Project Hellraiser 4

Page 4


Previous Update

Week #3 was a bolt on weekend.  My Dad lent a hand and installed a new spring and spacer into the oil filter mount which will boost the oil pressure up a bit.  While he was working on that I installed a ported throttle body.  The new throttle body is bored out to 72mm from the original 69mm. I decided to go ahead and do a few engine mods to boost HP while I had easy access to everything.  I also have an electric water pump to install but I may have to pull the radiator for that.

The first project for week # 4 was to turn my manual bender into a hydraulic bender.  Instead of going with a hydraulic power pack, ram, valve and lines I decided to go the low buck route and use an air/oil cylinder from an engine hoist.  I got the idea for this from a thread on the Off-Road fabrication Network forum.  I liked how I could re-use my existing stand and the cost was also very low.  The cylinder needed for this setup runs anywhere from $70-160.  I ended up buying one from Northern Tool (Item # 1459212) since it was in stock and ready to ship for $159.

Next I needed to fabricate some parts. From left to right in the first picture: tube for clamp (3.250 x .065 wall), 2 sleeves to go over existing posts on bender, cap for the end of ram, a pair of plates for the clamp and some 3/8-16 bolts.

I picked up a 4 foot piece of this tubing for $5 from a local driveshaft shop.  After cutting a 4" piece off, I cut a 1/2" wide strip from one side the tubing.

To make the clamp I slide the sleeve over the cylinder and placed a 1/2" thick block in the cutout, then I clamped the sleeve to the cylinder. Next up was clamping the two clamp plates to the spacer block followed by welding them to the sleeve.

The next step was to install the large sleeve I made over the stationary spacer on the bender.  The sleeve should be slightly shorter to allow the assembly to rotate.  Next the clamp is welded to the large sleeve.  Be sure and place a gusset between the sleeve and clamp.

There is a small pilot hole on the end of the ram which you can drill out and tap for a 1/4-20 screw hold the cap to the end of the ram on the return stroke.

I forgot to get a picture but basically I installed my smaller sleeve over the spacer on the benders arm, positioned the ram in the clamp and finally welded the cap to the new sleeve.  I still need to add a return spring between the cap and the base of the ram.

On Sunday I fabricated some mounts for a large extension spring I found at Home depot.  I could not get the spring to pull the bender all the way closed and notice an interference between the bender arm and base.

At first I tried chamfering both edges so they would ride up on each other but that didn't work .

A .109" thick shim between the bender arm and frame at the pivot pin did the trick.

I only had one piece of tubing long enough to bend, I loaded it up and gave it a go.  I am able to bend roughly 45 degrees before the ram will not push anymore.  I had ready that people were getting more angle out of their rams so I may have to do some investigating. You also notice I made a small "T" shaped handle and welded it to the pressure release knob so it can be done without a tool.

Here's a short video clip of the bender in action.

The finished exhaust with the new flex joint installed. As you can see in the second picture I had to notch the frame to clear the exhaust clamp.

With the bender modifications done it was time to finish cutting off the old tubing so I could start bending the new back half.

I placed the frame on jack stands so the rear frame rails are approximately 23" off the ground and proceeded to cut off the remaining tubing.

I have plans to re-arrange the suspension links so the old upper link mounts on the chassis had to get torched off.  I'll cover more of the suspension changes in a future update.

The next step is to swap the lower links with some longer temporary links.  The existing lowers are 33.5" long, I plan on using my old 37" long front lower links for mock up figuring it'll extend the wheelbase about 3". The plan is to do as little wheelbase extension as possible so the 3" extension is a good starting point. 

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