What is the proper routing of the 3 v-belts on a SBC

[goathearder]

I am one bracket modification away from finally having an AC compressor mounting in my 73 (just in the nick of time cause its getting HOT our here) but I can't find any diagrams for the proper belt routing.

I have looked up some pictures on the web but nothing seems to be consistent. I am running power steering, AC and the alternator and I have seen all sorts of combos out there.

Does anyone have a diagram of the FACTORY routing? Right now I have one belt going crank, wp, alt and one belt going crank, ps. I am pretty sure even that is wrong so I wanna get it all done right at once.

Thanks,
John

 

[imiceman44]

I have looked up some pictures on the web but nothing seems to be consistent. I am running power steering, AC and the alternator and I have seen all sorts of combos out there.

The reason you have seen all sorts of combos is that there are all sorts of combos.
If you can take a pic of what you have, I could help you figure it out as I have had a bunch of different ones and I learned a few standards.
Pic of overall and a couple of pics from the side showing alignment of pulleys will help.
But in general you will have a belt from crank to alt and fan and you will have one from power steering to crank and fan with the A/C sometimes A/c is separate.
SOmetimes the power steering has double belts and will be included with the alt on one of them.

 

[goathearder]

I can snap some pictures tonight but going off memory I believe the crank has 3 grooves, WP has 2 grooves, PS has two grooves, AC two grooves and Alt 1 groove.

 

[imiceman44]

I can snap some pictures tonight but going off memory I believe the crank has 3 grooves, WP has 2 grooves, PS has two grooves, AC two grooves and Alt 1 groove.

well if alignment works I would go with a belt on all 4 acc and another on the other 3, but guessing that won't happen so you will need to figure out which ones align and can be on the same belt.
Get me pics tonight and I will see what I can recomend.
There is no wrong way by the way as long as you can get enough wrap on each pulley and you can get as much belts on each acc as you can you will be in good shape.

 

[goathearder]

Cool, I'll grab some picture tonight and we can make a plan.

 

[goathearder]

Ok, here are some pictures. Taking a look at it last night I am thinking this:

Inner crank groove > inner PS groove
Middle crank groove> Outer PS groove > AC groove> Inner WP groove
Outer crank groove > Outer WP groove > Alt groove

I guess the real question is for the middle crank groove, should the belt run over the WP too or should I just leave the WP out?

 

[imiceman44]

Ok, here are some pictures. Taking a look at it last night I am thinking this:

Inner crank groove > inner PS groove
Middle crank groove> Outer PS groove > AC groove> Inner WP groove
Outer crank groove > Outer WP groove > Alt groove

I guess the real question is for the middle crank groove, should the belt run over the WP too or should I just leave the WP out?

I am sure the first one is what I had
The second one I think is that way, but you have to see if it will clear if you skip the WP and if you include it if you have enough belt on the pulleys.
The third one is the obvious one it's right.
Having 2 belts on one accessory will prevent squeling except if it's on the crank and doesn't have enough contact.
Also these 3 belt setups with dual belts per accessory are tricky for adjusting them, you need to figure out whcih comes first so when you tighten the last one you are make the others tighter not looser.
Happened to me once.

 

[goathearder]

Also these 3 belt setups with dual belts per accessory are tricky for adjusting them, you need to figure out whcih comes first so when you tighten the last one you are make the others tighter not looser.
Happened to me once.

Good call, I'll have to keep my eye out for that one. Its gonna be a little bit of trial and error the first time but will be worth it to finally have AC, hahahahaha.

Thanks for the help!

 

[goathearder]

How much wrap do you typically need on the pulleys? 1/4 circumference, 1/2 circumference?

 

[imiceman44]

How much wrap do you typically need on the pulleys? 1/4 circumference, 1/2 circumference?

I usually shoot for at least 1/3rd if it's a single belt, you probably would be OK with a dual belt if you get at least 1/4 each.

 

[goathearder]

Great, I think I'm good then. I just need a different upper radiator hose now cause its in the way of the new belt.

 

[imiceman44]

Great, I think I'm good then. I just need a different upper radiator hose now cause its in the way of the new belt.

maybe the belt routing is wrong, unless the hose you have is not a stock hose or it's booty fabbed?

 

[goathearder]

I think it was not stock from the PO. I had to mod it slightly to get it to fit right when I ripped out the crappy electric fan and put an engine driven one in so I think it's time to get a proper fit one now.