the engines.

I think they flip the sub to work on the upper crank..........

Actually the upper crank is on the top where you would expect the valves to be. Even has what looks like a big timing chain attached. Now that bottom crank has got to be a real bugger to get at. Puts new meaning to upper and lower gasket sets.

the Fairbanks-Morse is direct injection with fan spray nozzle, most use gear drive(lots of different marks on gears to line up) top crank is shorter stroke and timed just behind bottom crank. exhaust out bottom ports(looks like det-diesel liners bottom welded together) used to have lots of exhaust fires from running full speed then slowing down. not very popalar engine. but if you want to see neat setup of this engine style look for Napier Deltic, 3 crankshafts of s/s, 3 throws to section(18 pistons) think blocks were aluminum, brits used in minesweepers and post ww2 pt boats, us navy used in norwegien pt boats. knew the tech rep for them from ricardo-paxman said when had problem replace no fix 50-60's about $1,000,000.00 think could bolt 3 sections together believe each was 2,700hp@1800rpm. F-M's owns ALCO(16-251) good engine 2 shafts 750rpm cruising now thats exhaust, nice low drown. F-M 38-1/8 pretty much too dirty in 80's EMD's topdog for loco's, some ALCO's(American Locomotive COmpany) all direct inj, indirect also give you that Claterpillar sound, i quess thats enough.

Yep - so when the sub is flipped, the upper crank becomes the lower crank, and the lower cr...well, you know.

Real challenge is remembering whether the lower or upper gasket set had been used, after floating the crank.

I guess you know where floating the valves came from now. When the engine blew you would find them floating in the bilge, thus came the term "floating the valves".

Could be a real wash-out........

Of course the only valves that would float where the hollow sodium filled valves. I suppose the bottom piston where pop-up pistons. Does that mean the upper pistons where called pop-downer pistons?

When the sub went down to fast and sucked in water in the intake was that water injection or water ingestion?

Boy This thread is sinking fast :)

:d ..........