KB-2 Cummins 4bt swap


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Yard Art
Yard Art

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Joined: Wed Aug 16, 2017 1:21 pm

Location: Ohio

Post Thu Nov 09, 2017 6:03 pm

KB-2 Cummins 4bt swap

My little brother just got a 49 kb2 and wants to do the same treatment as my r110, a 4bt backed by a Ford ZF5 4x4. But he wants to keep the original frame and box it, then drop in the motor. I him no way the kb frame wouldn't take the torque. So i figured I would ask you guys and get your opinions.
55' R-110 w/Intercooled Cummins 4bt, Hoset HX30W, Ford ZF5, Borg Warner 1356 T-Case, Ford 8.8 w/3.73/9800 miles and counting/4x4 swap 50% done
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Golden Jubilee
Golden Jubilee

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Location: Bothell, Washington

Post Thu Nov 09, 2017 6:39 pm

Re: KB-2 Cummins 4bt swap

I'd say an R frame isn't much stronger than a KB, they aren't that strong to begin with, have to beef it up but sure why not, or get a Dakota frame
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Yard Art
Yard Art

Posts: 76

Joined: Wed Aug 16, 2017 1:21 pm

Location: Ohio

Post Thu Nov 09, 2017 7:57 pm

Re: KB-2 Cummins 4bt swap

I didnt beef my r frame up so i guess it should good then. I try to stay away from frame swaps, as the 40's and 50's steel is much better. Around here a Dakota frame looks like swiss cheese, darn rust mites!
55' R-110 w/Intercooled Cummins 4bt, Hoset HX30W, Ford ZF5, Borg Warner 1356 T-Case, Ford 8.8 w/3.73/9800 miles and counting/4x4 swap 50% done

Golden Jubilee
Golden Jubilee

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Post Fri Nov 10, 2017 12:14 am

Re: KB-2 Cummins 4bt swap

If a person does not know how to properly "box" a frame, poorly placed welds and heat can destroy the flexibility of an IHC frame. The frame will break where the welds stop.
A person contemplating "boxing" should first consider what amount of torque their engine will produce.
There are fuse points in a vehicle. If the tires break traction and spin first, that is the weakest fuse. If the tires have lots of traction, the fuse or break point will be moved to the next weak point. That could be a universal joint, transmission or even the clutch. Poorly designed motor mounts can be another fuse and when stressed may release the engine'
Breaking traction and smoking the tires to destruction looks really stupid to me, but, if that is another persons joy in life, have at it. The moment just before the tires break traction is where there is the most stress on the driveline. Once the tires start to spin and smoke, the melting tires lubricate themselves and the stress to the driveline is reduced.
An Old IHC frame does not need to be "boxed" to hold and control a Cummins4bta. The engine is very close in weight to the OEM lump of iron. The torque from a 4bta is higher, but is it high enough to be concerned about frame strength. These trucks were designed to work hard and be often overloaded.
I would rather have tools I do not need than to need tools I do not have
Thinking risks being controversial and possibly being offensive

Yard Art
Yard Art

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Joined: Wed Aug 16, 2017 1:21 pm

Location: Ohio

Post Sat Nov 11, 2017 6:11 pm

Re: KB-2 Cummins 4bt swap

Well i have only done a burn out once with my truck and it did it pretty easy, but never again will i do it. So far my frame has held up to some 0-60 take offs, pulling trailers, and going through ditches into fields. So i guess the kb frame would fine, ill probably plate the front half of the frame as it will be 4x4 too.
55' R-110 w/Intercooled Cummins 4bt, Hoset HX30W, Ford ZF5, Borg Warner 1356 T-Case, Ford 8.8 w/3.73/9800 miles and counting/4x4 swap 50% done

Golden Jubilee
Golden Jubilee

Posts: 8937

Joined: Thu Dec 27, 2012 12:45 pm

Location: Canada's left Coast

Post Sat Nov 11, 2017 9:44 pm

Re: KB-2 Cummins 4bt swap

Be careful with that "plating", what ever that means. The OEM frame is designed around twist and loading being distributed along the frame. Some sort of plating may gather the loading and concentrate it energy to the frame where the "plate" ends.
I would rather have tools I do not need than to need tools I do not have
Thinking risks being controversial and possibly being offensive

Rusty Driver
Rusty Driver

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Joined: Fri Nov 30, 2012 3:00 am

Post Sun Nov 12, 2017 11:37 am

Re: KB-2 Cummins 4bt swap

nikkinutshop wrote:Be careful with that "plating", what ever that means. The OEM frame is designed around twist and loading being distributed along the frame. Some sort of plating may gather the loading and concentrate it energy to the frame where the "plate" ends.

Nikki is rite, These frames were built so that they could twist when on uneven ground. That is why the rear cab mounts and rear gas tank mounts are attached using long bolts with springs under them so that they can move arround and not be affected by tortional loads.I have seen A few KB cabs that are cracked in the door jambs because the cab was mounted solid to the frame.

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