To answer the questions that have recently been asked regarding the M7 Speed Super Lightweight Crank Pulley we feel it is important to filter out the forum hysteria and mass amounts of mis-information from the technical facts.

M7 Speed is a High Performance Company engineering and manufacturing High Performance components in the High Performance marketplace. The definition of high performance is “modified to give superior performance”.

The M7 Speed Super Lightweight pulley is a very well-engineered and proven high performance component. It is intended to ADD performance to your vehicle buy reducing the weight (mass) of the rotating crank assembly. This equals better throttle response, quicker engine rev-up and more power.

Everyone accepts that every high performance engine and vehicle has one common element: “LIGHTWEIGHT”. Lightweight equals increased performance. Here is why;

Newton’s Second Law of Motion:

Newton's second law of motion can be formally stated as follows: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

Breaking this down into gearhead language: The lighter in weight (mass) of anything the faster it will accelerate….PERIOD! The goal of anything high performance with wheels and an engine is more speed and faster acceleration and velocity. More power and lighter weight equals speed. The Physics cannot be modified.

Yes crankshaft vibrations occur in all internal combustion engines. Most are caused by inherent “out of balance” designs such as the GM 60 deg V6 or the V-Twin Harley. Any inline 4 cylinder engine is a “naturally balanced” design. Fluid damping systems such as the ATI Super Damper are great products. They became popular with the onset of extremely high RPM and high power (high cylinder pressure) race engine configurations. Their intended function is to dampen out torsional (twisting) crankshaft vibrations caused by high cylinder pressure impulses occurring. 99% of all MINIs are not high RPM or high power builds. The added advantages of a lightweight crank pulley to a moderately modified MINI will outweigh any of the perceived downsides.

The M7 Lightweight pulley weighs a scant 14 oz, the ATI weighs 89.6 oz. and the stock damper weighs 113.6 oz. . Doing the math the M7 pulley weighs only 12.6% of a stock pulley and 16% of the ATI pulley. The pulley is a great easy bolt-on and low cost power adder.

If you want to make your car high performance and use your car as a daily driver, a spirited weekend canyon carver or autocross competitor then the M7 Super lightweight Crank Pulley will be a significant performance advantage at a very affordable price. It adds faster engine acceleration, a noticeable increase in throttle response and more power.

We have sold thousands of these over the 13 years M7 has been in business and have never had a complaint or report from any of our customers regarding bottom end engine damage.
Have FUN!

 

Does Newtons second law of motion prevent damage from this part?
If the factory has a damper why would you want to remove it?
Do you know what Fun stands for?

 

I'm pretty familiar with F=MA and I don't disagree that a lighter pulley increases performance, but at what cost? I don't have science or experience to back me up, but it seems reasonable that a motor designed and engineered to have a harmonic balancer/damper on it would have an increased probability of failure if you remove that balancer.

Alot of performance enhancing mods have the potential for increasing wear and/or decreasing the reliability. It's not the end of the world, but it does seem like it's something worth being aware of.

 

Please read again


To answer the questions that have recently been asked regarding the M7 Speed Super Lightweight Crank Pulley we feel it is important to filter out the forum hysteria and mass amounts of misinformation from the technical facts.


Yes crankshaft vibrations occur in all internal combustion engines. Most are caused by inherent “out of balance” designs such as the GM 60 deg V6 or the V-Twin Harley. Any inline 4 cylinder engine is a “naturally balanced” design. Fluid damping systems such as the ATI Super Damper are great products. They became popular with the onset of extremely high RPM and high power (high cylinder pressure) race engine configurations. Their intended function is to dampen out torsional (twisting) crankshaft vibrations caused by high cylinder pressure impulses occurring. 99% of all MINIs are not high RPM or high power builds. The added advantages of a lightweight crank pulley to a moderately modified MINI will outweigh any of the perceived downsides.

 

Seems the hysteria is coming from you M7. Oh my gosh these folks don't want to buy our lightweight undampened pulley!!! What to do, lets call those who don't want it hysterical. Yes that's it.....

Wellzy I agree with you 100 %.

 

Can anyone give an example of an engine failure due to a lightened pulley? If so speak up. I have been in minis from 02 and have never heard of it. Maybe you know something I don't know. Maybe not. Motor on.

 

I haven't heard of any mini's failing due to a lightened pulley, but I have heard of it on other motors.

 

I'm interested in any "horror" stories about lightened pulleys.

I had one on my 1994 Toyota Paseo for almost 50K+ and had no issues. I currently have one on my 2006 Scion Xb for roughly 10K and again no current issues.

