No More Water Pump Leaks When Tightening The Fan Belts

[BobS]

If you have an odd number of gears, counting the driver on the crank and the driven on the accessory pulley, you have engine rotation at the accessory pulley. If you have an even number of gears, you have a counter rotating output.

Simple to determine-count the gears after pulling the geartrain cover.

 

[swbradley1]

Moot point, all you have to do is look at the fan pulley which is amazingly enough attached to the fan. The new idle pulley is on the tension side of the belt.

 

[162tcat]

You guys have too much time on your hands.

 

[swbradley1]

Actually I was thinking about that but I'm killing time while a 2 gigabyte virtual machine image uploads to one of virtual hosts so I can how it performs on analyzing our netflow data.

Minute 30 to go..........

 

[BobS]

Moot point, all you have to do is look at the fan pulley which is amazingly enough attached to the fan. The new idle pulley is on the tension side of the belt.

You won't think it is moot when you launch that pulley into low earth orbit because it is on the wrong side of the belt. Which was the point of specificity doghead was making and I was agreeing with in generalities.

 

[swbradley1]

You won't think it is moot when you launch that pulley into low earth orbit because it is on the wrong side of the belt. Which was the point of specificity doghead was making and I was agreeing with in generalities.

I wasn't saying that was a moot point. The three of us agree that it is on the tension side of the belt.


But I do want to see a launch.....

 

[Tow4]

I don't think we are going to see it launch any where. It's a single belt, how much HP does it take to drive the water pump? I think the force load on the pulley will be within it's design parameters and the fabrication looks very professional so I doubt there will be a mechanical failure. If it doesn't start coming apart in the first 10 to 20 hours of operation, it will be fine.

It is always best to put the idler pulley on the slack side of the belt, but it is not unusual to have idlers on the tension side when there are belt routing or clearance issues. And what if there is no "slack" side? A good example is a reversible drive in a mill or other industrial machine. The drive runs both ways so the slack side changes based on direction of rotation.

The only real limitation is you can't use a swinging (spring loaded, self tensioning, etc) idler pulley on the tension side.

 

[doghead]

By engineering standards, it's a bad idea.

There is no need for it either, the water pump has provision for adjustment.

 

[Tow4]

By engineering standards, it's a bad idea.

Yes, I know. That must be why GM has been putting an idler pulley between the crank drive pulley and power steering pump pulley on their Corvettes all these years.

 

[Coffey1]

I have a headache now.

 

[Artisan]

I have a headache now.

My head contains more data now ( But I am grimacing w/ a lil data overload at the moment!)

 

[doghead]

Ray, your comparing apples to oranges.

This situation is cut and dry, one driven accessory.

 

[Tow4]

Eric, the Corvette is driving 3 accessories with the idler pulley next to the driven pulley and the OP's application is driving 1 accessory. Is that what you mean by Apples to Oranges? Please explain that if I have it wrong.

Which brings me to my first point, the force load on the Corvette idler pulley will be higher then the OP's application. The second point is, it is common practice to use idler pulleys on the tension side of a belt drive system. I doubt you will find many/any applications using a serpentine belt that doesn't have at least one idler pulley on the tension side. Idler pulleys are less common on V-belt drives, but the theory is the same.

Let me address your "engineering standards" comment. Every design is a compromise, rest assured, that things are designed and built all the time that may not follow a best design/engineering standard. The reason may be cost, space limits, ease of assembly, or as I have frequently done, to get around a patent issue. That doesn't mean it won't work, you just have to make a little extra effort to engineer it so it will.

The OP built his prototype, and will be testing it to evaluate the reliability and determine if any changes are needed. That is the design process. I hope he takes the time to follow up.

Last, I don't understand why so many people on here have to blast someone that comes up with an original idea. I know there are people that want to see vehicles kept original, I also know that there are very few of our MVs that don't have some part on it that is not the original design.

If someone is doing something that can be a safety issue, by all means chime in. If you want to offer advice, do it constructively. Telling someone you want to see their idea fail "launch into space" makes me sad. I expect better from the Steel Soldiers group.

 

[doghead]

Never mind...


Who got "Blasted"?

