ok guys a need a little help here. i need to know if there are any major exterior differences between the emd gp20 and the emd gp18 prototypes and any major ones between them and a gp7. i'm going to do some bicentennial units and am hopefully able to use the gp20's due to availablilty and price. thanks in advance mitch. ps any locomotive experts here?
Here is a shot of CG128, a GP7 without dynamic brakes. http://gelwood.railfan.net/other/sout/cg128.jpg ______ Here is CG174, a GP18 http://gelwood.railfan.net/other/sout/cg174.jpg ______ Here is SP 4052 a GP20 http://gelwood.railfan.net/other/sp/sp4052.jpg _______ Some differences are internal The GP7 and 18 were generally not turbocharged; the GP 20 was usually turbocharged. The HP ratings differed: GP7 1500 hp GP18 1800 hp GP20 2000 hp From an exterior standpoint most GP7s used the smaller 36" fans over the radiator at the back of the long hood. The GP18 and GP20 use the larger 48" fan. The GP20 has a tell-tale turbocharger bulge at the front of the long hood behind the cab (see the photo of SP4052 near the two handrail stanchions behind the cab). I believe Sunrise makes a turbocharger detail kit to modify the GP18 (LifeLike). Of course the LifeLike GP20 already has this feature molded into the shell. The GP7 is available from Atlas. eNjoy [ 12 February 2002, 23:48: Message edited by: dbn160 ]
I think the GP 7,9, 18 and 20 all had the same wheel base and truck centers. Don't have my resources handy to check. Are you trying to see if you can use the Atlas GP 7/9 mechanism with a LifeLike shell or GP 18 shell on GR 20 mechanism or some similiar combination?
Don pretty much nailed the differences. They are doable conversions. The carbodies are the same for the early geeps up through the GP20 (wheelbase, overall length, number of doors, etc.) The GP18 should be an easier conversion than the GP7. One thing you're lucking out on is that it appears 1776 was one of the locos that got the low hood conversion kit from EMD, complete with the one-piece windshield. For anybody who's interested, here are pics of the locos he's wanting to model: MP GP7 1776 MP GP18 1976 Dwight
ain't those babies sweet, i just got my oddballs decals sets for them and now have to get some engines. inkaneer i'm hoping to just use the gp20 frame since i won't have to chop it down to make a short nose however i will chop the gp7 shell and add a gp20 nose to it and it looks like i'll be chopping the **** out of another gp20 so i can do away with the turbo bulge and adding from another gp7 to replace them. thanks for the links don and dwight what can i say about those pics other than wow. btw if you guys haven't used any of oddballs stuff you should give them a try, lots of hard to find stuff. thanks again mitch.
Be sure to double check the photo of GP18 MP1976 - it is riding on AAR Type B (ALCO) trucks. Most of MoPac's fleet of GP18's are actually GP18m rebuilds. AFAIK these were done as an in-house capital rebuild program. MoPAC3092 -- were these done at North Little Rock, or ??? MP 1776 is on EMD Blomberg trucks. eNjoy
Actually, MP purchased it's GP18's new. The last (or maybe second to last) group rode on AAR trucks from traded in Alco's. They were rebuilt in the 70's (along with the rest of MP's normally aspirated EMD locos) with four exhaust stacks to relieve high back pressure. Mopac3092- I haven't used any of Tom's decals, yet. But I'm glad to see that he has filled some voids. I'm going to need to use his decals to build a model of the Texas Eagle when I get to it. Dwight [ 13 February 2002, 05:44: Message edited by: Dwightman ]
hey dwight when you order his form says 2 to 4 weeks for shipping try more like 8 days!!!!!!! my wife freaked when she seen the order form last night and realized i've spent over $130 on just decals between Tom and also microscale!
