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yep, I can and probably will. Anybody have any idea of typical balance variations stock and machine shop wise?

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Most any machine shop will get it within a 1/2 gram

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thanks, where is the best place to trim weight on pistons. On the pin pad, or the pad under the dome, and is it possible to lose 5g off a piston?

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You may need all the points you stated, dont take it
from the flat on the bottom of the wrist pin take
it at a 45* angle from the side to the bottom of the
wrist pin. See how thick the under side of the dome/top
is, if you can take it from there

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yep, I can and probably will. Anybody have any idea of typical balance variations stock and machine shop wise?

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I have never weighed any of the stock rods or pistons before having them balanced, I have weighed rods and shot for + or - 3 grams in picking the rods and made sure that they where within + or -.003 on the center to center length before starting. Most of the good automotive balnancing shops will shoot for + or - 1/2 to one gram on the rods and pistons . You can take those pistons to a good machine shop and have the 5 grams removed and use them that way. Five grams is a lot of aluminum to remove from a piston, take that from me. I have done that and I will take all of the pistons I need rebalanced to a shop from now on

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yep, I can and probably will. Anybody have any idea of typical balance variations stock and machine shop wise?

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Most any machine shop will get it within a 1/2 gram

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yep, I can and probably will. Anybody have any idea of typical balance variations stock and machine shop wise?

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Most any machine shop will get it within a 1/2 gram

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MAKE SURE YOU ASK!!!

I bought a crank, pistons and rods with rings and bearings from Scat last summer. I asked them if I should have them balance it or have my own balance done.

They went on to tell me how great their expensive balancing machine was, how experienced they were, how they balanced crate motors for mopar and all these big named drag racers etc.

So i said GO AHEAD.

When I got my kit, the pistons (KB) were STILL wrapped in factory plastic. No attempt was made to make them all the same weight.

Same with the rods. No grinding on big or small ends to match them.

So I got curious and weighed them. They were off +/- 5 grams on the pistons alone. I was pissed and called scat. got into a big argument as they were telling me they did it right and that 5grams doesnt matter and what do i expect for $150. I said, I didnt sset the price- you did. I expected it to be done right.

I did a charge back on my credit card for the cost of the balance cause they would NOT refund my money.

I got it balanced at a local shop. I too am a big fan of balanced motors

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MAKE SURE YOU ASK!!!

I bought a crank, pistons and rods with rings and bearings from Scat last summer. ...
So I got curious and weighed them. They were off +/- 5 grams on the pistons alone.

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MAKE SURE YOU ASK!!!

I bought a crank, pistons and rods with rings and bearings from Scat last summer. I asked them if I should have them balance it or have my own balance done.

They went on to tell me how great their expensive balancing machine was, how experienced they were, how they balanced crate motors for mopar and all these big named drag racers etc.

So i said GO AHEAD.

When I got my kit, the pistons (KB) were STILL wrapped in factory plastic. No attempt was made to make them all the same weight.

Same with the rods. No grinding on big or small ends to match them.

So I got curious and weighed them. They were off +/- 5 grams on the pistons alone. I was pissed and called scat. got into a big argument as they were telling me they did it right and that 5grams doesnt matter and what do i expect for $150. I said, I didnt sset the price- you did. I expected it to be done right.

I did a charge back on my credit card for the cost of the balance cause they would NOT refund my money.

I got it balanced at a local shop. I too am a big fan of balanced motors

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Well as I said it a street strip motor in a 4000lb! charger w/ a neutral balance stock 11" flywheel (ya I know but I run a scatter can, cant afford flywheel yet) would be curious what you think about over under balancing as you were talking about. Also aprox ,just because you brought it up, what are some of the over under balances youve seen.

Just to reiterate, it was a machine shop neutral balanced.

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I've seen 15 grams over or under. For me it's more about them being the same cylinder to cylinder. I'd rather be 10 grams heavy on every piston than to have just one heavy. When you think about what's going on in there just the weight of oil that's being slung around, the drag from the rings, the load differences through the RPM range, and a host of other things including side loading, 5 grams isn't the end of the world.

When we do a balance job for a customer we get no more accurate than a half gram, but more importantly trying to keep all 8 the same. With aluminum rods you'll find some variance too, but I won't go cutting on an rod without a balance pad like a factory rod has to correct a gram or two, it's not worth it, and it'll do more harm than good. I like things to perfect as much as anyone in the world. We've done balance jobs that cost $1500 with mallory and time when you have heavy parts, so I understand your feelings, but I wouldn't worry myself over what you've described.

There are also lots of arguments about how much oil weight to account for where 5 grams would be on both sides of the fence.

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I think I know the answer but must ask.A friend bought a crank from a vender and that vender is claiming that he balanced the crank. How can a crank get balanced without the rods,pistons etc??

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it's done all the time. all you need is the weights from the other components. obviously, without those weights it's an exercise in futility at best.

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I think I know the answer but must ask.A friend bought a crank from a vender and that vender is claiming that he balanced the crank. How can a crank get balanced without the rods,pistons etc??

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it's done all the time. all you need is the weights from the other components. obviously, without those weights it's an exercise in futility at best.

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