Internal or external
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
You might as well ask what's the best brand of oil. Lot's of opinions and some valid arguments on each side.
IMHO, as long as it's done correctly balance is balance. Internal uses a neutral balance flywheel/flexplate and front balancer which makes for easier swaps later. External balance those two parts are balanced with the rest of the parts. Or should be. Some stroker motors are external balanced because of the cost to do the internal. GM did the external on the 400 and the 454 because of the cost.
IMHO, as long as it's done correctly balance is balance. Internal uses a neutral balance flywheel/flexplate and front balancer which makes for easier swaps later. External balance those two parts are balanced with the rest of the parts. Or should be. Some stroker motors are external balanced because of the cost to do the internal. GM did the external on the 400 and the 454 because of the cost.
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Given a choice, go with internally balanced crank.
With externally ballanced cranks, your engine builder needs to balance the fly, harmonic, and crank as a set.
With an internally balanced crank the fly and harmonic are "neutrally" balanced.
Being neutrally balanced, there are many more options for harmonic balancers and flywheels (or flexplates).
With externally ballanced cranks, your engine builder needs to balance the fly, harmonic, and crank as a set.
With an internally balanced crank the fly and harmonic are "neutrally" balanced.
Being neutrally balanced, there are many more options for harmonic balancers and flywheels (or flexplates).
Instructor
Joined: Apr 2007
Posts: 177
Likes: 0
From: Collierville TN
As said by the previous poster, the best reason for internal balance is that if you ever have to change out harmonic damper, flywheel, etc, is that all you have to do is by one that is neutral balance and bolt it on.
Melting Slicks
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
But is int correct that all the flywheels/flexplates and balancers used in the externally balanced engines have the exact same 34.5 oz counter weights? .. Do the machinest have to drill holes in them to alter the amount of counter balanced weights?
