Bling!
Turbo Mini Forums

http://www.7ent.com/detail.cfm?pageid=1894


I want one!!!!

How about you?

with that sort of price tag i think ill be giving it a miss

I always thought (right or not ?) that the function of a crank damper was carefully calculated weights connected by the damping medium (rubber in this case) if the weights are changed the damping frequency will be changed.
In my poinion this is as per topic title all bling and no function.
What do you reckon?
Regards
Dave

Edited by danboy on 12th Jan, 2007.

danboy - correct explenation - the "mass" of cast iron on the rubber section will resonate at a pre-determined frequency - engine speed to counter act the 3 bearing crank having a whobbly attack and making the engine feel/sound harsh! - the reciprocating assy (crank/rods/pistons)will go through more than one reasonance point, the mass damper is there to take the worst one out. The alloy damper in the link is also on an elastomer but due to the mass being much lower, unless they've made the outer ring larger or used a harder elastomer - it will likely have a useful mass damping effect very very high up the rpm range - it takes specialist equipment to measure these devices and develop the damping effect - not easy things to design.

- but it does look good!

If Carling made Mini engines
it would probably be like this one!

so all the pulleys machined by Tom F and the like will move the damping frequency up in the rev range then?

John, couldn't have put it better myself. Just one thing, my brain is telling me that the elastomer would need to be softer to have the desired effect?
Regards
Dave

That is a good point. However, i'd expect the people that mades these, have taken this into consideration.

Lets not forget that the overall diameter will play a part also. These look bigger in all respects.

However, here's some more bling http://www.7ent.com/detail.cfm?pageid=1872 In steel this time.

While on the subject of the damper function being matched to the crank, what are people doing when stroking cranks, lightening cranks and machining the pulleys for a crank angle sensor. I personaly have never liked the latter, the damper is lighter and the ballance is all to cock.

Ok, here we go I am sticking my neck out on a subject I am not qualified in but maybe logical thinking might help.
By machining timing grooves round the perimeter will up the threshold where the damper works but not by a significant amount.
The rubber in most cases will be years old and much harder than when new and this also will move the resonant frequencey up the range? How many of us give a thought to replacing the damper to restore it's correct function?
The ali damper would need to be considerably larger than the steel one to have the same effect and the engine mounting bracket will not allow a big enough increase in diameter for the damper to be effective.
I have read in parts suppliers lists that the old cooper s damper is the one to have, Well if you remove the fixing rivets from the rear of a later pulley and remove the disc you finish up with a damper that looks (is) identical to a "s" one, At least the two in my garage do.
Regarding the missing tooth, on a 36-1 set up, upsetting the balance ao the engine. If any of us has an engine balanced that accuratley that is makes a difference why don't they just drill a hole diametrically opposite into the front face of the pulley to remove the required weight and all will be OK. Remember it's only at a radius of 50mm or so. There is probably lots more imbalance created by an unevenly worn starter ring gear.
One final point and it's not a dig at anyone but I think it's a little nieve (SP) to assume that all parts manufacturers do the correct amount of R&D because they do NOT.
Regards
Dave

Edited by danboy on 12th Jan, 2007.

Of course everybody on here is getting the damper machined first then having the engine balanced afterwards .... surely?

Not sure it would make a huge difference but that is the way that it should be done. The same as with John K's timing disc, fit it before balacing the assembly.

Every day is a school day ...........

How fast and how expensive ...... the same question...

I have the S one, its two piece, so it can not be "reproduced" by altering the other type. you can get the S ones new. Mine are new and machined like Tom does. Its balanced after that. I have broken a rod bearing after this, but that was not close to the pulley and is believed to be of another reason.

Andre How do you mean "two piece" can you put a picture on to explain to me. Please!
I would like to understandRegards
Dave

http://www.minispares.com/Product.aspx?pid=33426

http://www.minispares.com/Product.aspx?pid=36125

http://www.minispares.com/Product.aspx?pid=32804

i have a romax damper for my engine, the timing stamps are the wrong way round. Swiftune sell them if you want a uk supplier, last time i checked it was £140ish inc del.

I've seen the future and tbh its Pie

one thing to remember, that standard dampers are NLA. Cooper s ones are kindly reproduced by Mini Spares.

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Andre/Mini Sprocket,
It looks like I have been misunderstanding things for some time now regarding "s" dampers.
If you look closely at the picture below you will see that the black damper Has 3 holes just outboard of the boss and the green one has 2 tapped holes.
Toall intents the two dampers are identical other than the holes.
The green damper and another like it that I have were removed from 1275 "s" engines many years ago.
The black one is an A+ with the tin disc removed as per the previous post.
I assumed that the ones removed from the "S" engines were the correct part for an "S" but this is obviously not the case.
Can anyone tell me what they are from?
I am pretty sure they are early '70s vintage.
Regards
Dave