Cool, good to hear onasled. Since I'll eventually go with a lightened flywheel when the tranny get's openned, I can't wait to hear the reports from those who have both! I'm hoping that it won't necessitate a 3k launch, because if so, I'll do just one...

 

This article:

http://idisk.mac.com/thezachs/Public/MCS_Powertrain.pdf

discusses differences between the Cooper and S engine.

at section 4.2.1 it states:

"The basic engine for the Mini One and
the Mini Cooper is fitted with a conventional
torsional vibration damper at the front
end of the crankshaft. Calculations and
measurements showed that the addition of
the supercharger with its relatively high
moment of inertia was resulting in excessive
torsional vibration at about 1600 rpm.
This solution was unacceptable both
acoustically and in terms of component
strength.
"The torsional vibration damper used on
the Mini Cooper S engine therefore has the
belt pulley additionally isolated elastically
from the secondary mass, with belt drive
vibration damping. Vibration amplitudes
are significantly reduced by the isolated
belt pulley. However, the decisive factor is
that the most marked resonance is shifted
into a zone below idle speed and is therefore
outside the engine’s operating range,"

Now someone who understands this please comment. To me it seems that something was done to reduce the resonance below idle, but the job was done by additional isolation of the secondary mass (supercharger). Was that just the belt drive and idler pulley? If the crank pulley on cooper and S are same, then something else was done and maybe it's just the supercharger pulley drive and idler. If crank pulley for cooper and S are different, was the change to the pulley alone or was it to the belt drive mechanism (idler pulley?) also, or what?

 

Take alook at these 2 pictures. The Cooper does NOT have a damper, the S does. Looks like it is needed.

 

Yes, what happened to it? I don't see it listed on your website. Did problems develope?

 

No issues, and want to make sure of that in the long run.

 

how will yours compare to the alta unit... i realize the alta unit does not have the vibration damper... yet does it make a big difference to gains? i already have a 15% pulley, and still finding the engine bogging when i have more than 2 people in the car or when i have the a/c on... with the lower weight, will the alta outperform your unit in exchange for SOME long term ill effects?

thanks!

 

SteveS,
Good find, lots of good tech info about the mini in general. I don't think anyone will argued what the engine dampener is supposed to do. This has been discussed a few times in pages past and in some other threads. The question is "is it nessecary??" This article makes it out to be totally nessecary and it will cause major problems if they didn't have the dampener.

In this same article they boast how the mini IC is SO efficient, and how EASILY the air flows from under the IC out the engine compartment!! It seems as though they may not have look that close at the engine! There is hardly any room under the stock IC, and there is no clear pathway for the air to get from under the IC to the outside. So it seems as though there are some things about this article that are over stated or wrong.

No matter what, it will be about time. The longer people run our pulley, the more people will see it doens't matter to have the dampener.

I would recommend to all the new readers of this thread to read starting from page 1. There may be some answers to some of the doughts people might have about this part. One of the best posts is from Ryephile (page 3), when he talked to one of the engine designers about the pulley.

 

The main gain that is percieved is the extra boost in our case. We can make a 5%, a 2%, or a stock size with out much issue. It all depends on what you are looking for. We do remove a good amount of rotational weight from the pulley, and keep it's Dampening Charecteristics. That is what is important to me, and this is why I went this route.

 

Onasled's pics of pulley tools and their use and his install are not on the site anymore. Can Someone reload them.

I'd like to be able to figure out some way to improvise the puller or use traditional puller. Unless someone local (Santa Ana, CA) can rent or loan them to me.

 

I too am wondering about improvisation of tools for removing/installing the crank pulley. Thanks.
MinMax

 

I kind of look at this stuff and see the JFK grassy knoll. Only a bunch of failures are going to give enough evidence that the HB is really needed and it would take a forensic mechanic to figure it out anyways. In my opinion the gains outweigh the possible drawbacks. And if 1600 rpms are where the vibrations are, I'm just going step on the gas that much harder and rev on by that much faster and not worry about it. My worthless $0.02 worth.

 

ONASLED,
I'm not abble to see the pictures or the video. Could you check the links to the Pictures and video for the Crank tools. Thanks Henry

 

As I'm trying to decide if a crank pulley is a worth modification (consider that I have a non-S Cooper), I find myself upping this old thread, and particularly this interests me:

Now, since I'm going to swap my tranny for a 6-speed in the future and I'll probably go with a lightweight flywheel and stronger clutch since I'm at it, I was wondering if, done that, mounting a lightweight crank pulley is going to damage my engine.

