Another balancer/pulley question...searched still confused.

[nicpaige]

Okay I have been reading the awesome posts on this forum and have read many times about the spacer and long and short nose cranks and serpentine belt pulleys. I am still confused. If the 258 has a long snout crank (longer by 10cm) why would you want a spacer for the crank pulley when it is already too long? It seems like you would need to space all the other pulleys out or machine the crank nose shorter?
Also I am using a 258 four weight crank, do I use the 4.0 balancer or will I need a 4.2 balancer? Thanks for replies.

[akadeutsch]

You will need the 4.0 pulley

[jsawduste]

The pulley sets down the nose of the crankshaft so that the machined pulley surface is in contact with the seal in the timing cover.

The spacer goes in FRONT of the pulley so that when you tighten the crank bolt down the spacer contacts the bolt (technically the washer) and the pulley. Thereby seating the pulley and providing tension to the crank bolt.

Your thinking the spacer goes on first and then the pulley, nope other way around.

[jeepxj3]

That's always confusing. Crank--pulley--spacer--bolt

[nicpaige]

Ahhhh that makes more sense! Thanks. So which balancer the 4.0 or 4.2 or does it matter?

[SilverXJ]

Use the 4.0L balancer. 4.2L won't line up right.

[amceaglesx4]

Why would you use a crank pulley from a 4.0 if its a 258 crank ? That harmonic balancer is balanced for that specific crank. If its a serpentine one and youre running a serpentine setup use the 258. Not all 4.0 harmonic ballancers are the same. They look it but they are not. I have a 96 and 99 xj and the balancers look the same BUT... There is more metal drilled out of my 96 than myy 99.

[amceaglesx4]

I know my XJ's and have had 6. Strokers I don't know shit and get more lost everyday when I start reading.

[SilverXJ]

Not all 4.0 harmonic ballancers are the same. They look it but they are not. I have a 96 and 99 xj and the balancers look the same BUT... There is more metal drilled out of my 96 than myy 99.

Your wrong.The 4.0L balancers are all the same. What you are seeing drilled out is just for the neutral balancing of the balancer. There is no difference in their functions nor practical dimensions.

If its a serpentine one and youre running a serpentine setup use the 258.

Good luck with that.

[amceaglesx4]

Oh okay I was thinking the different size holes drilled in the harmonic was to be balanced for the crank but its for the harmonic to be balanced.

[SilverXJ]

The 4.0L, 258 and strokers are internally balanced engines.