Crankshaft Balancing - Part 1

In this episode of Steve Tech, Steve Morris breaks down what goes into a proper balancing job for a performance engine.

[@rocketsurgeon11]

You went over briefly the under and overbalance conditions and their advantages, but I'd like to know more about when it is needed or highly recommended. I've heard that certain V6 engines that run high rpm "need" to be overbalanced, but why? What are the consequences of not doing it? Obviously there's certain harmonics and such we are trying to deal with, so does this have an effect on being able to run the engine in an area where those harmonics would typically have detrimental effects and what does that do to the rest of the operating range?

[@ericacrider2825]

Yes! Part 2 is equally as interesting. Thank you for the videos!

[@bigredracer7848]

Steve you always give out the greatest information and help I wish for one time you would send out a list of your prices on what all these great ideas and motors cost

[@rmt5820]

It doesn't matter to know which way engine turns and then balance the Crankshaft to correct way?

[@figue_2797]

10/10

[@magnusdanielsson2749]

For V6 engines its such a wide target that it makes one wonder what would be the correct factor. The range Ive seen is 35-55%! Thats for both 60 and 90 deg engines and between. For the 65 deg dino v6 they used something like 35-48 %

[@EarthsMysterieswithKenKay]

on ford 460 external balance, what is the correct clock position for the weight on the flex plate in relation to the hatchet weight on the front of the crank? thanks

[@grantk.3860]

Thanks again Steve!

[@ericacrider2825]

I really want to watch part 2!

[@EngineBuilder]

It's up on the page now. Have you watched it?

[@duygukayhanisaskank4915]

@@EngineBuilder Hello Steve, I know you keep very busy & you're always working on new projects. Your KZbin Videos are interesting & helpful. Can you PLEASE explain the process to get the best balance on a flat-plane crankshaft? Is the procedure different than what you've demonstrated for balancing a typical cross-plane crankshaft? THANKS for your attention & I wait for your reply. Best regards, Ben

[@johnj2496]

That's awesome I love this part of engine building squeezing the last bits out of it You should put another scale under the dangling side so you can measure big n small end at once to speed this process up

[@hi-lineprecision.6796]

What's the crank throw on a GM inline 5?

[@JohnDoe-iu5xi]

I'm confused how this works. There are two rotating masses at the throw but the mass is being pulled in different directions. And the reciprocating mass for both pistons are also opposing forces. Which is why you divided by 2 instead of multiplying but dividing doesn't make sense to me either. You have a mass of 950.7 going up, and a mass of 950.7 going down. Wouldn't they cancel out?

[@philldownes8685]

exactly right.. all this bullshit is just to justify having an expensive set up when its clearly not needed.

[@bounzig]

@@philldownes8685 Wrong, of course it's needed. This is how to balance the CRANK, nothing else. If all the pistons and rods have been balanced to the exact same weight it would still cause vibrations if the crank is not balanced, since one side would weigh more than the opposite. It's not BS my man.

[@CalebsCars]

@@bounzig are cranks in production vehicles not balanced from factory?

[@bounzig]

@@CalebsCars Yes they are, but not nearly as good as in the video. And it depends on what car you get. Details like this is why some brands cost a lot more than others. And if you are thinking about tuning then balancing is key.

[@2secondslater]

So what does 0.8g mass equate to when the reciprocating mass accelerates through the the fastest part of it's acceleration at a piston speed of 27m/s/s? I think you will find it is not so inconsequential.

[@bigredracer7848]

Is the drag forces of the piston rings on a cylinder lock considered into the Bob weight at all

[@jaimecabrales5344]

When sending your piston rings in, do you need to file-fit piston rings before balance? And what gap would you recommend a twin turbo lm7 forged pistons?

[@ricardoespiritu8843]

How hard it would be to make a 2 liter 4 cylinder with a cross plane crankshaft? The max rpm being 7500 -8500 rpms?

[@ouarijimmy8858]

Thanks for the information.

[@regdor8187]

Your post-it note paper is likely less weight than a thin layer of motor oil over all of the rod/piston assy...

[@albertosibuyas1697]

Nice sir can i ask if how you calculate the tolerance for the crankshaft balancing thank you

[@cristianosilva6052]

Do you balance duramax rotating assembly? Thanks

[@anko6999]

jesus with u

[@philldownes8685]

he tell you the rod needs to be level and yet its well pissed with small end down a long way...

[@Rob-pg7rb]

Your balancing machine is too nice to be using with that cheap Ebay special scale.

[@bigbothoee8617]

Your not doing that correctly the spacer block should be same size as big end so you don't need to adjust the height

[@lilycao7958]

hello

[@gullreefclub]

I know this a bit off topic but WTF is up with every Tom, Dick, and Harriet on KZbin constantly using the word "So" and "Okay."

[@niceguy4928]

You definitely are watching the wrong thing when you pick up on those words instead of watching a crank get balanced.