7 replies to this topic

[robminibcy]

Hi I am swapping my worn a series for an a + engine. The a series has a non damped pulley whereas the a + is damped. Both are in good useable condition although there is slight cracking to the rubber in the damped one. What are the advantages /disadvantages for using one or the other.

Thanks

[Stu1961]

The 998 didn't use a damper where as the 1275 did out of necessity and was fitted as standard by the factory.

[robminibcy]

They're both 998s and the a+ is definitely damped. What's the purpose. Does it reduce vibration?

[jaydee]

To make it short, the longer the stroke the lower in the engine revs the crankshaft tend to have a vibration.

On a 1275 is at around 6k rpm so a crank damper is added to lower these vibrations and make the engine last longer.

I dont think 998 A+ engines ever came out the factory with a damper fitted though.

 

Note: never swap dampers from an engine to another or you'll have to rebalance the whole rotating assembly (flywheel-clutch-crankshaft-damper)

Edited by jaydee, 21 October 2014 - 06:51 PM.

[KernowCooper]

From memory its over 9000rpm when the 998 has issues with the harmonic.The larger damped pulley is a 1275 and the smaller if it uses one is smaller

Edited by KernowCooper, 21 October 2014 - 08:00 PM.

[robminibcy]

Thinking about it the a+ is a metro engine so the damper pulley was probably fitted to replace the origional as a metro is different to reduce the water pump speed. From that then should i use the non dampered pulley on the new a+ engine?

[robminibcy]

I don't think it will be going over 9k, not often anyway ;-)

[Craig89]

From my research when I was looking into this I found that the a+ engines had a damper fitted, a 1.3kg one for the 998 and a 1.5kg one for the 1275