question about pulleys. what do they do and how do thae do it? i heard they slow up the acessories and whatnot but thats vague. also, do they make them for an 89 4.9L? i see they make them for v8's but not for the 4.9's. will the v8 pulleys fir the 4.9 engine? if anyone can help, let me know. thanks, john

 

Goto the pre 97 section. i think CHADSIX is ruuning the underdrive pulleys for the 4.9 Good Luck

 

Accessories take power to run them. (ie. the water pump moves a certain volume of water per revolution) When different pullys slow them, they are moving less volume. Each revolution for each accessory requires power. Turn them less (slower) and they absorb less power. The less power your accessories take the more power is free to spin the wheels.

Think about it like this:

Your alternator takes one unit of work to turn it one revolution (Rev.), call the work it requires (W)

So from the factory

1Rev.= 1W

When a pully slows the speed to 1/2 the factory speed,

1/2Rev. = 1/2W

So essentially you are only required to use 1/2 the amount of work to run your accessories. (or whatever the pullys are set up for, ei. 3/4)

The work that was originally used for accessories can now be used for acceleration.

Here is the problem with pullys:

At low engine speeds the accessories aren't operating at capacity. The result is lower alternator and water pump outputs. Generally this doesnt cause big problems, but I wouldnt put them on a daily driver myself because I dont want to have to worry about it. I would put them on a race car, just not a daily driver. Tons of people have put them on thier vehicles and love them, its up to them. Just not my thing.



Also try fordsix.com for specifics to the 4.9L

 

Here you go.

http://fordsix.com/forums/viewtopic.php?t=3859

 

a friend of mine put pulleys on his '00 s10 4.3 and claims he got noticeable horsepower out of it...probably all in his head..but about a month later he had to replace his battery, another month or so later his alternator went out...is this the fault of the pulleys or the bowtie on the grille?

 

acarr83

It is your friend's own fault for having a bowtie in the driveway. I've got them on my '98 4.6 and love them. You can notice the difference.

I am going to put them on my wife's truck also. In addition, if you are considering pulleys, also think about electric cooling fan(s). I don't think I could get along without them now.

The only reasons not to install pulleys would be if: 1. a supercharger is in your plans. or 2. If you have or plan to have very large audio amps and say several off road lights running at idle. Otherwise get 'em and like 'em.

 

Reducing alternator output and increasing draw just isn't a good idea IMO. The biggest difference in reduced alternator output is at idle, but that is when your electric fans are running.

Also, your pully gains will be less effective with an electric fan.

1. A bigger pully will allow the alternator to turn easier, but your alternator responds to demand, so if it has a high demand it will provide more resistance, offsetting some of the gains.

2. Pullys are designed to slow the speed of the fan and clutch, making them easier to turn. Removing these components means that it is no longer neccessary to easy the resistance, other than the waterpump. The rotating mass of the clutch and the force required to spin the fan are a large factor in accessory power draw, removing these means you are not getting this gain.

It is not worth putting on pullys if you are going to install an electric fan. The free'd HP claims are of some of the same components, so you will not experince the full claimed gains.

An electric fan is a worthy mod IMO. I installed one on mine and it smoothed the idle, gave me more temperature control, and got a little power increase off the line. Its nothing major so dont go racing mustangs and cameros. I installed my fan because it allows for increased cooling capacity later on, when other mods are added. The power gains, although present, are more phsycological than anything. The 5-10 pony's gain is about like the engine running better on a cooler day. Sure theirs a slight difference, but only noticable because if you didnt you'd feel like you wasted your money on a wimpy power freeing device.

Granted, pullys AND an electric fan will run slightly better. If your looking to shave a few hundredth's off your 1/4 mi time at the track reguardless of drivability, forget everything I said.

 

as spaceman12321 pointed out i kinda asked this question at a similar site and got my answeres and came to the conclusion that underdrive pulleys on these 4.9Ls is pointless.

 

I put underdrive pullies on my '98 4.6 and they worked great driving around, definitely noticed the difference. Drove to the white mountains(cold weather) with my camper on and had serious overheating problems. DO NOT USE THEM if you actually plan to haul something in your truck or you will regret it.

 

or buy a cobra R water pump too.....

 

The purpose of the pullys is to reduce the resistive force required to turn the accessories. Its quite simple, decrease water pump output and poof, freed up horspower at the cost of reduced water circulation and the possibility of overheating. So, put on a bigger waterpump right? Increase water flow, increase the force required to pump the water and poof, $300 down the drain cause your right back where you started.

If you really want to free up horsepower, do this:
1. Electric water pump
2. Electric fan
3. 100-130 amp alt.
4. Leave crankshaft and alternator pully stock (not doing so will result in wasting the cost of a high output alternator)
5. Change power steering pump pully (if you dont mind slightly stiffened steering
6. Fork over $700+

Otherwise, stick with just an electric fan OR pullys. My reccomendation would be the fan. As I said before, doing both is partially counter productive and the likely hood of problems is not worth the minimal gains. After the fan, spend your money elswhere.

 

I happen to own both as several other posters here do. Not ever one single problem with overheating...Not even close. And my water pump is stock.

If your overheating it is NOT because of electric fans(which move MORE air than factory clutch). And it sure as heck is not because of a slightly different water pump pulley size.

I just thought of one exception for the electric fan kit. Not having the proper size kit could cause overheating.

Check for some other problem....

Rocks

 

I agree Rocks, a properly set up set of pulleys with electric fans should cool at least as well as stock. I have the FRPP three piece underdrives on my '95 and even with the stock fan have had no cooling problems.

 

signmaster:

You have only pullys correct? My post was directed to the use of pullys and an electric fan in conjunction. Please read further for the problems that adding an elctric fan may cause, and read my previous posts above for why the gains are not necessarily worth it.


Rocks:

Sure, changing the pullys does absolutely nothing to the operation of the water pump, right? It just makes power out of the air.... NO, it decreases how hard the water pump works.
You can expect the accessories to loose performance when adding pullys. If they dont they are broke and you should ask for a refund.

Please note I never said that you would overheat under these conditions, but you are decreasing their performance and output, so the possibility exists. This applies to all of the accessories, including the vital ones like the water pump and alternator. Will it circulate the water like it did from the factory? No. Will it cool enought under normal conditions? Probably. Will it keep your truck cool enough in extreme conditions? Maybe.

Please note that ksonger was in the mountains with a camper. A loaded truck climbing mountains is a more extreme conditon, but he stated "they worked great driving around."


You are correct in the fact that an electric fan should move as much air as a stock fan and if it doesn't you dont have the proper setup. Please note that electric fan output is DIRECTLY related to system voltage, and if the system is under a load (ie lights, a/c, windshield wipers) then your fan will not provide the output listed by the manufacturer (most are rated when 13.5-14 volts is supplied). How much? Who knows. Decreasing your alternator output may decrease your system voltage. Will it be sufficient under normal condtions? Probably. Will it be sufficient under extreme conditions? Maybe.

When using both pullys and an electric fan in conjunction, your power gains are diminished from the claimed numbers of each individual mod. This means that for the increased possibilty of problems, it may not be worth the diminished gains of the second mod. Usually the problems will be more electrical related than cooling, at least directly. This is because you are adding more draw to the electrical system and decreasing its potential simultaneously. Read my previous posts above to see why.



My point was "doing both is partially counter productive and the likely hood of problems is not worth the minimal gains." When using them together will they provide the accessory performance as compared to factory? No. Will it be sufficient? Maybe.

 

In my opinion electric fans combined with under drive pullies complement each other. One does not reduce the other or make the other less of a gain. Like I said, I have both and know of what I speak.

Rocks