What is it?

[NOS2006]

Random thing that came to mind, though probably easy. I'm not sure how many people know about it...

This rotating piece within the block can be found in the 3800 engine along with others. It's sole purpose is to reduce engine vibration for a smoother running engine. What is it?

[76ChevyTrucker]

Balance Shaft. It can also be found in some later 4.3L engines, along with numerous Honda 4-banger engines. If I remember right, the 60* V6s don't have such things as balance shafts, although I could be wrong.

Edited August 10, 2006 by 76ChevyTrucker

[NOS2006]

Yep.. do a lot of people know about these? I never hear of them mentioned. However, it was mentioned as being in one of the Opel Antara's engines, so I figured I'd see if anybody could guess it in here..

[Hudson]

I believe Mitsubishi invented the balance shaft but many manufacturers (Ford, GM, and Porsche among them) have licensed the concept.

[ocnblu]

Are you Paul Newman?

[FAPTurbo]

Are you Paul Newman?

178623[/snapback]

I don't get it, but why do I still find it funny!

[NOS2006]

I don't get it, but why do I still find it funny!

178686[/snapback]

haha Same here. Probably because it's random as !

[Sixty8panther]

I saw this hot chick today at a carshow... she was checking

out a 1970.5 Trans Am and when she bent over to look at

the shaker hood scoop I thought to myslef: I'd love to stick

my balance shaft in her intake.

[76ChevyTrucker]

That ain't even right. Most people don't know about the balancer shaft in the engine, but it is the one part that's responsible for the engine running as smoothly as it does, if your ride has such a monster. and believe me, if the balancer shaft belt (as in Honda Accords), that sucker will run ROUGH.

[ocnblu]

The Paul Newman thing was a reference to the movie "Cars"... Paul Newman was the voice of the judge, a Hudson. I don't know how I thought of it. :AH-HA_wink:

To Mr. Sixty4: long live pushrods!

from what I understand, a balance shaft rotates in the opposite direction of everything else in the engine to cancel out the shakes. 90 degree V6 engines are inherently unbalanced, so a balance shaft smooths them out. A 60 degree V6 is naturally balanced, so a shaft is less necessary.

I think the GM 4.3L V6 was a notorious shaker before they put a balance shaft in it (not that it's the smoothest with it, but it's a good engine otherwise.)

[76ChevyTrucker]

Yes, the very first generation 4.3s were very rough idling engines. At RPM you don't notice the shaking, but at lower rpms, and particularly at idle she will shake a little bit. And you are also correct, the balance shaft does rotate in the opposite direction of the engine and cam, so it cancels everything out. Normally if you were to yank the timing cover off say, my 3.8L V6 in my Impala, you'd see the timing chain (Long Live Timing Chains, they hardly ever wear out!), then beind that you'd see another gear set and chain, that's the balancer shaft.

[Hudson]

The Paul Newman thing was a reference to the movie "Cars"... Paul Newman was the voice of the judge, a Hudson.  I don't know how I thought of it. :AH-HA_wink:

That would be Doc Hudson.

I was Hudson before Newman played one on the big screen. But the animators did an amazing job on that car.

Edited August 14, 2006 by Hudson

[Hudson]

from what I understand, a balance shaft rotates in the opposite direction of everything else in the engine to cancel out the shakes.  90 degree V6 engines are inherently unbalanced, so a balance shaft smooths them out.  A 60 degree V6 is naturally balanced, so a shaft is less necessary.

A 60-degree V6 is not "naturally balanced," but it is closer than a 90-degree V6. In theory, a "naturally balanced" V6 would be 120-degrees, which makes it difficult to fit into many cars.

[76ChevyTrucker]

Hudson is right on that account. The only really true naturally balanced engines are V8s, and most I6 engines.

[76ChevyTrucker]

I honestly did forget them, but yes, they are balanced naturually too.