Mid 60s Peterbilt Unilite COE

[RoninUtah]

So, I'm in Peterbilt mode now- this build is one of three I have lined up- the other two are a current 579 using a 3-D printed body and a donor chassis, and a Revell wrecker- yes, the big tri-axle one with the rotator wrecker, and no, I didn't pay the crazy prices these are going for these days on eBay. That one I'll post-date to be a late 90s-early 2000s 379.

I actually built an AMT Peterbilt 352 when they first came out in the early 70s, and I still have it. It held up pretty well over the years, I think, considering how inexperienced I was at the time, so I'm not planning to replace it. Here is a pic:

Anyway, back to this one- Thanks to Mr. Peterbilt, Tim Ahlborn, who gave me advice and encouragement, as well as detailed directions on how to approach this build. First, a short history lesson- Peterbilt built COEs alongside conventionals, both confusingly with the same model name, from the end of the 40s to about 1960. In 1958, they came out with an all-new COE, the 352. The early 352s were built on a "unilite" body, similar to the conventionals at the time, until 1970 when the COE changed to the Pacemaker body. The Conventional Unilite cab continued to 1972, when it was replaced by the 1100 cab, so named because of the large windshield. The AMT kit dates the early 70s, and represents an early Pacemaker.

The majority of the work on this build will be to backdate the Pacemaker cab to a unilite. Overall, they were very similar, but with some subtle differences, most noticeably in the headlight bezels, the lower side cab skirts, and the cargo doors.  Here is an example (I plan to use a similar color scheme):

I'll try to get them as close as I can by scratchbuilding.  The chassis is basically the same- the AMT kit has the Peterbilt "Stabilaire" rear suspension, which first appeared around 1965, so my target date for this truck will be 1965-66. As usual for my builds, this will be a typical working truck of its day.

First up is the chassis. Straight-up box build so far, but I'm leaving the wheels incomplete, as I plan to use 6-hole Budd steelies that I 3-D printed.

Thanks for following, and I'll update this from time to time as I go along.

[BK9300]

It's amazing how much you and Jeff know about the 1:1 trucks - will you be building trailers similar to ones in your pic above?

[RoninUtah]

Thanks! The double flatbed pups would be a fun build… but I don’t have space for a lot of trailers, so I’ll probably pair this one with my 36’ ragtop trailer. Especially since it’s a tandem axle, since back then doubles were typically pulled by single rear axle COE daycab tractors, at least in California, because of length restrictions at the time. The AMT White Freightliner SD is a perfect example.

[Biggu]

Ok , I’m in the front row for this one. May have to toss mine in the garbage as this one will make mine look like a 4 year old built it. I am REALLY gonna have to up my game now …..I am going to watch this very closely and learn all I can. And I’m sure I can snag a few better ideas. An idea for the double flat bed pups…. And if room is at a premium, why not do a piggy back set up? The lead hooked to the tractor and the pup tied down on the lead as if heading out for a load. Used to see that configuration all the time. Just a random thought IF you wanted to do trailers and not a set up seen on this forum very often. I’m hoping for LOTS of updates for ideas. Thanks for sharing this build Ron. 
Jeff

[Biggu]

Ron. What power are you thinking? Sticking with the kit 318? Or maybe a Cummins? And I really like your idea of the 6 hole Budds are a great departure from the 10 hole ones and even different from my two hole set up on the Hayes. Are you doing a 6 hole on the steering axle as well? This is gonna be a great build. 
Jeff

[RoninUtah]

Thanks, Jeff, I’m blushing… I think you might be overestimating my abilities! I’m still learning how to do this stuff! The 6 hole Budds is a typo- I meant to say 5 hole. They’ll be on all 3 axles, I’ve seen some reference photos that show that setup. If I could get my hands on 5-hole alcoas for the steer axle, those would be perfect! But I don’t have a source since AITM went away, and I don’t see any 3-D versions out there, either. But yeah, I’ll save the 10 hole rims for another build.

For power, yeah, I’m going to use the kit 8V71, it was a standard option for this truck and I’m kinda fond of that engine. I’ve even ordered some paint in the correct Alpine Green color!

[Biggu]

I did think 5 hole but one never knows ,…… the 5 hole Alcoas are really cool old school rims. But I think your call is very period correct and will look excellent. The engine paint sounds interesting… and accurate. What about white? Was that a consideration? Just curious. What color are you thinking for the frame? A lot to consider with these builds. And that is where I am at…. Way too much to figure out ….. is that why I lay awake all night????????

[RoninUtah]

I get it, I’ll spend days planning a build in my head before I even break the wrap around the box. And then wind up changing it mid-stream!

White was Peterbilt spec for all engines for a while, mostly late 60s and early 70s, I believe. I think this one might pre-date that period, and even then there were occasional exceptions. So I’m good with Alpine Green. I did paint the engine of my California Hauler 359 white, though! The frame will probably be red, cab mostly red with white stripes, bumper will be red (I’m using an old- style narrow bumper) and wheels will be white. 

Unless I change my mind.

[Biggu]

I agree with the Alpine Green and the color choices are great…. I’m still waffling on that. Another sleepless night I guess???

[Jürgen M.]

