Crankshaft hub in too far?

[Loveofclassics78]

Good morning!
After reassembling everything after replacing my Timing Chain, I noticed that my back AC belt was rubbing slightly against my water pump.  All the other belts are aligned normally.  Possibly when the engine is started, it won't be that much of a problem, but what to do as a fix?  I could move the balancer hub back out a little or maybe shim the crank pulley out with a few washers.  Or just leave it alone and let the belt wear itself in, since I'm not running AC anyway?  I wonder do I even need the Back belt if I'm not running AC?  Decisions, Decisions!

Don

[35-709]

I wouldn't think you need dual belts if you are not running the AC.  Some seem to get along with just a single belt even while using the AC.

But, did you just replace your water pump?  The only new water pumps (as opposed to rebuilt) available seem to be pumps that were designed for the later single AC belt when Cadillac went to HEI.  There was more clearance for the inside belt designed into the water pump housing for the dual belt system which they eliminated when going to the single belt.  The new pumps fit the older engines just fine but the inside belt will rub on the water pump as you are finding.  My only solution to the problem was to get a rebuilt earlier style pump and to get my old pump rebuilt to keep as a spare.   

[TJ Hopland]

Same question I was going to ask about the water pump.   

If you are not using AC then yes you can just get a shorter belt and run from the crank to power steering.   The length of that belt is in many of the shop manuals and some computers as the not very common non AC option. 

[Loveofclassics78]

You guys are right.  I did replace the water pump with the MTS pump.  Looking back at it, the original pump is flatter at that end.  Learn something new every day!  However, if I do want to run AC, I'm pretty sure that I will need both belts.  I can just handle that when i'm ready to overhaul the AC system.

[35-709]

If you're gonna put the AC in service one day and run both belts, then you are going to have to change the water pump, or run one belt tight which may or may not work over the long run.  When Cadillac went to HEI and a single belt they made the single belt wider/beefier to handle it, unfortunately you can't run that single belt on a dual belt system either.

[Dan LeBlanc]

My 70 a/c is running off of one belt and works just fine - the previous owner put a single groove compressor on it.  There's a second shorter belt as well from a non-a/c car in the second belt groove on the ps pump.  In the event of compressor failure, I can take a pocket knife, cut one belt, and still have power steering and continue on my way.

[35-709]

   There ya go!