l92's on a lq4
 

I have a lq4 I am putting in my truck it is complete but stock. I want to replace the heads but still run the injection, I looking to make about 600hp. Can I use my factory intake with a set of l92s or would i have to get a lq9 intake or a carbed intake. I'm sure It will bolt up but I want sure on the port alighnment.

Re: l92's on a lq4
 

you would need the L92 or LS3 intake (or a carb'd one w/fuel rails) to go with the L92 heads on your LQ4.

Re: l92's on a lq4
 

thats what I was affraid of. Maybe I'lle just deck my stock 317 castings, I know the engine stock is 9.5:1. I woulnt mind gettin it up to 10.5 or 11:1 and I was also orignially looking at the gm "hot cam" (I thought about 9.5:1 and a turbo but that kinda fell through)
maybe a little biger cam and 11:1 would get me to about 500 or 525 hp.

Re: l92's on a lq4
 

the 317's aren't bad and will make some power for you....you can always upgrade later....

Re: l92's on a lq4
 

L92/LS3 all the retangular ported heads need a big engine and a decent cam shaft to use all that air. Sure the L92s flow alot of air and show decent dyno numbers...we consistantly out ET and MPH L92 headed cars with 243s.....
My issue with the L92s is that you need a 400+ cubed motor and the right cam to make it worth the effort, and when I say effort I am including just what you mentioned here, you going to need a specific intake, 1 set of offset rockers and the big motor.
I would take the 317s and you know they are 243s just with a larger chamber, send them to me to be worked/CNCd by Advanced Induction in NC. The results will be amazing, and you can get a used FAST 90/92 and a TB and be making good power to the tires.
Now if you are stuck on the L92s then FAST does make the 102 for those heads now but you will have to get a 'car' intake, thet truck one is catherdral ported. I also know where a LS3 intake is and dont forget the fuel rails and injectors.
Stock truck injectors are going to run out of steam on a stock 6.0 with with a cam swap and there are not any good Multec IIs out there so you will have to change the connector to either EV1 or EV6 style.

Re: l92's on a lq4
 

its funny to listen to the L92 stories.....too bad your not close enough to run mine Shon!

Re: l92's on a lq4
 

yeah, its too bad I am not closer to run a cam'd 6.0 with a stock LQ4.....

Not saying they dont work and make great power but when you are starting out with a complete motor already there is more to the L92 swap than just putting the heads on there, you got to have the rockers and intake and to really use the air flow, you need supporting mods and IMO that includes the right cam and a larger motor.

Re: l92's on a lq4
 

hey you're always saying that the L92/LS3 headed cars/trucks can't hang with a good cathedral port one! Just thought I'd give you a shot at mine when its ready. :lol:

Well the way I look at it.....the GM engineers must know what they're doing to bring us these fantastic motors in the 1st place right? And, since the factory is building 6.0L motors with the new genIV L92/LS3 style rectangular port heads (LY6, L76, etc)...they must not think that a 6.0L's bore is too small (or shrouds the valve too much) for the rectangular port genIV heads?

As far as the swap...only the intake rockers are different, but the exhaust have the same rockers as a catherdral port head. And you're right, no..........the big port heads aren't for everyone.

Re: l92's on a lq4
 

So you calling me out with a truck that is not even ready :lol:

And I might put some of these heads on the next set up...fixin to start another Z28 with at least a 6.0.....and a 200 shot.....

Re: l92's on a lq4
 

uh.....yeah. pretty funny huh? :lol: :lol: :lol:

Re: l92's on a lq4
 

Thought it was just an upstate SC thing but looks like the standard call out has a 6mth lead time :lol:

Re: l92's on a lq4
 

oh heck.....I can be ready before that!
by the end of the month maybe....hopefully before Christmas!

Re: l92's on a lq4
 

That's better turn around than most!! let me know what it runs and the DA!

