I need help in the selection of pulleys for my BB swap (with power steering and a/c). Could you go over the following:

1. LS4 or LS5? What year?
2. How many grooves on pulley bolted to the harmonic balancer?
3. How many grooves on pulley bolted to the water pump?
4. How many grooves on pulley bolted to alternator??
5. Explain belt routing..... With power steering AND a/c.........

These damn catalogs are confusing in their descriptions, so I figured I would get it straight from the experts here!

I appreciate the help. Pics would help as well.....

Bob :cheers:

 

This is all from memory as my car is in the shop...

71 LS5...

Crank: 2 grooves
w-pump: 3 grooves.
PS pump: 2 grooves
Alternator: 1 groove.
AC: 1 groove.

Belts:

1. short belt between crank and w-pump. Innermost groove.
2. Crank->w-pump->ps-pump. outer on crank, middle on w-pump, inner on PS-pump.
3. PS-pump->alternator
4. w-pump->AC.

 

OK I guess I'll start

1. 73 LS-4
2. 2
3. 3
4. 1
5. back harmonic balncer to water pump,front harmonic balancer to P/S back, front P/S to Alternator, the other two belts on water pump were for smog pump "middle if I remember" and outer for A/C.
6. P/S pump has two


:cheers:
Pat Kunz

 

Bob,

Anything for a fellow 1974 big block enthusiast - even if it's not originally a Z car!

I actually had to go and check mine out. It's consistent with the AIM for my 1974 LS4.

Crank pulley - 2 grooves
Water Pump pulley - 3 grooves
Alternator pulley - 1 groove
Power Steering pulley - 2 grooves
AC compressor pulley - 1 groove
Smog pump pulley - 1 groove

And it's all groovy!

I'll describe the belt arrangement in layers moving in the vertical plane forward from the engine.

Layer 1 - a belt goes from the crank to the water pump and around the idler pulley. My car doesn't have this belt, and I believe that this belt's purpose was simply as a backup to keep the water pump running in the event of a belt failure. It could also be that the idler pulley has failed somehow - don't know why it's missing.

Layer 2 - a belt goes from the crank to the water pump to the power steering pump

Layer 3 - a belt goes from the power steering pump to the alternator

Layer 3 - another belt goes from the water pump to the smog pump to the AC compressor pulley

Let me know if you need a picture of the AIM diagram - I don't know that a picture of my belt arrangement would look very good.

And good luck with your big block swap - you'll love the torque and the rumble of the big engine. I'm pretty sure it's what God intended.

 

I concur with 73 LS4. My AIM shows the pulley configuration pretty clearly. There is a tensioner idler pulley in there also but I do not have it.

 

Thanks, guys!! These bracket/pulley assemblies are expensive to buy brand new..... I want to get them right the first time!!

Thank you!

Bob :cheers: