Upgrading the N scale Intermountain SD45-2 with a Kato chassis

[kiwi_bnsf]

i am curious as to what would need to be milled on the Inter mountain frame to achieve similar results?? couid it be done?

The Intermountain chassis is fuel tank is 2mm wider than the Kato Mid Production fuel tank at its narrowest point, so you would need to mill off 1mm from each side for a portion of it. There may also be some interference with the pickup strips, but it looks possible. If your goal is to upgrade the looks of the existing Intermountain chassis + shell, I would go with the Keystone Details dress up kit that @Ed Kapuscinski linked to above, which would avoid any milling.

Even with the frame gaps dressed up, the Intermountain chassis has too many issues for me:
 - inferior IMRC/Atlas HT-C trucks (no traction motor detail, require upgrading to Kato wheels to stop wobbling, less depth of detail).
 - inferior motor and drive train (not as smooth running as a Kato, even after a couple of hours of tuning)
 - decoder sits lower, and motor drive train sits higher, leaving less room for a speaker enclosure and keep alive

The Kato swap addressed all of these (albeit at the cost of a Kato SD40-2, and a hour and a half of milling).

[CRR Chase]

The Intermountain chassis is fuel tank is 2mm wider than the Kato Mid Production fuel tank at its narrowest point, so you would need to mill off 1mm from each side for a portion of it. There may also be some interference with the pickup strips, but it looks possible. If your goal is to upgrade the looks of the existing Intermountain chassis + shell, I would go with the Keystone Details dress up kit that @Ed Kapuscinski linked to above, which would avoid any milling.

Even with the frame gaps dressed up, the Intermountain chassis has too many issues for me:
 - inferior IMRC/Atlas HT-C trucks (no traction motor detail, require upgrading to Kato wheels to stop wobbling, less depth of detail).
 - inferior motor and drive train (not as smooth running as a Kato, even after a couple of hours of tuning)
 - decoder sits lower, and motor drive train sits higher, leaving less room for a speaker enclosure and keep alive

The Kato swap addressed all of these (albeit at the cost of a Kato SD40-2, and a hour and a half of milling).

I agree / and see what your saying. The kato runs better than most any other brand. as far as milling goes.. I would be milling my first frame.. I was just looking at the engine last night and was wondering what needed to be done to current frame. thanks for the insight.

[craigolio1]

I don’t know if it’s worth anything, because I’m in agreement that using a mill is the BEST way to accomplish this…. However for the non mill owning crowd this conversion can be done with a Dremel and files. I did pretty much the same modification to fit my SD38-2 shell on to a Kato SD40-2 chassis. My shell was made using an Atlas GP long hood and so the mech needed to be narrowed. I started with the Dremel 5/16” high speed cutter and finished it with a file. Took some time but it worked. All I’m saying is don’t kill the idea of trying this is you don’t have a mill.

Craig.