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Discussion Starter #1 (Edited)
how many of you guys are running Eagle "internal balance" cranks. According to their newest ads, all their cranks are internally balanced. REALLY! Always wondered how Eagle managed to internal a 6.135 rod crank when NO ONE ELSE can do it. Including GM. Every internal balance crank I have ever seen except Eagles, requires a 6.385 rod to clear the larger counter weight needed. Well now I know. It's unbelieveable that any crank company would call this "INTERNAL BALANCE". That pork chop on the flywheel flange is on damn near the same plain as the flywheel/flex plate. Hell, it is on the same plain! and it is almost as big as the last inside counter weight. I wouldn't buy into that thing on a 4.5" crank, let alone a 4.00" How can this be better than a weight on the flywheel? Internal balance to me is between the front and rear mains. See the crank in the 3rd pic? that's internal balance.



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marina manor trash
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$$

got a new one & we had it checked,cost us more money for the Mallory to balance it then it cost for the crank-thats now a door stop
 

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Village Idiot
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O.K. I am not jumping in to start anything, but just throwing it our there as general info. We ran a Cola crank (yes American made) that had a rear flange just like that. We ran it for eight years in two of our funnycars without any problems. During one season we put over three hundred passes on the engine. Anyway, take the info for what it is worth. After the success of that crank we have used three more Cola cranks since. I would stand them next to a Lunati or Callies any day for durability.

Now as for the eagles, I have built a few engines with them, but could not tell you any details being that I have not inspected them yet.

Paul
 

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Premium Member
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Discussion Starter #6
O.K. I am not jumping in to start anything, but just throwing it our there as general info. We ran a Cola crank (yes American made) that had a rear flange just like that. We ran it for eight years in two of our funnycars without any problems. During one season we put over three hundred passes on the engine. Anyway, take the info for what it is worth. After the success of that crank we have used three more Cola cranks since. I would stand them next to a Lunati or Callies any day for durability.

Now as for the eagles, I have built a few engines with them, but could not tell you any details being that I have not inspected them yet.

Paul
not really trash talking Eagle cranks here, (although I do not or will not run them)or that any crank shouldn't or doesn't need a rear counter weight. Or that it is such terrible thing. 327 and 350 chevies have a rear counter weight. BUT THEY ARE NOT INTERNALLY BALANCED if they do. They are neutral balanced. Just saying that there is no real difference between the weight on the rear of the crank or being on the flywheel, it the same plain. So if you have problem with the weight on the rear of the crank then you should have no problem with a counter weighted flywheel. And it takes a whole lot less weight to accomplish.



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mo balls than $cents$
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my 4.25 stroke/6.385 eagle set-up is internal balanced, self racing in durant okla did the work and he said it balanced out very nicely, no heavy metal added, just material taken outta it. i've zinged it to 7800 many a time without issue, i run a 427 neutral balancer and 350 flywheel.
 

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Just another Wannabe
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The advantage as I see it is people have less to screw up by the possibility of puting the wrong balancer and flexplate on it. Just 'internally balanced' stuff.
Seen this too many times where someone puts on the wrong balance package on their balancer or flexplate and now know why the thing shakes so bad.
 

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Discussion Starter #10 (Edited)
The advantage as I see it is people have less to screw up by the possibility of puting the wrong balancer and flexplate on it. Just 'internally balanced' stuff.
Seen this too many times where someone puts on the wrong balance package on their balancer or flexplate and now know why the thing shakes so bad.
people who are that stupid can just as easy put a counter weight flywheel on a nuetral balance crank. It kinda goes both ways when you are that stupid. Not saying a rear counter weight is good or bad, but I am willing to bet that those that really trash talk external, really have external. SEE IMPATIENTS POST ABOVE



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Discussion Starter #11
my 4.25 stroke/6.385 eagle set-up is internal balanced, self racing in durant okla did the work and he said it balanced out very nicely, no heavy metal added, just material taken outta it. i've zinged it to 7800 many a time without issue, i run a 427 neutral balancer and 350 flywheel.
sorry, but I have seen those cranks, they are not "internal" check it the next time you have you flywheel off.



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mo balls than $cents$
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sorry, but I have seen those cranks, they are not "internal" check it the next time you have you flywheel off.
are you talking about the counterweight flange on the back that the flwyheel bolts too? kinda confused, i understand the difference between internal and neutral, but its always been my understanding that if the rotating assembly is neutral balanced without the help of externals weight(flywheel/dampner), that's internal balanced. my machinist is no fool and told me to run a hub if i wanted, and i told him i was gonna rev limit at 7500.
 

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Sit N' Spin
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Honestly, who really gives a shit if neutral balance is achieved with either a counterweight on the crank externally or if the counterweights are on the flywheel/balancer combo? If you spin check the crank and it checks out as a neutral balanced crank, run an internal balance flywheel/balancer combo and call it good. Who gives a shit what they refer to it as?
 