Re: l92's on a lq4
 

1/4mi tracks are closed....but there are a few 1/8mi tracks that might be open on a nice weekend. I need to take it easy at 1st tho....although my 12 bolt was rebuilt about a year ago w/3.73's and a new Eaton posi, and I just had a heavier driveshaft made...I don't think I trust it to nail it from a stand still on a sticky track and still get me back home. :lol:

Once I upgrade to a Dana 60 or 14 bolt...and upgrade the u-joints to 1350's minimum (couldn't do it with this new shaft w/o pulling the R/E apart again)... I should be able to start working on dialing in the 60' times. 13's, then 12's, then 11's...thats the plan.

Re: l92's on a lq4
 

LOL, I took my junk out and only thing changed was the U-joints on the trans side and hit it with a 100 shot and went 7.8s in 1/8th mile....i figure with those L92s and cam you have you should run low 8s on motor....

Re: l92's on a lq4
 

....I just need to get it together and running! Who knows.....I may not be able to restrain myself... and beat the crap out of it from the start. :lol:

Re: l92's on a lq4
 

Find the weak link!
I was able to pull a 1.76 60' on a very rich 150 shot on 28" slicks with 3.73s.
Here's some motivation:

Re: l92's on a lq4
 

mine also has 3.73's... and a 200-4r which has a little better 1-2 ratio to hopefully keep it in the powerband better then the old turbo350. I've been planning on running drag radials instead of slicks...to run steet/bracket?

Re: l92's on a lq4
 

My set up went alot quicker on 26" DRs.
8.8 on motor and 7.8 on 100 shot.
Went to 28" slick and went 8.0s on 100 shot and did not pick up any on a rich 150 shot.

I actually might be pulling this motor (6.0) and get a complete 5.3 and put a cam in it to tow the 94Z I just picked up, use the 6.0 out of truck to put in the Z with the ported 243s I got here and some cam...I think with that set up and a 200 shot the car should run pretty well (when compared to locals). And then if I get froggy I would port some L92s from the same place and just do a back to back comparison....not a good comparison b/c the L92s actually need a different profile but something to look into....

Re: l92's on a lq4
 

This coming May mine will be out at the track up here in Alaska, and we'll see what 1/4 mile times it'll do with the new LQ9 6.0L with L92 heads and cammed. I'm also running 3.73 gears with Positrac in a 12 bolt. 4L60E with 3200 converter. Need to get the tune finished before I head out to the track in the spring though! :chevy:

Re: l92's on a lq4
 

our trucks matthew....with both being L92 headed 6.0L's with the same cam and rear gears...but just different induction systems and transmissions. Oh and mine has a lower stall in it.

Re: l92's on a lq4
 

It should be very interesting to see how they do, basically Carb vs. MPFI! With some minor differences in exhaust and stall speed.

Re: l92's on a lq4
 

Yeah, Shon, def gotta swap to another cam profile more akin to the L92 heads to make that a fair comparision...if this thread were on 'tech their would be a firestorm. Mamo and patrick G would be doggin the L92's saying you need some AFR 215's and a bunch of others would be swinging on the L92's...IDK, I haven't seen a whole lot of impressive ET/MPH with the L92's...AI did their L92's with LG's G6x3 on a stock SB LS3 and made well over 500rwhp, but that's just dyno #'s. I've seen AI 243's on 6.0 stock sB with fAST, 23x's cam, headers make almost 500rwhp thru a stalled auto...so I see both sides...

Re: l92's on a lq4
 

Advanved Induction knows their stuff!!!
That 6.0/243/23x/500 thru stalled auto is probably my buddy Jeff's GTO you speak of...that car was fast. we had a track day where he was there and another GTO was there making about the same dyno #s with L92 but Jeff's car was out MPH'ing him.

Re: l92's on a lq4
 

Yeah, didn't he tear something up in the drivetrain before he got to maximize the combo? He had the Ed Curtis flowtech cam right?

Re: l92's on a lq4
 

Not jeff's he sold it in perfect condition, the new owner didnt make wise decisions but it still have FTI cam and AI heads but alot more displacement....and car is for sale...

