No, they are completely different. Not to mention we have members on here with the modification with plenty of miles and no ill-effects.

 

Yes I know this. Can someone please tell me what makes them different? So I can explain to my hard headed dad the difference and prove him wronge.

 

http://en.wikipedia.org/wiki/Balance_shaft

Balance shafts are most common in inline four cylinder engines which, due to the asymmetry of their design, have an inherent second order vibration (vibrating at twice the engine RPM) which cannot be eliminated no matter how well the internal components are balanced. This vibration is generated because the movement of the connecting rods in an inline engine is not symmetrical throughout the crankshaft rotation; thus during a given period of crankshaft rotation, the descending and ascending pistons are not always completely opposed in their acceleration, giving rise to a net vertical inertial force twice in each revolution whose intensity increases quadratically with RPM, no matter how closely the components are matched for weight

http://en.wikipedia.org/wiki/Harmonic_balancer

A harmonic balancer (also called crank pulley damper, crankshaft damper, torsional damper, or vibration damper) is a device connected to the crankshaft of an engine to reduce torsional vibration.

Every time the cylinders fire, torque is imparted to the crankshaft. The crankshaft deflects under this torque, which sets up vibrations when the torque is released. At certain engine speeds the torques imparted by the cylinders are in synch with the vibrations in the crankshaft, which results in a phenomenon called resonance. This resonance causes stress beyond what the crankshaft can withstand, resulting in crankshaft failure.

To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft. The damper is composed of two elements: a mass and an energy dissipating element. The mass resists the acceleration of the vibration and the energy dissipating (rubber/clutch/fluid) element absorbs the vibrations.

There is a big key right there. Balance shafts run at double the crank speed to cancel 4th harmonics, while a harmonic balancer runs at crank speed to cancel lower order harmonics.

 

The following post was hammered out over the morning's first cup of coffeee and without any research...

I been having a disscussion and argument with my dad about these two. Are they the same thing?

No, a crankshaft's harmonic balancer, usually fitted at the front of the crankshaft on the exterior of the engine, is a completely different item than what we here often refer to as "luxury shafts", or, balance shafts.

The term "balance shafts" is misleading to an engineer concerned with the balance of an engine's reciprocating assembly. Again, balance shafts are NOT the same thing as a crankshaft harmonic balancer.

If you remove the Balance Shaft will it have adverse affects on the Crankshaft?

You've answered your own question with the comments, "I told him about the engine in the ford ranger and how it doesnt have the BS and how the 2.0's [don't have any either]".

The 2.3 Duratec's crankshaft would actually be under LESS stress if the balance shafts' assembly were removed! but not much. Here's why:

The balance shafts assembly consists of two counter-rotating 6 lb offset weights that creating their own frequencies in an attempt to cancel some of the 2.3 displacement's inherent low-frequency vibration from getting to the passenger cabin. They are stricly a Noise, Vibration and Harshness aspect of Ford's vehicle engineering, and they are there to help create a feeling of refinement and smoothness when operating the vehicle.

Cosworth Engineering sells a balance shafts delete kit, if that says anything.

:thumbup:

he thinks because he has 2 "engineering degree's" he knows every little ****ing thing.

That's nice! Sounds, though, like he needs a refresher course on inline four cylinder engines. Big fours (larger than 2.0 litres) exhibit pronounced vibration regardless of how well the crankshaft has been balanced to the weight of the lightest piston and rod assembly.

Suggest to him that you and he both look at the existing balance shafts threads here in Duratec Tuning. Search "Duratec Balance Shafts" and see what you come up with. As I recall, there was one thread in particular that was very informative and included pictures of the balance shafts assmebly partially disassembled...

The performance gains associated with the removal of the 2.3's shafts is akin to the gain in performance when the A/C compressor shuts off.

 

So I can explain to my hard headed dad the difference and prove him wrong.

Don't make this about "who's right".

:bang:


You and your father need to be able to get along.

 

Its not whos right or who is wronge. Me and my dad are really close and get together really good. I was just pissed a little because he said I didnt know what I was talking about and he has 2 enginering degrees and he knows and bla bla bla. I just want to show him the right answer not just so I can rub it inhis face. My dad is my role model in life and if I can be half the man and army officer he is I will be happy.

 

Excellent.

Why not use a or a then, to show the rest of us that it's not too serious.

Example

So I can explain to my hard headed dad the difference and prove him wrong.

Awesome compliment to your dad, btw. :thumbup:

 

Its not whos right or who is wronge. Me and my dad are really close and get together really good. I was just pissed a little because he said I didnt know what I was talking about and he has 2 enginering degrees and he knows and bla bla bla. I just want to show him the right answer not just so I can rub it inhis face. My dad is my role model in life and if I can be half the man and army officer he is I will be happy.

I took special notice of this thread as my dad passed away just a few days ago. We were close, both army vets, although he had the greater service, being overseas and in combat for 38 months in Africa, Sicily and Italy in WWII. It's OK to bust your dad's chops once in a while and remain in a good relationship. Love your dad and enjoy him while you have him. By the way I'm going to do the BS delete myself.

 

I'm more worried about him having two engineering degree's and not being able to understand the clear and simple difference between harmonic balancers and any other type of balance shaft device.:dunno:

 

My dad is very smart. He got his Mechanical and Industrial degrees in 4 years while doing ROTC in college. He now has 2 masters one being in engineering. He knows so much its unbelievable. We talked about it and we were just mis communicating. He said he wasnt really disagreeing with me, he said he was trying to convince me that any extra vibration will cause some type of extra wear on the engine even though it could be very small. I do enjoy me and my dads time we get to spend together.

