1970 351 C Sanden Compressor Belt Routing

I've been working on a Sanden Compressor conversion for my '70 Cougar Convertible, which is a factory A/C car. The previous owner removed the original compressor, A/C hoses, and pulley system. So, the Sanden compressor is installed on the driver's side cylinder head, with a non-factory bracket much like the original. The Classic Auto Air system I purchased 3 years ago didn't seem to come with an idler pulley.

I know the crank pulley on my 351 C can accommodate three belts. The inner belt currently drives the water and power steering pumps. The middle belt currently drives the alternator only. The outer pulley sheave on the crank is not used, but it is a larger diameter than the other two. If I drove the compressor from this sheave, it would mean it would spin at a higher RPM than the two pumps. As an alternative, if I get a longer belt, I could drive the Sanden with the same belt used for the water and power steering pumps. I'm not sure that's the best approach, since the belt would be heavily loaded. On the plus side, I could save myself the cost of an idler.

I'm trying to find out:
1. Whether the outer sheave on the crank pulley was used for the orginal York A/C compressor (can anyone post a picture of their Cleveland setup?).
2. How other people have driven the compressor with a Sanden conversion, particularly for a Cleveland. Did you use an idler, and if so, where did you get it or make it? Classic Auto Air has a variety to choose from, but they're closed on the weekend.


Thanks!

Thanks. I've seen that picture, but it isn't helpful. The original York compressor bracket and idler system were removed, and I've never seen them. So, I'm using the aftermarket Classic Auto Air compressor bracket instead of an adapter. They had slighty mis-drilled the mounting holes on the Cleveland bracket, so I modified it to fit. I know I can't use the outer sheave without an idler, because the belt would rub the fan pulley.

69gmachine said:

Maybe you can find the bracket for the idler on a 351M or 400. Since you only need it for the idler, and not the compressor, bolt it to the water pump and then cut off the top. Take a piece of flat stock and drill a hole to bolt it to the Sanden compressor. Then weld the other end to the mounting bracket with the idler, making sure the face of the mounting bracket is square to the engine and compressor. I did basically the same thing with the AC compressor off a '84 F-150 truck. I'm not sure who really makes it but it's the same one used on the 5.0 Mustang except it has a V-groove pulley.

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Thanks. I'll look into it if Classic Auto Air doesn't have an idler pulley mount which I can bolt up to the water pump somewhere..

For those interested, I guess the question is what do I now need to do to get it to work? Classic Auto Air now tells me I never had the correct compressor bracket. I can tell the guy on the phone is looking at the same catalog page as myself, and he's really struggling... All I need is an idler pulley to keep the outer compressor belt off the Cleveland (single sheave) fan pulley. It can't be that hard, or could it?