ls3 or ls6 top end for my lq9?
The positive comments I saw were in regards to larger cubic inches, but nothing good to say about them on smaller combos.
It's funny you mention we are victim to marketing, but then you use the opinions of people who own businesses to convince us otherwise...
Last edited by KCS; Dec 14, 2013 at 02:30 PM.
I think it is interesting in itself that this debate is still going on after so many years.
This is the most compelling post that I read in that old 2010 thread:
This is the most compelling post that I read in that old 2010 thread:
I just want to post some of my experiences with l92's and cathedral port heads.
here are some of the combinations we have done.
6.0 gto wcch l92's ls3 intake 505 rwhp
6.2 vette wcch l92's ls3 intake 521 rwhp
416 gto va speed l92's ls3 intake 540 rwhp
427 vette wcch l92's fast 102 577 rwhp 656 fwhp
427 fbody wcch l92's fast 102 665 fwhp-not in car yet.
cathedral similar to above
6.0 gto tfs 225''s fast 90 525rwhp
416 gto tfs 235's fast 90 (a4) 505rwhp
427 gto tfs 235's fast 90 550 rwhp(a4) 654 fwhp
with that being said-the l92's have no place on a small displacement engine,especially a 4.0 bore engine. While they make pretty decent power on the smaller engine the low end sucks. The 6.2 vette actually drove really great and had excellent throttle response.
the bigger engines-416, 427, the l92's def shined on them. While we made similar power with the tfs heads, it should also be noted the cathedral's required a much larger cam. The larger cam actually sacrificed more tq down low than the larger port smaller cam did.
What it comes down to is this,every engine needs a different head. What works well on a 6.0 shouldn't and doesn't work nearly as good on a 427 and vise versa. Any good engine builder knows this. On smaller engines i will always defer to a smaller head-this is where catherdral ports shine,these engine need to make tq,always remeber you can't have hp without tq. On a larger engine 400+ with a 4.065 and larger bore, i will run a square port. On the larger engines i can sacrifice some low end for top end as usually there is too much for street cars anyway.
There are also other variables to consider too. How heavy is the car,what's it used for etc. The will determine which is better for the application. If it's something that's going to get sprayed, you can get away with a bigger port. Turbo,smaller port.
You simply cannot put a blanket statement that one type of head is better than another. Every head has it's place that it shines over the others. Otherwise everybody would only make one head at one port volume. Just remember, everything is a compromise. You have to sacrifice one thing for another when building engines.
here are some of the combinations we have done.
6.0 gto wcch l92's ls3 intake 505 rwhp
6.2 vette wcch l92's ls3 intake 521 rwhp
416 gto va speed l92's ls3 intake 540 rwhp
427 vette wcch l92's fast 102 577 rwhp 656 fwhp
427 fbody wcch l92's fast 102 665 fwhp-not in car yet.
cathedral similar to above
6.0 gto tfs 225''s fast 90 525rwhp
416 gto tfs 235's fast 90 (a4) 505rwhp
427 gto tfs 235's fast 90 550 rwhp(a4) 654 fwhp
with that being said-the l92's have no place on a small displacement engine,especially a 4.0 bore engine. While they make pretty decent power on the smaller engine the low end sucks. The 6.2 vette actually drove really great and had excellent throttle response.
the bigger engines-416, 427, the l92's def shined on them. While we made similar power with the tfs heads, it should also be noted the cathedral's required a much larger cam. The larger cam actually sacrificed more tq down low than the larger port smaller cam did.
What it comes down to is this,every engine needs a different head. What works well on a 6.0 shouldn't and doesn't work nearly as good on a 427 and vise versa. Any good engine builder knows this. On smaller engines i will always defer to a smaller head-this is where catherdral ports shine,these engine need to make tq,always remeber you can't have hp without tq. On a larger engine 400+ with a 4.065 and larger bore, i will run a square port. On the larger engines i can sacrifice some low end for top end as usually there is too much for street cars anyway.
There are also other variables to consider too. How heavy is the car,what's it used for etc. The will determine which is better for the application. If it's something that's going to get sprayed, you can get away with a bigger port. Turbo,smaller port.
You simply cannot put a blanket statement that one type of head is better than another. Every head has it's place that it shines over the others. Otherwise everybody would only make one head at one port volume. Just remember, everything is a compromise. You have to sacrifice one thing for another when building engines.
11 Second Club
Joined: Sep 2011
Posts: 390
Likes: 2
From: The Burnie, MD
Originally Posted by Shawn @ VA Speed View Post
I just want to post some of my experiences with l92's and cathedral port heads.
here are some of the combinations we have done.
