L92 Headed LS2 Valvetrain help
#1
L92 Headed LS2 Valvetrain help
Just got my L92 heads from WCCH and my L76 intake came in. Now I'm looking at the valve-train/cam. This will be going into a '99 Camaro with a T56 and 3.91 gears in the M12 and 1.75" Hooker headers. The heads are the WCCH L92 Stage 2 with 63cc chambers with REV intake valves and stock exhaust. Stock L76 intake, injectors and rail. Rebuilt LS2 shortblock. What would you do different? Its a daily driven car; I do not want a big cam that it going to be a pain to get tuned properly. Looking for high 400s hp with mid 400 tq.
1] My thoughts are the PRC .660 spring kit or the Patriot Extreme. Leaning Toward the Patriot for the included retainers. Would you do anything different?
2] My general idea for a cam is ~.615 and 223 @ .50 intake and ~.600 w/ 232 @ .50 exhaust. On a 114 +3 LSA. These are just general ideas from what I have read on the forum. Any changes needed with these specs?
3] And what rockers would you use? I can pull the stock off the LS1 coming out of the car and buy 8 offset rockers then do the trunion upgrades or purchase some aftermarket. I don't know which would be better?
1] My thoughts are the PRC .660 spring kit or the Patriot Extreme. Leaning Toward the Patriot for the included retainers. Would you do anything different?
2] My general idea for a cam is ~.615 and 223 @ .50 intake and ~.600 w/ 232 @ .50 exhaust. On a 114 +3 LSA. These are just general ideas from what I have read on the forum. Any changes needed with these specs?
3] And what rockers would you use? I can pull the stock off the LS1 coming out of the car and buy 8 offset rockers then do the trunion upgrades or purchase some aftermarket. I don't know which would be better?
#2
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That sounds like a great plan to me. Your cam is right where I would choose, and those Patriots should work good with that lift. If you go with much more lift, I'd go with PRC springs. My patriots installed a lot lower than the specified 1.8" height and would have been at coil bind with a .650 cam. Had I known at the time that my cam was going to only be in the .615 range, I probably would have kept them.
Last edited by Jim85IROC; 02-11-2012 at 04:52 PM.
#3
That sounds like a great plan to me. Your cam is right where I would choose, and those Patriots should work good with that lift. If you go with much more lift, I'd go with PRC springs. My patriots installed a lot lower than the specified 1.8" height and would have been at coil bind with a .650 cam. Had I known at the time that my cam was going to only be in the .615 range, I probably would have kept them.
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i can understand that.i just meant that since it's their heads they would have a better idea than anybody what cam would work for your goals.only advice i'll give is since it's a daily driver(and especially with L92 heads) go conservative on the cam duration.better to give up some power up top to have more power where you'll use it,plus better street manners.
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#8
Think low 220/230s is too much duration? Richard's, from WCCH, advice was the same don't overcam it. I'd love to put more lift in it though.
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weight of the car,gearing,etc.will dictate any cam choice. most people over cam their street cars anyway,at least in IMO.with that big intake valve on the L92s,have to keep overlap in check.if it was my car,i wouldn't have more than 0 degrees overlap.something around 216-220 int.,224-228 exhaust dur.111-113 lsa..keep the lobe intensity down,unless you don't mind frequent valve spring changes.. but again,i like smaller cams in general for the street.somebody else would be willing to live with more overlap/duration.if i were you,i would definately consult an expert,as i'm no cam guru.Pat G. on here specs a lot of cams. Ed Curtis at Flow Tech Induction is another guru that won't steer you wrong.it's worth it to pay someone to get it right the first time.
#11
Thanks Tim, I actually bought the Lunati kit after seeing your results with it over on Hardcore50. And think I have a handle on a set of stock LS3 rockers.
Anyone have input on which trunion kit?
WCCH likes the CHE that using a bronze bushing instead of bearings.
And then we have the Comp/Harland kits which are about the same.
Anyone have input on which trunion kit?
WCCH likes the CHE that using a bronze bushing instead of bearings.
