V12 Engine

April 2018 - October 2020

Background

I started this project my freshman year in high school while in my Project Lead The Way (PLTW) engineering class, Intro to Engineering Design (IED). It all started when I ran across a walkthrough-style YouTube series one night of CAD modeling an engine, starting with the piston (1). I only found out after starting the project that the later videos required payment, summing to over $80. As a 14 year old who has never had a job, that was a lot of money, so I went my own route and did it myself.

(1): The piston designed through the series, I based most of my constraints off of this model

Design Process

Being at the young age of 14, I didn't yet follow a methodical design process that I do now. It was certainly not the most optimal approach, but its all a part of learning and growing as a young engineer. The important lesson I learned was to not blend the design process into one step, but to break it down and make it more manageable. Looking back, my design process followed these steps:

  • Research

  • Preliminary CAD modelling

  • Finalize important geometry

  • Develop the rest of the model into the final product

I think it is important to note at this point that the model was never intended to be equal to a physically running engine, there are just too many variables to consider. The CFD, modal, and dynamic analysis required were something way beyond my comprehension and understanding at the time.

My independent design started with the engine block, the videos ended very early in the design. At this point, the block's constraints were limited to bore. I could make the stroke whatever I saw fit, so I researched V12 engines with similar bore and designed with a similar stroke. The block and crankshaft went through a simultaneous design process, I was constantly referring to each other and seeing if they would contact in assembly.

A real challenger approached, the camshaft with it's smooth lobes that contain no edges. I was yet to encounter this in my CAD career and it proved to be a problem. My savior was making the lobe profile into one surface into the four that it was.

After the bottom-end (block, crankshaft, and pistons) was complete, I turned my focus to the engine's cylinder head and valvetrain. My constraints consisted of the valve's diameter, angle between intake and exhaust valves, spacing between same-side valves, and combustion chamber diameter. Just like the majority of the project, this was a very open ended design where my creativity had a lot of freedom.

I stand back, proudly looking at my work, but I couldn't help but think,

"Well, now what Nick?"

My IED teacher gave me a challenge, something to test my skill. He quested me to design a V-twin engine, similar to what you could find on a motorcycle. The twist here is that this would be a cutaway model so you can see the internals and the motion of the parts.

I reused the V12's piston and split the cylinder head to give me two separate "slices" of the head. Designing the block and crankshaft was surprisingly more difficult than the V12's. The same simultaneous design revision process occurred between them which resulted in three complete redesigns of the crankshaft.

My teacher then suggested 3D printing my final assembly on our (new at the time) Lulzbot TAZ 6 printers. I printed the model in colorFabb PLA in full scale, for reference the piston has a 84mm (3.31") diameter and 202.5mm (7.97") length.

The block alone took two days to print and almost failed twice in that time. It's safe to say that he wasn't happy with me using all of his filament either. This sparked an idea in me to buy my own TAZ 6, which resulted in me getting my first job at McDonald's.

My mortal driving force, my ever burning infatuation, for all things automotive had led me to velocity stack intakes. These are seen throughout automotive performance history, with notable mentions being the Ferrari 250 GTO and Porsche 917K (coincidentally both having V12 engines). So, in short, I made my own rendition of it. In all honesty, this was the most difficult part I had made in CAD to date. Following the intake, I created an oil pan and valve covers so the entire engine looks complete.