Pros and cons of balance shaft delete

[Tylerwatson]

Hey so I’m just wondering what are the pros and cons to doing a balance shaft delete on a v6 Buick motor

 

[shane_3800]

Are you holding it at 7k all day? if not don't bother.

 

[losh1971]

Gets rid of the BS bearing noise. Saves a small amount of power. Cons, none in my experience.

 

[Immortality]

Less stress on the timing chain/tensioner, potentially less noise from balance shaft bearings, slightly less rotating mass.

Cons, maybe some increased engine harmonics at certain rpms but then throw in some new engine mounts and you probably won't won't notice anything. If you really want to smooth out the engine, fit a decent harmonic balancer, the OEM unit is a POS.

...and those feel good vibes about modifying your motor

 

[shane_3800]

Less stress on the timing chain/tensioner, potentially less noise from balance shaft bearings, slightly less rotating mass.

Cons, maybe some increased engine harmonics at certain rpms but then throw in some new engine mounts and you probably won't won't notice anything. If you really want to smooth out the engine, fit a decent harmonic balancer, the OEM unit is a POS.

...and those feel good vibes about modifying your motor

Not really, a crank balancer is there to take out torsional whip not the second harmonic.

 

[losh1971]

Balance shaft in Buicks do stuff all but create annoying noise when the bearing gets old. In my experience any extra harmonics are not even noticeable. If the timing cover is off then its worth removing the drive sprocket. If the cover is not off and it's not noisy then probably not worth removing the sprocket. If fitting a new chain then definitely remove it.

 

[Immortality]

Well yes, they cancel out certain vibrations from the engine which the 90° V6 are well known for. The balance shaft on the V6 engine is a bit different to the 2 balance shafts talked about in the 4 cylinder engine mentioned above.

Having owned and driven V6 engines with and without balance shafts including a VN which is well known as been the roughest of the V6 motors I can tell you it makes little difference with or without. The Buick 3800 V6 motor is a bit rough, it's one of it's charms, you either love it or hate it.

The harmonic balancer ( which is really a misnomer as it is a harmonic damper but because the 3800 V6 is a externally balanced engine the the harmonic damper is actually a balancer which is why the term harmonic balancer comes from) , it absorbs torsional and resonance vibrations. If you listen to any good engine builder they will tell you the damper needs mass for it to do it's job which is what the factory POS lacks.

And again, from personal experience, when replacing the factor POS on my old VN it got rid of a weird vibration at a certain rpm, one that manifested itself by causing the rear view mirror to vibrate.

My old VN ran smoother with the balance shaft removed and a proper high quality balancer fitted.

 

[Anthony .]

Balance shaft in Buicks do stuff all but create annoying noise when the bearing gets old. In my experience any extra harmonics are not even noticeable. If the timing cover is off then its worth removing the drive sprocket. If the cover is not off and it's not noisy then probably not worth removing the sprocket. If fitting a new chain then definitely remove it.

What sort of sound does a balance shaft make? Would it sound like a loose manifold heat shield when under load I.e going up a hill?
Or is it just idle?

 

[losh1971]

It makes a tick similar to a worn out lifter or five. It will be worst on start up but won't go away completely when hot. Not really an issue but I hate noises, so I made it redundant.

 

[Draimond]

Last time I had a look (recently in 2023), I think the only balancers available where OEM spec powerbond and a couple under drive SC balancers.
Would be nice if Ross or ATI still made a good V6 balancer.