360 Balance

[Aussie Challenger]

I have a LA 360 which is externally balanced, how hard is it to have it internally balanced, I am aware of how a crank is balanced, do they have to add/remove much metal? I am thinking of doing the internal balance if it is reasonably cost effective, I know I will need a neutral harmonic balancer and already have a neutral balance flywheel but also have the weight that can be added if I stick with the external balance. My pistons and rods will be lighter and that also effects the balance too. Thanks to any info from those that have done it.   

[Supercuda]

I haven't done it myself, but the crankshaft will have to have some heavy metal put into it on at least one counterweight (Mallory metal), and you need to take it to the best shop you can afford. Internally balancing the stock 360 crank is more difficult than doing so with an aftermarket forged unit. The ast crank is lighter, and already specifically designed for the external balance program. Some research should show up at least one forged crank that can be easily balanced internally. It can be done, but it isn't cheap. Depending upon your rpm and horsepower limits, you can get away with external balance on the 360, but there is a little loss of horsepower and smoothness.

[femtnmax]

It can be done, but it isn't cheap. Depending upon your rpm and horsepower limits, you can get away with external balance on the 360, but there is a little loss of horsepower and smoothness.

  Unless your building all out high rpm race engine I'm not sure it is worth it.  The money spent could buy all sorts of other performance parts.   The OEM cast crank 340's were externally balanced, similar to the 360's, neither had problems for street/strip use.

[72bluNblu]

I don't think I'd bother with spending that much on a cast stock crankshaft. They would need to add material, and mallory metal is far from inexpensive. Not to mention, I'd want a very reputable shop doing this work. If this isn't a high horsepower race engine, it'd be cheaper to get a new damper and flywheel.

Eagle also sells a brand new, 4.0" stroke internally balanced cast crankshaft for $273 at Summit. My bet is that turns out to be cheaper than modifying the old one.

[HP2]

Eagle also sells a brand new, 4.0" stroke internally balanced cast crankshaft for $273 at Summit. My bet is that turns out to be cheaper than modifying the old one.

This is a smoking deal. I recall spending around $400 having a 360 cast crank double shot peened, radius filleted on the journals, and internally balanced around 15 years ago.

[Aussie Challenger]

Thanks for the replies, I know how a crank is balanced I was trying to get some feed back from somebody who has done it, I know about Mallory Metal. That 4" crank might be a good price but then add the rest of the parts needed and shipping to Australia, the 4" cast cranks have a poor reputation. An extra 40 + CI certainly would give a bit more torque.