Hey everyone,

I was working on my super beater F350, the Stay Puft Marshmallow Truck, and while it currently is not locked up or anything, I typically like to eventually remove the smog pump off of my trucks. It usually isnt an issue, just pull the pump and get a smaller belt, but i was looking at the routing, and im not sure if it will be so simple on this truck.

Does anyone know the correct routing and belt size if it is just a 'pull the pump' situation? or do i perhaps need to get an idler pulley or something?

 

Ford used a few different belt routing schemes on these trucks. Some are more friendly for re-routing than others. So the answer depends on which belt/idler pulley this motor uses.

 

Here are 2 ways I did my 94 which may or may not be similar. First is with original belt, but I did not consider it very safe. Second is with a 96.08 inch belt & sorry but I can't find the Dayco number.





The tensioner wheel is a metal idler for a 5.8 F-250. For some reason the 150 was plastic.

The way I came up with the belt size, was using 1/2 inch high strength nylon rope, I strung it around the needed path & tied it with a square knot. Notice in the second pic the belt routs under the tensioner. This is important. It is not meant to put tension in that direction.

After I got a rough length with the rope, I took a 2x4 drove a nail in one end & stretched the loop out tight, drove another nail & measured the distance, then multiplied by 2. It took 2 trips to my mom & pop parts store to get the correct length. If there is slippage (squeal), you can use washers under the 3 alternator mounting pads in equal numbers.

No guarantees made, your results may vary.

Good luck.

 

thank you for the illustrations, the way you are suggesting is to go with the second picture, correct?

 

Yes, correct.

 

you mentioned concern about the tensioner pushing tension the incorrect way. what concern in particular do you have??

 

Its just the way the natural spring of the arm works verses how its utilized in the delete. There is not as much energy pushing down on the belt. I've never had a problem with it. But its only because the length of the belt is "just right" that allows it to keep the correct tension on all the accessories. It looks like its the same, but once you do it (not using the upper idler), it just feels wrong when you put a wrench on it to slip the belt on. Best way I can describe it.

And please take notice, I run an electric fan. I have no idea how it works with the weight & drag of a mechanical fan & clutch.

(Yeah, this was edited about 3 times)

 

The configuration in the first photo, will cause clearance issues with the radiator hose.

I have mine, setup as shown in the second photo, belt wanted to chirp on cold starts, i was using the absolute shortest belt possible (I bought all within range of my physical measurement, returned the ones that didn't work), so I put a spacer under the a/c compressor, no issues in years. I happened to replace a belt on a late 90s 5.7 bowtie, when I put the short belt on my Ford, was one and the same, so it's not an exotic belt length, just as common.

Ford also configured the alt bracket with the tensioner at the top, where the idler pulley sits on yours. In that situation, when running a short belt, bypassing the smog pump, the tensioner still behaves as it always had. In your situation, as well as mine, bypassing the smog pump, causes the need to move the belt from the idler pulley, down to the tensioner, changing how the tensioner applies tension to the belt. The correct way would be to use a smog pump eliminator bracket/pulley, reuse stock belt, life goes on but running a short belt, will work.

 

as a note, here is my current engine drive configuration

 

I know I know reviving a pump delete/belt length thread.

My truck runs flawlessly except for the odd slightly high idle at stop lights and what not. It's a five speed, the high idle isn't excessive and drops off after stopped momentarily. All normal maintenance is up to date , fuel pressure is perfect on both tanks 32/40, and no engine light or codes. I get a 111(I think that's the code or whatever it is for all systems ok) off the koer. Plugs, wires, rotor, cap and o2 sensor are new.

So I'm thinking I have a vacuum leak and since my truck has no cat and never will I'm also thinking to delete the air pump and associated vacuum lines and pipes and what not before replacing all the rest of my vacuum lines. I will not be removing the egr. I've read a lot of conflicting info on whether to run a idler pulley in place of the pump or short belt it like pictured a few posts above in the second photo of Scndsin's post. I'd rather run short belted and eliminate the stock idler and not replace the air pump with a idler as I'm not a fan of lots of pulleys. But I'd be curious for opinions on this if anyone cares to chime in.

My 95 351w truck has a belt routing like the last post/picture.

 

Hey at least you didn't dig one up from 2002...

My set up has been working for a dozen years now.

When I put on the 130 amp 3G on it developed a pit of a start-up, half second squeal which I'm fine with.

Understand I'm running a Taurus fan as well.

 

I had considered it.

i guess it would seem like for some it works and for others it doesn't. Just hate to waste a belt or have the hassle of throwing one.

Is there a reason for your fan swap? Do you have a thread on it? EDIT....I googled about the fan conversion. A trick mod but I don't think I'll be going electric fan anytime soon.

Thanks for the input.

 

My truck had 141k miles commuting in metro Atlanta & pulling a bass boat to lake Lanier on weekends near as I can tell when I bought it.

One of the first things I did was pull the pump, do a timing chain, std copper plugs & wires etc, new Flow Cooler water pump & fan delete with the Taurus fan.

Difference was night & day. Felt like 25-30 hp & the way the engine revs FREELY without all that mass revolving off it's nose was & is the first thing that jumps out at you.

Yeah, yeah... it's all the tune up so I've been told

With a gutted pump, you're still burning horse power to drag that belt in a 90* angle from one direction to another regardless of how little it's weighted internal drag.

A rotating fan is still doing the same with a clutch that is never 100% efficient.

I've got the solenoids for the AIR/EGR mounted on the fire wall now with the EGR still functional.

Just some food for thought. Good luck with your truck.

 

Interesting stuff. Maybe I will research it some more the electric fan conversion. I've been part of doing a couple electric fans before just seemed like a pain what we went through on a 4.3v6 in my buddies Toyota and same buddy with a Beemer too. But he swore up and down about performance gains that were had from it.

I guess my initial concern is about turning a mechanical fan into an electric one. But I am at the point of needing to replace my fan clutch as it's wore out and never locks up fully. So maybe I should consider this.

My 95 is relatively low mileage about 120,000miles.

I also dont plan to gut my air pump I want to take it right out.

Youve given me some things to think about. Thanks for the input.

 

It is NOT for everybody. But I sure like being able to turn it off or ramp it up as needed.