 

Just guessing, but if he's like most old school rodders, most of his experience is with classic V8s, and may not be fully up to speed on some of the other smaller engine technologies.

 

My dad is very smart. He got his Mechanical and Industrial degrees in 4 years while doing ROTC in college. He now has 2 masters one being in engineering. He knows so much its unbelievable. We talked about it and we were just mis communicating. He said he wasnt really disagreeing with me, he said he was trying to convince me that any extra vibration will cause some type of extra wear on the engine even though it could be very small. I do enjoy me and my dads time we get to spend together.

Okay that makes sense, and is correct. Thing is this isn't 1972. Those slight vibrations may cause you to only get 210,000 miles insted of 230,000 miles.

Now compare to "classic american iron" that would need major service at 30k or complete rebuild around the same time as the first required spark plug change of a modern car.

Here's the question, the engineers who designed this engine used it without any balance shafts as truck engine, then and only when dropping that engine into a car did NVH engineers demand the shafts so old people would be comfy. Then in ALL non 2.3 litre version they did not add the shafts.

Now consider what is the greater cost? The theoreticaly "earlier" demise of the motor (probably years after you've gotten rid it, or it died from something unrelated to vibrations), or the increased fuel costs of an extra dozen or so pounds (around 8 or so rotaing?, sorry don't recall the number off the top of my head) every second that motor is ever running.

I'd venture even a fraction of an MPG improvement over the 15-20 years would put more $$$ in your pocket than the value of the car would be at 15 years and 200k+ miles when the infintesimally small amount of extra vibration fatigue catches up to the motor.

 

wow this thread = Drama....

End of story..

Balance shaft is 100% safe

 

Egz you hit it right on the head. He use to drive around a Montego with a 427 cobra jet engine. But he actually loves the new smaller turbo engines, which is why he drives a mazdaspeed 6. Im about to order the BS delete because car is up for a oil change. Thanks for clearing this all up for me, always learning something new with you guys.

 

By the way, a big, hearty thank you from New Mexico for your father's service in the military. That goes for all active duty military personnel and veterans here on the Jet. You guys are heroes. :rock:

 

wow this thread = Drama....

End of story..

Balance shaft is 100% safe

Thanks for you input. Sounds like dad gets the highly technical and satisfying "because I told you so" argument.

 

I'm more worried about him having two engineering degree's and not being able to understand the clear and simple difference between harmonic balancers and any other type of balance shaft device.:dunno:

Sure, it sounds like he needs to do a little more homework. But I can definitely understand his skepticism about removing the balance shaft. As a consulting mechanical engineer, it's my job to be skeptical of anyone's technical solution or modification - that's how I protect my clients. Changes need to be examined in detail to prove that they won't cause more problems than they solve.

Personally I'm skeptical on the topic, too. That doesn't mean I think it's a bad idea, it just means I haven't completely formed a technical opinion on the topic yet. I'd love to see some vibration analyses on the Duratec motor with and without the balance shaft.

He said he wasnt really disagreeing with me, he said he was trying to convince me that any extra vibration will cause some type of extra wear on the engine even though it could be very small.

That possibility exists.

Those slight vibrations may cause you to only get 210,000 miles insted of 230,000 miles.

Every mile counts! :thumbup: I'm in for the long haul - I buy cars with the intent of driving them at least 250k miles.

 

I'd love to see some vibration analyses on the Duratec motor with and without the balance shaft.

I realize that what you're describing here is more than likely a lab test involving two or more Duratec engines, but to answer your question in the real world one need look no further than the countless number of 2.3 Duratec-engined Ford Ranger pickup trucks currently running everywhere across America and beyond.

As was noted elsewhere in this thread, it's the same engine sans balance shafts. Ford deemed the shafts unnecessary because it's a truck, and perceived vehicle smoothness in operation was not considered a priority. In this case, any "extra" external vibration "won't hurt the runnin' of it none".

 

When I removed my balance shaft on a NA 2.3L Automatic, with all 3 motor mounts, it smoothed out the whole driving experience. At idle the car would just shake like no other, and without them it purrs like a kitten. I deem them useless.

 

with all 3 motor mounts

Perhaps you should make clear the fact that the two of the three stock mounts are liquid-filled "hydromounts" and the third, lower mount contains soft rubber.

And when an ATX Focus idles in Drive, the torque converter is loaded against the mounts. When you switched all three motor mounts to, I assume, polyurethane, idling in gear became almost unbearable. It was when I tried just the urethane dogbone, lol.

Nice to know that when you got rid of four MAJOR NVH components, the idle smoothness returned as well as through the rest of the rev range? Amazing (not being sarcastic).

~

 

Yes, I replaced them all, as I destroyed a passenger mount, and had the dogbone, I went with the rest of them. Rear is CFM race, and the other 2 are from Focus Sport.

My idle was set for an even 1000 with the mounts before which was somewhat smooth. Now I have it in the 850 range and it is great. Smooth all the way up.

Yes it was pretty nasty with the 3 mounts and the Balance Shaft still in place.

 

Another possibility that I'd recently considered... is that the Ranger's oil pan would not have cleared the steering rack and crossmember of the truck with the balance shafts in place.

If you compare a Focus and a Ranger pan (we've got both in the garage), it seems pretty clear that it might not have been so much an NVH issue as a fitment concern.

 

...it seems pretty clear that it might not have been so much an NVH issue as a fitment concern.

The first published reports as to why the Focus got the shafts and the Ranger didn't mention the NVH scenario. Perhaps the writers were misinformed.

Add that to the fitment issue you've just cited, along with the cost-savings associated with building hundreds of thousands of Ranger engines without said luxury shafts... and there you go; no shaftz0idz.