Granted I'm not sure those had dampers but the noticeable acceleration are nice. I'm all for squeezing every bit of power out of a motor, but if there is a high risk of failure on something as expensive as a Mini to repair... You can definitely count me out if that's the case, haha!

 

2 words: Companion cylinders. Prevents imbalance.

 

Could you elaborate?

 

I put one on my Mini and I lay awake at night thinking of it exploding and sending me into the armco in a ball of fire.

Its been a long nine years

 

Hahahahaha!

 

Before I bought my Ireland pulley I did a lot of researching and phone calling, even pmd anyone I saw on the forum that had one installed. No one I communicated with could tell me an issue that the pulley ever caused, or even heard of an issue. Honestly I think m7 picked the correct word, "hysteria" I read the r53 engine is 70% balanced, wether that's a a good percentage or not idk.

 

A companion cylinder is one piston that is at TDC when another is at BDC. This helps to keep the engine running smoother by preventing vibration.

 

Is the mini engine one of these?

 

Yes, the Mini engine, as pretty much any other 2 or more cylinder ICE is designed with companion cylinders. 4 cylinder engines have the best low to mid primary balance due to the design, but more vibration at higher RPMs. Most MINI owners do not run their engines at high RPM for any amount of time, or on a regular basis this isn't an issue. In a MINI race engine, I would hesitate to run without a harmonic balancer.

Some good reading here:
http://en.wikipedia.org/wiki/Engine_...herent_balance

 

Combustion events cause pulses, which in turn cause torsional vibration. The next step from here is the harmonic crank resonance that the dampener is designed to absorb. Torsional vibration or said resonance without an absorption and dispersion method is transferred throughout the assembly. This particular assembly is a precision piece, containing most notably the crank and crank bearings. One can only assume that by eliminating the dampening mechanism, you're increasing bearing wear due to increased crank deflection & return.

All this talk about inline-4's being perfectly balanced is great and all, but there's no such thing. Bottom line, there's vibration occurring from combustion events and crank deflection; it needs to be absorbed, and will be, one way or another. By eliminating the dampener, you're choosing to have the crank & bearing assembly (among other things) absorb the vibrations, which it was not built to do.

Does this mean the motor is going to go KAPLOOEY? No, but it's ignorant to think that you're not increasing wear on parts which were not meant to see these forces.

Newton's Law of Motion is hardly enough to describe what's taking place here, as not only do we need to consider the intended function of the original part, but the inherent nature of the mechanism to which it's been applied to (and removed from).

 

increasing wear, perhaps, enough that it's causing an issue within the reasonable time these engines will run and be on the road, evidently not. Anyone who says crank pulleys are damaging MINIs probably believes in Bigfoot as well...

 

I believe in science. I believe in facts. I believe that something being 'good for the car' and simply being 'available' are not mutually inclusive. What's more, I have the education and experience to back-up my stance.

Just like this vendor believes his product is good for the car, there are just as many vendors / manufacturers who could easily produce such a part, but do not because of its potential to cause harm.

I mean, damn, step outside the NAM bubble for a second and do some research on your own; make a phone call. Try any big, high-end 4 cylinder specialist builder (Buschur, Crawford, Kings, Evans, AMS, etc) and talk to them about these types of parts. I know for a fact that Buschur uses OEM dampers only, and that's even on a "race car" that will likely see frequent bottom-end rebuilds. Newer Honda motors are "0 Gram Balanced", yet many builders still say to forgo the damper-less crank pulley. Is their word gospel? No, but it's something to consider.

Again, there's a difference between acute and chronic. Nobody thinks this will cause your crank to break one week in, but simple science and dare I say, common sense, says that it could increase long-term wear and for very little gain. None of this is to knock M7-- that's not the point. My point is that in order to make an educated opinion or contribution to the debate, you should first understand the science of it all.

Edit:

Steve Dinan (Yes, that Dinan) wrote an article called "The Danger of Power Pulleys & Understanding the Harmonic Damper". Find it, read it, think about it. Oh, and that's on a truly "perfectly balanced" inline 6

 

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Much the same could be said for the most popular power mod on the R-53, the reduced sized pulley .


Will it blow up the motor, NO


Will it accelerate wear , ABSOLUTLY


And yet its the main part of both the usual stage one mod not to mention the factory JCW kit. Of the approximately 35 HP increase you get from the $6000 JCW upgrade almost half of it is from a $ 120 pulley but that is another discussion altogether


After 13 years in production and hundreds if not thousands sold you would think there would at least be one documented failure directly attributed to a undampened pulley and yet the only thing that has surfaced is this discussion now and then .

