Discs in cooling fins??

[simonb]

Does any body know what they are for? Never noticed them until I found one on the floor and after having a poke about noticed them pushed between the cooling fins, seem to have lost some others before now. My guess is to restrict cooling?

[bluestoesonnose]

Usually to stop the fins "ringing" and reduce noise

[simonb]

Thanks for that! Is it necessary to have them as i seem to have only 3 left? If so do you know if there is a 'tech' name for them?

[The Caretaker]

'resonance dampers' i had them on my old honda, they stop the fins vibrating at certain revs and acting like a tuning fork :D



Duhh sorry bluestoesonnose, lol ill look next time !

[slob]

I rebuilt one of my motors about 15K miles ago and left them out, the motor clatters like hell between 5.5K and 6K RPM. I bought some more to put in and will be sticking new ones in the other motor that I'm currently rebuilding.

[simonb]

Thanks for the answers. Are they available from M-Rapido or widely available from auto suppliers?

[slob]

I got them from Moto Rapido.

I found them almost impossible to insert. Obviously they fall out when the lose elasticity and shrink a bit from the cooking they get. Conversely the new ones are so soft I couldn't get them in without pushing a screwdriver right through them, which is why they're not all replaced yet. I think I may have to make a 'disc pushing tool' and lubricate them with brake cleaner or something similar that will evaporate without leaving a residue.

[Dukedesmo]

I took them all out of my 900 cylinders fins, I have no idea what difference in noise they make but I won't be putting them back.

As such I've got quite a few in a box in the workshop, free to anyone who wants them...