I watched half of the video and I think this guy is an idiot. I had to stop at the part where he said this motor will fail at 8,000 rpm. Well duh, it was never designed to operate at that rpm. The Honda Fit motor that this was designed after has legendary reliability, and of course with the turbo this will prove less reliable, but there’s plenty of Civics, Accords and CR-Vs that have exceeded 120k miles in this motor with no problem.
^^ I agree. His "analysis" fails to take into account metallurgical and manufacturing advancements that have occurred (and which Honda has employed) over the years. As an example, my Honda motocross bike uses bolts across the entire bike that are smaller in diameter and have less "meat" in the head than my previous bike employed, all in the interest of saving weight. None of them has failed or led to a failure of any kind. Someone on another forum suggested that his use of different size crank bearings is contrary to express Honda guidance on rebuilding these motors and is likely the cause of the rod "failures" he's seeing.
Unless you're thinking of trying to turn this motor into a 500 HP racing engine, I don't think there's much to worry about here. It will go to 200K miles easily with simple maintenance.
I believe he is just opining this not a good motor to push to higher horsepower. It’s just fine for the purpose it is built for, street use. He gave argument that there are several aspects that are designed to that use, leaving little extra for pushing to higher power.
Modern motors are tweaked to such tolerances, so refined and balanced for fuel use. And there is a lot of involvement from the accountant types. Things done as thin as can be done and still fulfill the warranty.
Not as much room to play as the cars we grew up with.
I feel conflicted about this. (Disclaimer: I am not a wrench. I am a certified idiot.) While I get what he’s pointing out in terms of component beefiness/sturdiness, and that lighter and smaller components are more prone to fail with a 50% increase in horsepower and torque, I feel like the half-assed “I guess it’s okay if you aren’t tuning the engine and you value fuel economy and you want to keep it stock” tacked on at the end feels disingenuous. Just say it’s a bad engine if you are planning on significantly tuning it and move on. Saying it’s bad full stop is kinda bullshit, imho.
If you want to mod your car into a high-revving screamer, grab a K20 and go to town! Nothing wrong with that. But there’s nothing wrong with enjoying a new Integra or Civic Si out of the box, either.