Krupp Presta Cams

[Flats Man]

This is for L8 Apex or anyone with info. I have some cams that came out of a 2001 Roush 4.6L that say Krupp Presta and has two us patent numbers and a model number. I am told they are stock GT cams with Stock lift and duration. However, they appear to have more lift that the "lightning" cams I had. First question is the lift and duration of 2001 stock GT cams. Some of the Mustang boards are saying they are in the .500 neighborhood with duration around 200 degrees at .50. That sounds high to me for stock cams. Second question is the stock lift and duration on a Lightning which I am told is the same as a GT which is hard to believe. Thanks for any input!

[BigBob]

Here's the info someone was nice enough to give me recently:

From the Ford cam spec sheets..
'99-up PI cams:
Intake lobe lift, 7.11038mm, this translates to .503" of valve lift with a 1.8 ratio follower.
Exhaust lob lift is 7.49794mm, this translates to .531" of valve lift with a 1.8 ratio follower.
Intake duration at .050" lobe lift (1.27 mm), 186 degree's of duration.
Exhaust druation at .050" lobe lift (1.27mm), 194 degree's of duration.
115 degree's of lobe seperation.

'96-'98 Non-PI cams:
6.58mm lobe lift, both intake and exhaust, .466" lift
Intake duration at .050" lobe lift (1.27 mm), 186 degree's of duration.
Exhaust druation at .050" lobe lift (1.27mm), 194 degree's of duration.
114.5 Lobe seperation

JL

[Flats Man]

Thanks Big Bob, I am trying to justify some Moto Max or some other aftermarket cam. It looks like basically I am paying (through the nose) for duration. I am happy with the lift numbers but would like a little more than stock duration, say around 220 degrees or there about. I will be running a forged 4.6L with a D1sc ATI blower at 12 lbs to begin with. Any ideas as to lift and duration for this motor. Our target RWHP is 500. An identical motor with the same equipment just turned 529 RWHP on the dyno with custom cams.

[BigBob]

That's why I have the numbers. Like you noticed, stock cams are very short on duration. I was looking at the "Stage I" SC cams with 220 intake & 230 or more exhaust duration, but want a 114 lobe angle and probably a couple of degrees advance. Right now new billet cams are hard to find and custom grinds even harder. Be aware that the first set or two of Mod Max springs were prone to breakage according to posts and rumor. Even ported mod heads do not gain any flow much above 0.500 lift, so duration is where gain is. Looking for wider lobe angle and advance to perserve the boost and monsterous torque of the L. Have a very similar custom cam ordered for my KB SC 5.0 Twisted Wedge Mustang, if it ever arrives.