New CI Design in Princeton, NJ

[kspringer80]

I'm a Mechanical Engineer from the Princeton NJ area who is readying my first engine build. I'll be asking some questions in these forums that probably violate rule #1 that I've seen on other sites..."build a proven engine design first." After 5 months of research and a few spreadsheets I've decided upon building a 0.48" bore, 0.50"stroke compression ignition two-stroke. I've finalized 95% of the design but am working on the port time-area/volume ratios of this engine to determine the port timing and diameters. The biggest problem that I'm running into in this case is determining the engine RPM that I should design to. My initial thought is 9000rpm, but I just don't have any idea.

Please bear with me through this learning curve... I'll post stupid questions, and detail solutions as I come across them. I don't need any lectures as to building a successful engine first, I learn best by screwing stuff up (but do my homework and try to minimize those learning experiences.) I have a "low-budget" shop full of hobby equipment from China, so I realize I'll have to do a lot of hand finishing.

For any of you still questioning my sanity... I need a good winter project. I'm recently engaged and the new "provisional" mother in law will be living with us for the winter... I could use an excuse to spend lots of hours in the basement.

Cheers!

 

[Tin Falcon]

Welcome to the forum. Thanks for the intro.
We recommend building a couple of air engines as a foundation before going to IC.
Tin

 

[kspringer80]

Tin, I realize I'm violating "rule #1" but I learn best from my mistakes. I'm a decent machinist and I love figuring out why something didn't work and don't mind making a couple of tries at something. The entire point of this build is to keep it simple, design an engine tailored to machinability and to enjoy some quality time making chips. This is a great collection of users and information that you guys have here.

 

[Sshire]

Go for it. If you have machining experience and work safely, the worst case is that the engine doesn't run or doesn't run well. Then we all jump in with suggestions. Some may even be valuable.

 

[kspringer80]

Thanks Stan, The intention here isn't just to build an engine. My intention is to work from start to finish through the entire design, fabrication, testing, redesign cycle. My goal isn't just to build an engine and run it, it's the design part that I hold the most interest in. It's quite an interesting collection of technologies here Air, Steam, IC, Vacuum that are all gathered in one place.