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Discussion Starter #1
I have a Bryant that needs 120 grams mallory two front counterweights. Problem is there are mallory slugs side by side all the way across on the front tig welded. The shop says it's hard to drill the tig back out the bits like to walk.
The slugs currently are the 30 gram ones once installed. Is it possibile to add more malllory offset drilling or putting small pieces on the top side?
 

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Thats alot of wieght man. Maybe getting a strip of mallory and welding it to the counter wieght would be better. Or even just welding up the counter wieght.Or work inboard towards the center of the crank. Got any room to drill on the rod throws ?
 

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Discussion Starter #3
The rod throws already drilled from Bryant. Maybe i could weld mallory in the rod throws LOL. I don't get it because the rear only needs 36 grams but the front 120? Doesn't make sense crank was balanced before to a steel rod all we did was grind the front and rear counterweight only to clear a shorter steel rod. Didn't think it would take that much out of it. I can use aluminum rods that are 120 grams lighter (both) but just wondering about the mallory. I bet a strip of mallory is more than a crank LOL.
 

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The rod throws already drilled from Bryant. Maybe i could weld mallory in the rod throws LOL. I don't get it because the rear only needs 36 grams but the front 120? Doesn't make sense crank was balanced before to a steel rod all we did was grind the front and rear counterweight only to clear a shorter steel rod. Didn't think it would take that much out of it. I can use aluminum rods that are 120 grams lighter (both) but just wondering about the mallory. I bet a strip of mallory is more than a crank LOL.
Some BBF engines have a counter weight that slips on the crank snout between the timing gear and balancer.
 

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Discussion Starter #5
This one is actually on a SBF. I have an ATI blower hub with plenty of room between cover and balancer. I do have an old BBF sleeve you're talking about. I didn't think it was a good idea to externally balance a motor like this does it matter?
 

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This one is actually on a SBF. I have an ATI blower hub with plenty of room between cover and balancer. I do have an old BBF sleeve you're talking about. I didn't think it was a good idea to externally balance a motor like this does it matter?
Internal is the way to go. I don't know why you have such a huge weight difference front to rear. If it's full on mallory now, where are you going to put 120 grams more?
 

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Discussion Starter #7
Internal is the way to go. I don't know why you have such a huge weight difference front to rear. If it's full on mallory now, where are you going to put 120 grams more?
I don't know why the weight difference changed that much either. There is no more room thought i would ask what others have done being creative. I'm stuck with using aluminum rods. I can't get a 1200 series GRP rods with a 901 width why i wanted some steel rods in it. Kind of a messed up deal i might just order a new crank.
 

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Whats wrong with externally balancing it?? I know if you need to replace a balancer or flexplate it can suck other than that....
 

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Discussion Starter #9
My friend has a SBF with a 106 turbo externally balanced turns it 8200. I don't know anyone else doing it and never seen his motor apart.
 

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Its just a different location of the weight as far as I know, I would like to hear more on why internal balance is preferred besides being convenient.
 

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obviously, by the assorted answers, no one that has responded knows how to balance a crank.

your crank balance man should know what to do.

overall, it is still best to not add a hatchet weight to the snout or in/on the dampener itself....it makes the snout and front bearing twist/load uneven.

you have mentioned that the existing mallory is 30 grams each.
the location and diameter out near the edge of crank radius needs to be understood.
it may be possible to pop out the existing mallory/tungsten and then mount in a solid milling machine fixture and offset bore the existing hole to allow the larger diameter material...it aint going to happen with a common drill press!!!!
 

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most bryant cranks are made to the exact bobweight that is specified when the crank is ordered.
the have a in house computer program that can profile the counterweights along with the rod throws to make the crank real, real close to what your pistons/ rods / bearings / calculated bob weight should be.

obviously, the crank that you are wishing to alter... ............IS USED....
 

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IF THERE IS ROOM,

then oftentimes ( as CNC understands) ...
WE HAVE had the crank counterweight EDM burned to a specific undersize diameter to then be able to press in new larger diameter tungsten material.
but at approx 100 dollars a EDM hole, it will get expensive.
 

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Apparently you've not balanced an LS crank.

I have a brand new one here from Bryant with center counterweights, that has 16 pieces of mallory in it for an aluminum rod engine. Add that one up :(
 

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obviously, by the assorted answers, no one that has responded knows how to balance a crank.

your crank balance man should know what to do.

overall, it is still best to not add a hatchet weight to the snout or in/on the dampener itself....it makes the snout and front bearing twist/load uneven.

you have mentioned that the existing mallory is 30 grams each.
the location and diameter out near the edge of crank radius needs to be understood.
it may be possible to pop out the existing mallory/tungsten and then mount in a solid milling machine fixture and offset bore the existing hole to allow the larger diameter material...it aint going to happen with a common drill press!!!!
I have not balanced a crank myself, not everyone is a machinist. but I am going through the same deal now, machine shop says either punch out the existing mallory and machine a new hole in the next counter-weight for a new piece of mallory then reinstall the mallory in the outer counter-weight. Or do a external balance, and obviously machining and adding mallory is expensive. Not saying external is the best way to go by any means but do you really think a engine would hurt itself from being externally balanced?
 

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hanging weight off the end of crank / dampener is going to ALLWAYS stress the KEY...


you do understand that in order to put a hole into the second counterweight, the hole has to also be in the FRONT counterweight.
it is real difficult to put a hole in the second counterweight from the REAR, because most milling machines will not go that far down and clear the machine head.
this is why SOMETIMES the only mannor is to have the counterweight crank hole EDM "burned".

many will actually use the largest diameter weight in the furthest counterweight from the front, with slightly smaller diameter as you get closer to the frontmost...but then after the larger diameters are pressed in and confirmed as to balance,..then the front most can be made to a larger diameter slug.

also, the crank has to be looked at as like the face of a CLOCK.
there is a certain "hour" or "rotational degree" that the exact weight has to be placed in order to also correct the out of balance that the second rod throw encompases.

there is no need for me to explain more, since your crank balance man should know what to do...
and obviously, YOU YOURSELF aint no machinist!!!


or send the balance specKs / bob weight factors to BRYANT with the crank, and have them do it for you....

or send to ME...

but my place is only ten miles from BRYANT, so the shipping cost is the same.
 

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Discussion Starter #19
most bryant cranks are made to the exact bobweight that is specified when the crank is ordered.
the have a in house computer program that can profile the counterweights along with the rod throws to make the crank real, real close to what your pistons/ rods / bearings / calculated bob weight should be.

obviously, the crank that you are wishing to alter... ............IS USED....
Actually in my past Bryant can balance it axactly given the weights or desired BW. Bryant is great about it they only charge for the mallory itself and no labor to install Mallory like everyone else. This sarcastic phrase "IS USED" implies ???? Anytime rotating weights are changed either through pin size, larger bore, different rods, etc the crank has to be rebalanced. Do you just throw the crank away since it's USED? Don't worry i wouldn't buy a new crank and cut it just wanted to know how other people add bigger slugs.
 

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above reply.

the mannor is to OFFSET THE HOLE, then the WALL THICKNESS out towards the outer diameter of the counterweight will still be thick enough to hold the slug.

there is a calculation involved since you are removing tungsten/mallory, which has more weight than steel, and then making the hole larger...and then also the RADIAL DIAMETER of where the weight is pressed in is also "smaller radius" than where the original weight WAS.....

BBF,


sounds like you allready know that you should send the crank back to BRYANT and have them check and look at it.

ask for JOE SQUIRES.... he works there last I knew...
 
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