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Lord_Verminaard said:
All VAG engines are internally balanced. That's why you can zero balance everything and it's fine.

Brendan
I'm feeling like a broken record here. That AREA document is wrong. I asked my machine shop guy yesterday when I called about my VR6 head. He's been working on VW/Audi engines for 20 years, he said he has never had to re-balance a VAG crank.

I just swapped the flywheel on my 20v for a spare used flywheel that I had turned. Didn't balance anything. Put on a new Southbend Clutch too. Didn't balance that either. Hey guess what? The engine doesn't vibrate. How amazing is that. If it actually were an external balance engine, I'd be screwed because I didn't balance the clutch/flywheel to the crank.

That's the beauty of internal balance. You can swap pistons and rods, and as long as the weight match between all of them is pretty good, the engine will not experience an out-of balance situation.

Brendan
 

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glibobbo21 said:
To get back to before, no im not kidding.. Thats why the fiddle sticking tool works. It doesnt take an engineer to figure this stuff out. Just BTDT. If you didnt engineer the damn thing its all speculation. Ive swapped pulleys(crank), FW's(resurfaced/balanced individually) and never had a problem. Everyones shit stinks on this forum, so take it down a notch, its a discussion.

How do you propose we stop the crank to tighten/remove the 27mm bolt without this "CHUNK". Also, about the pulley shifting on the rubber.. The stock 7a i guarantee will shift the pulley because I've seen it rotate almost 90 deg on said stock motor, BEWARE.
Don't mean to ruffle any feathers, but I'm having a discussion a group that although are very smart and know tons about Audis, probably have never balanced a motor. I've been a machinist
for 15 years and have balanced hundreds of motors.

If someone in the Seattle area has a balancer and flywheel I will spin them on the balancer
so we can get some accurate numbers. I'm not sure why everyone is so against external
balance, I've done lots of race motors that rev over 9000 all day long.

On the imbalance weight on the balancer, many motors with internal balancing use just as big of
bolt and have no "CHUNK". Some have threaded bolt holes to attach tools and some like the Audi V8 have another matching weight 180 degrees to zero balance it. Check it out.
 

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quattro87 said:
RSCoupe said:
All I know is that I had mine zero balanced without any significant material removed.
Mark, what are you talking about...the balancer right? No significant material sounds like zero balancing to me. I assume that you are running a lightweight zero balanced flywheel.
Pulley, crank, alum. flywheel, and pressure plate.

Lord_Verminaard said:
...I just swapped the flywheel on my 20v for a spare used flywheel that I had turned. Didn't balance anything. Put on a new Southbend Clutch too. Didn't balance that either. Hey guess what? The engine doesn't vibrate. How amazing is that. If it actually were an external balance engine, I'd be screwed because I didn't balance the clutch/flywheel to the crank...
What are you revving to?

I'm a little surprised the clutch didn't need some balancing, or are you saying you didn't even have it checked?
 

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They ground a little off at the very edge at one spot. Not sure if I have a pic, but I'll look.

*edit - Nope, no pics.
 

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RSCoupe said:
What are you revving to?

I'm a little surprised the clutch didn't need some balancing, or are you saying you didn't even have it checked?
Dunno, tach doesn't work. All I did was have the flywheel turned, and I got the new clutch disk and pressure plate from SouthBend and slapped it all together. The same way I've always done any VAG clutch, (at least a dozen) only I actually used the alignment tool instead of my finger this time. :p It's just as smooth now as it was before I swapped the clutch.

If the flywheel was already zero balanced, and the machine shop took an equal amount of material off of the face, then it would still be in balance since no material was unequally removed from one side or the other.

When I worked for VW, they never balanced clutches/flywheels and they probably did 10 of them a day.

Brendan
 

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I have done both. I have had audi flywheels balanced and fidanza flywheels for that matter.. They always can balance more then audi balanced them. Having all of your internals balanced combined with your flywheel/pressure plate is awesome.. Afterwards, regular oem motors feel like 5hp Briggs motors.
 

