# MOTOR BLOCKS



## John J (Dec 29, 2007)

How do you find out if a motor block is interchangeable between engines.


Like what other engine is the motor block from a NW-2 used in? 

What about SD-45?

SD40-2?


I am looking for motor blocks for a NW-2.


I thought I saw something about someone putting a motor block from a Aristo engine on a USAT engine or maybe the other way around.


JJ


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## Jim Agnew (Jan 2, 2008)

JJ, the NW2 and S4 use the same motor block.


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## Ted Doskaris (Oct 7, 2008)

JJ, 

Aristo SD45 that have 3 axle motor blocks, also, apply to Aristo GE Dash 9, EMD E8/9 - all having the same wheel tread diameter. (I have many of all of them.) 

It appears that the USAT SD40-2 that have 3 axle motor blocks with characteristic "floppy axle" would apply to PA/Bs, SD70; however, there may be difference in gearing? And there are differences in wheels with respect to, size, style, and tread diameter. (I have one SP SD40-2 and two SP SD70s.) 

Some folks have fitted Aristo 3 axle types to USAT, and also the opposite, fitting USAT 3 axle types to Aristo. The operating characteristics are very different if comparing the Aristo and USAT motor blocks to one another. Perhaps this is one reason why it has been done if you want to mix brands in a train. 

-Ted


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## NTCGRR (Jan 2, 2008)

JJ 
I have some 2 axle USAT motor blocks. is your NW 2 motor its selef bad or the whole block giving problems. You can buy just the motor its self for those. If in stock. 
call me later today.


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## Santafe 2343 (Jan 2, 2008)

*Ted, I have done and also seen several people that have installed Aristo Blocks in USA engines. As of yet, I have never seen or heard of anyone doing the opposite. If there is I would like to see a picture of it.*


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## Ted Doskaris (Oct 7, 2008)

When I use to participate in the Aristo Forum, there was someone by the name of Jens Banks? or something like that (I think - need help here). I recall that he had a very large outdoor model railway that he used to drive around in an old battered mini truck. If I recall correctly, he stated he put USAT 3 axle blocks in his SD45s. It kind of stood out in my mind at that time - a long time ago. I think he used battery power. 

-Ted


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## SD90WLMT (Feb 16, 2010)

My work so far on motor blocks has taught me this info: 

USA 3-axle motor blocks look the same. 

Meaning here - SD40-2 / PA -1 / SD70 locos 

each does have a different wheel diameter, like 36'', 40'', 44'' - respectively 

there are clearance grooves molded in the outer surface - this will cause a problem if trying to install a 70 ish axle into a 40 block or a PA block.. 

One can install a 40 axle in a 70 block tho, without problems...same as installing a PA axle in a 70 block... 

A 40-2 and 70 motor block are also the same wheel base, where as the PA block is much longer... 

I do not know if a NW-2 and a GP-38 are a match yet tho... would think this is at least a possibility tho! And then the GP30 can get thrown in here also...? 
................................ 

My current pet project involves reworking a set of 40-2 side frames to be mounted on a 70 block - using the metal brackets from a 70..and of course the 70 motor block.. 

I have a set running using a 70 block with 40-2 side frames, but also used the matching 40 style plastic pivot brackets.. 

As the mount - a flat tab sticking above the side - reduces the usable turning radius - which USA got around by making a ''mock frame'' much wider than even close to scale. It has been my goal to have more scale loco frames - the I-beam running the frame length - and have them be narrower also, I concluded I would remove the tab to increase the clearance and improve the turning radius and have a frame the way I want it, that can also turn better!! This is pretty much the same as 70 style side frames... 

I'm in the middle of this project so not ready to release it as a thread yet... 

One of my near future reworks in line will be to - Yes - install a USA motor block in either a SD45 or Dash-9 loco.. they are the same - but I suspect the Dash-9 will be first. 

Dirk - DMS Ry.


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## bnsfconductor (Jan 3, 2008)

All the GP series and F series blocks are the same. I'm not sure about the NW series as I don't have one, but I would suspect that they are similar. The GP and F unit motor blocks might not have the same wheel spacing as the NW... but I could be wrong. 
Craig


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## John J (Dec 29, 2007)

Thank you all for your replies. 


I saw a NW-2 on E Bay that was missing the motor blocks.

Where as the engine was a smoking deal by the time I got motor blocks and mounting frames the deal went south......Way South 



JJ


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