HOW TO Balance Your Rotating Assembly on A Budget Save Money Do it Your…
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- Опубліковано 26 сер 2024
- Balance your Rotating assembly before building the engine! This video will show you how! Note this does not including crankshaft balancing, which is high recommended. This will however help primary balance & harmonics over slapping it together.
![How To Balance Your Pistons And Connecting Rods [#TECHTALK]](http://i.ytimg.com/vi/1Bqa3v5AfoA/mqdefault.jpg)
![How To Balance Your Pistons And Connecting Rods [#TECHTALK]](/img/tr.png)
Fantastic home/garage how to balace video. With patience, calulator, paper-pencil-sharpee and a high-end scale a person could acheive .5 grams of balace like you shown, and i thank you sir.
Weight matching helps but in reality, you can have perfectly matched piston/rod pairs that are still quite off from each other if you don't balance and equalize all of the rods on the small and big ends with the proper jig first. Ring packs, bearings and wrist pin clips/keepers should be weighed and computed into every assembly as well if this is a high rpm build. Check everything!
I am not a pro at balancing but what you did does make sense with getting the pistons and rods weighting all the same so when they go up & down on the crank at high speed it does not create any type of vibration or off balance, but someone did mention having the flywheel and harmonic balancer balanced with the crank should also be done, yes or no? Also: after installing the piston rings, will that offset the balance or will the rings not make much difference? Great video...
Wrist pin or the proper term is gudgeon pin.
Must agree with peggy. You weigh each part individually and then match the heaviest pin with the lightest piston to see if that gets the balance in spec. Then the rings and pin retainers which should be very close. The con rods are weighed big end and small end with the other end supported. Then remove by grinding a bit off the big end balance pad to reduce the weight down to the lowest weight. Then do the same for the small ends. The final rod weights should be very close; big ends, pin ends and total weight. The small and big end weights need to be known for the bobweight calculation with the piston, pin, rings and retainer weghts added to the pin end weights.
Thank you sir for helping me understand this
Did you balance the crankshaft to the new pistons and rods? From my understanding the factory or aftermarket crankshaft has to be balanced together with the new pistons and rods, rings etc. as a rotating assembly. Its nice if you have the flywheel and the clutch and the harmonic balancer or crank pulley as well. Just making all the pistons and rods weight the same is not balancing the engine. If you notice on a crankshaft after it has been balanced there is holes drilled in the lobes. Thats because those lobes are balanced with the pistons and rods of that cylinder. Just my $.02. A new crank might be neutrality balanced but not when you add weight to it ai. pistons, rods, etc.
That would be correct for an externally balanced crank. Some if not most inline cranks are internally balanced independent of the rotating assembly; and the flywheels/pulleys are neutrally balanced. As long as the pistons and rods aren’t extremely different in weight as opposed to the stock weight, and the compression of the engine is the same, balancing an internally balanced crank won’t be necessary. After all, the crank is really battling against compression and combustion, not so much the pistons and rods. The pistons and rods already counter balance themselves as one goes up and one goes down. Or like with my inline six, two go up and two come down.
Confusions say if weight added is equal balance remains...
take the caps off the rods and balance all to lightest one, then do the rods the same, then do the pistons. forget that math as its faster to just grind the tops of the little end balance pad and the bottoms of the caps. Pistons are tricky, I just take the weight out of the pin end on a press fit pin as its heavier metal than the AL of the piston. you can even add weight to the inside of the piston pins with a zip of a MIG welder. Remember you got reciprocating (everything shown but the big end of the rod, ie caps) and rotating weight: caps, and counterweights. and then add 5 to 10g (small and big block) for oil to the reciprocating weight. Good luck.
Dude you look like Charles Leclerc. Cool video too.
That wasn't actually balancing but matching or blueprinting to get more or less equal total weight.
The rotating weight (big end + portion of rod) needs to be close to equal to balance rotating assembly which is why manufacturer had the weights on chart
Personally, I would be modifying the pins to get things right as it's very easy and simple to grind internal taper on each end at around 10 or 15 degrees which won't have any effect on strength, plus, as pointed out in a different comment, steel is much heavier than the alloy forgings (don't even need any real special equipment, a Dremel and small stone will do it but may take a while because Dremel is such low power compared to a die grinder or lathe and toolpost grinder
Camara quality on point
Junkyard LS, widen ring gaps, look at rod bearings, add turbo and burn E85.
