Re: Under Drive Pulleys..and the problems they cause.
 

i do find it odd some 99-01 cobras have 100+k with pullies and no problems.

Re: Under Drive Pulleys..and the problems they cause.
 

Not every fat person will have a heart attack either.

Re: Under Drive Pulleys..and the problems they cause.
 

that makes me feel better
<-fat guy

Re: Under Drive Pulleys..and the problems they cause.
 

i guess im ***ed then. cuz my redline starts at 5,800 and i take it to 7,100.

going TO or NEAR redline wont do anything lol. its hitting the rev-limiter thats HORRIBLE on parts.

Re: Under Drive Pulleys..and the problems they cause.
 

im an ex-auto.

i made da jump to a T-56 :smokin:

Re: Under Drive Pulleys..and the problems they cause.
 

Yep...I used to have a set of Steeda's......the alt pulley is already a 'UD', that's why they say not to install it. Just because Motoblue has made some FRPP pulleys, doesn't mean they are safe.
Let us know your track times shiftin' at 5500...I'm curious to know how that works out.


Look, every one has their own opinion. I used to have the pulleys installed (on my Ex's car) and I paid to take them off......it just wasn't worth the risk IMO. We dont' ahve a 2V car, so you can't compare them. The Cobra's are a slightly different 4V as well. You can't compare our motor to other modular's all the time. Do as you wish.........some of us just think it is better to not install them.

Re: Under Drive Pulleys..and the problems they cause.
 

U/D dampers have broken many 96-01 Cobra and 2V GT oil pump gears as well, don't think for one second they are immune. And there are Machs out there with alot of miles on the sorry u/d dampers, but that doesn't mean those Machs won't lose their engines tomorrow.

Re: Under Drive Pulleys..and the problems they cause.
 

I'm sorry but i work for a lab that specializes in failure and analysis. In order to state these claims you better have all these steps. (please keep yourself from acting childish. I'm only trying to help in what i believe is correct. you may have your own opinions and i apologize if you feel threatened or offended. That is not my intention)


1.Collection of background data and selection of samples
2.Preliminary Examinatio of a failed part
3.Non-destructive/destructive testing
4.Mechanical testing
5.Macroscopic,Microscopic examination and analysis
6.determination of failure mechanism
7.chemical analysis (if applicable)
8.Analysis of fracture mechanics
9.testing under simulated service conditions
10.analysis of all the evidence, formulate conclusion, and write the report

This is what i do for a living 9hrs a day. May be of some importance may not.

i dontk know if this would help too..i posted it on another thread but read this

Okay, so how does all this scientific mumbo jumbo translate into the real world dynamics of a spinning crankshaft? A crankshaft, like a flywheel, is a heavy rotating object. Whats more, it also has a bunch of piston and rod assemblies reciprocating back and forth along its axis that greatly complicate the problem of keeping everything in balance.

With inline four and six cylinder engines, and flat horizontally opposed fours and sixes (like Porsche and Subaru), all pistons move back and forth in the same plane and are typically phased 180 degrees apart so crankshaft counterweights are not needed to balance the reciprocating components. Balance can be achieved by carefully weighing all the pistons, rods, wrist pins, rings and bearings, then equalizing them to the lightest weight.

On V6, V8, V10 and V12 engines, it is a different story because the pistons are moving in different planes. This requires crankshaft counterweights to offset the reciprocating weight of the pistons, rings, wrist pins and upper half of the connecting rods.


With "internally balanced" engines, the counterweights themselves handle the job of offsetting the reciprocating mass of the pistons and rods. "Externally balanced" engines, on the other hand, have additional counterweights on the flywheel and/or harmonic damper to assist the crankshaft in maintaining balance. Some engines have to be externally balanced because there is not enough clearance inside the crankcase to handle counterweights of sufficient size to balance the engine. This is true of engines with longer strokes and/or large displacements.

When rebuilding an engine that is internally balanced, the flywheel and damper have no effect on engine balance and can be balanced separately. But with externally balanced engines, the flywheel and damper must be mounted on the crank prior to balancing.

