XE-R vs XFI Lobes
01-21-2009, 11:46 AM
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XE-R vs XFI Lobes What would be the better choice between the XE-R 228@.588 or the XFI 224@.609 on the intake side. What would produce the better cylinder filling.....the longer duration shorter lift (XE-R) or the shorter duration larger lift (XFI). Both thru the same LS6 intake.......
Last edited by zx9rgreen; 01-21-2009 at 12:11 PM.
01-21-2009, 12:25 PM
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If your heads can take advantage of the high lift then the XFI would be better. They will have roughly the same duration at .200" where the flow really starts and will sit on the seat a little easier than the XE-R (50 degrees from .050 to .006 vs. 49 degrees).
01-21-2009, 12:47 PM
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Not sure on those heads, but your flow sheet should tell you how they flow above .600" lift or if they stall. A thread with a lot of good info on the cam specs is
https://ls1tech.com/forums/generatio...mpilation.html
In this case, the XFI is makes up the 4 degrees on the XER from .050 to .200 (149 for both at .200") and it should have a little better valve control since it sets down a little softer.
https://ls1tech.com/forums/generatio...mpilation.html
In this case, the XFI is makes up the 4 degrees on the XER from .050 to .200 (149 for both at .200") and it should have a little better valve control since it sets down a little softer.
01-21-2009, 01:47 PM
#6
Even if your heads fail to flow more air over .550" lift, as long as they don't back up, you still stand to gain from the higher lift cam. What you also gain is a greater dwell time at lifts above .200". How much is tough to say without a cam doctor report from someone who has the lobes.
PRC 220cc 5.3L Stage 2.5 CNC Ported Heads
Intake Flow Information:
.300 208
.400 257
.500 290
.600 312
Looks like you can take advantage of the extra lift
Code:
Lobe Seat .050 .200 Lift XE-R 277 228 149 .588 XFI 274 224 149 .609
Originally Posted by zx9rgreen
PRC 2.5 5.3 heads with 2.04 intake valve....
Intake Flow Information:
.300 208
.400 257
.500 290
.600 312
Looks like you can take advantage of the extra lift
Last edited by hammertime; 01-21-2009 at 01:57 PM.
01-21-2009, 08:51 PM
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Even if your heads fail to flow more air over .550" lift, as long as they don't back up, you still stand to gain from the higher lift cam. What you also gain is a greater dwell time at lifts above .200". How much is tough to say without a cam doctor report from someone who has the lobes.
PRC 220cc 5.3L Stage 2.5 CNC Ported Heads
Intake Flow Information:
.300 208
.400 257
.500 290
.600 312
Looks like you can take advantage of the extra lift
Code:
Lobe Seat .050 .200 Lift XE-R 277 228 149 .588 XFI 274 224 149 .609
PRC 220cc 5.3L Stage 2.5 CNC Ported Heads
Intake Flow Information:
.300 208
.400 257
.500 290
.600 312
Looks like you can take advantage of the extra lift
