I was just curious if some of the loco diesels in use today have ‘blown’ engines, and if so do they use superchargers or turbos?
I think most modern diesels use turbos.
The short answer is ‘yes’.
Two-stroke diesels e.g. all EMD engines (apart from the recent four-stroke H-series used in the 6000hp SD90MAC’s) - have to be ‘blown’ to work at all, normally turbo-charging on modern engines (aided presumably by a mechanical blower at low rpm when turbo’s don’t work well) or a mechanical blower on older non-turbo engines (which I guess qualifies as a super-charger).
Four-stroke diesels can be ‘normally aspirated’, but turbo-charging is almost standard these days on any sort of big diesel (not just locos) because it improves the efficiency (= better fuel economy) as well as giving more power for a given engine capacity. So yes, locos with four-stroke diesel engines e.g. GE and Alco are normally turbo-charged (the whistling noises you hear usually come from the turbo-charger).
Tony
Isn’t that turbocharged loco whine just a wonderful thing to hear!
I stood next to the turbo of a 2 Megawatt diesel generator one time. The turbo was huge and it was blood red…and it was not a pretty whistle coming from it (like you hear from trucks ) it was multiple high pitched sounds that all together sounded like something you expect to hear in hell!
Nothin beats the sound of a turbo diesel. Specially when puttin sports cars in their place…
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This is non-turbo but still also sounds good… [:D]
I own a 1968 Plymouth Satellite Sport Convertiable with a 440 in it…now that sounds nice…and some day might sport a supercharger!! 
Desiels need that Turbo. Works better that way.
Blowers would not benefit them too much, remember they are low RPM monsters.
If you have a blower on engines, make sure you have the displacement to back it up. I hate to see chargers on a small V6 because they would only be good at 55 mph 2 miles above Sea level.
CrazyDiamond, that pretty whistle sometimes disappears in a metallic choking just before you spritz all of your crankcase oil straight out of the stack behind the cab.
Adrian…I’ll just take a chance and enjoy the sound of say a…Z06 Corvette…But I must admit there is another one coming {Stingray}, that will have a blower on top of that Z06 engine with 600 plus hp. That should have some nice sounds too…
If its a non-turbo charged emd 2 stroke EMD (567,645) it needs forced air of some kind. In that application it has a roots type blower. If its a turbo charged EMD 2 stroke unit the turbocharger is engine driven until there is enough exhaust gas to drive the turbo and overrun the manual drive. You need forced induction air on a 2 stroke diesel to make it work.
How’s that Randy…see we do listen!
[bow]
I still think its cool on the smaller detroit 2 strokes to see a turbo and a blower!
Not a rail application, but JCB (a well-known UK earthmoving equipment manufacturer) has just set a new world diesel powered land-speed record of over 328 mph at Bonneville Salt Flats.
The car is powered by two 4.4 litre, 4 cylinder diesel engines using two-stage turbo charging, with a power output of 750hp each - a heavily developed version of the standard (150hp) production engine which chugs around all day on construction sites !
More info here - http://www.jcbdieselmax.com/html/home.php
Tony
Displacement should have no effect on any kind of blower, provided that your source of boost (turbo or supercharger) is matched well to your engine. I’ve seen small 2-cycle engines with an automotive smog pump rigged up as a supercharger before.
Matching engines to sources of boost can be an artform. Of course it can be an artform practiced in junkyards…check out www.toohighpsi.com
I believe the proper technical name for these is Turbo-Supercharger.
I don’t know if it was the very first, put the WWII era P38 Lightning fighter plane had Turbo-superchargers that were top-secret. During the early part of the war the plane wasn’t allowed over Germany for fear it would fall into German hands. The turbo’s were located behind the engines in the twin booms and I believe that was partly why the plane was arranged the way it was. Still for pure sound enjoyment, it’s hard to beat a Rolls Royce Merlin as in a P51 Mustang or some of the early Unlimited Hydroplane racing boats.
I’m pretty sure UP was the first to turbo-supercharge an EMD.
I am still amazed at how puny the frame is that holds an engine in the airframe on a P51. It looks more like the struts hold the airframe to the engine, than vice-versa (I guess it is both).
The WW2 Lightning was a awesome plane for it’s engines. That engine is a prime example of how to build powerful engines.
I’ll tell you another tidbit. Lighting Pilots always was out of fuel or running out when returning from combat in the pacific. Lindburgh taught them how to adjust the manifold to more than double the range and half the fuel supply problem.
I used to fly a virtual lighting in a Air Museum near Polk City Florida in thier simulator and cannot remember if it was effective at low level or up high where the zero did not have the umpth to get out of dodge.