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Modify a HO scale SD40 into a SD38-2

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Modify a HO scale SD40 into a SD38-2
Posted by Lazers on Thursday, September 24, 2020 10:02 AM

Hi, I was just wondering if anyone knows of the major asthetic differences between these two locos?

To my untrained eye, they both look similar, except for the Cooling Fan arrangement on the Long Hood Roof

The chance of an Intermountain Iowa Interstate R/R SD38-2 at a bargain ebay-UK price is very unlikely.

However there are plenty of 'old' Athearn SD40's available and the Bachman version also looks quite good (to me)

The model I would like to achieve would be CSS 804/805, which were previously Iowa Interstate SD38-2 Locos.

Any advice received with thanks. Paul

"It's the South Shore Line, Jim - but not as we know it".

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Posted by Doughless on Thursday, September 24, 2020 10:18 AM

To answer your question, are you converting an SD40 into a SD38-2...or an SD40-2 into a SD38-2?

Between the dash units I'm only aware of the cooling fan differences, the 40-2 has 3 and the 38-2 has 2.

Same with the nondash 40 and 38.  3 fans vs 2 fans.

There may be some differences with the size of the fuel tanks, 40 maybe having a larger tank, but that would be dependent upon the roadname. 

If you're actually asking the difference between a non dash 40 and a 38-2, there are likely many differences, although minor. 

The new Athearn RTR SD40 and SD40-2 are probably the best versions out there now.  Better than old blue box and even recent RTRs.

But as an alternative, are you aware that both Athearn and KATO made SD38-2's?  You're gonna have to repaint anyway.  KATOs can be pricey but they are very good.  Both are available on ebay frequently.

https://www.youtube.com/watch?v=0Kys8agyQbM

 

- Douglas

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Posted by NHTX on Thursday, September 24, 2020 10:40 AM

     The SD38-2 shares the same frame dimensions as the SD40-2.  The original SD40 was built on a frame that is three feet shorter than the -2.  I would use the -2.  If I'm not mistaken, Athearn made a regular SD38 vs. a -2.

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Posted by cv_acr on Thursday, September 24, 2020 12:01 PM

Shorter radiator (so shorter rad intakes, different number of radiator fans), different exhaust arrangement (38 series is non turbocharged, 40 series is same engine block with turbocharger), prominent air filter box ahead of the dynamic brake blister which is a distinctive spotting feature of any 38-series unit), etc.

Plus if you actually meant SD40 (no -2) to SD38-2 you have the -2 specific details to contend with: hood sight glass in door on engineer's side, overhang at rear of cab roof, larger batter boxes on conductor's side, etc. on top of the singificant frame length different between SD40 and SD40-2.

Once you really get into it, there actually is hardly anything that's actually the same between an SD40 and SD38-2.

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Posted by Doughless on Thursday, September 24, 2020 12:32 PM

NHTX

     The SD38-2 shares the same frame dimensions as the SD40-2.  The original SD40 was built on a frame that is three feet shorter than the -2.  I would use the -2.  If I'm not mistaken, Athearn made a regular SD38 vs. a -2.

 

Yup, thanks for the correction.  Athearn's is a 38, not a dash 2.

And the obvious differences between the 38 and the -2 is the length of the frame.  I was focusing on body details and didn't even think of the frame.

And between the 40s and 38s the major difference would be the fans and exhaust stacks.

Didn't think it through very well before my original answer.

- Douglas

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Posted by Lazers on Thursday, September 24, 2020 2:23 PM

Hi, thanks for your all replies and insight. This hi-lites my lack of knowledge in that I did not even realize there are major differences between a 40-no dash and a 40-2

I would therefore obtain a SD40-2, to convert to a SD38-2, however the way it's panning-out, it might be better if I wait for a SD38-2 to come along at a price I can manage, since there are small detail differences - as well as the main ones. The irony is that the availability of UK 40-2's outweighs 38-2's.

CSS 804 photos shows a Dynamic Brake, in the usual position. Cheers, Paul

"It's the South Shore Line, Jim - but not as we know it".