Consider that the lightweight flywheel I'll be using will be lighter than my stock one, yes, but not so much because to fit a 6-speed I'll have to purchase a flywheel for Cooper S and the S flywheel is significantly heavier than the "juastacooper" one...

 

^^^Years...and much experience with the Tritec engine later, I would revise my statement to say that a ~1 pound crank pulley paired with a ~12 pound flywheel [assuming a stock-ish clutch configuration] is my recommendation for lowest acceptable mass for all but the most extreme endurance applications [read: 24 hour races].

 

So with this clutch:

http://www.clutchmasters.com/shop/?p...053&AppID=6925

and this flywheel:

http://www.clutchmasters.com/shop/?p...053&AppID=6979

would you mount a 0% lightweight crank pulley? I think I've read the Clutchmasters flywheel wight somewhere in the forums but I can't remember where...

 

The flywheel


The pressure plate

 

Personally, I run a Clutchmasters FX200 clutch and flywheel combo with an ALTA 0% crank pulley in my '02 MCS track-toy. I'm not very talented at heel-and-toe, so the light rotational inertia helps me downshift in the brake zones while minimizing front axle lockup.

 

Thanks to both of you for the reply, I think I'll go with the FX100 clutch and flywheel combo plus the 0% pulley then. A FX200 might be too much for the level of power and torque I plan to achieve...

 

k-huevo, have you ever done a how to on this?

I am about to change out the 03 pulley for an 06 one and have a good generic Harmonic balancer/pulley puller that I can use. Just came back from the hardware store with my guess on pulley bolt size, I'm guessing by test fitting my spare 03 and 06 pulleys. So I picked up 1- 12x1.25x75mm, 1 - 12x1.50x80mm, 1 - 12x1.75x80mm, if it's 12mm one of those should work.

Do you know the pulley bolt size and pitch?

I'm going to make my own crankshaft pulley holding tool for tightening up the new one. I found the puller holes in the 03 and 06 pulley are 6x1.0mm, so I got some that are 75mm long and a bunch of flat washers for spacers if needed..

 

Here’s a how-to in PDF using OEM tools https://www.northamericanmotoring.co...light=bomboasy

The crankshaft bolt is 12X1.75X74, the extracting bolt grip size & pitch you have is correct. I recommend using a new OEM bolt when installing, there is a risk of bolt stretch on the original and the new bolt will have proper thread lock applied. If you intend on using the 12X1.75 bolt as a thread protector, the OEM tool is 100mm, and the pulley sleeve depth about another 36mm. The 6X1.0 OEM extractor bolt grip bolts are 65mm.

A holder tool can be omitted by placing in gear and having an assistant step hard on the brake. The OEM installation tool is worthwhile; I would imagine an alternative could be found (rather than using progressively shorter bolts which may gall the crankshaft threads), like those installers for power steering or alternator pulleys, but I haven’t looked.

 

I do intend on using the 12X1.75 bolt as a thread protector. Having both pulleys on hand at the store allowed for some guesstimating. The 6X1.0 OEM extractor bolt grip bolts are 65mm, this works for me with the 6X1.0X75mm bolts because the puller is 10 or so mm thick.
Nice tip;
A holder tool can be omitted by placing in gear and having an assistant step hard on the brake. < or lock them up with an old screw driver in a rotor vent so it can't turn in the caliber.
Was planning using progressively shorter bolts/washer stack or standoff spacers with graphite grease on the bolt threads to prevent galling of the crankshaft threads. Allowing at least 1/2" bolt purchase in the crankshaft before force is applied to the pulley being installed.
Approximately how deep are the crankshaft threads?
Couldn't find a 12mm bolt long enough to make an install tool from.
So I just had an idea for making one up from a 12X1.75 bolt, cut the head off drill and tap that end the scew in another bolt and use those threads with two nuts spot welded together to push the pulley on.

Are the BMW tools very expensive?

 

Crankshaft threads are ~30mm deep, only ~23mm used by the pulley bolt.

Good idea on the installer tool, it doesn't require much torque if there is no friction at the contact surface, but it must be true.

Expensive is relative, I think they are compared to Snap-on (which are high to begin with) for instance, but well worth it for ease of use.

 

That OEM crankshaft bolt in the PDF file looks to be a special app. bolt, noticed the shoulder under the head.
This PDF file should be a How to Sticky. Great job

http://www.mini-mods.com.au/files/ho...rankPulley.pdf