Got my XFI lobed cam in today
06-05-2006, 06:35 PM
#1
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Got my XFI lobed cam in today Some of you showed interest in the Comp Cams XFI lobes, and I said I would post what my cam Cam Doctored at when I got it. This is from one of my earlier posts with the specs.
And here are the Cam Doctor specs: (are they usually this far off??)
Lobe # 3761R Int @.006 272.4, @ .050 222, @ .200 145.6, Lift .599
Lobe # 3015R Ex @ .006 278, @ .050 226.2, @ .200 150.3, Lift .614
Here's where it get's a little confusing for me
Int centerline 109.2 ATDC
.050 lift C/L 105.9 ATDC
Ex centerline 109.2
.050 lift C/L 112.6
Why is there 6.7 degrees difference in the .050 lift C/L's?? Is this because of the two lobes having different ramp rates?? Anyway, these are the numbers Jonathan @ Thunder gave to me. Please feel free to offer suggestions, comments (good or bad), advice, or anything else that comes to your minds. There are a ton of numbers on this Cam Doctor sheet, if you need any more of them, feel free to ask.
Originally Posted by Gearhead1
I just ordered a cam Thursday from Jonathan @Thunder Racing. It has an XFI exhaust lobe, (274, 224@.050, 149@.200, .609 lift) but they didn't have an intake profile that matched what I needed. What I wound up using was a lobe not in any catalog, but found by one of the Comp Techs in their files. It specs out at 269, 220@.050, 145@.200, .597 lift. It's between a XER and a LSK lobe. It won't be installed until July, so I can't give you dyno results yet. But I'm having it Cam Doctored if you guys would be interested in the results.
Lobe # 3761R Int @.006 272.4, @ .050 222, @ .200 145.6, Lift .599
Lobe # 3015R Ex @ .006 278, @ .050 226.2, @ .200 150.3, Lift .614
Here's where it get's a little confusing for me
Int centerline 109.2 ATDC
.050 lift C/L 105.9 ATDC
Ex centerline 109.2
.050 lift C/L 112.6
Why is there 6.7 degrees difference in the .050 lift C/L's?? Is this because of the two lobes having different ramp rates?? Anyway, these are the numbers Jonathan @ Thunder gave to me. Please feel free to offer suggestions, comments (good or bad), advice, or anything else that comes to your minds. There are a ton of numbers on this Cam Doctor sheet, if you need any more of them, feel free to ask.
Last edited by Gearhead1; 06-05-2006 at 06:55 PM.
06-05-2006, 11:03 PM
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Originally Posted by Gearhead1
Here's where it get's a little confusing for me
Int centerline 109.2 ATDC
.050 lift C/L 105.9 ATDC
Ex centerline 109.2
.050 lift C/L 112.6
Why is there 6.7 degrees difference in the .050 lift C/L's?? Is this because of the two lobes having different ramp rates?? Anyway, these are the numbers Jonathan @ Thunder gave to me. Please feel free to offer suggestions, comments (good or bad), advice, or anything else that comes to your minds. There are a ton of numbers on this Cam Doctor sheet, if you need any more of them, feel free to ask.
