Alt/water pump belt issues.

[Mazdabater]

So my S4 is finally registered and on the road over here and I'm just about ready to put it up for sale. I haven't done much driving in the thing so I'm trying to find all the little issues with it now. First one was I went to drive it up a hill to see how it went under load, got about 100m up and the temp started climbing. Went home and discovered the alt belt is loose as. Tightened it up and changed the coolant. Ran alright then the belt came loose again and was too streched to be re tensioned.

So I went down and purchased a new one and it's chewed this one out too. So obviously there is a slight alignment problem but also the previous owner has removed the air pump.

Now I was looking around on the pineapple racing site as I'm buying the EGT gauges for my s5 this week and noticed the yoohoo belt.

Is this worth buying as a precaution? My s5 has some sort of aftermarket belt setup on it so I have never noticed that the water pump might slip without the air pump. Not really keen on going to a dual belt setup on a car that I'm going to sell but my missus has been driving it around lately and I'm worried if the temp gauge starts going up she will keep driving.

[TitaniumTT]

No. Get a dual alt pulley, or a gilmer drive. or something. There's no way to tension the yohoo belt.... I'm sure it does something but how much? Probably very little.

Or, put the air pump back on....

[bumpstart]

Originally Posted by bumpstart

waste of time
alum pulley chews out
you cannot tension two belts the same
( so you will find it will soon squeal and slip again )
when the loose one throws,, it often takes out the other


10a 550 belt,, around water pump and main pulley ( no tensioner )
wind it on with same method you use on a bicycle chain

problem solved , permanently,, for around $10

PS
yes this is same trick as the pineapple yahoo belt
yes i have run both dual pulley and the yahoo belts individually for many many daily use years

yahoo is the winner,, it will not cause an issue with bearings ,, but an over-tight dual pulley is not great for the alt bearing
( and does not solve the chew out belt or squeal issue permanently,, take it from a guy with 20 years of DD rotary )

[Mazdabater]

Would love to put the air pump back on, but neither of my fc's came with one lol and I'm leaning towards the yoohoo belt option purely because I don't plan on keeping the car very long.

[RETed]

Single (alternator / water pump / main) belt + no air pump is asking for trouble.
There is very little contact of this belt with the water pump pulley.
You can spin the water pump (pulley) by hand pretty easily, no matter how tight you adjust the alternator.
This is where double (sheave alternator) pulleys are popular - very popular in Japan.

The key to this set-up is to run two brand new belts.
Watch out for Gates belts - Gates makes more than one type of belt with the same part number that are slightly different dimensions.
(I've seen three different types myself.)
Lots of chain auto parts stores use rebadged Gates belts as their own.
Easy to check at the counter by pulling both belts together and check the tension - it'll be obvious if one is smaller.

No reason to worry about overtightening.
Use the rule-of-thumb of 1/2" deflection at widest part, and you should be good.
There is always the danger is problems due to overtightening, whether it be two or one belt.

I don't like that yoohoo belt, cause I'm at the mercy of a single vendor.
I never bothered to look up the generic corresponding part number myself.
It's just easier to just order two belts for the vehicle application.
I've been running double pulleys and double belts almost ever since I've had my FC from 1995 - over 15 years ago.
In fact, this was one of the very first mods on the car.
I've never had a single problem running my car this way.


-Ted

[Mazdabater]

Alright alright you guys win, I just bid on a steel dual pulley on ebay.