Biodiesel Sportster Land Speed Racer - Troy Mini Maker Faire

The Biodiesel Sportster has been accepted as an exhibit at both the Troy Mini Maker Faire and the NYC World Maker Faire!! Here is a link to the post from the Troy Faire:

Meet The Makers - John Petsche

Biodiesel Sportster Land Speed Racer - Ohio Mile 2016 Part 2

Here are some photos from the other competitors who showed up!

This is a homemade steam car :-D

They used a Doble-style flash boiler fired by propane, and the engine is a heavily-modified Mazda rotary engine. They machined custom rotor housings out of solid stainless to prevent rust and optimize the port positions. Unfortunately, they suffered a valve failure on their first pass and had to retire without completing the run.
 

 This is a land speed racing Ford tractor with a flathead V8. Apparently, this was a factory-available conversion back in the 30's and 40's. The rear tires are sourced from a Boeing 747.

MERCEDES 300 SLR GULLWING!!!!

 

Biodiesel Sportster Land Speed Racer - Ohio Mile 2016 Second Pass (Video Post)

After we discovered that the CVT was either slipping or not fully shifting, we moved the GoPro mount to the left side of the bike and pointed the camera towards the transmission. During the next run, we were able to document the CVT behavior.

 

It appears that the CVT simply does not shift all the way to top gear. We suspect that this is occurring because the diesel engine's redline is much lower than the redline of an equivalent gasoline engine. The CVT primary has three weighted rollers that are thrown outwards by centrifugal force and push the plate inwards, which changes the effective diameter of the pulley. If the engine rpm is too low, then they would not have enough force to completely shift. The solution is to either make custom heavyweight rollers, install weaker return springs, or some combination of the two. 

 

 

Adjusting the transmission alignment with shims. Unfortunately, this didn't help all that much.

Biodiesel Sportster Land Speed Racer - Ohio Mile 2016 First Pass (Video Post)

Here is a video of the first pass! The Comet Series 40 CVT did not shift fully, so unfortunately the fastest speed I could manage was 67mph. This was still enough to set the record, but I have a lot of tuning and improvements to do for next year.

We examined the CVT, and determined that the centrifugal weights in the primary are not heavy enough. This transmission is set up for a gasoline engine with a redline around 5000-6000 rpm. On a diesel engine that peaks at 3600 rpm, there simply isn't enough centrifugal force to make the current weights shift all the way. I will be experimenting with custom weights, and will post my results here.

Biodiesel Sportster Land Speed Racer - Ohio Mile 2016 Part 1

 I have a ton of pictures and videos to sort through and edit, so the updates from Ohio will be coming in drips and drabs. First off, it was amazing! Many, many thanks to coachgeo from the DieselBike.net forum for coming out, lending a hand, and generally being awesome all day Saturday. He helped with troubleshooting and tuning, and he and my girlfriend basically kept me vertical and hydrated the entire day. It was a scorcher, and certainly wasn't helped by the armored leather tights I had to wear all day, but they both got me through it. He also introduced us to some traditional(?) Ohio cuisine, consisting mostly of pasta, chili, and beef in varying combinations. :-D

The trip began on Thursday. Anyone who has ever been to New York City will tell you that the traffic is insane, and the roads are Third-World, so I set aside an entire day just to get from Long Island to New Jersey. I loaded up all my parts and clothes, hitched up the trailer, and fought my way over the Hudson.

On Friday, I picked up my girlfriend, and we hauled across Pennsylvania towards Ohio. Along the way, we stopped in Lancaster to visit my grandparents for breakfast, and Pittsburgh to visit her cousin for dinner.

 We rolled into Wilmington, Ohio around 1AM, overslept, and nearly missed the driver orientation meeting in the morning. After rushing to the track, sitting through the rookie orientation meeting, and registering, we brought the bike to tech inspection, which it passed with flying colors. Next, it was time to actually go racing.

Biodiesel Sportster Land Speed Racer - Part 17 - Billet Battery Tray

During testing, I determined that the fuel pump was not running once the battery umbilical cord was disconnected. These pumps require clean 12VDC to run properly, but the output from my alternator is pulsed 12VDC. I had installed a large capacitor in the system to attempt to smooth out the pulses, but apparently this wasn't sufficient.

Unfortunately, the stock battery tray in a Sportster is inside the oil tank, so I could not install a factory replacement. There are not many mounting lugs in this section of the stock frame, so I designed a battery tray that clamps to a frame rail. I cut a pieces of 3/4" 6061 aluminum plate on my bandsaw, finished with a hand file, and machined a pocket with my mill.

Biodiesel Sportster Land Speed Racer - Part 16 - Rebuilding The Nose Cone

The final countdown to Ohio has begun, so I wanted to post the rest of the build pictures beforehand. This nose cone has spent nearly a decade hanging from a hook in my garage, and it is finally being used for its intended purpose.

This fiberglass nose cone was homemade by myself and my friend Ben for my first land speed attempt. This early bike was not well-made, and I ultimately saved a few of the better pieces and scrapped the rest.

This post is also a memorial of sorts. Through a cosmic twist, I am posting these pictures precisely five years to the day that Ben was fatally injured in a motorcycle accident. He was one of my closest friends, and I still think of him often. I am grateful that I have one of his expertly-fabricated pieces of bodywork, and that I can honor his memory by using it on this bike.

RIP You Goofball

The donor was a heavily thrashed Suzuki dirtbike, and it was hilariously badly assembled by a high-school-age your truly, with zero build quality or safety features. Ultimately, the gas tank, foot pegs, nose cone, and some wiring were put into storage, and eventually recycled into the Biodiesel Sportster.

I made a large and heavy mold out of plywood, screen, and several gallons of Bondo that was then hand-sanded into the final shape. Ben was employed at a marine store at the time, and had become an expert at creating fiberglass parts, so he laid down the glass and made a strong and flexible cone. It was then cut and sanded into shape, given a thin coat of Bondo to smooth out the outer surface, and installed.

 

 The cone hung on my wall through college and various jobs and projects, before we decided to give it a second life on the Sportster. I sanded off the old peeling red paint, trimmed it down, repainted it Satin Black, and built a new mounting bracket to bolt it to the Sportster.