So I was rushed by someone and accidentally cut through the bushing I meant to cut through and into the crank a little. I feel like I can sand down half of the gouge by uniformly sanding down the whole inner bore and not compromising strength but the other half I am not sure about. It's about half a cm square maybe less of material lost. What are your thoughts?

 

Okay so I did some research asked some people. One guy said I am totally screwed but another said I am fine because of how close it is to the center. I did lots of research and found other idiots like myself but no one seemed worried about the balancing rotational issue. I found this article:
https://www.onallcylinders.com/2016/...alance-part-2/

Apparently even 7000rpm high performance street machines and drag racers are not even balanced to within 14.5 grams 1 inch away from crankshaft center line and that is almost double of the largest amount of mass I gauges I could of lost. (One square centemeter of steel which is approximately 7.8grams)

Just to be safe I am going to sand down some on the opposite side and also just create a nice new face for the flywheel to mount.

BUT now I am curious how much material people have safely removed and what horsepower and torque numbers were they running? Surely someone has bored out the inner diameter of where the flywheel bolts to just to experiment.

Also, who here has a custom balanced or billet crankshaft? I know the lifters start floating around 8000rpm but that can be fixed so why am I not seeing more of any 9000rpm builds? I mean people get to 8000rpm on completely stock VW Jetta/Golf 1.8T engines and we all hear about 10,000rpm Honda's. Frankly I wouldn't think about running 800hp if I couldn't get to 8000-9000rpm because that only leaves too small of a window for my liking to drive around in.

 

im no engine builder... but i would think balance wise... you are fine.

another concern is all that metal in that main seal.

 

The metal was just lightly resting on it from cutting through the bushing. Our engines aren't balanced within 14 grams from one it from the crankshaft center line and a square centemeter of steel is approximately 7.8grams so because it is so close I am in the clear but I am inspired to get my crankshaft balanced/buy a different better one that might reduce harmonics and vibrations when I do my engine build next year. I was going to just leave it but after reading about all the benefits! Plus it would be worth getting coated along with a bunch of other stuff in this low friction material.