[me2dumb4college]

So thinking of getting a smaller water pump pulley so that my belt doesnt rub with the ati idler, which logic would make me think that a fast spinning water pump pulley would cool down the motor and not cause all sorts of problems; however, nothings ever that easy... I'm guessing the faster pulley might cause small air pockets reducing the effectiveness of the pump?

Anyone an expert on water pumps?

[DickH]

worst case senario you spin your pump too fast and it dies, but I cant see that happening with just a slightly smaller pulley. You shouldn't expect any problems, but if you are worried maybe you should get a different idler.

[me2dumb4college]

i got the smallest idler they sell... 1.95

was on the phone with procharger and they suggested either a smaller tensioner or water pump pulley, but i'm not finding any in my google search

arent underdrive pulleys larger than stock water pump pulleys?

[DickH]

yes, under drive is larger. Something you should watch out for is that you can get a wrong pulley. I think it was somewhere in 01 that ford changed the waterpump/pulley setup so a 99 pulley wont work out with an 03 pump.

[me2dumb4college]

right i have a late model 01, but i'm having a hard time finding any water pump pullies smaller than stock

[stal94gt]

it sounds to me it maybe cheaper and less head ache to find the proper bracket to fit your year. since that pulley looks to hang to low going to a smaller pulley or altering that setup may have issues with reducing belt wrap and causing un-needed belt slip

[me2dumb4college]

Originally Posted by stal94gt it sounds to me it maybe cheaper and less head ache to find the proper bracket to fit your year. since that pulley looks to hang to low going to a smaller pulley or altering that setup may have issues with reducing belt wrap and causing un-needed belt slip

thats the thing... it is the proper main bracket for my year... there's only one place for that idler pulley to go and thats right there by the alternator

[me2dumb4college]

anyone on coagulation?

[number1gt]

Maybe an electric water pump? That probably comes with basically an idler pulley which would probably be the same size, I honestly don't know just throwing it out there

[WickedSnake00]

Originally Posted by me2dumb4college anyone on coagulation?

Coagulation? You mean cavitation?

Yes, this can happen if you spin the pump too fast. If the impeller is spinning too fast, you get sort of a venturi effect between the impeller and casing, which in that low pressure area will cause vapor pockets, and thus cavitation.

However I don't have the efficiency/velocity maps from Ford to determine how far you have to go for this to happen. I imagine that this would be feasible if you kept the engine RPM low, but would bring the prospect of cavitation at high RPM. Bottom line, I wouldn't chance it.

Another failure mode would be bearing failure. Spinning it faster means higher rotational velocity, which can kill bearings. Your bearings go out, and suddenly it's either leaking like a seive, or the damn thing seizes up and things go south real quick from there.

I would stay away from a smaller water pump pulley unless you go electric, in which case the pulley diameter wouldn't matter.

Look for a different idler.

[number1gt]

Can you use an adjustable idler? I know kenne bell has adjustable idlers

[me2dumb4college]

Originally Posted by WickedSnake00 Coagulation? You mean cavitation? Yes, this can happen if you spin the pump too fast. If the impeller is spinning too fast, you get sort of a venturi effect between the impeller and casing, which in that low pressure area will cause vapor pockets, and thus cavitation. However I don't have the efficiency/velocity maps from Ford to determine how far you have to go for this to happen. I imagine that this would be feasible if you kept the engine RPM low, but would bring the prospect of cavitation at high RPM. Bottom line, I wouldn't chance it. Another failure mode would be bearing failure. Spinning it faster means higher rotational velocity, which can kill bearings. Your bearings go out, and suddenly it's either leaking like a seive, or the damn thing seizes up and things go south real quick from there. I would stay away from a smaller water pump pulley unless you go electric, in which case the pulley diameter wouldn't matter. Look for a different idler.

Sorry thats what I meant, so without changing the water pump, what else can I do though?





Gates makes some idler brackets, http://www.gates.com/idlers/Idler%20Catalog.pdf, but will that work since it's right there at the alternator thats the problem?