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Old 15-11-11
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Help 2.0 TS balance shaft question.

Hey there.
Just wondering if anyone can help answer my question.

Yesterday i took the balance belt off just as a bit of a "lets see how it goes" kind of thing. Well ever since doing so, my gtv now feels a hella lot free'er through its rev. Before it felt as if something was making the engine work a lot more than it should.

So. Getting to the point. I think my balance shafts are bent or damaged in some way.
When i took the belt off, i gave the shafts a spin. Well one spins freely through about 90% of its travel then you have to forcefully turn it to "un-jam" it.
The other is worse! The only way i can think to explaine it, would be to break up one revolution in to 10% segments. Well every other 10% it jams like the other shaft.
Any ideas of why they are like this?
I would be happy to put the belt back on if they felt free and smooth. As this is not the case, for the moment its staying off. It has also stopped my revs bouncing free 1000 to 800 constantly.

Any ideas on this?
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  #2 (Post Link)  
Old 16-11-11
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I think the balance shafts run in bearing shells like the camshafts, so it could be one is worn/damaged.
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Old 17-11-11
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that's the logical conclusion...

vibrationwise - how do you find it w/o the belt? if you like it, keep em off...

it's a low chance, but some BBs have come off and taken out the cambelt...

unless people insist on keeping it, i recommend leaving it off...

alfas meant to be rough & ready IMO...
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Old 17-11-11
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To be fair. Vibration wise. Long as your foot is constantly on the accelerator, there is no vibration at all. The only time there is vibration is either when youre coming down thru the gears instead of braking, or you take your foot off the accelerator and let it run under its own momentum.
Apart from that, no other vibrations at all.
I much much prefer it without the belt, feels more free and a lot, lot more responsive.
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Old 17-11-11
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I'd leave it off then.
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Old 19-11-11
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yea, don't forget BB seals are common problem w/ the TS... if you don't mind the little extra vibration

full oem BB kit damn near same cost of cambelt + aforementioned issues.... - i'd be rather done w/ them myself...

plenty of 4 bangers w/o it (including those in the TS range below 2litres!)
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Old 21-11-11
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Just an update;

The belt has now been off for week now, and I have had no problems at all with it being off.

Like I mentioned before, a little more vibration than usual, but I'm used to solid mounted engines so its no bother to me! Haha

So, the conclusion is - the belt is staying off while the car is in my hands! And that will be for a long time!!
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Old 22-11-11
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As long as you are happy!

I once had a 2.0 that the indie had put the balance shaft belt back on at 90 degrees out. Now that was interesting!
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Old 22-11-11
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I am also not a fan of these balancing shafts. It is a misnomer, and should rather be called gyro-shafts, or something like that.

In theory it is NOT able to counterbalance any imbalances that may be present, since it turns at twice the rate of the crank-shaft. Check the size of the pulleys to see for yourself. At the very best, it may have a gyro-effect, stabilizing any vibrations that may be present.

Lots of cam-belt failures have been caused by balancing shaft belt or pulley failures. IMO, it is not worth the risk. After removing the belt, I have not noticed any vibrations, but then again, this may be a false sensation, caused by the peace of mind that I now have.

What I did notice without any doubt, was the quicker throttle response. In the long run, you may also be able to detect an improvement in fuel economy.
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Old 22-11-11
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At the end of the day, it's your car, it's your choice.

However, to suggest they don't do anything is daft. Balance, vibration whatever you want to call it, they do make the engine smoother. Maintained correctly, there is no danger to the cam belt.

I will be keeping mine.
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Old 22-11-11
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Originally Posted by Mitch166 View Post
However, to suggest they don't do anything is daft. Balance, vibration whatever you want to call it, they do make the engine smoother. Maintained correctly, there is no danger to the cam belt.
Yup, even my 2.0 track car had its balance belt.
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Old 23-11-11
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Originally Posted by Mitch166 View Post
At the end of the day, it's your car, it's your choice.

However, to suggest they don't do anything is daft. Balance, vibration whatever you want to call it, they do make the engine smoother. Maintained correctly, there is no danger to the cam belt.

