Could someone please explain the differences/improvements between the EMD 567 & 645 prime movers-specifically with regard to the potential power output, apart of course from the extra cubes.

Thanks



Superheater@rrmail.com

The cylinder liner outer diameter is the same, so that a 645 liner (power assembly) will fit into a 567-C or -D engine frame. This was a relatively common upgrade-- putting 645 power assemblies into a 567 frame.

The 645 frame was more ruggedly designed, particularly in the mounting for the crankshaft and main bearings. The 567 (a blower engine design) was turbocharged (in the 567-D version), but the 645 was designed to be a turbocharged engine from the beginning, and to better handle the stresses imposed by the higher horsepower.

The 710 was a bigger version of the 645, but with no interchange of components-- power assemblies were different diameter, for example.

hpincus@mindspring.com

I'd like to add a few questions to Superheater's questions. In terms of block size, and mounting, would you be able to drop a 645 engine block in a space for a 567? I'm sure there would be some modifications, but can it be done? What about cooling? Since the 645 puts out more horsepower, does the cooling system need to be upgraded? Thanks in advance

J.T.

jtjjtb@aol.com

You should also watch the capacity of your electrical system if you're increasing the HP of the diesel engine. The switchgear and motors might not be able to handle it.


Electric City Trolley Museum Association

> I'd like to add a few questions to
> Superheater's questions. In terms of block
> size, and mounting, would you be able to
> drop a 645 engine block in a space for a
> 567? I'm sure there would be some
> modifications, but can it be done? What
> about cooling? Since the 645 puts out more
> horsepower, does the cooling system need to
> be upgraded? Thanks in advance

As to the physical size and mounting of the 567 vs. the 645, it looks identical to me. I would caution that if such a swap is contemplated, careful and extensive measurements should be taken on the engines as well as on the locomotive carbody mounting and other clearance points (like any overhead hatches, piping, obstructions, etc.).

What is the planned service for the re-engined locomotive? In all but the most extreme environments (like desert opertion in the summer), the cooling systems have enough capacity to handle a few additional horsepower. If the 567 coming out is a 1750 hp engine, and the 645 (16-cyl., blower engine would be 2000hp) is going in, there's only 250 hp additional heat load on the cooling system. What shape is it in (radiators, piping, oil cooler)? And, how much time will the locomotive be fully-loaded? Most of the time, in preservation railroading service, these older units rarely see 8th notch operation, and then only for short periods of time. Remember, the cooling systems were originally designed to handle full-throttle, full amp operation for long periods of time.

It should also be possible to set the injector rack "back", to provide a bit less fuel for each throttle setting, thereby developing less power for each throttle notch.

Hope this helps.



hpincus@mindspring.com

Thanks Howard. That helped a lot. I was just throwing some ideas around. I don't own or even work on diesels, was just wondering. Thanks alot.

J.T.

jtjjtb@aol.com

> It should also be possible to set the
> injector rack "back", to provide a
> bit less fuel for each throttle setting,
> thereby developing less power for each
> throttle notch.

I do not believe that changing the rack would work when trying to reduce the power output of the engine. The govenor will move the rack wherever it needs to in order to obtain the correct rpms associated with the requested run notch. If you were to start the engine, and then somehow "lengthen" the linkage from the govenor to the rack (which would require shortening the other linkage rod), then the engine would lose rpms. The govenor would then respond by pulling out the "length" that you put in the shaft, so that it could get it's rpms back.

For example, if the engine is idling, the only load would be the friction in the bearings/belts/etc plus the load from the water pump, oil pump, and aux gen. Lets say it takes 40HP to keep the engine at a constant rpm with this load. If the air compressor then starts to pump air, that takes an additional 60HP, lets say. If the govenor does not move the rack when the air compressor cuts in, then the rpms of the engine will decrease. This never happens (for long) because the govenor will pull the rack open so that the rpms are kept, and the engine puts out the needed HP to pump air too. When the air compressor cuts out, the govenor reduces the rack setting so that the rpms are held. The same happens when you move the throttle from Idle to Run 1. The rpms are maintained, but now there is an additional load on the engine from the Main Gen, thus causing the govenor to open the rack to maintain the rpms. (the same rpm is used in Idle and Run 1)

When the throttle goes from Run 1 to Run 2, the engine will increase the rpms to the Run 2 setting.

The other factor here is the load regulator. This is controlled by the govenor, and it controls the level of excitation that the Main Gen gets. The higher the excitation, the more power the Main Gen asks for from the engine. If the govenor dutifully opens the rack to produce the power (all the while holding rpms), then the traction motors get the amperage. This is why the amperage slowly rises even though the throttle and rpms may change quickly. Bottom line, the engine only produces as much horsepower as is asked for, no matter the size of the cylinders.

If you were to try to decrease the power asked for from the Main Gen, I can see two possible methods. One would be to change how far the govenor opens the load regulator, thus changing the excitation to the Main Gen. This would require getting into the guts of the govenor, which I would not recommend. It will void the warrenty if nothing else, and there is alot of stuff in there that should not be changed except by a qualified govenor mechanic. The other would be to add or reduce the resistance in series with the load regulator. Thus changing the Main Gen excitation for any given Load Regulator setting.

I have not ever tried either of the above. I would suggest a long conversation with someone who has before you start taking any engines apart!

Ryan

lima709@aol.com

Oh come on it's fun to play with govenors and load regulators. Just make sure you have it hooked to a load box so you get what you want.
We redid a GP-7 for a customer. It was putting out 1,600 hp. Thier consultant only wanted 1,300. Probally still more than they need.We spent 2 days on the load box and finally gave him what he wanted.Balance beams ,power pistons, Rack setings, full field, minimum field. what a pain in the A@# !!!

irss@eriecoast.com

> Oh come on it's fun to play with govenors
> and load regulators. Just make sure you have
> it hooked to a load box so you get what you
> want.
> We redid a GP-7 for a customer. It was
> putting out 1,600 hp. Thier consultant only
> wanted 1,300. Probally still more than they
> need.We spent 2 days on the load box and
> finally gave him what he wanted.Balance
> beams ,power pistons, Rack setings, full
> field, minimum field. what a pain in the A@#
> !!!

........easier to cut off two cylinders, Jack!! LOL!! Grab the Sawzall!!!