You know nothing about how a motor assembly is balanced ! You weigh the big end first ,by hanging it on the scale with a floating pin in the pin hole! Then grind them all to match the lightest one, Then weigh the rod and grind the pin end to match the lightest rod, add all components weigh and that weight needs to be added to the crank and spun on a balance machine with a computer to tell you how much weight to add or drill out and at what area !!
On any V application or 4 banger I completely agree. I6s this is a decent DIY method with the crank being neutrally balanced.
@@Pete_Tech_ That said, it would be wise to include somewhere in the title or description that this mostly applies only to inline sixes. While I appreciate the effort, the info in this video is misleading to anyone NOT building an I6.
Yup. You got it.
Piston and rod has to be half the weight of the counterweight on the crankshaft in order for it to actually be balanced
Good job weight matching the the components, but that's not balancing your rotating assembly. You take the weight of the components, simulate it with bob weights on the crank journal and balance the crank.. what you did means nothing without the crank being balanced..
Does the weight of each piston need to be balsnced to each then each rod or can the piston and rod assembly be weighed as a unit....just wondering you have one piston and rod weighs xyz then the next one weighs the same but the most weight in piston 1 is in the rod but more of the weight on piston 2 is in the piston ie the other way round.
Oookayyy, Mmmkayyy
You're weighing the pistons without the rings?
Yes, the biggest deviation I’ve ever seen in rings is 0.25grams. Basically irrelevant.
What rods and pistons were your crank balanced to?
On a straight 6 that is not necessary as the pistons and rods can balance each other out perfectly.
Balancing your reciprocating assembly
Did you balance crank
Thanks
Anytime!
What's the matching process if the pins weigh different?
that just gives you three ways to reach an equal total weight of piston, pin and connecting rod.
Good video man.
That is semi balanced...
Ok I catch the whole idea your talking. What about the crank being balanced with a different overall weight due to the factory crank being balanced with factory rods and pistons rings etc… so basically you have to match the weight of the original pistons rods, rings, pins and bearings as a whole to the new set your installing.!?
Thats not "Balancing the rotating assembly" all you are doing is static balancing the rods and pistons. If you send the assembly to a machine shop to be balanced they would start of with the cranking on a rotating machine that spins it up to 400 rpm they would then balance the small end firts then the side with the clutch then add the clutch ect ect. If it came back being to grams out then you are going to the wrong machine shop. That is the only way to balance a rotating assembly
You don’t weigh rods by laying them on a scale
Elaborate pls
@@christopherparis6841they have a jig that holds them. They have some cool videos on UA-cam of that.
People weigh the big end and small end separately usually
Thanks!
You bet!
theres zero way this will work .. what bobweight was used to balance the crankshaft.. after the pistons rods pins bearings clips, rings plus a bit of oil weight are weighed and made to be as close as possible to each other .. only then is that bobweight number used to balance the crankshaft at rpm to the weight of those parts.. this is an absolute no go, if you have the bobweight number from the crank, its still wont matter, theres zero possible chance you can get this right because you cant take into account rotational masses and harmonics goin on her.. my balancer does not consider it balance until its less than .25 grams that being said, .25 gram on a modern balancer is easy. what you should mention is that because this an inline 6... if you have a zero balance crank.. you can get away with this but for how long and how much rpm and power.... because its a inline 6.... but I would not go this route when spending this much time and money and effort on a rebuild . the stuff your saying is true but this is very bad advice. balancing is not that expensive. compared to what your spending on everything else anyway.
Your comment wins. Right on par. So crankshaft was balanced separately at a MS and yes this method only works for I6’s with good secondary balance from the factory. But you can’t argue with being multiple grams out on Cyl 1 vs Cyl 6. This definitely helps. Engine is currently at 826whp and running strong. Mostly due to proper ring gap 😂
Crazy these parts dont come balanced from factory, it's not that hard especially with todays automation.
This is called static balancing and is only the beginning of a proper balancing job. Unless you spend north of $10k on a pro forged crank that has been balanced itself, its the crank that needs the most work to achieve a dynamic balance. Some cranks even omit balancing throws on the mains. These should be avoided. You get what you pay for.
Yup.
Another GENERAL IDEA of how things are done but definitely not a balancing job. He said perfection, this is NOT perfection.
This is a COMPLETE nonsense and pretty clear the author is clueless as to the theory of crank balancing.
What you did is not balancing. Unless you do an actual spin Balance you are doing nothing. All you are ding is prepping for a real balance.
Nice finger nails
you dont have a clue.
thats not balancing and engine, what your doing will mean nothing to the engine sorry bud but your talking rubbish