CHE Precision rocker arms are a premium upgrade to the factory GM units. Their unique trunnions retain the stock geometry while eliminating the caged needles of the factory bearings. No more scattered needles when a bearing cage breaks apart! CHE replaces the needle bearings with a bronze alloy busing and hardened steel shaft and they add heavy duty locking clips. They have retained all the excellent qualities of the factory rockers, low polar mass yet stiff. Correct geometry for smooth valve action at high rpms. CHE rockers have been Spintron tested and proven stable to 10,000 rpms.
#13
Ordered a set of "SLP take off" LS3 rocker arms and they showed up today. Only seven offset and nine straight. But besides that they look practically new. Hope to get it resolved with SLP here shortly.
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im in the process of having an lq9 with ls3 heads built this year for my 72 nova and have been doing some research like you. i have noted the following:
pat g went with a 223-231 with 60x lift, dont recall lsa, but made some like 466hp and 446tq. somewhere else i saw pat g recommend a 226-234 eps cam with 598-600 and 113+4. somewhere i read pat g state exhaust duration shouldnt be more than 239. somewhere ed curtis of flowtech recommended a 224-232 with 600 lift and 111. corvette forum member spinmonster ran a 230-234 cam that made 474hp, less split duration but i believe heads were mildly ported on exhaust. some other forum member ran a futral with 228-242 and 598-604 that made 46xhp and 43xtq. somewhere else i read l92 and ls3 headed 6.0s respond well to low 22x-23x duration with xfi lobes.
based of that, i am considering possibly milling my ls3 heads some and going with the eps 226-234 with the lower 598-600 lift or ed curtis/flowtech 224-232 with 600 lift.....
OR not mill the heads, benfit the most from the ls3 stock flow numbers and go with my own designed 224-609 on xfi lobes for intake and 238-612 on lxl lobes with higher lift. somewhere pat g stated the lxl lobes are quieter. a lil concerned however on exhaust ptv???.
either way i am planning on myself mildly porting the exhaust ports and porting the l92 intake which has proven to perform better than the ls3 intake due to taller runners. i will also be runnning some new upgraded harlan sharp rockers but the CHE ones mentioned above sure sound better. wonder the price on them though as this the first i hear of them.
hope this helps you some. i look forward to other opinions to hopefully come up with the best combo for the buck. good luck with your project, rob
pat g went with a 223-231 with 60x lift, dont recall lsa, but made some like 466hp and 446tq. somewhere else i saw pat g recommend a 226-234 eps cam with 598-600 and 113+4. somewhere i read pat g state exhaust duration shouldnt be more than 239. somewhere ed curtis of flowtech recommended a 224-232 with 600 lift and 111. corvette forum member spinmonster ran a 230-234 cam that made 474hp, less split duration but i believe heads were mildly ported on exhaust. some other forum member ran a futral with 228-242 and 598-604 that made 46xhp and 43xtq. somewhere else i read l92 and ls3 headed 6.0s respond well to low 22x-23x duration with xfi lobes.
based of that, i am considering possibly milling my ls3 heads some and going with the eps 226-234 with the lower 598-600 lift or ed curtis/flowtech 224-232 with 600 lift.....
OR not mill the heads, benfit the most from the ls3 stock flow numbers and go with my own designed 224-609 on xfi lobes for intake and 238-612 on lxl lobes with higher lift. somewhere pat g stated the lxl lobes are quieter. a lil concerned however on exhaust ptv???.
either way i am planning on myself mildly porting the exhaust ports and porting the l92 intake which has proven to perform better than the ls3 intake due to taller runners. i will also be runnning some new upgraded harlan sharp rockers but the CHE ones mentioned above sure sound better. wonder the price on them though as this the first i hear of them.
hope this helps you some. i look forward to other opinions to hopefully come up with the best combo for the buck. good luck with your project, rob
Last edited by low2001gmc; 02-20-2012 at 09:59 PM.
#17
Money mostly and you actually lose compression with the OEM valves; WCCH installed a Stainless REV intake valve and if I was to switch to a OEM LS3 they have more of a dish causing you to gain some CC's in the chamber.