Cam specs

[bobalattie]

I’m looking to add a little more grunt to our 4.6l Crown Victoria that we race in 24 hour of lemons.

Looking at some of the shelf cams from different companies they list specs for the lobe and what the valve is seeing/doing. This has me kinda confused.

281 inches, oem intake and exhaust, 9:1 PI engine moving a 3600lb car, we have increased the breathing a little with bigger Maf and throttle body, 2.5” exhaust, we are still using the automatic trans and have 3.73 rear gear. I think I would want something in the 220@.050 with .550 lift, but those turn into big durations at the valve and I’m a little confused by it.

Maybe 200-210 @.050 at the lobe then gets us 220 ish at the valve?

Can someone help make this a little more clear for me? Thank you

[96blackgt54]

Just grab a set of cams from a newer pi 5.4l 2v. They had the most breathing aspects of all the stock cams for modulars. By staying stock cams, no computer tune will be needed.

[rfoll]

Of course, if you have access to a 5.4, you could install that for more grunt.

[96blackgt54]

Good idea, but a computer tune would be needed to understand the extra cubes.

[bobalattie]

We are on an eec-4 obd1 ecu.. we upgraded to the Lincoln Mark 8 ecu to raise the rev limiter and a more aggressive timing profile. The long block is out of a 04 f150. So it’s kinda a mishmash of parts that work well so far. I was looking at the Crower stage 1 cams. 200/204 @.050 at the lobe and 216/220 @ .050 at the valve .540/.549 lift.. I think I could get away with no tune with these?

[427dart]

Don't go to wild on the cams since those stock heads run out of breathing at 5000 RPM and you still need some good low and mid range torque.
I had a 2001 Mustang Bullitt GT for 14 yrs. Just a peep of daylight under that left front!

[96blackgt54]

Im gonna dis-agree about the heads running out of breath at 5k rpm. I will agree about keeping a low end torque type cam for the 4.6l. The one i suggested earlier would open up the upper rpm and keep the torque unlike the stock vic cam.

[427dart]

Im gonna dis-agree about the heads running out of breath at 5k rpm. I will agree about keeping a low end torque type cam for the 4.6l. The one i suggested earlier would open up the upper rpm and keep the torque unlike the stock vic cam.

Well they do! The 4V 4.6 Cobra of 2001 and the later Mach 1 would run away and hide after 4500 RPM.
The Bullitt came with the Ford Racing 2V intake which flowed more air than the heads could use and only added about 5-10 HP to the stock
2V 4.6.
With headers,tune and a custom JLT cold air setup I could run 13.05 on the drag radials at a bit over 105 MPH.

[Walter R. Malik]

Port the heads ... be sure to lower & pull back the "mask" around the intake valve diameter in the combustion chamber.