6.0 gto wcch l92's ls3 intake 505 rwhp
6.2 vette wcch l92's ls3 intake 521 rwhp
416 gto va speed l92's ls3 intake 540 rwhp
427 vette wcch l92's fast 102 577 rwhp 656 fwhp
427 fbody wcch l92's fast 102 665 fwhp-not in car yet.
cathedral similar to above
6.0 gto tfs 225''s fast 90 525rwhp
416 gto tfs 235's fast 90 (a4) 505rwhp
427 gto tfs 235's fast 90 550 rwhp(a4) 654 fwhp
I just want to post some of my experiences with l92's and cathedral port heads.
here are some of the combinations we have done.
6.0 gto wcch l92's ls3 intake 505 rwhp
6.2 vette wcch l92's ls3 intake 521 rwhp
416 gto va speed l92's ls3 intake 540 rwhp
427 vette wcch l92's fast 102 577 rwhp 656 fwhp
427 fbody wcch l92's fast 102 665 fwhp-not in car yet.
cathedral similar to above
6.0 gto tfs 225''s fast 90 525rwhp
416 gto tfs 235's fast 90 (a4) 505rwhp
427 gto tfs 235's fast 90 550 rwhp(a4) 654 fwhp
IIRC, I saw a few tests where the Fast intake was no better than the stock LS3 intake.
Look, the simple fact is that people are sketchy about change. People tend to stick to what they know works.
If you wanna compare a L92 to a LS6 head, the L92 will win every time. The cathedral port fan boys always revert back to the same thing "oh will this $2500 AFR head makes more power" so yeah, an aftermarket casting hogged out and CNC ported with a CNC'd chamber makes more power, big surprise. Lets stick to our guns here fellas. Compare apples to apples. The L92 setup on a 6.0 outperforms a LS6 setup stock for stock. If you are baller enough to afford some $2500 heads then by all means.
KCS you are correct but what you're failing to realize, or admit, is that there are people in that thread that is over 3 years old that make that setup work. Just because its not unanimous across the board doesn't mean people didnt have it figured out. They sure do now. If I were building a 5.7 or 5.3 I'd have cathedral port heads on it. On a 6.0 I'm going to upgrade to the new technology every time, spec a cam designed to work with the square port and go racing. Enjoy the flow competitive to a CNC'd aftermarket casting for a fraction of the price.
If you wanna compare a L92 to a LS6 head, the L92 will win every time. The cathedral port fan boys always revert back to the same thing "oh will this $2500 AFR head makes more power" so yeah, an aftermarket casting hogged out and CNC ported with a CNC'd chamber makes more power, big surprise. Lets stick to our guns here fellas. Compare apples to apples. The L92 setup on a 6.0 outperforms a LS6 setup stock for stock. If you are baller enough to afford some $2500 heads then by all means.
KCS you are correct but what you're failing to realize, or admit, is that there are people in that thread that is over 3 years old that make that setup work. Just because its not unanimous across the board doesn't mean people didnt have it figured out. They sure do now. If I were building a 5.7 or 5.3 I'd have cathedral port heads on it. On a 6.0 I'm going to upgrade to the new technology every time, spec a cam designed to work with the square port and go racing. Enjoy the flow competitive to a CNC'd aftermarket casting for a fraction of the price.
11 Second Club
Joined: Sep 2011
Posts: 390
Likes: 2
From: The Burnie, MD
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Verdad Gallardo Y'all are arguing two different points here on the fast intake stuff.
MX6.0 is saying a Fast intake is an upgrade on a set of cathedral port heads that accept an LS6 intake.
You obviously can't bolt a cathedral port LS6 intake up to a L92 square port head.
LS3 intake vs a fast intake is a different animal. There is a slight amount of power to be gained under the curve with the fast on a square port head but it isn't enough to make me pull the trigger on a $1000+ setup.
MX6.0 is saying a Fast intake is an upgrade on a set of cathedral port heads that accept an LS6 intake.
You obviously can't bolt a cathedral port LS6 intake up to a L92 square port head.
LS3 intake vs a fast intake is a different animal. There is a slight amount of power to be gained under the curve with the fast on a square port head but it isn't enough to make me pull the trigger on a $1000+ setup.
Look, the simple fact is that people are sketchy about change. People tend to stick to what they know works.
If you wanna compare a L92 to a LS6 head, the L92 will win every time. The cathedral port fan boys always revert back to the same thing "oh will this $2500 AFR head makes more power" so yeah, an aftermarket casting hogged out and CNC ported with a CNC'd chamber makes more power, big surprise. Lets stick to our guns here fellas. Compare apples to apples. The L92 setup on a 6.0 outperforms a LS6 setup stock for stock. If you are baller enough to afford some $2500 heads then by all means.
