balancing internal parts

[hahaboy]

hi, i'm planning fully balancing and lightening the AE111 4age 20v's crankshaft, rods, pistons.
crankshaft i send to machine workshop, can i balancing n lightening rods n piston myself ? just make all of them weight wif dirrential 0.1g.

[Jason]

english please?

so you want to balence them yourself? or lighthen them then send them away for ballencing? In that case ive herd of people doing that.

[psychofox]

So there are many ways to lighten rods and pistons and cranks. But the trick is in the balance.

1. Static Balancing. Make all things the same, the same weight. So you make all the pistons within 0.1g and all the rods within 0.1g of each other. You also need to measure the front to back on the rods and check them for twist. There are only certain places you an lighten the rods (even less on AE111 rods). What about the crank? hwo do you statically balance it?

2. Dynamic Balancing. Bolt it all together, clearance it, then hook it up to a dynamic balancing machine that will tell you the rotational out of balance - kind of like a wheel balancer - except they go to the nearest 5 grams, whereas you want to go to the nearest 0.1g.

So in the real world, your engine builder had to close and hone the rods and linish the crank, which meant he had to put thicker bearings in, and he tunnel bored the block and the mains had to be linished and the crank was a bit of out of balance to start with. Boom, you are now waaay out of balance as your rods and pistons (and flywheel/clutch and main pulley) are all bolted together to be balanced. Yes inidvidual balancing helps, but it's better to balance the whole kit and caboodle.

So unless you have a dynamic balancing machine at home, you won't be able to get anywhere near a 0.1g, let alone a 1 or 10g dynamic balance on the rods/pistons/crank/flywheel/clutch/pulley. Leave it up to a professional engine builder, but be prepard to fork out lots of cash for him to do it.

[slide86]

yep you need to balance all the rotaing parts together and even send your bolts for clutch and all that too so they can be weighted and balanced togoether.

i had this done on my gze. i had the block tunnel bored and everything. took em a while but its all worth it

[lo_rolla]

When some one wants some thing balanced at work we machine all the engine parts and then send 'em out to a balancer.


All I'm gonna say is, pay some one to do it.

[hahaboy]

ya, i do static balancing on rods, pistons at home. other parts like crankshaft, pulley, n the flywheel i 'll send to machineery shop do the dynamic balancing.
but , issit really worth to do that, any benefits from fully balancing ?

[hahaboy]

i have planned lightening the crankshaft too,

[terryo]

let me clear up some mis-conceptions......
you do not fit the pistons etc to the crank to balance them as a lot. On certain crank designs dummy weights are added to simulate a rod
each part is balanced individually . there is no point statically balance anything that rotates, you must spin it, eg crank , flywheel, clutch and front balanacer/pulley
normal engine rebuilding processes rarely change balance to any significant amount, as they remove so little metal.
rods are static balanced both end-to-end and whole. the hard part of doing this at home is making a jig to hold them in EXACTLY the same way every time you sit one end on the scales. franctional errors in hanging the rod, will give errors of a few grammes, so you are wasting your time.
most sets of toyota rods are balanced to within about 4 grammes (prettly ordinary), however there are big variations in weights of the forgings between different engines of the same model. there is no sign on most 4AG rods (for example), they were ever end-for-end balanced, one end only.
most modern engines are reasonably well balanced so there is little to gain, however we still see some engines very poorly balanced. the worst Toyota parts are flywheels and clutches.
most of our perforamce engine rebuilds involve some level of balancing

[hahaboy]

ya, thanks your information. now i'm facing the balancing rods problems, because i can't balancing end-to-end. so, i just balancing the whole rods only. so will any effects to it ?

[terryo]

you really should balance them end for end. any good performace engine shop can do this, or send them to me