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Posted by wjstix on Thursday, September 24, 2020 3:08 PM

A lot of the "dash 2" changes were internal, like improved electronics.

May be a minority opinion, but if you accurately painted, decalled, and weathered an SD-40-2 model to represent an SD-38-2 without doing any major modifications, I don't know that it would be all that noticeable to most folks?

Stix
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Posted by Lazers on Thursday, September 24, 2020 3:35 PM

wjstix

A lot of the "dash 2" changes were internal, like improved electronics.

May be a minority opinion, but if you accurately painted, decalled, and weathered an SD-40-2 model to represent an SD-38-2 without doing any major modifications, I don't know that it would be all that noticeable to most folks?

 
Hey Stix, thanks for that. I certainly wouldn't notice any differences and an SD40-2 masquerading as a 38-2 would be 'good enough' for me. But there was a nice Atheran B/B SD40 on ebay UK last week, which I let pass due to my uncertainty and I am grateful for the previous info' not to make that mistake in the future. Paul

"It's the South Shore Line, Jim - but not as we know it".

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Posted by Doughless on Thursday, September 24, 2020 5:15 PM

Lazers

 

 
wjstix

A lot of the "dash 2" changes were internal, like improved electronics.

May be a minority opinion, but if you accurately painted, decalled, and weathered an SD-40-2 model to represent an SD-38-2 without doing any major modifications, I don't know that it would be all that noticeable to most folks?

 

 

 
Hey Stix, thanks for that. I certainly wouldn't notice any differences and an SD40-2 masquerading as a 38-2 would be 'good enough' for me. But there was a nice Atheran B/B SD40 on ebay UK last week, which I let pass due to my uncertainty and I am grateful for the previous info' not to make that mistake in the future. Paul
 

Stix expressed my first post better than me. 

The major differences between the 40 and 38 dash 2's are the number of fans along the hood and the number of exhaust stacks. 

An older Kato SD38-2 would be a better buy than buying an Athearn SD40-2 to convert into a 38-2, but I've never seen a KATO SD38-2 for less than $100.

 

- Douglas

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Posted by dehusman on Thursday, September 24, 2020 5:38 PM

Hey Stix, thanks for that. I certainly wouldn't notice any differences and an SD40-2 masquerading as a 38-2 would be 'good enough' for me.

The two engines have very noticeable differences when viewed from the top  The SD38 has two fans, the SD40 three.  The SD40 has a turbocharger exhaust (one big one) and the SD38 has two small exhaust stacks.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by cx500 on Thursday, September 24, 2020 7:00 PM

In my experience, SD40 trucks are not quite the same as on the SD40-2s.  The differences are not huge, but they are easily visible if you look at the details.  I don't know if the same is true for the 38s.

John

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Posted by NHTX on Thursday, September 24, 2020 8:51 PM

     All EMD six axle -2s, except for some Conrail SD40-2s, rode on the HT-C truck with three holes in the sideframe between the journals instead of the two in the regular flexicoil truck.  The HT-C truck also has the center axle dampening strut which the regular flexicoil truck does not have.  The HT-C truck experienced early teething problems with failures of the dampening strut mountings which caused some roads to restrict their -2s to 50 MPH until an improved mounting was divised.

    Kitbashing a credible SD38-2 from an SD40-2 is doable, by removing the forward radiator fan and replacing the radiator grille with a Cannon & Co. part.  Remove the turbocharger exhaust stack and replace it with Roots-blown stacks fore and aft of the dynamic brake fans, if the unit has dynamics.  If it doen't have dynamics, non-dynamic roof sections with exhaust stacks have been made by Athearn and also Atlas.  An air filter box can be constructed from sheet styrene. 

    An article on kitbashing four or five different EMD models using the Athearn SD40-2 as the starting point appeared in "Model Railroader" magazine in the 1980s.  The SD38-2 was among them.  Unfortunately at this time I cannot locate my MR back issues disc.

    ( I still say Class 37s sound just like Alco RS-11s. )

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Posted by OldEngineman on Thursday, September 24, 2020 9:30 PM

My opinion:

Just buy an SD-38.

