02RedHawk

iTrader: (17)

How much power would you say is being "left on the table" if a 214/218 112+2 cam was chosen with XE lobes, instead of XFI lobes? (Assume its with a great set of ported heads that flows well to .600" (ie, 300+cfm, along with PRC dual-springs .650", and LT Headers). See comparison below....

214/218 112+2

Lobe:________________XE___________________________ _XFI_______
Lift (1.7 rocker)____.559"/.563"_____________________.600"/.590"_______
___________.006"____.050"_____.200"_________.006"_ ___.050"_____.200"
Duration___267/271__214/218__133/136______264/270__214/218__139/141
IVO________23.5______-3______-43.5_________22_______-3______-40.5
IVC________63.5______37______-3.5__________62_______37______-0.5
EVO________69.5_____43________2___________69______ _43_______4.5
EVC________21.5_____-5_______-46__________21_______-5_______-43.5
Overlap______45______-8______-89.5_________43_______-8_______-84


I know the XFI 214/218 will idle slightly smoother than the XE 214/218, however the XFI should also have more valvetrain noise and reduced valvespring life, correct?

But beyond that, how much HP/Tq (educated guesses) would stand to be gained with the extra .041"/.027" lift, and the more agressive lobe (ie, more "area under the curve") that the XFI has?

Thanks!

Tom@SpeedInc

iTrader: (5)

If you want to compare XFI vs. XER, minus the intake advertised duration vs. duration @ .050" this gives you an intensity number. The XE has an "intensity" of 53* the XFI cam is 50*. The smaller the intensity number the quicker the valve is open, the XFI has the intake valve open for longer period under the curve.

XFI more valvetrain noise? My 402 was whisper quiet with a XFI cam. XFI cams are better for a daily driver.

02RedHawk

iTrader: (17)

Thanks for the reply; any feedback from others?

GMH GTO - can you clarify why you say that XFIs are better for a DD, versus the XE?

Christopher Sims

iTrader: (1)

I have an XFI 214/218 on a 112 with ICL of 113. You can barely hear it w/o a tune (6 sp). It will give a good DCR with stock heads. With CNC LS6 heads and cometic .040s it's a torque monster and wears the rev limiter out. Also, the valvetrain is quiet. With a tune, it'll be stealth. I wish I had gone with the 218 XFI intake and a XE-R 224 exhaust (it's a lil' quicker off the seat than XFI exhaust). Good luck!

JZ'sTA

iTrader: (23)

I would go XFI myself.
Personially I would go with a cheeter cam over the 214/218.

PREDATOR-Z

I would prefer a LSK/XE-R, int/exh

02RedHawk

iTrader: (17)

Too much for a DD, that's why I'm looking at the comparison between the XFI and XE....

JZ'sTA

iTrader: (23)

Why do you say that's to much for a DD?
Have you tried it before or are you just guessing?

02RedHawk

iTrader: (17)

Don't want that aggressive of a lobe for a DD, that's all. Looking for a little better valvetrain longevity than what the XER/LSK would provide.

JZ'sTA

iTrader: (23)

I don't know if you have noticed but people continue to get 30,000+ miles out of the XER stuff with 918 springs.

PREDATOR-Z

Some poeple are getting 30K miles with duals and the LSK lobes, not an issue if setup properly.

02RedHawk

iTrader: (17)

That's cool...But, XE-Rs aren't available in smaller than 220 durations. And if we can get 30k+ out of XE-Rs and LSKs, then thats all the better for my goal of getting 40k+ out of the XFI or XE!

TTT for more responses to my original questions in my first posting above.

Ragtop 99

iTrader: (7)

XFI's work well. You pick up 6* at .200 lift and that works out to about 4% more area. That's a nice gain. Probably as much area as 218/222 XE cam (I didn't look it up, so that is an estimate) At .300 it is much bigger relative gain. Plus they should idle nicely.

With your combo, I'd put it on a 111 straight up. If your heads have raised your CR, you'll have a very high DCR and that's still -6 overlap so it should be a snap to tune. That will give you strong low end and still pull through 6200 or higher.

CHRISPY

How are the stock lifters holding up to the XFI cams?

Bo White

iTrader: (59)

Im runnin the 218 XE lobe in the intake side of my cam and its a DD with the stock converter. Super "stock like" driveabilty so dont worry about going slightly larger on your cam choice.

LsReddog

You wouldnt know/feel/measure the difference