Does anyone know what the purpose of the balance shaft is

 

To counteract second-order vibrations from the crankshaft. Basically it makes it so the engine doesn't vibrate as much, primarily for comfort but arguably prolonging engine life as well.

 

ok thanks i got a engine out of another prelude and there was no balance shaft belt on it and i put one on and have crazy noise comeing from that area and the motor don't want to run right it keeps seting of the check engine light (not sure if thats the balance shaft) code 4 which is chrankshaft posion

 

assuming it ran with no cel before putting the balancer belt on... you may not have aligned the balancers correctly. i believe the balancer toward the front of the car has some markings on it that have to be lined up and the rear balancer must be lined up via a hole in the block (yes you must remove a bolt and poke a screw driver (or something) through the block and through a hole in the balancer shaft itself.)

however im not sure what code if any would come up due to misaligning the balancers.

 

ok so theres a balancer in the back also ? is that what the sensor reads off of

 

so wat happends if u dont aligned ? wat kind of noise does it make?

 

The check engine light shouldn't come up just because the balancer shafts misalignment. You would get more vibration. If you have H22A4 (97 and up) the crank sensor is mounted on the oil pump housing so check for it.

 

i have a 93 h23 so do you know where that sensor would be

 

That one will be in the distributor.

 

Question on the side:

What value does the balance shaft bring if you built the block using lighter pistons and rods?
All dynamics of the rotating assembly must have been changed.......!!!

Ive done the above and still have the balancer system intact.......Ive noticed a vibration at 2500 - 2700 rpm, then it goes away.......

sorry for the hijack

 

Yeah with lighter rotating assembly you have changed the amount of vibration that must be countered, I would say remove the belt and see what it does to your vibration.