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Rock Bug 2.0: And So It Begins

January 3rd2011
 By Thom Kingston on 2011-01-03T20:38:42-07:00 | The Rock Bug

It feels like only yesterday that we saw a fully disassembled Rock Bug in our shop. When I say yesterday, I mean of course nearly 2 years ago when we set off to build an ultra high strength & ultra light weight rock crawling machine dubbed “The Rock Bug” (see “Say Hello to the Rock Bug” from November 19th, 2008).  So why then is the Rock Bug back in our shop? After a fairly successful run in the Ultra4 Stampede (4th place out of nearly 55 racers), we decided to give the 2011 Ultra4 Tour, an extremely brutal 6 event rock racing competition, a chance this year. That’s where this build comes in, dubbed “Rock Bug 2.0”, we’ll focus on key driveline changes in an effort to make this light weight machine one of the meanest rock racers around.

The most prominent change in this build will be swapping out the ever so tiny Scat V4 for an LS style motor. After the countless hours of tuning/machining/re-turning/re-machinig we put into the Scat, it’s hard to say goodbye to this little engine. Unfortunately, the power necessary to be a top placing rock racer was just not happening with the Scat. Combine this with the fact that the Scat was a ticking time bomb, an LS motor sounds pretty sweet.

The biggest question up front was answered early on; will an LS motor fit in the small framework of the Rock Bug? Yes, as it so happens, it does but with little room to spare. As shown in the video above, the LS is now mounted in place and with surprisingly little chassis modification needed. With the exception of removing a small x-style crossmember & relocating the radiator & orbital steering valve, the LS looks right at home in the bug.

In terms of engine specifics, this LS started out as a 5.3L ’06 Trail Blazer junkyard motor. With the help of an LS3 intake LS2 intake, 90 mm throttle body, Schwanke cam, and the skilled hands of Dave from Powerhouse Motorsports, this all aluminum V8 factory engine will now put out nearly 430 HP & 420 ft-lbs of torque. By comparison, this is nearly 60% more power then our Scat V4. Although we are adding almost 200 pounds of sprung mass to make this all happen, the investment should pay off well for an LS powered rock racer under 3000 lbs.

With the motor in, we were also able to make quick work of the next upgrade on the list, replacing the Stak D300 with an Atlas 3.0. This has been on this list for some time now and since undertaking a complete engine swap, this modification sounds easy. So, with some effort and a little patience the Atlas is now in place and ready for action. Due to the larger size of this transfer case, the driver’s seat will be about 3/4″ higher then before (passenger seat will stay as is). However, we were able to save the existing front cross member so the entire dashboard, along with the rest of the cockpit, will remain the same.

The last item we wrapped up literally yesterday was the ultra compact header. I’m not sure if you’ll find a V8 header this compact elsewhere, but the size constraints of the chassis left no other option. The header was shipped out today for some “Jet Coating”, a high temperature (2500°F) plating process that not only protects the header from corrosion but can also reduce heat under operation by as much as 60%.

So there you have it, the progress of Rock Bug 2.0 so far. We still have plenty to do before the kick off event of the year, The King of the Hammers on February 11th. Next up, we’ll be mounting cooling accessories, radiator included, along with other plumbing odds and ends. Stay tuned to our blog for updates as they happen with our next update due out sometime this weekend. Don’t forget you can subscribe via e-mail here so you can get these updates as soon as they hit the interwebs. In the meantime, I do hope you enjoy the quick video above along with the photos below of the progress to date. See you soon!