GP40 conversion

[TRAINNUT]

Now I know this is an odd topic but is there any cosmetic differences between a GP40 and A GP38 other than the fans, dynamic brake, and vents.

Anybody know if the body was longer, a different fuel tank, is all I notice

 

[bnsf971]

Different exhaust, different air filter, different radiator, different fuel tank (though that may very by railroad).

 

[TRAINNUT]

Different exhaust, different air filter, different radiator, different fuel tank (though that may very by railroad).

My general plan is to turn a bluebox GP40 Into a gp38, its undectrated and I can't find any scheme I like on the 40. So Im converting it.

 

[bnsf971]

My general plan is to turn a bluebox GP40 Into a gp38, its undectrated and I can't find any scheme I like on the 40. So Im converting it.

The 40 has an extra radiator fan and longer radiator. You "could" make a credible GP39-2 out of a GP38-2 and the center hood section from a GP40.

 

[wright]

There are also differences between the GP38 and GP38-2 (and GP40 and GP40-2) and even differences by year of manufacture (two fans far apart on earlier models, two fans close together for later builds). If you go to rr picture archives, there are nearly 63,000 photos of GP40-2s, you might find one you like there. If you want an undec BB GP38-2, I have an extra I've been meaning to sell.

 

[Rico]

I think you’ll need a specialized tool for this conversion, like maybe a can opener?

 

[J.Albert]

Not worth the effort.
If you want a GP38, then BUY a GP38.
Many possible choices available.

 

[bnsf971]

Not worth the effort.
If you want a GP38, then BUY a GP38.
Many possible choices available.

I agree with that. The days of having to roll your own because there wasn’t anything available are behind us. And if you want a GP38 that’s so hyper-prototypical that one of the many factory-built options aren’t acceptable, you won’t be starting with a Blue Box GP38-2 to begin with.

 

[Rico]

The days of having to roll your own because there wasn’t anything available are behind us.

Geez I can remember a time when a guy brought a loco to the club that had MU lines on the front.
Look at that, MU lines, wow! Now that was something.

Not intending to deter your project Trainnut.

 

[Colorado Midland Modeler]

Maybe this can be of some help if this project is something you truly want to do. If I may quote a few things from Kalmbach's (now Firecrown's) Trains Guide to North American Diesel Locomotives: "The GP38 was the non-turbocharged (2,000-hp) version of (and built concurrently with) the turbocharged GP40, with both using 16-cylinder versions of the new 645 engine." "The GP38 shares the the GP40's body, but has two 48" radiator fans at the rear of the roof compared to three on the GP40." "Some GP38s have a longer cab, with the front wall moved forward to accommodate dual control stands. Paper air filters were an option; these were located in a box just behind the forward air intake. Several fuel tank sizes were offered." This is what it says for the GP40: "The GP40 can be identified by its three large (48") radiator fans at the rear of the roof. Early units had "button-top fans, with circular plates in the middle; later engines had all-open fans." "Three fuel tank options were available." "Early models had screen-covered radiator openings, and later units had wire grids." "Very late GP40s had the option of extended-range dynamic brakes, these are marked by a small door at the front of the dynamic brake housing." "Late GP40s have an electrical cabinet air filter box on the walkway behind the left side of the cab." Hope this proves helpful to you.