how to balance an engine?
 

like the topic says: how is an engine balanced?

i'm building an engine with new rotors and a new lightweight flywheel and i want to balance i but i can't find any info on how doing that

what year are the rotors? If they are 86-88, then the front and rear counterweight needs to be for those years.

Also, the rotors have a letter (A-E) stamped on them. The rotors you use should be within 2 letter codes of each other. So If you have a rotor with A stamped on it, the other one should be A, B or C.

all the internals are from 13B-REW engines but the rotors and the counterweights are from different 13B-REW engines.

Basic and necessary engine balancing is matching the rotors, flywheel, and counterweight. The goal is to make the rotating mass as balanced as possible. Your parts should match up as Project84 said.

There is a more advanced balancing. It does the same thing except to a greater degree. In a boinger it involves making all the pistons and rods the same weight (usually +/- 1 gram). This helps to keep things from vibrating and offers less parasitic drag and allows the engine to rev higher. I'm sure there is a rotary shop that can balance your engine to such precision, but I doubt its neccessary.

The stock flywheels have the counterweight cast into it. After market flywheels have counterweights that are detachable. You have to specify what year you want so it matches the rest of the engine parts. The type or size of the after market flywheel doesn't matter.

all parts of 13B-REW and from 1993 engine:
1 set of perfect rotors
1 shaft
1 stock flywheel

everything is used but reusable. yes i can bring the stuff away to a shop but i want to know how balancing takes place

and yes i used the search button plenty but found nothing :)

if you're going to have the rotating assembly balanced, then all you need to do is have the front counterweight, rotors, eccentric shaft and flywheel. the codes and original specs don't much matter anymore because as long as you're gettig done by someone who knows what they're doing, then they'll be able to remove weight from whatever and wherever they need to ...

balancing is (very simplistic explanation) just taking your parts and making sure all the weights counteract each other front counterweight-to-flywheel and rotor-to-rotor. you keep rotating the parts and grinding until the weights match and the harmonics are canceled. it's not as easy as it sounds, but ... :)