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

Once again in order to make those claims read what i posted. Take those steps, and then this claim can be rendered true. Not bashing on you in any way. :3amin: I just dont see the logic in what is being posted. I know Al and others explain it and have dealt with it, but its only theoretical at this point. Take the step and measures in analysis to determine what other factors contribute to this outcome of damaged gears. To the gentlemen who mentioned balancing and harmonics dont co exist with one another; Last time i checked it did:)

benefits of balancing from within benefits in reduced wear of components, reduce vibrations transmitted throughout an engine. Able to reduce the size and weight of components without any disastrous output. keep in mind on how i said disastrous not negative. It is still feasible to experience a negative output with any modification but disatrous? higly unlikeley unless you are incompetent.:claus:

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

Have to warn you, this argument is about faith to most people vs proof. With that being said, it's akin to arguing which religion is better. There's no clear winner to the argument, only a bunch of pissed off people in the end.

Tony

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

UDP = :mean!:

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

http://www.corral.net/forums/search....archid=4216206

'Nuff said. :claus:

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

The Corral is sloooooow. Its a link to numerous threads where Al comments on u/d dampers and stock oil pump gears.

One of the threads does include those pics, or at least did last time I read it. The posts are a few years old now.

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

Nice find but still considered inconclusive. You understand why, right? and Voodoo..:smack:

Out of the thousands pumped out of production (cobras, machs and 2vs) how many have experienced this dilemma? what is the ratio of damaged to not damaged? what percentage had it on a drag application? etc etc. Its questions like these that'll help you determine or guesstimate a problem. It wont find the solution, but you'll be one step closer in getting your answer. And please stop with the he said she said. Its very childish and the "evidence" isnt detailed enough on ANY of those post. No matter who its from. Sorry.

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

Inconclusive to you maybe, but to me there is a very clear trend.

Ford produced a unique damper for the 2000 Cobra R. With the 08 Bullitt, Ford decided to extend the rev range on that engine and they also felt the need to introduce another damper design with it. Ed Olin, one of the guys involved with the development of the 2000 Cobra R powerplant, made numerous posts on this very topic. The testing has been done, whether you choose to accept it or not is up to you.

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

Seems like LXH89 was correct.:what: Where may i locate this "testing" analysis? As an engineer im sorry but i disagree with you. I have to look at things from a closer stand point. Im not your typical forum user who believes everything the gentlemen with 1k post has to say. Anyways, Thank you for the information you've provided.

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

Look for posts by EDO (Ed Olin) on the Corral.

I'm not the type to believe whatever I read on a web forum either, in this instance the information provided is fairly convincing.

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

yes i am familiar with vibrations or resonance transferred throughout an engine by a lack of Balancing and other alternatives as well. why? I believe these were internally balanced so an offset on external weight should not affect it. Not even by a fraction of a percentage.

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

Thank you. I will see what this man has done to confirm this theory. I most likey will stop posting about this subject. its obvious its a lose lose situation no matter what the outcome or development of this is. Thank you all.

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

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.


:confused: :confused: :confused: lets lay this matter to rest. its heading no where.

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

Im not trying to find a gap or alternative to turn this around on you but they each correspond to one another.

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

Engine balance is the design, construction and tuning of an engine to run smoothly. Engine balance reduces vibration and other stresses, and may improve the performance, efficiency, cost of ownership and reliability of the engine, as well as reducing the stress on other machinery and people near the engine. therefore, it being internally balanced and a weight difference if a pulley swap should not have any affect on this mechanism.

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

Do you understand that the harmonic damper on a Modular engine, or any internally balanced engine, does not contribute to balance? These dampers and flywheels are nuetral (zero) balance.

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

Yes. Just some food for thought.


Torsional vibration is a concern in the crankshafts of internal combustion engines because of several factors.

Alternating torques are generated by the slider-crank mechanism of the crankshaft, connecting rod, and piston.
The motion of the piston mass and connecting rod mass generate alternating torques often referred to as "inertia" torques
The cylinder pressure due to combustion is not constant through the combustion cycle.
The slider-crank mechanism does not output a smooth torque even if the pressure is constant (e.g. at Top Dead Center there is no torque generated)
Engines with several cylinders can have very flexible crankshafts due to their long length.
There is inherently little damping in a crankshaft to reduce the vibration
If torsional vibration is not controlled in a crankshaft it can cause failure of the crankshaft or any accessories that are being driven by the crankshaft (typically at the front of the engine, the inertia of the flywheel normally reduces the motion at the rear of the engine).

This potentially damaging vibration is often controlled by a torsional damper that is located at the front nose of the crankshaft (in automobiles it is often integrated into the front pulley). There are two main types of torsional dampers.


Tuned absorber type of "dampers" often referred to as a harmonic dampers or harmonic balancers (even though it technically does not dampen or balance the crankshaft). This damper uses a spring element (often rubber in automobile engines) and an inertia ring that is typically tuned to the first torsional natural frequency of the crankshaft. This type of damper reduces the vibration at specific engine speeds when an excitation torque excites the first natural frequency of the crankshaft, but not at other speeds.

Over time, the energy dissipating (rubber/clutch/fluid) element can deteriorate from age, heat, cold, or exposure to oil or chemicals. Unless rebuilt or replaced, this can cause the crankshaft to develop cracks, resulting in crankshaft failure. (have these ever been looked into as a factor?)

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

In what shape or form? i cut and paste from reliable sources (i'd be glad to give you all the information you want such as web addresses and such) so those that are ill-informed to further read up on the matter and subject to gather enough detail and information to come up with a logical explanation of things. This has been carried far enough. A man of your logic id expect YOU to reason and understand that a guess is a guess and there is no EVIDENCE that can attribute to these losses. Once again this has been proven to be a "religious battle" and i refuse to continue and i'll let you all wither away with this false assumption. Thank you once again M1M and all of you who participated in posting YOUR belief.

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

M1M if you (or anybody) can somehow manage to solve this by adapting these formulas to calculate the output of amplitude through a crank. I'd be more than happy to oblige to these statements you hold on to dearly. :smokin: This all can be done with exact measurements of the 2 different pulleys that are in question. Gather spec info like weight, size etc etc. these here have to be considered and nearly each one has its formula. The output has to be either identical or close to as factory specifications.

Center frequency
Driven harmonic motion
Formant
Harmonic oscillator
Impedance
Q factor
Resonator
Vibration
Schumann resonance
Simple harmonic motion
Tuned circuit
Wave
Sympathetic string