I will be keeping mine.
who said it doesn't do anything? we're all in accord it removes a bit of vibration esp, at low rpm...

and how many 'maintained correctly' belts, cam or balance have still gone awry?

we're simply saying you don't harm anything by leaving it off and the benefits are:
1) improved economy and crank hp (however small)
2) reduced risk of leakage due to worn balance shaft seal wear (common issue)
3) completely removed risk of BB failure leading to cam belt failure
4) (optional) raucous and a bit more raw engine trait...

I would argue that on 10yo+ cars, it may be smart to remove it - unless you are keen on repalcing seals and expensive BB kits... (just as the cam belt kit it gets expensive to replace the lot, not just the belt)

NB: the 1.8 and 1.6 does not feature the BB at all, and really there isn't that much of a performance gap b/w the 1.8 and the 2.0... sooo... make of that what you will.

As pointed out - it's up to the owners of the cars - but i feel there is some slavish commitment to what alfa (or i should say fiat) did with the design... If you like it, good for you.... but there are tinkerers out there who like to experiment, and the insinuation that it is wrong to do so, isn't really what a technical forum is about IMHO..

we certainly shouldn't be scaring people off a harmless 'modification' that can bring reward and savings, if the owner doesn't mind a bit of vibration at low engine speed. A lot of people won't mind that at all - especially the kind on a technical forum.
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Old 23-11-11
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official figures for readers to decide if the whole extra 15nm or so of torque of the 2.0 vs 1.8 makes a BB essential...

from wiki's TS engine entry (4v)
1.8 L 1747 cc 103-106 kW (140-144 PS) @6500 rpm, 163-169 N·m (120–125 ft·lbf) @3500-3900 rpm
2.0 L 1970 cc 110-114 kW (150-155 PS) @6400 rpm, 181-187 N·m (133–138 ft·lbf) @3500-3800 rpm

obviously it is the 'eccentricness' of the motor that matters.. FYI the 1.8 was more or less square at 82 x 83mm with the 2.0 under @ 83 x 91mm

Last edited by wankski; 23-11-11 at 02:31.
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Old 23-11-11
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Being the original poster; I have to say I agree with wankski. Yes they do, 110%, remove some degree of vibration, whether it being a small ammount or, in my case, a fair amount.

But people, we have to remember that everything is opinionated. Some will say, my god why did I take my BB off! I've lost a squillion horsepower and I can only do 2 to the gallon! (figure of speech)
But then again, in my case and I expect maybe others, I dont know, I am 110% confident that I have gained a little more power and the car doesnt feel like its struggling.

That is just my 2 pennies
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Old 23-11-11
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But your engine obviously has a fault.

If your engine was 100% I suspect the only difference you would notice is the extra vibration.

To my mind, the fact the 1.6 and 1.8 do not have the BB simply reinforces the point that the 2.0 needs it. Otherwise, why did Alfa bother?
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Old 23-11-11
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Mitch166 - I definitely agree with you about the 1.6 and the 1.8 not having them, but the 2.0 does. They wouldn't have just put it on the 2.0 to look pretty, it has a purpose, and that purpose is just for ride comfort (in my mind) but we will never know, unless we can find someone who was on the 2.0TS design team...

And yes, my engine does have a fault, I found out from Gazza82 that my shells could be worn/damaged, so I am most likely going to say yes they probably are damaged.

But fear not. I have got myself a new 2.0TS for Ł100! I got it from a friend in a garage, works perfect. The only work needing is a cambelt change as the one currently on it, was damaged (funnily enough) by the BB! Still runs fine, but obviously I'm not going to chance it, I'll change it.

I couldn't help but smile to myself when he shown me the damage from the BB, after the discussion we're having on here!
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Old 23-11-11
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i told you why the 2.0 has it even tho it's only marginally more torquey than the 1.8.... it has a more eccentric crank, with a much longer under-square bore/stroke ratio (see above) 83 vs 91mm..

the balance shafts are to cancel out the vibration and harshness from the more eccentric crank...

that's it... w/ the 2.0 being the premium 4 banger package - alfa did it for more 'luxury' and improved NVH....

at the time in the motoring press the 2.0 TS was highly regarded for its 'turbine' like smoothness.

my point is now, the BB requires a tensioner and pulley just as the cam kit... it's almost as expensive....most people don't correctly attend to it (just change belt at most) it can cause cambelt failure as it is not partitioned away from the cam timing system as it is in the v6 (fully enclosed by the pulley and cam covers away from the external accessory belt.

also now the balance shaft seals are old now and can, and often do, go wrong.. that's nothing to scoff at.... you need to crack the g/b to get at it...
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Old 23-11-11
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I got 171ftlb of torque out of my tuned 2.0 engine
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Old 23-11-11
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I fully agree with all contributions thus far. For completeness sake, I will add the following:

If all four pistons and con-rods have exactly the same mass (and center of gravity), they should cancel each other out, with two going up while the other 2 are going down, no matter what the bore or stroke is.

