[DaFlake]

I've been contemplating the crank pulley upgrade, but have been reading a lot about pulling the harmonic damper off and putting one without not being that great of an idea due to vibration.

What are everyones thoughts on this? I mean for a track car who cares as you are trying to maximize performance but for a daily driver, I would rather not shorten the engine bearing life for the extra power.

Comments?

[batou]

Very interested in this myself too.... good question.

[Snowie]

I have GTT + 3% crank pulley, it has been on for about 10,000 miles

There is no noticeable difference in engine vibration at all. A very discrete way of achieving more SC boost.

Alan

[DaFlake]

There apparently was a huge debate on this at NAM, but nothing ever came of it. I am just curious as to what the thoughts of our vendors might be and from people that have done the mod.

It just seems to me that you would be putting a lot of stress on the engine by getting rid of the damper.

[Fisher]

I am thinking about the lightened crank pulley but I have already got the lightened flywheel.

What about that combination? It's OK to get the pulley too or not?

[GTT 280]

I'm running a +1% and no vibration. It's a lightweight one too

[Keano]

I found this:

Mini Harmonic Damper

explains the need / purpose of the harmonic damper...

hope it helps

My understanding of this is that the harmonic damper dampens the larger vibrations associated with the natural frequency (frequency at which the amplitude of vibration is larger than normal) of the crank.

The article implies (to me) that any alteration to the rotational mass of the crank would result in the need for an adjustment to the harmonic damper to compensate. Removal of the damper would mean that there is no dampening of forces from the crank which could potentially cause damage. However there doesnt seem to be anyone who has actualy had a problem with a lightened crank pulley (that I have seen) so maybe these forces are negligible. It may also be that if the crank is designed well enough in the first place that there may not be a need for the damper...

Keano

[MINIMANIAUK]

On some engines the damper can have a huge effect and engine life be shortened drastically, the crank mass and stiffness are the main problems -larger engines and longer engines v8/v6 would be very susceptible, however the MINI is blessed with a small engine ,low mass crank with good torsional stiffness so less of an issue
External items driven by the crank also have an effect on the resonant frequency (read supercharger) so changing s/c pulley also has an effect on vibration
Any major effect on longevity would have shown up by now with bearing failure and oil pressure issues .
If chasing large power outputs a degree of loss of longevity must be accepted,but I doubt the damper is a major issue

[sam_a156]

Quote: Originally Posted by Snowie (original)

I have GTT + 3% crank pulley, it has been on for about 10,000 miles

There is no noticeable difference in engine vibration at all. A very discrete way of achieving more SC boost.

Alan

Second that. I also have the GTT +3% crank and I am happy with it. No noticeable downsides, just more midrange punch.

[MINI-Morgan]

I have a GTT +1% crank or +4MM not sure im confused on that one still. But my experiences seem to be different from others but then maybe its either my setup or im really picky and notice everything.

I find that the engine feels rough compared to with the standard and very heavy crank(Wow its heavy! and mines a facelift model!) and most of all in summer when you put the air con on it feels like the engine is being dragged down so bad. You really know when the air con clutch goes big time. **Click** suddenly the revs go down and come back up again but then the engine justs feels really rough and then **Click ** the clutch disengages and the revs jump slightly and back down again to normal smoothish drive till the clutch goes again.

Ok so thats not the worst thing in the world... but.....I drive one of the first facelifts and as many people know the idles are rubbish and erratic sometimes. So add aircon being on at the same time as a minute of rough idle and you either switch the air con off, rev it for a sec or get one hell of a vibration massage.

So if you dont have aircon I would seriously recommend one especially on a works But I would recommend an enlarged alternator pulley too. Some will laugh but I witnessed a major drop in mpg when I have the music going on a journey with the sub going. Related or not.... well I do believe that anything connecting to the crank pulley will cause much more drag on the engine with an enlarged pulley.

But hey mines coming off in the next couple of weeks so I will be interested to see how it performs then.

P.s. how many of the +3%s have Works? All? Mines 17% and a +1 so I do think mines a bit too far to be smooth.

[Bhozar]

My works has had a +3% crank on it for 32k miles now with no problems. I didnt notice anything with regards to smoothness or idle after it was done.

[Revolution Mini Works]

I know this is a touchy subject but I have seen personally 4 engines break oil pump gears and all 4 of them had crank pulleys......

take it for what it's worth

[DaFlake]

Guys, just to make this clear, this is not vibration that you would feel but rather vibration that your engine would. Your engine mounts would dampen the effects of what you, as a driver, feel.

MINIManiaUK has a very interesting point but where my concern lies is that MINI was concerned enough to put a more expensive crank pulley on there then why do it? However, his response does make sense.

[DaFlake]

Quote: Originally Posted by Revolution Mini Works (original)

I know this is a touchy subject but I have seen personally 4 engines break oil pump gears and all 4 of them had crank pulleys......

take it for what it's worth

Hmmm... Could it be that we are finally starting to see the affects of this? I mean failure wouldn't be right away but over a period of time.

[Revolution Mini Works]

Quote: Originally Posted by DaFlake (original)

Hmmm... Could it be that we are finally starting to see the affects of this? I mean failure wouldn't be right away but over a period of time.

these were all 230whp+ cars with crank pulleys.... the oil pump gears are made of powdered metal. We will be designing some that are billet

[DaFlake]

It is the age ol debate.... I want more power without sacrifice. The idea is to get more power without severely shortening the life of the engine so I am a bit concerned about this mod.

[GTT 280]

Quote: Originally Posted by Revolution Mini Works (original)

these were all 230whp+ cars with crank pulleys.... the oil pump gears are made of powdered metal. We will be designing some that are billet

...ah, so you do need to upgrade other parts to become more resiliant when upgrading the power.

Cheers,
K.

[Paul Webster]

Quote: Originally Posted by GTT 270 (original)

...ah, so you do need to upgrade other parts to become more resiliant when upgrading the power.

Cheers,
K.

How big was your smile when you read that

You will always find more weak links as power levels and rpm are raised, I suppose thats what they call progression.

Thinking about it Karl it might be worth you putting a 15lb pressure oil light in before your next outing, a light is better than a guage because I defintley dont look at mine

Auto Meter Pro-Lite Pressure Loss Warning Light - JEGS

[GTT 280]

Ha ha, yes, indeed

An interesting gauge. Is it easy to fit something like that?

I am getting the DashDyno SPD and that can take 4 external sensors - perhaps one could be an oil pressure sensor?

Cheers,
K.

[DaFlake]

Quote: Originally Posted by 1320autos (original)

How big was your smile when you read that

You will always find more weak links as power levels and rpm are raised, I suppose thats what they call progression.

Thinking about it Karl it might be worth you putting a 15lb pressure oil light in before your next outing, a light is better than a guage because I defintley dont look at mine

Auto Meter Pro-Lite Pressure Loss Warning Light - JEGS

I think that is pretty normal when you are taking a stock engine and trying to increase power. Parts have a certain threshold that if crossed will cause failure. It isn't like we are taking a an engine, breaking it down and then rebuilding it will better specs. Ah the good ol days... I remember building that 450 in my friends garage with this dad. What fun....