p2v clearance question
03-08-2011, 08:09 PM
#1
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p2v clearance question I am in the process of assembling my lt1 with new bearings rings stock pistons and rods with new arp rod bolts.
the cam that is in it is a 242 242 572 572 112 solid roller, Right now the mockup heads are stock, the other set are heading out to get ported. I am wondering if i need to worry about p2v clearance, I dont have a test spring to check it right now, I will get one if needed. the block is stock deck height and the gaskets i have are felpro stock replacements, the heads have been checked out before and do not need milling.
thanks in advance
the cam that is in it is a 242 242 572 572 112 solid roller, Right now the mockup heads are stock, the other set are heading out to get ported. I am wondering if i need to worry about p2v clearance, I dont have a test spring to check it right now, I will get one if needed. the block is stock deck height and the gaskets i have are felpro stock replacements, the heads have been checked out before and do not need milling.
thanks in advance
03-08-2011, 09:41 PM
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clay testing it is what i was gonna do if it is a possibility of interference, I am just wondering if the cam is big enough to need to worry about it
03-08-2011, 11:19 PM
#6
they just don't work that well with the ltx platform. It doesn't have so much to do with I/E flow, it has to do with the intake design and what it needs to work as good as it can. Not that your cam won't work, I just see big-ish duration, wide-ish lobe separation, and not enough overlap.
03-09-2011, 01:44 AM
#7
I'm not sure what you'll be running for heads, or how high you plan on spinning the motor, or what the rest of your combination will be, but strictly looking at the cam, I'd go a little less duration on the intake side, and bring your LSA closer to a 108 area.
As for your actual question, I'd do (I personally always do it) what AC said and clay test it.
As for your actual question, I'd do (I personally always do it) what AC said and clay test it.
Last edited by 93Z2871805; 03-09-2011 at 01:52 AM.
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03-09-2011, 01:49 AM
#8
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I already have the cam, its gonna have longtube headers, ls1 air intake, 3200 stall and i gotta get gears, cause i sold my 4.11 axle to get the motor, probably going 3.73 next time.
gonna spin it as high as it needs
gonna spin it as high as it needs
03-09-2011, 02:03 AM
#10
The rockers would only really change the lift (with a very small influence on the duration) and pop the valve off the seat a little quicker (speed wise, not position wise). The actual concern here is the duration (more on the intake side) and the overlap that you wont have alot of due to your lobe separation angle being wide.
03-09-2011, 02:18 AM
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what about advancing/retarding the cam, would that make any difference? sorry about the questions, I dont know all that much when it comes to cams. gotta learn somehow right
03-09-2011, 02:20 AM
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i know that doing that wolnt change the cam specs, or anything, but what about power wise? I do have some offset cam bushings to do that if its needed, and the cam card as well
03-09-2011, 02:47 AM
#16
Well, depending on your heads, if your ICL is closer to 106, I see it making good torque down low and falling off around 5.5k. If it's closer to 110, I see it making good midrange between 4.5k-6k. The problem will be either nothing to carry it into the higher rpms, or a very narrow power band. You could go with a 1.6 rocker on the exhaust and -2* cam timing to try to push the power band higher.
03-09-2011, 03:06 AM
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on the scr, I havent gotten around to calculating that yet, it will be stock pistons stock deck height and stock head cc chambers, as well as a fel pro stock replacement gasket (i can get the part number if needed)
03-09-2011, 08:31 AM
#18
Well, depending on your heads, if your ICL is closer to 106, I see it making good torque down low and falling off around 5.5k. If it's closer to 110, I see it making good midrange between 4.5k-6k. The problem will be either nothing to carry it into the higher rpms, or a very narrow power band. You could go with a 1.6 rocker on the exhaust and -2* cam timing to try to push the power band higher.
03-09-2011, 08:58 AM
#19
LT1s don't typically have P2V issues.
I ran a 236/248 104LSA .610" cam in my 383 with -13cc pistons, a zero deck and .029" gaskets.
No issues at all with 2.055" and 1.600" valves.
Oh, and my heads were milled down to 56cc.
I ran a 236/248 104LSA .610" cam in my 383 with -13cc pistons, a zero deck and .029" gaskets.
No issues at all with 2.055" and 1.600" valves.
Oh, and my heads were milled down to 56cc.
03-09-2011, 10:50 AM
#20
Well, depending on your heads, if your ICL is closer to 106, I see it making good torque down low and falling off around 5.5k. If it's closer to 110, I see it making good midrange between 4.5k-6k. The problem will be either nothing to carry it into the higher rpms, or a very narrow power band. You could go with a 1.6 rocker on the exhaust and -2* cam timing to try to push the power band higher.