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Rob 930 Rob 930 is offline
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Join Date: Dec 2002
Location: Seattle
Posts: 661
I believe that John Dougherty, "camgrinder" on this board, does not favor regrinding 930 cams to other specs. That's certainly true for the 930 to 964 change (I'm not sure about 930 to SC). Though some grinders will still do it (Elgin, for one), and I had it done long ago on one of my engine iterations, it has at least one disadvantage. In order to obtain the correct lift/duration numbers (say, for the 964 cam), the base circle must be ground smaller than stock, which means that the adjusting foot on the rockers must be screwed in quite a bit further than stock. Though it works okay, it's a little disconcerting to see those adjusting screws cantilevered out so far. There may be other problems as well; I'm sure John should address this for the final word.

But when you buy a new cam from John (and likely, from other grinders as well), all the new blanks are of the later style (sprockets held on with bolts rather than nuts), and both the left and right cams come with provisions for driving the scavenge pump (on the left side) and the power steering pump (on the right side). Depending upon your configuration, the grinder simply cuts off the unnecessary drive bosses. That way, there's only one universal blank for all 911 based engines.

Old 12-12-2007, 09:15 AM
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