View single post by Judson Manning
 Posted: 06-10-2005 08:33 pm
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Judson Manning



Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406
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We've discussed cams at length elsewhere on this board...you may want to do a search.  Also, Greg has done a lot of explaining in the JHPS store.

One of these days we're all going to get around to doing some dyno tests to show exactly what to expect from this kind of upgrade.  Until then, you'll have to rely on people who've done...all of which will tell you their's is the best solution!  lol

All cams use the same sprockets.

Not all cams can use stock springs and followers (i.e. 104 cams).

The 'flat-top' 9.5:1 piston is the single best upgrade anyone can do on a 907.  I cannot begin to tell you the huge difference between engines I rebuild 'stock' vs. stock w/ 9.5:1 pistons installed.  It's an easy 20% boost in torque across the board.

I would call the 107 cam a 'Phase I' upgrade.  It has less duration than the stock cam, but more lift resulting in a broader torque curve and better drivability.  Unless you are living above 5500rpm on a daily basis, the 107 is a fantastic cam.

Any other cam will require you to do some additional work...specifically, the cam breathing potential will exceed the JH head flow ability.  Using stock Strombergs and a less-than-optimum exhaust makes this problem worse.  Low end drivability typically suffers as well.

Boosting the engine performance by 10%-30% is easily done with stock Strombergs, Flat-top pistons and the 107 cams.  Getting more power out of the 907 requires A LOT more than just swapping cams.