Engine Balancing?

[wardog]

Im rebuilding my 7mgte engine and with eagle rods and Probe pistons for a 500 rwhp DD . Is it Necessary to balance the assembly? I running into money issues, anybody done some good power with out balancing the rotating assembly? Any input is always appreciated

[zachm611]

if you are shooting for power then yes it is necessary and highly recommended.. i say sit on the build for a little bit to save up the money for the balancing.

[Tanya]

It's highly recommended in any situation where you're changing engine internals.

VERY much worth the money.

[Rennat]

my motors revs like it has a lightened flywheel, rev matches like a honda, and when your shifting in "racing" type situations it seems to fall right in the right rpm to match the next gear.

and BTW, i have eagle rods and probe pistons... i vote 100% necessary.
this is also on a stock flywheel too...

[91TurboDave]

Absolutely Necessary if you want your motor to last for more than the first pull....

[oldsking]

Any motor I have dealt with I had balanced and blue-printed! Def worth the investment for durability and performance.

[StiCk3]

with brand new parts out of the box it is 100% required to balance the internals unless you want your engine to rattle apart and suffer premature engine failure.

[suprarich]

Plenty of people have just installed the new forged parts without balancing and had it work fine. Our crank is some what balanced from the factory. The damper is balanced, and the flywheel/flexplate is balanced. So in theory, if you install a rod/piston combination across all 6 holes that are very close in gram weight, then you will be within a close percentage of being in a passable balance.

You match lighter pistons from the group, to heavy rods from the group, to try to make all 6 rod/piston combinations close to the same gram weight.

Now all that being said, you could get away with not machine balancing your rotating assembly, but why? It is not a high cost to spin balalance the entire assembly. For any higher HP car, I mandate that the entire rotating assembley be high speed spin balanced to under 1 gram accross 3 points of the crank.

To do a high speed spin balance, you need: The finished crank, the damper, the flywheel/flexplate, the flywheel bolts. Also, you will need the weight in grams of: each piston with the pin and rings, Each rod with its bearing installed. You could just give the piston and rod assembly to the machinist to gram scale, but if you don't want to mail all of that stuff, just gram scale it yourself.

[mk3ukr]

excellent article
http://www.eatonbalancing.com/blog/2007/11/
http://www.eatonbalancing.com/blog/2007/11/page/2/