I messed up balancing a crank, what can I do?

[francisjohn]

I'm embarrassed to even post photos. x3 holes on each side, the photo that only has one hole isn't accurate as the additional holes were drilled.

I botched my center holes. I botched the first center hole and was suggested by Ryan (RDM) to intentionally offset the center hole on the other crank halve to "even it out"

I went too far in the offset (photo 2) and now my center holes are both off center (other holes are fine)

The second photo is off by 2mm

Potential Options

1) "send it" and see what happens? or if it's beyond repair.
2) Due to the diameter and depth of each hole being the same, I'm wondering if filling it with JB weld would help? Even though JB weld has a different weight than the mass removed, I'm curious if filling the holes would dampen the expected adverse affects?

 

[GW's Motorized]

I don't know much about balancing cranks, but I think your best bet is ordering a new crank

 

[Wrench]

Sometime ya gotta pay for your education, that Crank was for learning what not to do,

 

[francisjohn]

I don't know much about balancing cranks, but I think your best bet is ordering a new crank

While that would be an easy solution, I don't care so much about peak preformance. If it will run that's all I care about at this point.

Sometime ya gotta pay for your education, that Crank was for learning what not to do,

Very true.

 

[Al Regresar]

I'm embarrassed to even post photos. x3 holes on each side, the photo that only has one hole isn't accurate as the additional holes were drilled.

I botched my center holes. I botched the first center hole and was suggested by Ryan (RDM) to intentionally offset the center hole on the other crank halve to "even it out"

I went too far in the offset (photo 2) and now my center holes are both off center (other holes are fine)

The second photo is off by 2mm

Potential Options

1) "send it" and see what happens? or if it's beyond repair.
2) Due to the diameter and depth of each hole being the same, I'm wondering if filling it with JB weld would help? Even though JB weld has a different weight than the mass removed, I'm curious if filling the holes would dampen the expected adverse affects?

‘Send it!’ Hilarious though potentially destructive. That is what they say at the House of Drift (Irwindale) as both cars leave the starting line: SEeeeeeeeennnd
It!!”

 

[Nickt919]

This is not rocket science.
The off center holes are ok.
As long as the very center hole is somewhat deeper than the outer holes I would run it.

If the left and right holes aren’t equally spaced from center then do the other other side exactly the same but let the off center holes go the other way.
For example… if the holes are 3mm off to the right of center then do the other side 3mm off to the left.

Remember to do the hanging weight and try get somewhere around 45% balance factor.

I have purposely drilled holes off center and more holes. I made them progressively shallow as they went out from center.
I did these to try to find better total balancing.
Usually a balanced crank will still have some vibes at certain rpms.
I have found no configuration any better than the way member StreetRyderz instructs in his video.
I would imagine he too drilled up quite a few cranks looking for the perfect balance.
I would run that crank as long as the opposite side matches AND you’re within the BF weight of your piston n parts.

Follow this video for

One of the greatest things about this hobby is parts are very cheap compared to other hobbies.
A new crank shipped is $30 from CDHPower. So if your crank doesn’t work out you can look at it as a $30 learning lesson.

 

[Nickt919]

Precise and accurate work is obviously best… But…

You’d be surprised at what will still run and run well.

I post this pic below in a thread yesterday. A rod bearing cage came apart and went thru the engine. The piston kit was very new so I cleaned everything up and I’m still running it today. I just changed the piston ring and ran the new ring for the first time yesterday. It still runs like a champ.

The piston top and head were the only things damaged when bearing failed though…
Had either the piston skirts or cylinder gotten scarred I would not have run it again.
The cylinder and piston skirts were fine.

 

[robe]

Thanks for that. Certainly takes the mystery out of the magic.

 

[darwin]

This thread reminds me of why I like Hondas.

 

[Al Regresar]

This thread reminds me of why I like Hondas.

Oh yeah!