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Cantard
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I know some big name engine builders do not like these cranks and I also say that they are thinking if its half the price it must be half as good but I can tell you I have seen some crazy #,s put down with these and more and more guys are running them. I have yet to see a broken eagle rod. I have seen a set of melted ones and I do mean MELTED but never broken.
 

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mo balls than $cents$
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I know some big name engine builders do not like these cranks and I also say that they are thinking if its half the price it must be half as good but I can tell you I have seen some crazy #,s put down with these and more and more guys are running them. I have yet to see a broken eagle rod. I have seen a set of melted ones and I do mean MELTED but never broken.
13.5 to 1 505 and i spray anywhere from 125-400hp of nitrous , been runnin it hard all summer:)devil never broke, never towed, always turnkey;)
 

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Honestly, who really gives a shit if neutral balance is achieved with either a counterweight on the crank externally or if the counterweights are on the flywheel/balancer combo? If you spin check the crank and it checks out as a neutral balanced crank, run an internal balance flywheel/balancer combo and call it good. Who gives a shit what they refer to it as?
I would like to throw my .02c into the ring here, the origional idea on an internally balanced crankshaft is to keep th balance throughout the entire length of the rotating assy. An internally balanced crank can be up to four plane dynamically balanced (limited by the number of support bearings), this would allow the crank to spin at rediculous RPM without any ill-effects of dynamics and harmonics (we're talking 10's of thousand RPM). An externally balanced crankshaft on the other hand (with counterweights on the harmonic balancer and the flywheel) have a rediculous amount of harmonics and dynamics which have parasitic effects as far as vibration, fatigue and horsepower.

I think what is being said here is that the term "internally balanced" is used very loosely and IMO is completely false. Even most OEM internally balanced are not completely internal as we are learning here, they are counterweighted on the outside of the main bearings which I would totally consider to be external.

If you have ever had a rotating assembly balanced while building an engine (have not built an engine yet without balancing) you would quickly discover how far off they can be and still run fairly smooth, however once balanced are like night and day, even still if it were a true balanced crank the difference would blow your mind (think Formula 1) an outboard is an OK example, they can run up pretty high and get smoother the faster they run (until a rod hits you in the head).

I built a 350 Chevy and had it balanced, while running at 1500 RPM you could stand a nickel on its edge on the air cleaner, but as soon as it sped or slowed would fall over, that is the harmonics taking over.

I understand what GN7 is saying and as an engine builder would love to see a four plane balanced big block shaft, but would be difficult (maybe build a 180* motor).

Just my opinion, but a true internally balanced setup would be the shizzle.;)

GT :)hand
 

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balance

Honestly, who really gives a shit if neutral balance is achieved with either a counterweight on the crank externally or if the counterweights are on the flywheel/balancer combo? If you spin check the crank and it checks out as a neutral balanced crank, run an internal balance flywheel/balancer combo and call it good. Who gives a shit what they refer to it as?
I would like to throw my .02c into the ring here, the origional idea on an internally balanced crankshaft is to keep th balance throughout the entire length of the rotating assy. An internally balanced crank can be up to four plane dynamically balanced (limited by the number of support bearings), this would allow the crank to spin at rediculous RPM without any ill-effects of dynamics and harmonics (we're talking 10's of thousand RPM). An externally balanced crankshaft on the other hand (with counterweights on the harmonic balancer and the flywheel) have a rediculous amount of harmonics and dynamics which have parasitic effects as far as vibration, fatigue and horsepower.

I think what is being said here is that the term "internally balanced" is used very loosely and IMO is completely false. Even most OEM internally balanced are not completely internal as we are learning here, they are counterweighted on the outside of the main bearings which I would totally consider to be external.

If you have ever had a rotating assembly balanced while building an engine (have not built an engine yet without balancing) you would quickly discover how far off they can be and still run fairly smooth, however once balanced are like night and day, even still if it were a true balanced crank the difference would blow your mind (think Formula 1) an outboard is an OK example, they can run up pretty high and get smoother the faster they run (until a rod hits you in the head).

I built a 350 Chevy and had it balanced, while running at 1500 RPM you could stand a nickel on its edge on the air cleaner, but as soon as it sped or slowed would fall over, that is the harmonics taking over.

I understand what GN7 is saying and as an engine builder would love to see a four plane balanced big block shaft, but would be difficult (maybe build a 180* motor).

Just my opinion, but a true internally balanced setup would be the shizzle.;)

GT :)hand
 

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What makes the difference if the counter weight is ahead of the rear main or behind?

I knew someone would ask that.............

If the "out of balance" per-say is outside of the mains, there is no "opposite end" support.

Seems stupid but its all I have to compare to, have you ever fired off a drill motor with a bulkhead bit (like a 24" long drill bit) on it? It will literally shake the drill out of your hand without support.

I know, stupid example but took some Benadril a while ago (this wind is killing me with allergies) so I'm a little punchy:)sphss

GT :)hand
 

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I forgot something, I have heard it called the "jumprope theory" and the "whip theory" if that makes sense..


GT :)hand
 
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