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Dwight Southerland · 07-01-2011, 08:49 AM

Bill -

If you are working on the turbo slant 6 project, it might be that the effort ($$ & time) spent trying to put a roller cam and lifters into the motor would not have enough ROI to be worth it. I do not believe that there is enough power to be gained above 6000 rpm or so to warrant the roller setup. The slant 6 valve train is light enough to be controlled with available valve springs at that engine speed. Remember that a flat tappet arrangement has the design characteristic to have much faster off the ramp acceleration and faster ramp action under .150" lifter rise than a roller cam and that is a great benefit to the performance of a boosted engine. I would spend more energy on camshaft profile for a flat tappet cam than get anal about a roller lifter moving the valves. I bet there wouldn't be a 2% difference in power output after five years of thrashing between a flat tappet engine and a roller tappet engine. IMHO

The cylinder head flow is your biggest limitation on that combination.

07-01-2011, 08:49 AM	#21
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,001 Likes: 64 Liked 780 Times in 194 Posts	Re: Is it feasible to metal spray a cam? Bill - If you are working on the turbo slant 6 project, it might be that the effort ($$ & time) spent trying to put a roller cam and lifters into the motor would not have enough ROI to be worth it. I do not believe that there is enough power to be gained above 6000 rpm or so to warrant the roller setup. The slant 6 valve train is light enough to be controlled with available valve springs at that engine speed. Remember that a flat tappet arrangement has the design characteristic to have much faster off the ramp acceleration and faster ramp action under .150" lifter rise than a roller cam and that is a great benefit to the performance of a boosted engine. I would spend more energy on camshaft profile for a flat tappet cam than get anal about a roller lifter moving the valves. I bet there wouldn't be a 2% difference in power output after five years of thrashing between a flat tappet engine and a roller tappet engine. IMHO The cylinder head flow is your biggest limitation on that combination.