Max duration on heads milled 30?
Thread Starter
Joined: Jan 2002
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From: Casselberry FL
Max duration on heads milled 30? I've got a set of 5.7L heads milled 30 w/ 2.02/1.57 valves. What's the recommended max I/E duration for safe PVC?
I was considering something like the Futral F6 cam, which is a 226/230. I wouldn't mind a few more degrees of duration on both sides. Who else makes an upper 22x intake, lower 23x exhaust cam...something like a 228/234'ish? How unfriendly will this type of cam be for a daily driver?
I was considering something like the Futral F6 cam, which is a 226/230. I wouldn't mind a few more degrees of duration on both sides. Who else makes an upper 22x intake, lower 23x exhaust cam...something like a 228/234'ish? How unfriendly will this type of cam be for a daily driver?
Thread Starter
Joined: Jan 2002
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From: Casselberry FL
Re: Max duration on heads milled 30? ttt
My current cam is a 218/226 527/535 112LSA/108ICL. How big can I go without worrying about PVC? My heads supposedly flow 277 @ 550, but I don't have numbers above that lift. They were ported by CNC Heads in Florida. I'm looking for a cam with 224+ intake lift. Currently using 918 springs, but willing to switch to the Rev dual setup if necessary. Not terribly interested in notching pistons due to difficulty.
Even if I go as big as I could, what's the reasonable increase in HP/TQ I could expect?
My current cam is a 218/226 527/535 112LSA/108ICL. How big can I go without worrying about PVC? My heads supposedly flow 277 @ 550, but I don't have numbers above that lift. They were ported by CNC Heads in Florida. I'm looking for a cam with 224+ intake lift. Currently using 918 springs, but willing to switch to the Rev dual setup if necessary. Not terribly interested in notching pistons due to difficulty.
Even if I go as big as I could, what's the reasonable increase in HP/TQ I could expect?
10 Second Club
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From: Fenton, MI
Re: Max duration on heads milled 30? I have MTI stage 2 heads, 2.055, 1.60 exhaust valves, milled .030. My cam is an XE-R 226/236 .588/.602 with a 112 LSA 108 ICL. I dont have any piston to valve issues with the stock shortblock.
Hope this info helps.
Jordan
Hope this info helps.
Jordan
TECH Senior Member
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From: Chi-Town, IL
Re: Max duration on heads milled 30? With my MTI S2 heads, milled .30 I had problems running the X1 230/227 cam...
When the heads were pulled there were little valve marks on each piston...
When the heads were pulled there were little valve marks on each piston...
Thread Starter
Joined: Jan 2002
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From: Casselberry FL
Re: Max duration on heads milled 30? Jorday: Which springs are you using? Do you have a cam card you can e-mail me? Do you have a dyno graph, also?
BIGBOS: I presume it was the intake which was hitting the piston. Did you switch cams, if so, to what?
I presume both of you have stock pistons, btw.
BIGBOS: I presume it was the intake which was hitting the piston. Did you switch cams, if so, to what?
I presume both of you have stock pistons, btw.
Re: Max duration on heads milled 30?
I have MTI stage 2 heads, 2.055, 1.60 exhaust valves, milled .030. My cam is an XE-R 226/236 .588/.602 with a 112 LSA 108 ICL. I dont have any piston to valve issues with the stock shortblock.
Hope this info helps.
Jordan
Hope this info helps.
Jordan
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Teching In
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From: Surprise Az
Re: Max duration on heads milled 30? I am looking at a .581 lift on my cam,and a 224 duration on a 110 lsa,with my heads with .030 off is that to much lift? duration is 224. its going to be a custom grind.
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Re: Max duration on heads milled 30? Jordays cam is actually a 228/236 BTW...thats a typo. It had plenty of clearance. I think we could have fit a 230 in there.
Lawman & KillenSS-Its not the lift that makes the valves have clearance issues, its the duration LSA and ICL. By the time the valve is at max lift, the piston is 110 deg down the bore. MTI ought to know that its not the lift...wonder who you talked to over there? FWIW, Raughammer is using an X1 cam with his milled LS6 heads. Not sure if his pistons are stock or not though.
Lawman & KillenSS-Its not the lift that makes the valves have clearance issues, its the duration LSA and ICL. By the time the valve is at max lift, the piston is 110 deg down the bore. MTI ought to know that its not the lift...wonder who you talked to over there? FWIW, Raughammer is using an X1 cam with his milled LS6 heads. Not sure if his pistons are stock or not though.
Re: Max duration on heads milled 30? Yeah, your heads should work. That 110 icl tightens things up in there, but it should still be ok. When in doubt though, check the clearances before running the engine.
Thread Starter
Joined: Jan 2002
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From: Casselberry FL
Re: Max duration on heads milled 30? I wouldn't be interested in something which has over, say, 560'ish lift. My heads just won't take advantage of it and I don't want needless valvespring torture. I just don't see enough gains from the added lift vs. duration...and that's what I'm after...big gains.
Maybe I just should say F'it and try to get the pistons notched to use the G5X2. Damn that cam sounds mean.
What's the flycutting process? Does that weaken the piston since you're removing material? What other cams out there should I consider which will fit w/o notching the pistons? Anyone make lobes steeper than an XE-R?
Maybe I just should say F'it and try to get the pistons notched to use the G5X2. Damn that cam sounds mean.
What's the flycutting process? Does that weaken the piston since you're removing material? What other cams out there should I consider which will fit w/o notching the pistons? Anyone make lobes steeper than an XE-R?
D(irecto)r Pepper
Joined: Nov 2001
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From: Houston Raceway Park...in TEXAS.
Re: Max duration on heads milled 30?
FWIW, Raughammer is using an X1 cam with his milled LS6 heads. Not sure if his pistons are stock or not though.
Bone stock from the factory.
I am milled 30 on the LS6's and was milled 60 on the LS1's.
Works for me... though i recommend every check their set up during assembly.
On The Tree
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From: Vegas
Re: Max duration on heads milled 30? I am hitting intake and exhaust with the folliwng:
226/230 .568/.571 113LSA
A&A Heads Miled .043, 2.02/1.60 valves
7.350 pushrods
At TDC, valve drop is .115/.165, no head gaskets
Many tuners say I shouldn't be hitting, but I am. Now I have small valve reliefs from the clay test. I am currently waiting for solid lifters and test it again with head gaskets. I am 90% sure that I will have to fly cut the pistons at this point.
226/230 .568/.571 113LSA
A&A Heads Miled .043, 2.02/1.60 valves
7.350 pushrods
At TDC, valve drop is .115/.165, no head gaskets
Many tuners say I shouldn't be hitting, but I am. Now I have small valve reliefs from the clay test. I am currently waiting for solid lifters and test it again with head gaskets. I am 90% sure that I will have to fly cut the pistons at this point.
10 Second Club
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From: Fenton, MI
Re: Max duration on heads milled 30?
Jordays cam is actually a 228/236 BTW...thats a typo.
Jordan
Teching In
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Re: Max duration on heads milled 30? I have TEA stage 1.5 LS1 heads milled .030 with a 228/228 .588 .588 114 lsa installed at 111 icl. No P to V issues here.
Whatever cam you go with, make sure you check to be safe.
Whatever cam you go with, make sure you check to be safe.
Re: Max duration on heads milled 30? Milling the 5.7 heads 30 and or 50, what is the compression ratio, and what length Pushrod do you use? For a .030 mill, is it better to stay with hardened 7.4's or drop to the 7.35? I guess for the .050 just use the 7.35 right?