 

[swbradley1]

Even though I would want to see a launch I want to buy one as soon as they are available as it will be going on my 813. I've already said I thought it was a good idea even if it is on the tension side. I also don't want to adjust a belt by moving a water pump. Now that is a stupid design IMHO.

If it is going to fail on anyone it will be me and my truck.

Can we order yet?

 

[Lonnie]

Rifleman, The adjustable pulley is a great idea.... what I think some are referring to is that your tensioner setup has adjustment which can pivot off a single point, relying on the tension of a single bolt to keep adjustment.
This is critical on the tension side. If you added an adjustable stop bolt or a spring loaded tensioner to the pulley you would have a bullet proof setup.

It wont fail because of this, but it could eventually rotate out of adjustment or come loose.
Even putting the pulley on the opposite side of the mounting bolt would help, as belt tension would atttempt to tighten the mounting bolt instead of loosen it.

The Vette pulley setup referred to is not a good comparison because it refers to a "non adjustable"idler pulley, not something adjustable, which is used for tensioning, shown on the passenger (slack) side of the engine.
Idler pulleys can be wherever needed, but tensioners should be on the slack side or have a mechanically adjustable stop to hold them in position.

 

[BobS]

Eric, the Corvette is driving 3 accessories with the idler pulley next to the driven pulley and the OP's application is driving 1 accessory. Is that what you mean by Apples to Oranges? Please explain that if I have it wrong.

Which brings me to my first point, the force load on the Corvette idler pulley will be higher then the OP's application. The second point is, it is common practice to use idler pulleys on the tension side of a belt drive system. I doubt you will find many/any applications using a serpentine belt that doesn't have at least one idler pulley on the tension side. Idler pulleys are less common on V-belt drives, but the theory is the same.

Let me address your "engineering standards" comment. Every design is a compromise, rest assured, that things are designed and built all the time that may not follow a best design/engineering standard. The reason may be cost, space limits, ease of assembly, or as I have frequently done, to get around a patent issue. That doesn't mean it won't work, you just have to make a little extra effort to engineer it so it will.

The OP built his prototype, and will be testing it to evaluate the reliability and determine if any changes are needed. That is the design process. I hope he takes the time to follow up.

Last, I don't understand why so many people on here have to blast someone that comes up with an original idea. I know there are people that want to see vehicles kept original, I also know that there are very few of our MVs that don't have some part on it that is not the original design.

If someone is doing something that can be a safety issue, by all means chime in. If you want to offer advice, do it constructively. Telling someone you want to see their idea fail "launch into space" makes me sad. I expect better from the Steel Soldiers group.

Some of us have over 40 years of experience AS engineers in this industry. Some of us have RUN the NATO 400 hour durability test and have seen failures of this type. Some of us DO NOT have to guess on the outcome. Some of us finally DO know what we are doing.

 

[BobS]

Lonnie....

You have touyched on the problem comparing the Corvette drive routing with the modified NHCs. That is the fact that the idler used in the Corvette is used to add belt wrap (the number of degrees the belt wraps around the driver) due to accessory drive positioning requirements and is NOT adjustable.

 

[Scar59]

Even though I would want to see a launch I want to buy one as soon as they are available as it will be going on my 813. I've already said I thought it was a good idea even if it is on the tension side. I also don't want to adjust a belt by moving a water pump. Now that is a stupid design IMHO.

If it is going to fail on anyone it will be me and my truck.

Can we order yet?

My sentiments exactly. I could use two of these assemblies. The OP needs a little more interest to start fabrication and to cover cost.
He needs about 20 of us to pony up. I'll take two.
JC

 

[Rifleman]

UPDATE: Well i just got back from a 100 mile test drive and so far the idler is working great. Now time and miles will be the real proof if this pulley is a help or not, but i do have to say i did notice a difference today. Today out side temps were right around 80, i took the truck for a drive a few days ago, same temps, the only difference today is the water temp never got over 180. The other day while i was driving the fan clutch would cycle on and off at 190, that didn't happen today. I am not sure if it was the new idler keeping the water pump belt tight or what. Once i have put 500 and 1000 miles on the idle i will report back and let you know if it has any issues.