 

I never said the inline 4 was perfectly balanced. It is inherently balanced due to it's design. At low to mid RPM the harmonic imbalance is minimal, and causes minimal stress on the crank and bearings. Does it cause stress? Yes. Will it shorten the longevity of the engine? Perhaps. Perhaps there is enough of an oil wedge to prevent it. Maybe instead of getting 500,000 miles you will get 490,000. There has been no side by side test of two MINI engines out of the box to determine it. Do your research before installing one. On a race engine that sees high RPM, I would definitely stay away. On a DD or occasional track day car, then perhaps. If your goal is to have an engine that revs extremely fast, then by all means, lighten everything.

 

I'm going to play Devil's Advocate for a second here, or at least 'Skeptical Susan'. When someone tears down a motor and notices excessive main bearing wear, it'd be very, very difficult to confidently attribute the wear exclusively to an undamped crank pulley. Likewise, if you 'spun a bearing' during operation, it'd take a more than a keen eye to say that this part alone caused it. The cause of wear or failure probably wouldn't be as obvious as say, crankwalk markings.

Having said all of that, the fundamentals have already been stated above: Each power stroke of an engine produces torsional vibration on the crankshaft. The crankshaft resonates, much like ringing a bell or a tuning fork. By adding the damper to the end of a rotating crankshaft, you add not only inertia mass, but a combination of materials with the intended function of absorbing the resonance. This is basic harmonic distortion cancellation using intermodulation.

Yes-- the R53 has a very short, flat-planed, forged crankshaft, but that doesn't mean physics don't apply here. If BMW could have saved $$, and built these cars without this part, they would have. This freaking part has existed since like 1902, so lets stop pretending the R53 is a unique snowflake to which physics, historical experiences and common sense does not apply. Stop being so hard-up to gain 3whp that you'd remove a fundamental part of your engine.

What's more, let's consider the fact that this motor is supercharged! Another large, balanced assembly which our engine's longevity depends on. MINI had the foresight to not only dampen vibration from combustion events at the crank, but did the same for the supercharger by "elastically isolating" the belt, as it was adding excessive torsional vibration at low RPM, per BMW's own documents.

You want throttle response? Go get a tune. You want reduced weight? Ditch the 26lb wheels & run flats.



Don't even get me started on smaller blower pullies. I run one. We all run one, and once again, the FACT is that with a stock crank pulley and stock blower pulley, the M45 is spinning @ 14,317 RPMS making about 10psi (1.6 on the Y Axis of Eaton's chart). Once again using Eaton's own efficiency map (http://www.eaton.com/ecm/groups/publ.../ct_128483.gif) you'll see that the 15psi typically seen from a reduced pulley puts you at 2.02 on the Y Axis, and literally off the chart @ ~16,000 RPM on the X Axis. Waaayyyy the F*** out of it's efficiency range. I personally can sleep at night overspinning the Eaton because it can be replaced in my garage for $800, whereas this is not the case with my main bearings or crankshaft. The facts remain though, much like they do for the crank pulley argument.

 

I just wanted to add something. It took all of about 10 seconds to find something that I found very interesting regarding this debate.

http://www.d-series.org/forums/engin...lley-read.html
Read Post #1. The quoted text was provided by Larry Widmer, owner of ENDYN and master engine builder. Check out his history and Facility here: http://www.theoldone.com/about/default.asp

Additionally, I called Eagle Specialty Products and SCAT Crankshafts yesterday, because I wanted to get some information first-hand from an established engine component manufacturer, rather than take the anecdotal evidence of Forum members, nor do I want to operate exclusively on my own opinions (as much as I think I'm right..). In short, everyone I spoke to at both shops balked at the idea of eliminating the harmonic balancer from an engine, and replacing it with a super lightweight billet piece. The reasons they gave have already been given above, multiple times.

Again, if you have any doubts about things like this, contact an expert; an expert who is not personally vested in one side of the debate or the other. No offense to M7, UR, or the others, but they are trying to sell a product which they produce. These guys build pulleys, air boxes, little fittings, etc. They are not precision engine builders, nor are they crankshaft manufacturers / balancers, etc.

 

Let's move outside the American V8 world for a second and look at something a little more advance.

Porsche GT2 factory crank pulley.. solid steel

http://www.6speedonline.com/forums/9...ulley-kit.html