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Re: [GMCnet] Cad 500 Serpentine Belt [message #78124 is a reply to message #78079] Fri, 26 March 2010 20:35 Go to previous messageGo to previous message
GMCWiperMan is currently offline  GMCWiperMan   United States
Messages: 1248
Registered: December 2007
Karma:
Senior Member
Les,

The key to the whole thing, really, was finding the '89 Mercury Marquis dual
crankshaft pulley. Looking a other junkers all around that one, probably
all big Fords & Mercuries of that era had similar pulleys. Also, my looking
at Fords in general was because others had referred me to Tauruses as having
similar pullies. I never saw one of those because of the obstructions
imposed by cross-ways engine mounting.

I used the water pump pulley from that Mercury also -- 'cause it was there.

Gene, the beauty of using two serpentine belts is that it's not necessary to
drive the water pump backward. That has apparently been the root cause of
the problems others have had with single belts -- there's simply no way to
route a single belt to have sufficient wrap without driving something
backward. I have been very surprised, during my recent junkyard
examinations of serpentine belts, at how many (most) cars run the water pump
backward off the back of the belt. And if you look at lists of water pump,
it's surprising how many engines have reverse rotation pumps available. I
did that when I first got interested in a serpentine belt for the 455 --
until Leigh built one, there was not one.

As I've said before, neither Bobby Moore nor I ever had any cooling problem
with a standard pump running backward. Others did. The only modification I
made to standard water pumps was to grind away as much as feasible of the
sharp corners of the pump casting interfering with the water seeking to
change direction exiting the pump. I know Manny went much farther, grinding
completely through the casting and welding new passages. Why others had so
much trouble and I didn't escapes me.

While I have only 25 miles on my Cad 500, I'm convinced the serpentine belts
are going to work out well. I've got several hours of 1500-2000 rpm run
time. The temperature climbs quickly to the 195*F thermostat setting -- and
stays there. The belts can be seen running smooth and steady, with NO
flapping as you see with V belts.

Developing a 2-serpentine setup for the Olds, using a more modern alternator
(and perhaps PS pump) is a worthwhile effort which can probably result in a
valuable, inexpensive, upgrade.

Ken H.


On Fri, Mar 26, 2010 at 1:39 PM, Mr.erf ERFisher <mr.erfisher@gmail.com>wrote:

> You might want to enquirer further, there were several GMC folks who went
> to the serpentine belt system for the GMC 455, and then discarded it.
>
> Wonder what Jim B has to say about it.
>
> gene
>
>
>
> > I want to upgrade to the CS130D alternator and also upgrade to a Sanden
> > type
> > A/C compressor. Going to a serpentine system at the same time makes a bit
> > more sense since I already need to fabricate some custom brackets for the
> > alternator. I'd like to source as many of the required parts as possible
> > from the men's mall.
> >
> > Thanks,
> > Les Burt
>
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