Engine question for an 1951 GMC Truck

[Arnd]

Hi guys

I got a special question up to the technicians here. I looked through the Internet and find a very interesting page about logging equipment, www.heavyequipmentforums.com . And wile I looked and read the different treats I decided to start again a logging project. I dug out an old project I started some time ago and stopped because some problems with the engine. It is a 1951 GMC DW 970. Normally it was powered by a Detroit Diesel 6-71 but I don’t have such an engine. SO the big question. Would it have been possible to put a Detroit Diesel 8V-71 or an "Iron Lung" Cummins NHRS supercharged diesel under the hood of that truck? Or is there not enough space for such engines?

Here a pic from the cab. Only from the back but I think enought to know what type of truck am I meaning:



Perhaps someone of you can help me a bit with that problem. Thanks for your efforts.

So long Arnd

[muleskinner]

Arnd,

If you are building this model to represent a logging truck from the early to late fifties, I would find a Cummings and build it without the super charger on it to represent a banger Cummings from the logging era. I worked in the logging industry for many years her on the west coast of the US and some of the older trucks which were used for logging trucks had an array of engines in them but the Banger Cummings was the most popular here on the west coast.

Add a 4/4 or a 5/4 twin stick shifter and you got the basic for an old logger from the fifties. Also if you are doing this model of a west coast logger, you will have to take the California trike rims off of it and find a set of steel wheels for it. Logging companies frown on the use of spokes, because of the prospects of having a flat tire in the mountains and having to change it. The steels are easier to change on a dirt logging road in the middle of nowhere.

You can still find one of these old rigs occasionally here in Oregon still in use and hauling hard. Drive on. I will be following this build as I am also a modeler of/ from the logging industry.

William

I should mention you can also power the rig with a big block commercial GM gas engine 396 C.I. to what ever, as they were common in a lot of older trucks.

[amcdude]

Here's a little reference, this lives at the Collier Logging museum here in southern Oregon, only pic I got of it, IIRC it did have a Detroit 6-71 in it.

[Arnd]

Hi William

Thanks a lot for your help. I think I will have to ask you many questions on technical details for that type of trucks during this build and I hope it will be ok for you. Now to come back to your answer:
The engine do you think of is that a Cummins NHC 250 like the one from the Autocar dump truck?
And for place the truck was and is running, I was thinking about BC or Alaska but Oregon in enough in the north too.
What you mentioned about the rims makes sense, so I decided to use the rims from the International Paystar dump truck, I think they have the right shape.
The transmission will be the one from the Alaskan Kenworth, what do you think?



And now the next question. The Rockwell tandem axle from the Autocar dump truck is right for that truck, but what type of brake system does it has and how is it called? How was the parking brake working?

@ amcdude thank´s for the pic. I don´t want to use a DD but I am not sure if there is enough space for a Cummins under the hood of my GMC.

Thank´s a lot to all of you for your help.

So long Arnd

[muleskinner]

Arnd,

The Rockwell's will work fine, as a lot of the older loggers built their rigs to their own requirements back then. They kind of kit bashed you might say when it came to their trucks and equipment in most cases.

The old Banger Cummins from the Auto car dump will work just fine for this type of rig. The main and Spicer trans from the Alaskan hauler will also work. Although I think you may have to lengthen the frame a few scale feet as most logging trucks have lengthened frames and stinger tails for the trailer connection. I'll look again at the pictures you have posted at the frame again and see.

William

I looked at the frame, and it is a good length and you have the stinger long enough, from what I can see. As for the brakes, you can either use conventional or air, as this was the big transition era for the change over on a lot of older rigs here in the Pacific northwest. Its like I mentioned before, Loggers kit bashed a lot of their equipment to cut down on expenses when they could.

For the exhaust stack a plain piece of tubing with no fancy attachments would work also. If you look at the picture posted by the other member, the stack is nothing fancy, Just plain piping.

Another recommendation I can give you is mix up the type of tires you use as the older loggers used any type they could find to run on because of the old saying; "Down Time Doesn't Make Money!"

I should also mention that Logging trucks back those days had water cooled brakes and most carried a Bunker type water tank on the top of the frame behind the Head ache rack.


This picture is of an old Mack Off highway truck I have in the making and you can see the Bunker tank for water sitting on the frame behind the Head ache rack. They also used what we call a saddle tank for water, which was attached to the side of the main frame and looked like an extra fuel tank, but the bunker was the most commonly used as they were larger and held more water. Hope this helps.

[tufftin]

Yep! Gotta have a water tank for the brakes. Many older loggers were "kitted" together and many of them ran Mack bogies. Also they ran older cab guards that didn't have the high sides on them. Just up to the top of the cab and pretty much straight across.
Mike