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LQ9/L92 Need Help!
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Teching In
Joined: Apr 2007
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From: Hutto, TX
LQ9/L92 Need Help! I have a 45k stock LQ9 Shortblock with true flat-tops and no valve reliefs. I would like to top it with shaved L92 heads and L76 intake. My question is how far can i go on the cam lift and duration without running into valve to piston interference issues?
I would rather not have to tear down this shortblock if possible, i was hoping to install a cam in the 230-240 range with over 600 lift but i fear these flat tops with no valve reliefs may not allow that. Thanks for your help.
I would rather not have to tear down this shortblock if possible, i was hoping to install a cam in the 230-240 range with over 600 lift but i fear these flat tops with no valve reliefs may not allow that. Thanks for your help.
Thread Starter
Teching In
Joined: Apr 2007
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From: Hutto, TX
Does the Ls2 also have flat top pistons with no valve reliefs? If so surely someone has used L92 heads on an ls2 with an aftermarket cam? If you have what cam specs did you use? How much was L92 heads milled? and gasket thickness? and what clearance did you have between the valves and piston?
Teching In
Joined: Feb 2006
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From: Montreal Region (Canada)
I have the same question. (sans L92's) and was told and read ± .630 lift and 237-240 was OK and thats what i'm looking at right now, i spoke with Dan at Wegner and Jeff at Lingenfelter, so they know what they are talking about, and they reccommended around .575 lift with same duration.
Hope this helps....
Anyone else?
Or try www.ls1tech.com
I posted the question there without an answer.
Lead.
Hope this helps....
Anyone else?
Or try www.ls1tech.com
I posted the question there without an answer.
Lead.
Thread Starter
Teching In
Joined: Apr 2007
Posts: 34
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From: Hutto, TX
Thanks for your response, but this question is going to be L92 specific, since the intake valves are 2.16 as opposed to the much smaller LS1 valves that you have.....
Has anyone on here put L92 heads on an LS2 or any other 6.0L engine with stock pistons? If so refer to the above questions on the first of this thread please>??????????????
Has anyone on here put L92 heads on an LS2 or any other 6.0L engine with stock pistons? If so refer to the above questions on the first of this thread please>??????????????
Teching In
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From: Tempe, AZ
Originally Posted by Y2K-WS6
Does the Ls2 also have flat top pistons with no valve reliefs? If so surely someone has used L92 heads on an ls2 with an aftermarket cam? If you have what cam specs did you use? How much was L92 heads milled? and gasket thickness? and what clearance did you have between the valves and piston?
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We build our PRC 6.2l CNC Heads with 145 valve drop & 64cc chambers. With our cnc program it allowed us to build the valve job to flow well & still keep decent p/v! My car made 440rwhp & 400lb ft using a automatic car & cats!
Jason
Jason
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Jason
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Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
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Teching In
Joined: Apr 2007
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From: Hutto, TX
Originally Posted by Jason 98 TA
We build our PRC 6.2l CNC Heads with 145 valve drop & 64cc chambers. With our cnc program it allowed us to build the valve job to flow well & still keep decent p/v! My car made 440rwhp & 400lb ft using a automatic car & cats!
Jason
Jason
What kind of lift and duration did the cam have in this car? If it did have flat tops with no valve reliefs what was the p/v?
Thanks for your help!
Thread Starter
Teching In
Joined: Apr 2007
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From: Hutto, TX
Originally Posted by stevewix
my intake lobe, 220 @ .050" XE-R on LS2, .582 lift had .090" Intake PTV clearance.
Launching!
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Originally Posted by Y2K-WS6
Steve, This is some extremely helpful information! Thanks!!!!!!!!!!!! Do you recall if your LS2 pistons had any valve reliefs or were they flat top with no valve reliefs like my LQ9 ?
Thread Starter
Teching In
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From: Hutto, TX
It seems that no-one knows just how much cam you can put in a stock 6.0L LS2/LQ9 shortblock, (using L92 heads with flattops and no valve reliefs) without running into P/V interference. I am ready to buy heads, intake kit and camshaft after this gets confirmed............. vendors listening??
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From: Texas
Originally Posted by Y2K-WS6
can anyone tell me if the LS2 pistons and the LQ9 pistons are the same? ie do the LS2 pistons have valve reliefs or are they flat tops with no reliefs like the LQ9?????
Originally Posted by Y2K-WS6
I have a 45k stock LQ9 Shortblock with true flat-tops and no valve reliefs. I would like to top it with shaved L92 heads and L76 intake. My question is how far can i go on the cam lift and duration without running into valve to piston interference issues?
I would rather not have to tear down this shortblock if possible, i was hoping to install a cam in the 230-240 range with over 600 lift but i fear these flat tops with no valve reliefs may not allow that. Thanks for your help.
I would rather not have to tear down this shortblock if possible, i was hoping to install a cam in the 230-240 range with over 600 lift but i fear these flat tops with no valve reliefs may not allow that. Thanks for your help.
Last night I just fired up a lq9 shortblock with no valve reliefs stock 6.2 l92 head gaskets and stock l92 heads, springs only and a MTI Y1 cam which has .608 lift. Took it to 7000 last night = no issues. Hope this helps. I am curious what the compression ratio is with this combo?
