I have finished the project but wasn't completely successful in getting it running properly. Even though it did run very smooth on just two cylinders, it absolutely refuses to run on all eight. This is caused by tolerances on the valves (leading to air gaps and jamming parts) and also friction on the rotating points of the arms.

I have decided not to machine all the parts needed to get this engine (first attempt prototype) to function well. Instead I will use the acquired knowledge to design and build a much better one which I am looking forward to!

Amazing.

I'm looking forward to the second one running.

I have patience.

ShopShoe

Hi Jack and welcome to the forum. Hopefully someone can help answer your question. In the mean time, please tell us a bit about yourself and your interests in the "introduce yourself" section so that those not watching this thread can welcome you as well.

Bill

Thanks for the reply Wesley,

This is a really slick idea. I might give it a go on my engine as well. I did some brainstorming with some other students and this is better and simpler than anything we came up with.

Another question for you. What did you use for compression rings and lubrication on your engine? I figured with compressed air as the energy source, an o-ring with a nice spray down of WD-40 might suffice.

Thanks for your input and good to hear from you,
Jack

Hi everyone, it has been a long time since I posted any updates. So it's about time to post one!

First of all, I hope everyone here is still doing well amidst the corona outbreak. Stay safe!

Before designing the Marchetti V2, I wanted to broaden my understanding and expand the research. It is interesting for me to understand the consequence of changing parameters such as wheel diameter and swing angle of the arms. By doing this I found that there is a steep acceleration drop near the "hollow part" of the cam. This means that the wheels may slip here because they are still "spinning". Therefore, reducing acceleration could possibly increase the lifetime. All new research is published on marchetti-engine.com under the section "The math & how it's used to estimate the historical dimensions". For those who are familiar with programming in Python, I also included a fully functional script in the PDF article.

For the design of the Marchetti V2, I am considering to make it solenoid driven. Since it is the mechanism that interests me most, it's nice to be able to show it inside a living room without much noise (or exhaust gasses). I have no experience with solenoids, so I will make a simple 1-cylinder engine beforehand.

The design of the V2 will take at least 3 months, using my spare time. Getting all details correct before manufacturing is critical this time because I want to invest more money into manufacturing. The V1 was made by me as poor student, but now I have the ability to outsource wire EDM to make the cams, for example.