I have a 2 litre pinto which has a 11.5cm. double pulley which I want to replace with a single pulley of the same diameter. Someone has kindly given me a single pulley but the diameter is 13.5cm. This makes it difficult to fit a trigger wheel for a megajolt but it also makes me wonder whether the higher revs. will cause damage to both water pump and alternator ?? Does anyone want to swap my double pulley (new one) for a single ??

I should have said that its a crankshaft pulley!

I am not sure, but the double pulley also acts as a damper for the crank and stops the crank whipping out the front main bearings

Mark,
Thanks for that response. I'm puzzled how the extra pulley would act as a damper but bow to your knowledge. Perhaps it would drive another ancilliary eg. power steering pump? I only want a single pulley to drive alternator and water pump and think that the 13.5cm. is too large to enable my trigger wheel to function. Do you have a spare 11.5cm single pulley?

^^ its the rubber isolator bit in the middle of the double one he's talking about

ford never bothered with it on the older engines and I've never heard of any problems - so I guess its something to do with the extra stuff like the power steering......