View Full Version : L92 Headed LS2 Valvetrain help


Matt0matic
02-11-2012, 02:34 PM
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?

Jim85IROC
02-11-2012, 03:26 PM
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.

Matt0matic
02-11-2012, 08:09 PM
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.

Any input on rockers?

westtexasbuff
02-11-2012, 08:27 PM
Stock rockers with the trunion upgrade.

gtotoocool1
02-11-2012, 10:35 PM
why don't you ask WCCH?they should know how to pick you a cam to meet your goals..

Matt0matic
02-11-2012, 10:59 PM
why don't you ask WCCH?they should know how to pick you a cam to meet your goals..

Just trying to become more informed.

gtotoocool1
02-11-2012, 11:44 PM
Just trying to become more informed.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.

Matt0matic
02-11-2012, 11:57 PM
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.

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.

gtotoocool1
02-12-2012, 09:29 AM
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. 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.

Gray86hatch
02-12-2012, 01:19 PM
Lunati dual spring kit.

Stock rockers with a trunion kit.

Tim

Matt0matic
02-12-2012, 02:09 PM
Lunati dual spring kit.

Stock rockers with a trunion kit.

Tim

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.
http://www.proheads.com/images/chels1rocker.jpg
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.
And then we have the Comp/Harland kits which are about the same.

westtexasbuff
02-12-2012, 03:01 PM
Anyone have input on which trunion kit?
WCCH likes the CHE that using a bronze bushing instead of bearings. How much is the CHE upgrade? I already have my rockers, just need to get them upgraded.

Matt0matic
02-20-2012, 06:02 PM
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.

Zbinkley
02-20-2012, 06:06 PM
Keep in mind the L92's can give you some P.T.V. issues with the large intake valve.

Tainted
02-20-2012, 09:01 PM
Double check your ptv clearance with those milled heads!! The intake valve is very close to the cylinder wall on our 6.0 Also why dont you upgrade the intake valves to the hollow stem ls3 valves? A lighter valvetrain is a stabiler one!!

low2001gmc
02-20-2012, 10:49 PM
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 :usa:

Matt0matic
02-20-2012, 10:57 PM
Double check your ptv clearance with those milled heads!! The intake valve is very close to the cylinder wall on our 6.0 Also why dont you upgrade the intake valves to the hollow stem ls3 valves? A lighter valvetrain is a stabiler one!!
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.

Tainted
02-21-2012, 09:57 AM
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.

ahh ok didnt catch that part. I figured they were just stock heavy ass l92 valves.
and the cam lobes i'd run LSL lobes or whoever else sells proprietary lobes. smoother operation, easier on springs, more life from your valvetrain.

3pedals
02-21-2012, 10:42 AM
The stock L92 valves are NOT overly heavy, mine only weighed 109g, the LS3 valves are 91g, and I'd bet money the REV valves are heavier than the oem L92 stuff.
my set up is stable to 7700rpm with oem L92 valves
Choose wisely based on your application

Tainted
02-21-2012, 10:49 AM
All I know is people such as Pat G preech about having the lightest valvetrain possible. Not saying a heavier valvetrain cant or doesnt make power is stupid, but lighter would be nice ;)

3pedals
02-21-2012, 10:52 AM
All I know is lighter would be nice ;)

AGREE'd

Matt0matic
02-21-2012, 11:02 AM
I agree lighter is better and if the heads where bare I would have stuck LS3 valves in it.

From this thread: http://ls1tech.com/forums/generation-iv-internal-engine/638990-will-someone-weigh-stock-2-16-l92-intake-valve.html

They are 76 g., not 74, my REV L-92's were 103g., with a quality spring, you should not have any valve control issue's. I have a set of AFR 205 valves, I'll pull the scale out and see how much they are for a comparision. I ran those heads to 7k with the 8019 springs and LSK lobes with no issues.

Matt0matic
02-21-2012, 11:04 AM
103g is less that what most stockers weigh. Another good post:

FWIW I weighed up some valves a while back:

Stock L92 intake-108.6 grams -- Some non magnetic alloy
Manley 11620 -119 grams- Intake- The Manleys are solid SS
Manley 11621-92 grams- Exh
LS3 intake -89 grams -- hollow alloy and my current favorite (NA) with single springs
LS3 exh same part# as L92 Exh- some non magnetic alloy

Matt0matic
02-21-2012, 11:05 AM
And 3pedels your setup is screaming, saw your thread on Yellowbullet with the new build. Congrats! Crazy cam btw.

3pedals
02-29-2012, 12:02 PM
And 3pedels your setup is screaming, saw your thread on Yellowbullet with the new build. Congrats! Crazy cam btw.

Thanks

xBoostx
03-11-2012, 01:34 AM
You owe it to your self to get a cam spec for your own particular purpose, and app, and for only $25. is the best deal in the performance world today. camhelp@Guerragroup.com is where to go, if you want to get max power and not over cam your car for the st ask for shifting point at 6,600 and red line at 7k great for a dd.

racecar
03-12-2012, 02:58 PM
Your cam specs are in the ballpark. 223/232 is a good split. I'm not sure what lobes you are using, but I would keep the intake <.600 lift for a DD. Somewhere around .590 would be easier on the valvetrain. I have a 233/239, love it, but it is not a DD. My freind has a 228/234, it's borderline streetable. 223 should work great.