Just bought some S2 heads, now have to flycut pistons. Can someone explain why?
08-05-2002, 11:31 AM
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Just bought some S2 heads, now have to flycut pistons. Can someone explain why? I have a T1 cam right now in my car and Just bought a set of S2 heads
Casting #241(01 heads), 2.02/1.60 valves, heads milled .060, radius valve job, hand ported.
Those are the heads I got and was told I will need valve reliefs cut into my pistons.
Just wondering why I would have to do this if everything works right now.
I am still getting it done to stay on the safe side, this is just one of those things I am curious about.
<small>[ August 05, 2002, 12:20 PM: Message edited by: swtvictory ]</small>
Casting #241(01 heads), 2.02/1.60 valves, heads milled .060, radius valve job, hand ported.
Those are the heads I got and was told I will need valve reliefs cut into my pistons.
Just wondering why I would have to do this if everything works right now.
I am still getting it done to stay on the safe side, this is just one of those things I am curious about.
<small>[ August 05, 2002, 12:20 PM: Message edited by: swtvictory ]</small>
08-05-2002, 11:41 AM
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Re: Just bought some S2 heads, now have to flycut pistons. Can someone explain why? Posibly with the heads cut that far and with the lift of the cam you have run out of clearance from the valve to the piston. The shop may just be covering there end. You can have them clay checked with your motor and your lift by a good engine shop.
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08-05-2002, 02:04 PM
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Re: Just bought some S2 heads, now have to flycut pistons. Can someone explain why? You will be fine Raughammer has his milled 60thous and he has a 224/224 581/581 lift cam on a 112 with 4 degrees ground in.
<small>[ August 05, 2002, 02:09 PM: Message edited by: Alonzo ]</small>
<small>[ August 05, 2002, 02:09 PM: Message edited by: Alonzo ]</small>
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08-05-2002, 03:25 PM
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Re: Just bought some S2 heads, now have to flycut pistons. Can someone explain why? My cam that I have is 227/227 599/599 and my heads are milled 30thous and I have thinner head gaskets and I have no piston to valve contact on either side.
08-05-2002, 11:11 PM
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Re: Just bought some S2 heads, now have to flycut pistons. Can someone explain why? I would flycut them. You may be fine with the actual set up, but the first time you over rev your engine you will wish your flycuts were there. Dont ask how I know this. <img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />
08-06-2002, 12:40 AM
#12
Re: Just bought some S2 heads, now have to flycut pistons. Can someone explain why? From my experience, you won't need to fly-cut valve reliefs with LS1 heads cut .060 (with 2.02 intake valves) until you reach around 230 @ .050 duration. With a T1 running around 221 duration @ .050, you should be fine. Valve reliefs are always a good idea...especially if you accidently over-rev the motor. Best thing to do is to check piston to valve clearance, but in my experience, your valves and cam are too small to justify valve reliefs.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
08-06-2002, 12:57 AM
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Re: Just bought some S2 heads, now have to flycut pistons. Can someone explain why? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Patrick G:
<strong>From my experience, you won't need to fly-cut valve reliefs with LS1 heads cut .060 (with 2.02 intake valves) until you reach around 230 @ .050 duration. With a T1 running around 221 duration @ .050, you should be fine. Valve reliefs are always a good idea...especially if you accidently over-rev the motor. Best thing to do is to check piston to valve clearance, but in my experience, your valves and cam are too small to justify valve reliefs.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I was looking for an answer like that, I will be revving to 6800 shortly "at 6600 right now).
Are you 100% I wont need them with the information I gave you? is that enough info to say whether or not I need the flycuts?
<strong>From my experience, you won't need to fly-cut valve reliefs with LS1 heads cut .060 (with 2.02 intake valves) until you reach around 230 @ .050 duration. With a T1 running around 221 duration @ .050, you should be fine. Valve reliefs are always a good idea...especially if you accidently over-rev the motor. Best thing to do is to check piston to valve clearance, but in my experience, your valves and cam are too small to justify valve reliefs.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I was looking for an answer like that, I will be revving to 6800 shortly "at 6600 right now).
Are you 100% I wont need them with the information I gave you? is that enough info to say whether or not I need the flycuts?
08-06-2002, 01:47 AM
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Re: Just bought some S2 heads, now have to flycut pistons. Can someone explain why? alright, alright, im gonna flycut them <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" /> <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" />
08-06-2002, 07:27 AM
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Re: Just bought some S2 heads, now have to flycut pistons. Can someone explain why? Ron you'll be fine...
But if you are doing something "unproven" like putting .060 milled heads on with a certain cam...its always best to clay the chambers. I did mine and I only had ~.060 PV clearance on the intakes. So I flycut .020 to get some clearance back...but the more you clearance the less your compression ratio...remember that <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
But if you are doing something "unproven" like putting .060 milled heads on with a certain cam...its always best to clay the chambers. I did mine and I only had ~.060 PV clearance on the intakes. So I flycut .020 to get some clearance back...but the more you clearance the less your compression ratio...remember that <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