Crank shafts are only partially machined, and could have some uneven mass distribution over the length of the crank shaft, as a result of the roughness of the castings. In the old days, crank shafts were balanced by partially filling pre-drilled holes with lead, after spinning the crank in a balancing machine, much in the same way as wheel balancing.

Any imperfections in the above, are exaggerated by longer stroke engines (2.0l), causing more noticeable vibrations, in comparison to shorter stroke engines (1.8l & 1.6l). It may be that the balancing shafts were introduced by the designers in the 2.0l engines as a precautionary measure, knowing that components are not selected and exactly matched on an assembly line, as is the case when hand-building a blueprinted engine.

This boils down to pure luck when buying an assembly line engine: One engine may have all components closely matched, while the next may have one con-rod that is slightly heavier (but still within specifications) than the others, and now cause noticeable vibrations when run without the balancing belt.
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Old 24-11-11
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The 1.8 16v doesn't have balance shafts and feels a bit "Free-er" than the 2litre in my experience. The balance shafts do weigh a bit.
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Old 24-11-11
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I just don't buy it. On this logic, a car with air con won't feel as "free" as one without.

But, at the end of the day, if it feels (psychosomatic) good, do it!
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Old 24-11-11
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Originally Posted by marlon View Post
The 1.8 16v doesn't have balance shafts and feels a bit "Free-er" than the 2litre in my experience. The balance shafts do weigh a bit.
The main reason it will feel "free-er" is that the 1.8 has a shorter stroke.
It also has a smaller bore, so lighter pistons, than the 2.0
The 1.8 also makes it peek BHP 100rpm higher than the 2.0

I could feel the same differences between the different size Sud engines many MANY years ago.
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  #23 (Post Link)  
Old 01-12-11
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Try this:
2.3 DOHC Overview

balancer shafts use a bit of power, wiki says about 15hp, but it seems a bit exagerated.
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Old 02-12-11
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Originally Posted by DawieS View Post
If all four pistons and con-rods have exactly the same mass (and center of gravity), they should cancel each other out, with two going up while the other 2 are going down, no matter what the bore or stroke is.
Hey, Dawie I gotta disagree with this because even a perfectly balanced (component mass wise) inline 4 cylinder, 2 stroke engine, will be unbalanced when the cylinders are firing.

Edit: although you are exactly correct, 2 pistons go up while 2 go down

The inbalance isn't very serious, and it happens at twice crank speed. Hence, the balance shafts spin at twice crank speed to correct it.

I bet they consume less than half a horsepower.

Last edited by Turtle4288; 02-12-11 at 16:27.
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Old 04-12-11
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As Turtle says the power consumption will be negligable.. there is viltually no resistance when turning them by hand.. I guess pick up would improve as there would be less mass to accelerate.. my only concern would be that any vibration in any engine can lead to unwanted stresses/fatigue.. the 2 litre TS engine is oversquare.. the longer the stroke, the higher the piston velocity at any given frequency/revs.. the smaller engines are square or under square.. lower piston velocity, therefore less vibration..
so for the stroked 2 litre, any reduction in vibes is good.. maybe the balance shafts aren't just about driver comfort ?? crankshafts do not like vibration.. When engines have been 'stroked' to increase capacity.. the red line has to be reduced a grand or so.. four cylinder engines are inherently unbalanced and the crankshaft will flex.. work hardening at a stress raiser.. usually at the main journal/web.. = snapped crankshaft or increased bearing wear.
In other words.. removing the balance belt MAY reduce the engine life..

unless of course you are a complete nutter and have had to get rid of the BB to fit a blower.. in which case.. go for it!!

I may sound all old and sensible but there was a time when I used to drill holes in con rods.. based soley on the premise that a hole weighs less than metal..

Last edited by seadart; 04-12-11 at 22:44.
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