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Excessive Engine Vibration or Normal?

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  #1  
Old 10-13-2024 | 02:34 PM
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Lando Evo
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Default Excessive Engine Vibration or Normal?

I rebuilt top end 99 FLSTC (Heritage) Evo 20k miles at rebuild.

honed cylinders
Wiseco 10:1 domed pistons, hastings rings
Cometic gaskets
MLS .030 head gaskets
V Thunder EVL 3020 Cam (.50 lift)
Adjustable pushrods
Cleaned heads, lapped valves, new seals
New cam bearing, spacer, breather gear and spacer, cam seal
New ultima single fire ignition and coil
CV40 carb jetted 48, 195, 3 turns
Used 10w40 conventional oil for first 50 miles then put in royal purple break in oil for next 500-1000 miles.

the problem is it vibrates so hard at high rpms my feet vibrate off the damn footboards. Even at high highway speeds in 5th gear.

This softail has solid motor mounts and I'm just wanting to confirm this can be expected from the new cam or not. I don't know what else it could be caused by.

I just got done double checking cam, crank, and breather gear alignment, it was good. Also checked adjustable pushrods 4 turns, 32 pitch

Do you have to make sure front cylinder is on compression stroke at TDC when you align the marks or just rotate it all until it's all lined up doesn't matter about when they line up? Cuz cam gear rotates slower than the others.
 

Last edited by Lando Evo; 10-13-2024 at 03:25 PM.
  #2  
Old 10-13-2024 | 04:26 PM
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Depending on weight difference in pistons...May have negatively affected Balance Factor..
 
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  #3  
Old 10-13-2024 | 04:46 PM
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Wiseco pistons are substantially lighter and that changes the factory balance factor.

Last time I ciphered it - the stock bore Wisecos are 45 grams lighter than stock. That's 45 x 2 = 90 grams and doing the math it changes a balance factor of 60 to about 63.4 best I can remember.

Yeah, it gives them the shakes.
 
  #4  
Old 10-13-2024 | 05:29 PM
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Im interested, whats the cure?
 
  #5  
Old 10-13-2024 | 05:54 PM
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Split the cases, have it balanced. Finding someone near to do it correctly is the hardest part.

Simple fix, put OEM pistons back in it.
 
  #6  
Old 10-13-2024 | 08:54 PM
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I thought EVOs were rough balanced at 52-53% at the factory.
 
  #7  
Old Yesterday | 07:52 AM
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Originally Posted by Max Headflow
I thought EVOs were rough balanced at 52-53% at the factory.
Even so...Changing weight...changes Factor...sometimes Negatively...at some times in a Positive direction...depending on RPM operating Range!
 
  #8  
Old Yesterday | 08:55 AM
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Originally Posted by Racepres
Even so...Changing weight...changes Factor...sometimes Negatively...at some times in a Positive direction...depending on RPM operating Range!
But with a rigid mount motor, I remember that hot setup was to balance towards 60%. Going lighter pistons will bring the balance factor closer to 60%.

FWIW I wonder if pick up in vibes resulted from the motor having a higher compression ratio and it's making more power. Also since the combustion efficiency has increased, the motor needs less timing.
 
  #9  
Old Yesterday | 10:46 AM
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Originally Posted by Max Headflow
since the combustion efficiency has increased, the motor needs less timing.
Heard this alot... Did Not work that way when we were Racing.. But...we aint Racing...so...Carry on.
 
  #10  
Old Yesterday | 10:49 AM
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Originally Posted by Racepres
Heard this alot... Did Not work that way when we were Racing.. But...we aint Racing...so...Carry on.
Shovels or EVOs?
 
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