Customers should be told what type of engine balance they have (internal or external), and warned about indexing the position of the flywheel if they have to remove it later for resurfacing. Owners of externally balanced engines should also be warned about installing different flywheels or harmonic dampers and how it can upset engine balance.

In other words, If you dont have any balance to any of these (cranks, pistons etc etc) than you're more than likely to experience a failure due to small/large amounts of harmonics that can harm certain FRAGILE parts in the motor. Being that this is internally balanced, the pulley should not have a negative output. However, a matter of testing would have to be performed in order for either you or myself to claim our statements as valid.

Re: Under Drive Pulleys..and the problems they cause.
 

This issue is more about controlling harmonics, not balance. Even though they are related they are different issues with different solutions.

Todd

Re: Under Drive Pulleys..and the problems they cause.
 

Here is an Experts opinion: Sean Hyland Mustang High-Performance Builders Guide 1994-2004 Cobra/Mach1 Reference info: .....The factory crankshaft damper, water pump pulley, and alternator pulley can be exchanged for underdrive units that reduce parasitic losses and reduce the speed of the accessories. This is especially helpful for the water pump, which can cavitate at higher RPM, reducing cooling efficiency. .... Many of the aftermarket underdrive pulley kits on the market reduce the effectiveness of the damper, resulting in increased harmonics and contributing to oil-pump-gear failures. Our newest design retains 92 percent of the original mass, reducing drag, but still providing adequate damping characteristics. The factory had a couple of different crankshaft bolts on the 4-valve over the years, and more than one torque specification. Since inadequate clamping load creates oil pump and crank gear problems, it's important to only use the black crank gear bolt (not the inferior silver one), replace the crank-gear-bolt every time it is removed, and torque it to 125 ft-lbs......

Like I said earlier...,aftermarket underdrive pulley oil pump failures can be caused by poor design / manufacturing or improper installation.:3amin:

Re: Under Drive Pulleys..and the problems they cause.
 

thats a good post there! is this sean hyland book available at any major retailer?

Re: Under Drive Pulleys..and the problems they cause.
 

I know he has a book for building 4.6L motors at book stores

Re: Under Drive Pulleys..and the problems they cause.
 

Every crank damper bolt I've bought through Ford has been silver. I've only seen the black bolts from the factory.

Does anyone have a part number for the black bolt?

Re: Under Drive Pulleys..and the problems they cause.
 

cant you reuse the black ones? why buy a new one?

Re: Under Drive Pulleys..and the problems they cause.
 

The Ford crank to damper bolt is TTY and should not be reused.

Re: Under Drive Pulleys..and the problems they cause.
 

The one I got from the local Ford Dealer was the black oxide coated one.

Re: Under Drive Pulleys..and the problems they cause.
 

It seems Ford has only been selling black crank damper bolt for a while now.

Re: Under Drive Pulleys..and the problems they cause.
 

Black crank bolt F5RZ-6A340-B $4.06 from the SVT parts guy on SVT performance.

Re: Under Drive Pulleys..and the problems they cause.
 

Cool! Pretty cheap too...

Re: Under Drive Pulleys..and the problems they cause.
 

the in theory by what i have read in this thread.....i theory a black bolt with a Steeda UDP wont cause problems.....

Re: Under Drive Pulleys..and the problems they cause.
 

I wouldn't listen to people that can't read and write english correctly, either.:)

Re: Under Drive Pulleys..and the problems they cause.
 

I think you've misunderstood the thread. The Steeda UDP does an inadequate job of damping harmonics regardless of what bolt is used to secure it.

Re: Under Drive Pulleys..and the problems they cause.
 

well it seems that none do...but i dont really get how the bolt matters....

Re: Under Drive Pulleys..and the problems they cause.
 

The stock dampers do a more than adequate job when the factory rev limiter (for that particular crank/damper combo) isn't exceeded. ATI dampers do a more than adequate job for higher rpms.