Well-Known MemberHMEM Supporting Member
- Mar 8, 2019
- Reaction score
- Charlottesville, VA
Ah, some of those British engineers were brilliant, and prolific. Thanks for those references. And it seriously is amazing how prolific some of the best of the best were. One new idea after the last, with many completely changing the course of prior technology. Zora Duntov was one in the United States. He designed the first Small Block Chevy V8 engine in about 1953. Arguably, the first "modern OHV V8." It started out as a 265 cubic inch and eventually grew to 400 cuin. And the basic design is still in use today. There were so many millions of them produced that they became the engine of choice for hot rodders, for many years. The main reasons being that 1)there were so many of them in existence that they were cheap, 2)after-market manufacturers jumped on the band wagon and made all sorts of hop-up equipment that was affordable, and probably most importantly, 3)Duntov's design was so good that almost no changes needed to be made to the basic design, which led to, 4)a very broad family of engines with very amazing amount of parts interchangeability, which means, cheap aftermarket parts. Genius!Aha!
Found the article I was looking for...!
Inside the Cylinder of a Diesel Engine – by Harry RicardoSir Harry Ricardo was one of the foremost engine designers and researchers of the internal combustion engine. In this article, he takes us through the first moments of combustion in a diesel engine…oldmachinepress.com
With that said, yes, I think I am more or less finished with the reinventing the wheel stage, but I will probably have a relapse.....soon. Given that the basic concept of the model I am building is the Detroit Diesel 2 stroke (another amazing family of engines), and now that I have the Roots blower and the Unit injector built, probably trying to scale the model to the basic Detroit Diesel design (including the combustion chamber design) will be a reasonable approach. Physically, the injector ended up being larger than I had hoped, so the basic scale of the blower might not be visually correct, but I hope it is.
And I also realize that if the model is, lets say, 1/4th scale, that the piston area is 1/16th, and the cylinder volume is 1/64th, and that the stiffness of the crank pin is 1/256th??? So, if the engine power is proportional to the cylinder volume, i.e., 1/64 the power, does that mean the crank pin will end up being only 1/4th as strong/stiff as it really needs to be? So the crank pin will really need to built to 1/2.8 scale to the original? That is, 2.8 being the 4th root of 64? So as to keep the stiffness of the crank pin in proportion to the power? Or, because the crank pin is also 1/4th as long, and stiffness changes with the cube of the length, will doing a simple 1/4th scale of the crank be ok. Or maybe I am overthinking it, but maybe not. Ha ha, I was just going to say that this is rhetorical question and I need to figure it out myself first, but there I go re-inventing the wheel again. But the journey is more fun than the destination.
I know there are some older threads about the complexities of scaling engines, so I better dive into those first.