Hi everyone,
This is my build diary of my supercharged 1968 CL175. I am new to land speed racing, so any advice is welcome and encouraged.
BACKGROUND:
Back in June of this year (2021) a coworker of mine told me he had an old motorcycle in one of his barns that he wanted to scrap, but he would give it to me if I was interested in another project. He knew it was a Honda, it didn?t run, it has no title, but he didn?t have anymore information than that. Later that night he sent me a picture of the bike and it turned out to be a 1968 CL175 (sloper), and it actually looked to be in pretty decent shape for sitting in a barn for God knows how long. I wasn?t sure what I would I do with the bike, but I couldn?t pass up a free motorcycle.
Once I received the bike, I quickly realized the engine was in rough shape. It was locked up completely. The cam shaft was seized in the head, and the right piston was seized in the cylinder, among some other issues.
Long story short, since the bike had no title, and it was going to need quite a bit of work to get running, why not do something different with it. After doing some research , I decided it would be cool to build a bike for Bonneville. It looked like the records for supercharged 175cc bikes for few and far between (for modified production). With that, I got to work.
CURRENT STATE OF THE PROJECT:
As of right now, I am still very early on in the build. I?ve stripped the bike of most of its stock components, and also rebuilt the engine. The engine is bone stock, besides slightly gapped rings. With that said, I plan to only run the bike at around 5 psi to start, but I am fully expecting to run into failures at some point, and learn from them. Believe me I would love to go crazy and do everything under the sun, but time and money are always a factor. I really would like to get it running, and go from there. I don?t want to try to do everything, and never complete the project.
The plan is to run a draw through supercharger setup. The supercharger I decided to use is an AISIN AMR300. They are fairly cost effective and seem to be readily available if I were ever to need parts or to replace it. In the pictures you can see at this point I have mounted the blower to the bike and designed a belt tensioner. This was the best place I could find to mount the blower without having to do major frame modifications, or run a jackshaft. This mounting spot still gives me room for my legs and it is easy to access. With the current pulleys it should run around 5 psi, but I have other pulleys to adjust that when the need comes.
I am currently working on the intake system. The plenum is about 80% finished, and I just finished mocking up the tube going from the blower outlet to the plenum. I am just waiting on the tubing and v-band to arrive so I can fabricate it. Once I complete that, I will make the top blower mount that will tie in the top ear of the supercharger to the frame. I wasn?t sure where the intake tube would be, so I waited to do that mount for last.
As of right now, I am planning on using a Mikuni TM33 (w/ accelerator pump) carburetor. I spoke to a couple small race engine vendors at the recent PRI show in Indy about the project and they both seem to think this would be a good option, but I am open to suggestions.
The ?tank? that is currently on the bike is just a 3D printed mockup that I designed. I just wanted something there that would give me a sense of where I would be sitting on the bike.
I think that?s it for now. Thanks for reading!
-John