11 hours ago, Biggu said:

I did think 5 hole but one never knows ,…… the 5 hole Alcoas are really cool old school rims. But I think your call is very period correct and will look excellent. The engine paint sounds interesting… and accurate. What about white? Was that a consideration? Just curious. What color are you thinking for the frame? A lot to consider with these builds. And that is where I am at…. Way too much to figure out ….. is that why I lay awake all night????????

Question: since I'm not as aquainted with the rim types concerning their names, what exactly is an Alcoa rim?

I've probably seen them lots a times but never knew what they were called!

How about designing and printing them?

 

[RoninUtah]

Hi, Jürgen! Alcoa is sort of shorthand for aluminum wheels, like the 10 hole aluminum wheels you typically see these days on modern trucks and are included in most truck model kits. The earlier ones were similar, but they had five holes, such as the wheels on the 1:1 example truck photo above. In the 50s and early 60s, they were common on West Coast trucks; or you would often see Alcoa front wheels and steel rear wheels.

I would love to design and print my own, except I don’t know how to design them! I just started getting into 3-D printing, but I don’t have the capacity to design. If somebody could be able to design a five-hole front Alcoa wheel based on photos, that would be great! 

 

[Jürgen M.]

Hi Ron,

thanks for the explanation of the Alcoa rims! Didn't want to misuse your threads for my learning lesson. Hope you didn't mind! 

If you give me the exact measures of the rims you want I'd be happy to design them for you! I could then send you the gcode file for your printer!

Generally I would need a sketch with the exact measures of inner and outer diameters, ...! What ever is neccessary to make an exact 3D drawing!

Rims are meanwhile Not a problem anymore!

It's a serious offer! Think about it! ?

[Biggu]

Very cool ….. you guys are so generous. What a nice gesture, Jurgen. That’s what makes this place and hobby so much fun. 
 

Jeff

[Jürgen M.]

Anytime guys! 

Always willing to help if I can! I can learn so much from all of you, why not Help my way?

[Jürgen M.]

Anytime guys! 

Always willing to help if I can! I can learn so much from all of you, why not Help my way?

[RoninUtah]

That's awesome, Jürgen, thank you so much! I'll do that! I'll send you a private message with some sketches and photos. If you can send me a .stl file, I can print it!

[Jürgen M.]

By the way, did I mention that this is a very nice build to be?

As you can see in my recent thread the 352 is one of my favourites!

 

[Jürgen M.]

Anytime guys! 

Always willing to help if I can! I can learn so much from all of you, why not Help my way?

[Jürgen M.]

Sure, send me drawings with details and measures and I'll send you the stl If you have a slicer or the gcode!

I'll send you pictures of the 3D designs first so you can see if it's what you expect! 

[RoninUtah]

that’s awesome, thanks again! Yes, a .stl file would be great, I can slice it. I’ll try to send pics the evening (U.S. Mountain time)

[Jürgen M.]

No problem. I´ll take a look at them in the morning! (CET)

[RoninUtah]

Okay, more progress... I finished the chassis and engine, nothing interesting there, just built per the instructions. I'm having second thoughts about the engine, though- this rig will have a single exhaust, since there will only be one exhaust cutout on the cab (more about that below). So, it might make more sense for a six-cylinder engine like a Cummins, which only would have one exhaust manifold to tie to. Also, I recently saw some photos of a '66 352 that had a white Cummins in it. So, maybe I'll find a Cummins in the parts box and do it as a naturally aspirated engine, painted white- I don't think there wasn't much physical difference otherwise between the 220s and 250s of the '60s and the typical AMT Cummins, except for the turbo. I stand to be corrected by any engine experts out there! Your thoughts will be welcome.

So, anyway, while I'm waiting for my paint order to come in, I thought I'd get started on the cab... it'll take some surgery, since I'll be replacing the lower parts of the cab, opening the rear windows and making a cutout for the exhaust. First step is to mark where I want to make the cuts:

And here it is after surgery. It's still pretty rough... I'm gonna need to buy more putty!

I also ground off the louvers and rivets, etc., as those were fewer and in different locations prior to the Pacemaker. I'm saving part of the corner that I cut off to re-attach inside the exhaust cut-out. I'll use a styrene tube to close it off. Also, the hole for the air cleaner stack needed to move rearward and a little inboard.

Luckily, the 352 cab is pretty boxy, with straight lines, flat surfaces and minimal curves so, hopefully, cutting and installing the plastic strips for the replacement pieces should be relatively straightforward.

We'll see.

[Biggu]

Ron, and you said I was ‘over estimating your abilities’  HAH !!! NOT… this is going to be better to watch than I first thought. I am really looking forward to the next up date. A VERY interesting build to say the least. 
As far as the Cummins is concerned, doesn’t the AMT Autocar come with a 230 or 250 non turbo engine? I think the manifolds are a little different on the non turbo version …. I think ….. I might have some pics in my fav file .

Jeff

Edited October 23, 2024 by Biggu

[Jürgen M.]

Wow! That's gonna be interesting to watch! Can't wait to see more!

[RoninUtah]

8 hours ago, Biggu said:

As far as the Cummins is concerned, doesn’t the AMT Autocar come with a 230 or 250 non turbo engine? I think the manifolds are a little different on the non turbo version …. 

Thanks, Jeff, for the tip on the Cummins! I think I’ll go with that, I went ahead and ordered one off eBay. It looks like a NH 250, which would be right for this build.