Makes things a heck of a lot easier...  Wink

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Posted by Lazers on Friday, September 25, 2020 7:58 AM

NHTX

     All EMD six axle -2s, except for some Conrail SD40-2s, rode on the HT-C truck with three holes in the sideframe between the journals instead of the two in the regular flexicoil truck.  The HT-C truck also has the center axle dampening strut which the regular flexicoil truck does not have.  The HT-C truck experienced early teething problems with failures of the dampening strut mountings which caused some roads to restrict their -2s to 50 MPH until an improved mounting was divised.

    Kitbashing a credible SD38-2 from an SD40-2 is doable, by removing the forward radiator fan and replacing the radiator grille with a Cannon & Co. part.  Remove the turbocharger exhaust stack and replace it with Roots-blown stacks fore and aft of the dynamic brake fans, if the unit has dynamics.  If it doen't have dynamics, non-dynamic roof sections with exhaust stacks have been made by Athearn and also Atlas.  An air filter box can be constructed from sheet styrene. 

    An article on kitbashing four or five different EMD models using the Athearn SD40-2 as the starting point appeared in "Model Railroader" magazine in the 1980s.  The SD38-2 was among them.  Unfortunately at this time I cannot locate my MR back issues disc.

    ( I still say Class 37s sound just like Alco RS-11s. )

 

 
Hi NHTX, thanks for this. I located the article in the digi-archives, October 1985 by Tom Busack, "Athearn SD40-2, Kit-basher's Goldmine". It looks a real-good read, with with drawings for various locos. I must admit, I should have looked there first, myself.
Hi, Engineman - SD38-2's are a bit rare in the UK, even new ones, which I cannot afford to buy.
Regards, Paul

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Posted by dehusman on Friday, September 25, 2020 7:04 PM

Quick and dirty conversion can be an "SD38-2M" type engine.  Remove the turbo charger exhaust and replace it with two exhaust stacks, then just keep the 3 cooling fans, modeling an engine that was an SD40-2 and was de-turbocharged to make an SD38-2.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by cv_acr on Monday, September 28, 2020 12:00 PM

Unless he's trying to represent a specific prototype unit which was originally built as a "natural" SD38-2, and he referenced a pair of actual Chicago & South Shore unit numbers.

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Posted by Lazers on Monday, September 28, 2020 3:43 PM

cv_acr

Unless he's trying to represent a specific prototype unit which was originally built as a "natural" SD38-2, and he referenced a pair of actual Chicago & South Shore unit numbers.

 
Hi Chris, Yes he as in 'I', am referncing a CSS unit which was previously Iowa Interstate SD38-2 (154) as per my original post. I'm not sure if this loco started-out as a 40, sometimes loco's are de-rated, I believe?
Regards, Paul
 
Moving on, there is a nice-looking Bachmann HO model of an SD40-2 on ebay UK. I have only Atlas models (GP38's) in my roster and I wondered if anyone had any experiences of a Bachmann SD40-2 and it's suitability as a doner, for my project?
Thanks, regards, Paul

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Posted by wp8thsub on Monday, September 28, 2020 6:04 PM

Lazers
I have only Atlas models (GP38's) in my roster and I wondered if anyone had any experiences of a Bachmann SD40-2 and it's suitability as a doner, for my project?

The Bachmann shell is poorly tooled.  I wouldn't recommend it for any kitbashes.  Any of the other current SD40-2 shells in HO would be better.

Rob Spangler

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Posted by Lazers on Tuesday, September 29, 2020 7:43 AM

wp8thsub

 Lazers

I have only Atlas models (GP38's) in my roster and I wondered if anyone had any experiences of a Bachmann SD40-2 and it's suitability as a doner, for my project?

The Bachmann shell is poorly tooled.  I wouldn't recommend it for any kitbashes.  Any of the other current SD40-2 shells in HO would be better.

Hi Rob, thank you very much for that advice, which I will stick to. There are several Athearn versions up for grabs - B/B and later ones. Much appreciated, Paul

"It's the South Shore Line, Jim - but not as we know it".

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