Sunday, July 31, 2016

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

Saturday, July 2, 2016

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.


Friday, July 1, 2016

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.