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GRV-2 Jet Bike Project 10/1/09

Posted on October 1, 2009

       OK, back to the grind! (literally :0) The GRV-2 needs a set of fenders to help reduce the amount of dirt that will be flung up at the engine’s intake. A constant flow of dirt being “ingested” by the engine will cause damage to the compressor wheel and deposit dirt in the evaporator tubes. To avoid this problem I will need to build a set of fenders to deflect any debris that the wheels will pick up during a run. The most important fender is the one on the front wheel as it is in front of the engine’s intake.         

       I purchased a set of go cart fenders that I will be using to fabricate the two fender sets. Unfortunately I was unable to find a set that would fit either tire so a modification will be necessary (as usual). To make the rear tire fender I will need to splice two fenders into one which starts out by cutting two of the fenders to size.

       Once the fenders were prepared for welding I tacked them together with the TIG welder. The TIG process (Tungsten Inert Gas) will afford me the most heat control and reduce warping of the finished product. Actually this part reminds me of something I might of seen on “American Chopper” :0) I really love to watch those shows and to be experiencing some of the same fabricating challenges is a real treat ;o)

       I used a very low heat to “blob” on the filler rod and join the seam in the fenders (not very pretty). I then used the flap disc to even out the seam as if it were a continuos piece of metal.

       I sprayed a coat of primer paint on the fender to “see” any imperfections as it was still wet. Glossy paint will do the same thing.

       I checked for any high spots with a sanding pad once the primer had dried. Luckily the first try was a success and it was ready for mounting :0)))

       I used a set of clamps to position the fender on the rear frame in preparation for drilling the mounting holes.

       I drilled four 1/4” holes in the fender and supports. 1/4-20 stainless steel screws were then used to mount the fender into place.

       It was now time to shape the back end of the fender for a more streamlined look. I marked out the shape to be cut and removed the fender for trimming.

       I added a bit of curve to the rear of the fender to match the tire being used. Not too shabby :0)

       One of my pet peeves is rust!!! I cannot stand it when bare steel rusts as I once learned when I neglected my mill & lathe for a few months :0( To prevent the rear assembly from rusting during construction I applied a coat of primer. This will save some trouble later on and prepare the frame for paint as well.

       Note: I would like to share a cool product that I use on all of my bare steel tools. It is called Boeshield T-9 and it is a real gem of a product. It was developed by the people at Boeing to prevent corrosion on aircraft parts. Boeshield is a paraffin wax based formula that coats parts and leaves a protective wax film that will stay in place for months. I coat all of my bare steel tools and even my workbench with the product which can even be buffed to a shine!!! Never again will I let my tools see rust!!!!!!!
       Maybe the nice people at PMS products (Boeshield USA) would consider sponsoring the GR series projects ;0) Just a thought....

       It was now time to start work on the front fender. I used the same process of joining two fender pieces with the TIG welder as seen below.

       A support bracket was fabricated for the front fender which will hold it fairly close to the wheel. I used the stock fender mounts on the forks to attach the bracket. The threaded mounts were trimmed down a bit to improve wheel clearance as were the heads of the 10 mm screws.

       I welded in the fender bracket and added a couple of stiffener bars to the underside of the fender.

       Once again a coat of primer to finish off the job...

       You will notice that I offset the fender toward the back of the wheel. This is to improve the fenders ability to deflect the dirt coming off of the tire at a low angle. The more sand and dirt I can keep out of the intake the better!!!

       The next item to tackle is the stainless steel gauge panel plate. This plate will support all of the gauges, control switches and indicator lights. I wanted to build this one out of 304 stainless as it will be the easiest surface to maintain. However as you may know, stainless is a little difficult to work with :0/
       I started out by cutting out a piece of .060” thick stainless from a 12 x 24” sheet with my plasma cutter. I made sure to be careful not to scratch the “finished” side of the steel.

       After I removed the rough edges on the plate I removed the protective plastic film on the finished side to inspect for any surface damage.

       I covered the finished side with a couple of layers of blue painters tape (not shown) and flipped the plate over to start laying out the mounting screw holes. Once I was happy with the pattern I drilled them out with the aid of a little cutting oil. I undersized the holes as to allow me to use the plate as a drill jig for the bike frame.

       I drilled and tapped two holes on either side of the plate and then temporarily mounted it to the frame. This is so I could drill out the other twelve holes in the frame for tapping. Once the pilot holes in the frame were tapped I re-drilled the remaining holes in the plate (off of the frame) to accommodate the mounting screws.

       I removed the blue tape to test fit the panel to the bike for a look see. The fit was perfect, just how I like it :0)))

       I am making good progress on the bike now and intend on keeping up the pace until it is done. I look forward to eventually installing the gauges and building the Control Interface Module or CIM that will “talk” to the ECU when the engine is running. Everything is going to plan.... So far......

       Hope you can visit RCDON.COM again for the next round of the GRV-2 project!!! See you then......

Don R. Giandomenico

 

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