Quote:
Originally Posted by DavieOxide
Hi folks,
I'm new to this forum but have had been reading through through this thread with great interest. Lots of really good information on here!
I have been running the cosworth SC for about 9 months now and have put about 16k miles on her . Beginning to get itchy fingers again so i have just ordered forged internals and a bunch of other good stuff.
I am going to make up a set of pulleys to speed up the SC. Does anyone have any thoughts/comments on running a secondary set of pulleys in front of the crank pulley? It would save changing all the stock pulleys and you could run a really neat short belt. As far as I can see the only thing in the way is the inlet pipe and I would think this could be re routed. I'd really appreciate some ideas on this.
Cheers in advance.
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if you're going SD ( speed density) then yes you can modify the inlet pipe to not include the stock airbox and MAF meter , if you need some support to achieve this then I'd be happy to help where I can
the minimum radius you can run is 25mm on a PK tooth belt so bear that in mind when designing your nose pulley and you'll need to run about a 3:1 ratio to get the boost into the sweet spot for the unit, so as the crank pulley is 137mm diameter ( I think from memory) then you will need to make the crank pulley bigger and possibly require 8 ribs not 6 to account for the extra power to drive it.
however one issue with extending the length of the pulley so its no longer overhung means that you will be canterlevering the bearings in the nose casting
now they will cope with a certain level of load but the overhang needs to be kept to a minimum and some kind of tensioner will be required as you need to try and achieve a minimum of 180 to 200 degrees of belt wrap on the charger pulley