Welcome to the Poly Thunder

Poly Thunderhas been a student project in the Cal Poly Tractor Pull Club for the past 3 years.  Many students under the advisement of Gary Weisenberger and Dr. Mark Zohns have redesigned and reconstructed the modified pulling tractor. Before going into the reconstruction of Poly Thunder we would like to thank our sponsors who made this incredible dream a reality.

J.B. Dewar  Pacific Ag Rentals  Abate A Weed

Groppetti's Automotive
Villa Automotive
Enos Custom Components
San Luis Truck
D'Angelos Paint
San Luis Motorsports
Linson Signs


Poly Thunder was originally built as Rocky Mountain Thunder by Albert Wada, a potato farmer from Blackfoot, Idaho.  He built and operated the tractor during the 80s until one of the engines was fatally damaged.  The tractor then sat for over 10 years until he decided to donate the tractor to Cal Poly.  Special thanks goes to Mr. Wada. In the fall of 2002, a group of students took the trip to Idaho to pick up the tractor.  When the tractor arrived at Cal Poly the project began with disassembly, and the revitalization followed.


This is what Poly Thunder / Rocky Mountain Thunder looked like originally.

The disassembled tractor. 


We had to straighten the frame after disassembly.  As you will see, we had to weld in new cross members to keep the frame straight and rigid.

Bryon grinding unnecessary parts off the frame.


More grinding.

Matt installing the transmission with new mount.

Thanks to Dr. Zohns the transmission output shaft support bearing aluminum housing turned out really spiffy.

The front axle was completely redone.

Another angle.

The new roll cage.

And wheelie bars.

The newly rebuilt motors glistening in the morning sun.  They are 519 cid Chevy marine blocks with Chevrolet High Performance aluminum heads which are ported and polished.  They have 1271 Mooneyham Blowers, Mallory Ignition, and they run on ethanol.  They were built by the legendary engine builder, Joe Boghosian.

Bryon and Matt checking out the rebuilt motors.

Gary finishing the welds on the new cross-members before it gets sandblasted.

The frame before sandblasting.

Gary and Bryon got pretty dirty sandblasting the beast.  Ask them how much fun they had doing this job.

Mark and Gary checking the fresh coat of primer.

Here is the final coat of yellow paint.

Gary getting the first motor settled into the frame.

Is that good enough for you Gary?

The second motor mounted.

Gary getting the feel of it.

The wiring diagram.  It's a good thing Gary can decipher his own writing.

Hitch modifications.

Dr. Zohns welding on the hitch.

Almost finished!

The Fever and the Thunder.

Well, its finally done.  This is at the Tulare tractor pull, September 2004.

Poly Thunder's first showing at Cal Poly's Open House in April 2005.

As you can imagine, this moment was particularly special for those involved with bringing Poly Thunder to life.

We had a little trouble getting Poly Thunder to run right in the beginning, but we finally figured it out.  She ran beautifully in Hollister, October 2004.  Unfortunately, in the second pass that night the crankshaft in the second motor broke due to the original engine mount design not being so great.  So it sat until we could raise enough funding to replace the crankshaft and check for any other damage in the engine. We finally got Poly Thunder all back together with Cal Poly designed engine mount improvements by Poly Royal 2005.  This tractor is going to give the competition a run for its money.