Hey, Mitch, I thought I was bad buying $65 worth of OddBalls Decals when they were 20% off! Decals - A word of advice - coat them with MicroScale's liquid decal film before use. The ALPS printed decals are prone to damage when being moved into position but a coat of film keeps the printing intact and has no effect on the end result. The decal film Tom uses is VERY thin so is hard to use with full strength Solvaset, but the suggestion is a 50/50 mix with water to thin it down. With the liquid decal film coat full strength Solvaset is no problem. I have 3 C&NW yellow PS2-CD 4750's with the coated decals on them, snugged down with full-strength Solvaset with no discernable decal film edge. I'll get some shots organised for you if interested. Locos - Thanks for the links, Dwight. Mitch, I think it's been nailed above as to how to do the rebuilds. Go with a couple of GP20's. The GP7 uses the GP20 nose and sub-base boxes so a GP7 body from Atlas is the go - it fits on the GP20 sill and saves problems with front side handrails. The GP18 is also straight forward as it has the same fans as the Life-Like model. The nose is a seperate piece to the body on the 18 so you can utilise the second GP20's nose and cab no probs. If you need a GP18 body, give a yell. I'm certain I have a spare. For the filter box on the hood use a Sunrise Enterprises N-629. The chassis will need modifying to handle the GP7/9/18 tank. Have a look at this - http://www.pnc.com.au/~audiosat/models/projects/LLGP20/index.htm The trucks on 1976 may be as simple as substituting Atlas AAR-B sideframes for the Life-Like's Blomberg B's. I'll check that out for you and if it isn't possible, the swap out of the trucks complete (I have a set of AAR-B's for a future SOO GP30). Gary.
what about using the aar-b's from a b23 from atlas. the gp35 atlas frames drop right in the gp20 and i was thinking maybe b23's might do the same. gats thanks for that page it will be great for instruction.as soon as i get something going i will post some pics and also gats i was wondering if i could use microscales microsol without damaging the decals any. i know tom would kill me if he heard this but. [ 13 February 2002, 18:49: Message edited by: Mopac3092 ]
Mitch, I think the the Blomberg B and AAR-B trucks are the same gearboxes but with different frames, so they would be interchangeable. I have tested the GP30 with a swap. From what I read of your last reply, am I right in assuming you have swapped the Atlas and LL sideframes before? If you have, then I don't see a problem doing the same with the Atlas AAR-B frames onto the LL gearboxes. Saves having to buy complete trucks. But I will check later and get back to you. I feel Microscale's decal setting line is somewhat gentler than Solvaset so you wouldn't have any problems with the decals. I doubt Tom would mind - he's sold you the decals. Dwight, it would be easier to use Atlas components if they fit rather than LL. From what I understand it is difficult to get parts from LL. Atlas is a breeze! (As an aside, I am still waiting for an order of parts through the Aussie Atlas distributor ordered over 12 months ago. I do have that order - made in TN 3am on a Thursday, delivered NJ late Friday afternoon back last September - free shipping too!!) Gary.
Ahh... I was just thinking of using LL parts with a LL loco so you'd know they work. I wasn't thinking of being able to get the parts. Dwight
Good thinking, Dwight. After playing around for 30 mins this afternoon checking out the theory, I have to go with your idea of using FA-1 sideframes but not sure of the parts backup from Life-Like. Here's what I found, based on using a LL GP20 chassis - Atlas AAR-B trucks (from the U23B/U25B (China) ) A straight change out with the GP20's trucks. I do have an issue with the main gear/worm meshing. The main gear in the Atlas truck is not as high as the LL truck's. This allows the teeth to skip when I held the wheels and turned the motor. This could be a problem under load. A possible fix would be using the GP20's main gear in place of the Atlas gear. I don't know if it would fit, but I suspect there could be a binding problem introduced between the main gear and idlers when this is done. Life-Like FA-1 AAR-B truck I took a truck off one of my FA-1's and fitted it to the chassis. The contact tab sits a lot lower on this truck so the contact strip is quite noticeable. Possibly, the contact tab from the GP20 truck could be used in the FA-1 truck. I didn't try this, sorry! Life-Like GP20 truck with FA-1 AAR-B sideframe The next step was to seperate the sideframes and place the FA-1 frame on the GP20 truck. The fit is a little looser than the the GP20 frame on it's own truck, but not so to drop off unexpectedly. The contact tabs are taller so the contact strip sits at the same position as the GP20 and Atlas trucks. Overall view - LL FA-1 sideframes w/GP20 gearbox front, GP20 rear, GP20 chassis with GP18 body My recommendation would be try to source the FA-1 sideframes from Life-Like. If this proves to be hard to do, then try the Atlas trucks and make any modifications necessary to make it work if the gear meshing proves a problem. Gary.
