68notray

I'm stumped - working to undo some of Bubba (the drag racer) handiwork on my 69 427/390 car with PS and AC. I have the original 3 groove water pump pulley, the original 2 groove crank pulley, and what appears to be the original 2 groove ps pulley. All are deep grooved too. I think I am missing the "add on ps pulley" for the crank. The rear crank groove belt goes only around the rear wp groove and has a side tensioner. The front crank groove belt goes around the wp middle groove and the rear ps groove. The alt is driven from the front ps groove. So I need another groove on the crank to drive the front wp groove and AC compressor.

so......why is the extra pulley I am missing off the crank called "add on ps pulley" if it doesnt drive the ps? Or do I have belt routing all wrong? I have seen different routings online.

ddawson

Review this.

Rescue Rogers

how was the #1 belt tensioned in the circled diagram

68notray

That is the diagram I found that confused me. So it looks like I have all the correct stuff already - the AC is not crank driven. Sweet!

530planeman

it's just tensioned buy having correct size and having to remove water pump pulley every time you changed it .later on they added a tensioner.A real p.I.a. to change that belt.
Merry Christmas
Wes

sullyman56

I think this is the tensioner (idler pulley) that Wes is talking about.

Merry Christmas!

20mercury

FWIW, I added Vintage Air to my 454 in my 68 and never could get the a/c belt to stop squealing until I went back and added the idler pulley shown above. So, I ended up following the AIM dwg completely and all works fine now, duh! No AIR on mine so just a shorter belt from the WP to the a/c compressor. Hope this might help.

Faster Rat

I am still missing the smog pump. Your A/C and smog run off the open front groove of the WP pulley. The added load of the compressor on A/C cars required a tensioner on the short inner most belt. The alternator is driven off the power steering pump and requires the special pulley with a built-in spacer

69Vett

this is my belt config. mostly stock with NO Idler pulley.