408 not making power
10-27-2007, 09:56 AM
#41
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anyone else ever had trouble with pushrods that were too short causing a loss of valve lift and valvetrain noise? I'm using CTSV-R lifters, which are supposed to be quiet and they're quite noisy. I didn't measure the Comp Cam base circle that was installed in my motor but with .600 lift I'm sure it's at least .050" smaller than an LS1 cam. How much power could I lose this way?
10-27-2007, 10:32 AM
#42
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anyone else ever had trouble with pushrods that were too short causing a loss of valve lift and valvetrain noise? I'm using CTSV-R lifters, which are supposed to be quiet and they're quite noisy. I didn't measure the Comp Cam base circle that was installed in my motor but with .600 lift I'm sure it's at least .050" smaller than an LS1 cam. How much power could I lose this way?
My 408 made 520rwhp 500trq with A4!
10-27-2007, 10:41 AM
#43
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Check your pushrod length. My L92 setup with Patriot Extremes and stock L92 rockers used a 7.3 pushrod...... just like folks with trickflows needing a 7.5 pushrod................... 7.4's dont go in every car.
10-27-2007, 02:32 PM
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I think you need the mill the heads for some more compression as well as changing the cam. You dont nessecarily need to go bigger on the duration but I think if you went with a cam with more lift you would gain some power. A lot of the aftermarket ports for the L92 heads flow the best around .650" lift, so if you can find a cam with lift in that area I think you car would pick up some power. 1 7/8 headers would also help. Good luck with the set up.
10-29-2007, 06:12 PM
#45
I tried to find mention of degreeing the cam. I didn't find it, so have you degree'd the cam? Anyone that has built alot of engines will tell you that they have put a cam in straight up and had the valve timing way off due to a funky grind. Degreeing the cam might be a suck job with the cam in the car, but it's better than fighting demons with your cam timing off!
