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Author Topic:   1 to 1 billet pulley question
Dirt Maniac

Total posts: 145
posted December 20, 2004 10:46 PM  
Is it recommended to use a 1:1 billet pulley kit on a gas engine that will turn around 8000 rpms?
Archives suggest use a 1:1, but I was told not to use 1:1 if turning high rpms.
If not, what is best (25 or 30% reduction)?

Dirt Freak

Total posts: 229
posted December 21, 2004 06:52 AM  
I cannot see why you wouldn,t be able to use those pulleys and turn 8000 rpm, I would suggest using a stewart stage 3 water pump with a 3/4" shaft and make sure your power steering pump can handle those high rpms.
I know the KRC cast iron pumps cannot spin more than 5500 rpm, and they suggest using a aluminium pump for high rpm. or using a reduction pulley to slow the power steering pump down.
Measure the diameter of your crank pulley then measure the diameter of your p/s pulley, if your crank pulley is smaller you are reducing the speed of your pump, if the crank pulley is larger you are speeding the pump up, if they are the same then it is 1 to 1. I use 1 to 1 pulleys with a cast iron pump, my crank pulley is about 25% smaller than my p/s pulley and I turn around 6500 rpm.
Hope this answers your question-sorry for the novel.

Dirt Forum Champ
Total posts: 2007
posted December 21, 2004 07:54 AM  
yes you can use them. If you consistently turn that high of rpms you could prob get by with a 10% reduction if you wanted.

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