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more aggressive cam

SgtMarshal

SgtMarshal

Active member
I currently have an XP cam with ported L32 heads. I want to do a more aggressive cam and valve spring combo, but not remove the heads. I was thinking about doing an XPZ, but don't really wan't to take the heads for machining, so I'm considering other cams such as the S2X or S3X and maybe an NIC. what do I need to consider when evaluating a cam for the heads I have?
 


I've looked into the IS3 cam before and i think with stock rockers you can get away with just stronger springs (130 or 140#) double roller and ported heads. I would be sure you have more than a quick port job though, because there is a lot of lift with the IS3.
Check this out.
http://www.3800pro.com/forum/cams-heads-valvetrain/22382-is3-cam-stock-heads-lots-machining.html

and from here
http://www.grandprixforums.net/threads/45313-Intense-Stage-3-Cam-and-S3-heads-as-a-Daily-Driver

Honestly man. Nitrous with your XP and call it a day
 
S3x at 1.6 - .540/.550
xpz at 1.6 - .563/.532

Now the s1x at 1.6 - .514/.526

Stock l67 - .413/.413 (I think)

so mill the guides cause I think it maxes out at .530 for stock head but the Anything more than that needs porting or else all that is gone to waste
 
SgtMarshal said:
I currently have an XP cam with ported L32 heads. I want to do a more aggressive cam and valve spring combo, but not remove the heads. I was thinking about doing an XPZ, but don't really wan't to take the heads for machining, so I'm considering other cams such as the S2X or S3X and maybe an NIC. what do I need to consider when evaluating a cam for the heads I have?
Click to expand...
Curious to know why do you want change cams? Do you feel that you maxed out the xp? Probably not .. I would stick with your setup plus the xp cam idles wayy better then the xpz... And since you really dont want to do porting for heads.. You should stick with it ... Goin bigger isnt always better... Be surprised how much power you would make with that cam And surprised what those cams wouldnt make at the dyno..lol
 


Of all the normal cams I've played with, I really liked the XP, my least favorite is the XPZ, because it's tough on the valvetrain. My car that's getting the turbo soon had this crap thing in it, and it ruined both sets of heads because it chewed up the valves, and wore the guides. Honestly, the only remote way to run that thing is roller rockers, so it doesn't **** your heads.
My Bastard car has the BBC prototype, similar duration but more lift...and I love love love the cam. My specs are 224/236 duration, 573/571 lift, 115* LSA.
My opinion though, you've already got the cam....work on a good set of good flowing heads.
 


Port the heads, mill the guides , keep the cam, get 1.8s

or get a s3x - love it Can't wait to post some timeslips soon
 
You would be simply amazed at how much of a restriction is in the heads. By not wanting to swap them, you are doing yourself a great injustice.
 
BillBoost37 said:
You would be simply amazed at how much of a restriction is in the heads. By not wanting to swap them, you are doing yourself a great injustice.
Click to expand...

I have already swapped the heads to a set of L32 heads ported by chris hinson, they are one of his earlier sets. I also had a valve job done on them before installation.
 
Well that's a huge detail gone unknown to me lol
i hear "ported" and think home port job and assume the guides aren't milled.

Do know the specs of the head work he did ?
 
the guides probably aren't milled. Chris never really published any specs for his ported heads, really all he said was that with an xp cam he can maximize the airflow through the heads.

sorry, sometimes I forget to leave out details.
 


Now...you need to find out the details about the guide. Because.. since you technically have ported heads. I'd recommend a rocker on top of the cam.
 
that's all I have, they are on the car now, and no one has taken measurements. at this point I'm thinking I will just do a set of 130 lb springs with a double roller and maybe a balanced harmonic balancer. if I did take measurements, I would just check the distance from the bottom of the spring pocket to the top of the valve, right? and that should allow for an installed spring height of 1.8 inches. am I understanding that correctly?
 
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