5.2 Magnum Swap Part 15: Custom Tube Bumper

by ThreeThirdsFab
October 6, 2015
In The Shop
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Welcome to part 15 of our 5.2 magnum swap, follow along as we swap a 5.2 magnum from a 1993 ZJ into our 2004 4.0 TTB WJ. This week we sent the 5.2 to the shop for some much needed cleaning and rebuilding. With the motor out we had ample room to finish weld some plates, motor mounts and start building our bumper.

Read The Rest
Part 1: It’s Finally Happening
Part 2: Out With the Old
Part 3: The Last of the Stock Components
Part 4: All About Brakes
Part 5: Pulling the 5.2 (time lapse)
Part 6: The Test Fit
Part 7: Cutting and (not) Fitting
Part 8: Broken and Upgraded Parts
Part 9: Leaky Plenum Gasket
Part 10: Side Projects and Summer Fun
Part 11: Setting the Motor
Part 12: Custom Exhaust & Driveline
Part 13: Cutting and Rebuilding
Part 14: Giant Radiator in a Little Jeep
Part 15: Custom Tube Bumper
Part 16: Driveshafts
Part 17: A Real Firewall
Part 18: Starting Final Assembly
Part 19: Extending The Engine Cage
Part 20: Still Assembling
Part 21: It Lives!
Part 22: Brakes and Wiring

Custom Tube Bumper

We ended last week with the lower radiator mounts complete but not much else up front. After getting the stock lights and grill aligned how we wanted, we started with a tube across the front just under the lights. We had planned to have a straight tube directly in front of the grill, then roughly 30-45 degree bends back to the lights, keeping it nice and simple. But, by adding two smaller bends just inside of the vertical support tubes we were able to give the bumper a larger flat area to mount our LED bar in front of the grill. The extra area will allow us to keep the LED bar pushed back and safe in the event we need the bumper to push something out of the way.

With the main tube in place, we added a few smaller tubes to complete the lower bumper structure. We wanted to copy our old bumper design and run tubes back through the grill to protect and support the top of the radiator. But the front end looked so clean with just the single tube, we decided to redesign the radiator support to keep the remaining tubes hidden behind the stock grill.

To protect the top of the radiator we are going to extend tubes from the existing cage forward in front of the radiator then bend down and tie into the frame just behind the grill. Adding a cross bar up top will protect the radiator and tie it all together.

Finishing Some Odds and Ends

With the motor out and at the engine builder, we took the opportunity to finish the frame work that needed to be completed. We had to notch the frame to clear the exhaust so new plates were cut and welded in to tie the frame back together. We added two fish plates to tie the interior frame plates together, strengthening the entire frame structure. We also cleaned up some of the original frame plate welds since they were welding in with the stock 4.0 in place. Lastly we finished welding all the motor mounts and transmission mounts both in the car and the mounts that bolt to the motor and transmission.