Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Removing balance shaft ?

NOT 38

New Member
Joined
Jan 26, 2011
Messages
93
Reaction score
0
Points
0
Location
brisbane
Members Ride
vn commodore
hey guys
i have a question for you about the removal of the balance shaft in the buick v6.
im wanting to run a double row timing chain. however to run the double chain you need to remove the shaft as some of you probly already know, has any one done it and what needs to be done.
 

immortality

Can't live without smoky bacon!
Staff member
Joined
Apr 15, 2006
Messages
17,227
Reaction score
6,574
Points
113
Location
Sth Auck, NZ
Members Ride
HSV VS Senator, VX s2 Calais S/C
no oil galaries to worry about on the buick motors. so you have a couple of options. you can just remove the drive gear for it and leave it in place or you can pull the entire thing out and get rid of some dead weight. to pull it out though you will need to remove the intake manifold unless you have access to a slide hammer.
 

GTP 85

291 hp @ the wheels
Joined
Aug 23, 2006
Messages
1,462
Reaction score
21
Points
0
Age
35
Location
Murray Bridge S.A
Members Ride
MY04 WRX, VS SSenator & VS V6 track weapon
^^ as above... just yank it out and put it in the bin. did this on my v6 v6 i had a while back. eliminated a rattling on idle

I did the double row chain too
 

padrickz88

Rick =]
Joined
Dec 15, 2005
Messages
1,555
Reaction score
36
Points
48
Age
32
Location
sunshine, melbourne
Website
www.facebook.com
Members Ride
VN V6, nothing special
I say give it a go, its alot better without it.... My engine is so damn quiet (for a buick) because i dont have the balance shaft bearing making noise or the timing chain tensioner letting the chain flop around..

Also my engine mounts are pretty new-ish, and I didnt even notice the vibrations everyone talks about?

no oil galaries to worry about on the buick motors. so you have a couple of options. you can just remove the drive gear for it and leave it in place or you can pull the entire thing out and get rid of some dead weight. to pull it out though you will need to remove the intake manifold unless you have access to a slide hammer.
Or a big screw driver and pry it out :D worked for me lol
 

vtmomentum

New Member
Joined
Oct 12, 2006
Messages
24
Reaction score
1
Points
0
Members Ride
VT SII V6
Hey Ev1,
i am also planning to remove my balance shaft from an ecotec i am rebuilding, i was wondering if anyone could explain the process involved after the removal e.g balancing of engine ect ect.
i am planning on putting mace ported heads and a stage 2 cam in the engine. i am also planning on doing the oil pocket work and tossing up between a custom intake manifold and twin plemimum's or just some mace spacers to extend the runnes. any advice would be apreicated. some one told me if i remove the balance shaft i need a good harmonic balancer and the engine balanced by a expert ?
 

383 hatch

Well-Known Member
Joined
Jun 14, 2005
Messages
3,922
Reaction score
65
Points
48
Age
39
Location
Cowes, Phillip Island
Members Ride
VG Ute 5.0,Torana hatch 383,WB Ute 5.0,VR stato5.0
Nothing needs to be done, just remove it, throw it in the bin and block up the rear oil gallery. Done.

Some interesting reading taken from another site:

Engine balance and deleting the balance shaft


With any engine balance is important, especially for high rpm operation. It’s a common misconception that the balance shaft is used to balance the engine. It is not. An engine’s rotating assembly is balanced so that when the crank is spinning in a circle the weight at any one point is the same. This makes it so that no uneven forces to try and move the engine in a particular direction at any point in it’s rotation. Hence the spinning is ‘in balance’. A great example is a tire. Have you ever had tire shake or driven a car before the wheels were balanced? Same thing. These forces at high rpm turn into a vibration which literally shakes your engine apart. In a motor, you add or remove weight from the crank, make sure the rods and pistons weigh the same. The 3800 uses external balancing as well, with a weighted balancer and a weight on the flex plate. The better the balance, the higher the rpm the engine will survive at.



Consider the math. An imbalance of one ounce (the weight of a rod bolt) 1” away from center at 2,000 rpm will be subjecting a force of 7 lbs. At 4,000 rpm, the force grows to 23.5 lbs! Double the speed again to 8,000 rpm and the force becomes 114 lbs! Keep in mind, this is one 1” away from the center of rotation. The idea is to show why balance issues are negligible at low rpm but insanely important at high rpm.



The 3800 has 6 cylinders, two banks of 3, 90 deg apart (90 deg V6 engine). This engine is actually 2 inline 3 cylinder engines together. At any given time a cylinder on the front is in the same position as a cylinder in the rear. The crank shaft has 30 deg offsets for journals where rods are next to each other. This 30 deg, plus the 90 degree V gives you 120 degrees. 3 cylinders x 120 degrees gives you 360 degrees or a full circle.



This design has some inherent problems though. As the 3 cylinders on one bank move up and down a shock is generated as they change direction (at the top and bottom of stroke). This shock cannot be countered by the other bank because they are on a 90 deg plane from each other. This creates an annoying harmonic that doesn’t affect engine balance or performance but it is noticeable in the car. As the engine speed rises, so does the frequency of this shock and it’s not felt much as it’s absorbed through the mounts and chassis. A good example of this is a subwoofer vs. a tweeter. Bass is low frequency sound and you can hear it for a long ways, it shakes your car. But no one ever complains about a neighboring cars mids or tweeters because higher frequencies do not travel as well or shake other objects. Same principal.



The balance shaft is an out of balance rod that create a harmonic to counter the feel of the inherent engine shake. The balance shaft is statically balanced so it will roll smooth but it is dynamically out of balance with weight on one end and an apposing weight 180 deg off on the other. This is done on purpose to cancel out the vibration inherent to a 90 deg V6 cylinder engine. Mainly it does it’s work at idle and low engine speeds where vibrations are felt the most. It does not keep your engine in balance; in fact it is purposely out of dynamic balance which is bad for performance. This trade off is worth it for the average consumer. The real problem comes when you want to use the engine at high engine speeds. Remember the math above about forces as they relate to rpm? It just so happens that the radius of a factory balance shaft is just over an inch but the out of balance (counter weight) is a lot more than an ounce! This translates to terrible internal engine shake and HP being used to create this vibration. For high rpm engine operation, it is recommended to eliminate or disable the factory balance shaft.
 

vtmomentum

New Member
Joined
Oct 12, 2006
Messages
24
Reaction score
1
Points
0
Members Ride
VT SII V6
thanks so much blown v6 hatch you answered all my questions
 

LeighGray

New Member
Joined
Apr 8, 2021
Messages
10
Reaction score
0
Points
1
Age
24
Location
Napier, New Zealand
Members Ride
VP Executive V6 Ute
Sorry to open up an old thread but do or don't you need to block up the oil gallery if removing the shaft? Engines from a VP - so buick not ecotec. Cheers
 
Top