Re: l92's on a lq4
 

Ahh, ok...I noticed he no longer had it...didn't know what happened to the car after he sold it. I have heard the "GM went with these heads, so obviously they know what they are doing" before...and especially considering that they use these on trucks and heavy SUV's...I can certainly see where folks would have that belief...but at least to this point, we really havent see the L92's pay off in terms of ET/MPH performance (sorry VA Speed LOL)...at least as far as I can tell (dyno #'s don't win races).

Re: l92's on a lq4
 

Its all interesting to hear and listen to...and my guess is most folks would side with whatever type heads they are running. I've got a 243 headed 6.0L LS2 in my TBSS that came that way...and bought a new 6.0L LY6 because it (came that way) had the L92/LS3 style heads and I see them making more power. The TBSS is still under warranty and since its had trans issues I prefer to leave it that way until out of warranty and paid off...then its time to increase the performance on it. Until then...I'll be making what I can out of the LY6...and my guess is, it just might be surprising some folks? Or at least...hopefully the guy in the other lane! :lol:

Re: l92's on a lq4
 

Haha, I guarantee it will be surprising some folks! :lol:

Re: l92's on a lq4
 

Check my sig...there are alot of folks over on TBSS owners that have 6.0 and larger ci motors running "BOTH" L92 and cathedral port heads...you will get some insight into results of both castings. My motor is low compression, set up for boost right now, and I'm running a conservative cam and turbo stall (2800), and the stock intake (no porting), yet my AI 243's helped me to become the fastest all motor AWD TBSS (i'm full weight btw). From what I have seen, the L92's are hit and miss on the TBSS on stock cubes. There was one guy that ran 12.29 with them...I believe he was the fastest. Running well with those heads has EVERYTHING to do with proper cam selection...you CANNOT use cathedral port style cam specs and expect it to do well on L92 heads, I think that is a big part of why so many folks don't run well with those castings. But the major thought, "port velocity" so important for TQ and overall responsiveness on the hwy (and to some degree at the track)...the smaller casting, even if it doesn't necessarily match the peak flow #'s, if designed well and velocity is good, its gonna likely perform more acceptibly on a street driven vehicle over the larger port head. $0.02

Re: l92's on a lq4
 

well my truck is quite a bit lighter then our TBSS...not sure I would change the heads on it either....just throw a intercooled maggie on it, replace trans with a beefier unit (6L80e would be nice) and add trans cooling, and open up the exhaust system. And I can see where a normally aspirated 6.0L on a heavy TBSS might do better with the smaller ports and then it would the L92's larger ports.

And as far as my cam choice goes.....for sure you can't just throw just any cam in a L92/LS3 headed motor. IMHO Comp rates their cams (and springs) strange somtimes anyway. They show this cam as a catherdral port cam. Truth is, I planned to by MTI Racings Stage I cam...but found I could get 20% off the Comp cam LSr version when I was ready to buy making it like $80 cheaper, for a cam with the same duration and lift specs. MTI Racing Stage 1 Camshaft Specs are: 223/231 .610/.617 (they won't give more info) and its in their LSX line and specifically engineered for the L99 Camaro. Truth is my cam guy that spec'd it for me wanted me to go a bit bigger and I'm sure I will...but you have to start out somewhere right? And since the goal has always been 11's (but secretly hoping for better w/o caging it yet) and still drive it home....I'm sure I'll be making other changes to get there and run consistently.

Re: l92's on a lq4
 

6L80 woulda been perfect had they put it in the TBSS...I used to have Jeep SRT8, with the 5 sp auto, and even the extra gear there was VERY noticable. There is a guy on TBSSowners working on a retro fit kit for the 6L80...to me, whether it be a 60's truck or a newish tbss, that is a great tranny to go with.

Re: l92's on a lq4
 

I have to agree with Shon and Pharmd on the L92's. They flow well and make good numbers but they have a lot bigger runners. A good cathedral port head that's less cc's and flows the same will make more power. It takes a big cam and some cubic inches to make the L92's shine. I had a set when they first came out that flowed 375 on the intake and 285 on the exhaust. I about fell over when I cc'd the runners and they were 260 cc's.
If I already had a set on a engine I'd go ahead and roll with it, but be careful on cam selection.