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ShavedQuattro said:
I have done both. I have had audi flywheels balanced and fidanza flywheels for that matter.. They always can balance more then audi balanced them. Having all of your internals balanced combined with your flywheel/pressure plate is awesome.. Afterwards, regular oem motors feel like 5hp Briggs motors.
:stupid:

I'm not saying just throwing them in without balancing is bad, not at all, I've done it many times on street cars. But as Hank said, it does make a difference, especially on a motor with solid mounts and that is revving to 8000+.
 

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RSCoupe said:
ShavedQuattro said:
I have done both. I have had audi flywheels balanced and fidanza flywheels for that matter.. They always can balance more then audi balanced them. Having all of your internals balanced combined with your flywheel/pressure plate is awesome.. Afterwards, regular oem motors feel like 5hp Briggs motors.
:stupid:

I'm not saying just throwing them in without balancing is bad, not at all, I've done it many times on street cars. But as Hank said, it does make a difference, especially on a motor with solid mounts and that is revving to 8000+.
:stupid: x2.

If I were doing a top-notch rebuild I'd balance everything anyway, especially if I were using non-stock rods/pistons/fasteners.

My machine shop guy said that he's checked OEM VAG rods/pistons (on an 8-valve) and they are usually within 2-5 grams of one another, he said most OEM domestic engines aren't even close to that.

Brendan
 

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balancing an assembly is cheap. 200 dollars is worth every penny to not have a smooth engine like my URQ's, or other balanced i5s I have been in. I would do it to any motor that plans to rev past 7500, or has a bigger turbo that needs to rev
 

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It has been a while but I do know for a fact that the inline 5cyl is externally balanced. Now what this means is there was not enough material on the crank to successfully balance and addition weight had to be added out side of the crankcase. (flywheel and balancer)
I don't remember exactly how much but it is between 20 and 35 grams.

Also when balancing the inline 5cyl the formula for finding the correct bobweight and that is using 50 percent of the reciprocating weight.

Which means taking 100 percent of the rotating weight (big end of con rod and bearing) and 50 percent of the reciprocating weight (small end of con rod, piston, pin, rings, and locks) and placing this calculated weight on the each rod journal of the crank and spinning the assembly.

This is necessary as the pistons are at different positions as the engine is running. This is why it is ideal to have the rotating assembly balanced when changing rods or pistons on a 5cyl.

On inline 4 cyl there is no need for a bob weight because as one piston and rod assembly is coming down the other is going up which in theory cancels the out the weight. Not so on the 5cyl.

Most american v8 are usually lucky to be within 25 grams of imbalance. So you probably could just slap on a zero balance flywheel and balancer and may not feel the difference. But your rod and main bearings will thank you in the long run.

As far as balancing the clutch assembly I prefer to balance as complete assembly, balancer, flywheel, and pressure plate. I just think the balance comes out better. I will always zero the rotating assembly then bolt on and balance the pressure plate. That way if it needs to be swapped out at a later time it won't affect the overall balance as much. I have once found a brand new Centerforce pressure plate to be out of balance by 50 grams and this was for a late model corvette. After coming across this I will not balance a rotating assembly with out the pressure plate.
 

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In my other car life I had a 1970 SAAB 96V4 that I put together a stroker 1.7L with 10.3-1 pistons, cam, solid light lifters,etc, etc.

I had it balance and it rev'd to 8500rpms in a blink. Was/is awesome. Man that engine would rev. I still have it incase I ever need it again. :woowoo:

The flywheel and pressure plate were matched to the crank and everything balanced and upon assembly the marks had to line up. I asked the machinest/ owner what happens should I need a new flywheel or pressure plate. He said not a problem. He would balance the new stuff to the original ones spec's.
 

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Probably old topic, but I read a lot of posts and forums about balancing and I am completely lost. I have prepared diesel block + crank with some aftermarket rod and pistons. Question is, is better to balancing that internally, externally? or rather nothing , just match each piston/rod ?
This question is killing me. I will be using 7A flywheel and 7A damper.
I am like put engine together, but i cannot decide which way is the right way, but i want to have my engine built :D
 
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