KCS you are correct but what you're failing to realize, or admit, is that there are people in that thread that is over 3 years old that make that setup work. Just because its not unanimous across the board doesn't mean people didnt have it figured out. They sure do now. If I were building a 5.7 or 5.3 I'd have cathedral port heads on it. On a 6.0 I'm going to upgrade to the new technology every time, spec a cam designed to work with the square port and go racing. Enjoy the flow competitive to a CNC'd aftermarket casting for a fraction of the price.
If you wanna compare a L92 to a LS6 head, the L92 will win every time. The cathedral port fan boys always revert back to the same thing "oh will this $2500 AFR head makes more power" so yeah, an aftermarket casting hogged out and CNC ported with a CNC'd chamber makes more power, big surprise. Lets stick to our guns here fellas. Compare apples to apples. The L92 setup on a 6.0 outperforms a LS6 setup stock for stock. If you are baller enough to afford some $2500 heads then by all means.
KCS you are correct but what you're failing to realize, or admit, is that there are people in that thread that is over 3 years old that make that setup work. Just because its not unanimous across the board doesn't mean people didnt have it figured out. They sure do now. If I were building a 5.7 or 5.3 I'd have cathedral port heads on it. On a 6.0 I'm going to upgrade to the new technology every time, spec a cam designed to work with the square port and go racing. Enjoy the flow competitive to a CNC'd aftermarket casting for a fraction of the price.
You're the one acting like you don't know how lol. If you'd rather put a stock set of LS6 heads on a 6.0 because they make more power than a properly cammed and tuned L92 setup then it's pretty clear that you really don't know how to make it work.
im actually in a dilema myself at the moment about this, iv got an ls2 block with ly6 internals sitting in my garage also a new set of ls3 heads and an l92 intake. my truck currently has 225k on it (06 2500hd) with a lq4 and a tbss intake, im guessing with the ly6 pistons my cam choices are a little more broad. ill also shave a few lbs with the ls2 block.
i do tow 8-10 from time to time, not that often mostly 4 wheelers ect stuff an other time.
question i ask myself should i go through the trouble or just leave it. what could i really squeeze out of an ly6 set up with milling the ls3 heads.
i do tow 8-10 from time to time, not that often mostly 4 wheelers ect stuff an other time.
question i ask myself should i go through the trouble or just leave it. what could i really squeeze out of an ly6 set up with milling the ls3 heads.
im actually in a dilema myself at the moment about this, iv got an ls2 block with ly6 internals sitting in my garage also a new set of ls3 heads and an l92 intake. my truck currently has 225k on it (06 2500hd) with a lq4 and a tbss intake, im guessing with the ly6 pistons my cam choices are a little more broad. ill also shave a few lbs with the ls2 block.
i do tow 8-10 from time to time, not that often mostly 4 wheelers ect stuff an other time.
question i ask myself should i go through the trouble or just leave it. what could i really squeeze out of an ly6 set up with milling the ls3 heads.
i do tow 8-10 from time to time, not that often mostly 4 wheelers ect stuff an other time.
question i ask myself should i go through the trouble or just leave it. what could i really squeeze out of an ly6 set up with milling the ls3 heads.
To give you an idea, my car makes 450 to the tire with a crap tune. I have a LY6 with milled heads and a big cam. 1st and 2nd are worthless on street tires. I bought the car in this condition and am in the process of piecing together a nice list of bolt ons and other stuff and ill be looking for 470ish to the tire all said and done with a nice tune. That's stock LS3 intake and un ported heads. It's not much from idle to 3k but that's the big *** cam and not the heads.
What a lot of people don't understand and can't figure out is how to make that torque but I believe it's all in the cam. If you spec the cam to work with the heads and use a cam whose valve events are geared more towards torque then I'd be surprised if you lost hardly anything down low. A cam like that will make you sacrifice up top but Im still inclined to believe you'd out power a stock LS6 setup with a cam designed for torque and towing in the upper RPM ranges just because of how much the L92 heads flow.
Don't listen to the people in here saying "you can't do this and you can't do that". All that means is they have not done it yet either because they haven't tried or they don't know how. What sets good shops apart from bad ones is their ability to adapt to change and make new technology work and use it to their advantage to make it better than a set of heads produced in 2002. I guarantee you Martin at tick can spec you a cam that will yank your fillings out with the L92 heads right off idle.
i think thats the way ill ultamately go, i wont be using vvt at all. this will be in an nbs truck. i think sometime after the holiday, ill call them to have them sepec me a cam. along with how much i can mill the heads and still be safe. im just going to do it. the truck already moves for a 2500 lol. got it down to 6100lbs, it can still tow a ton and i run with the diesel guys pretty good. i think an extra 80 ponies or so will be nice, not to mention a fresh engine 225k and still pushing strong!
The guys at Tick will hook you up for sure. Martin spec'd a cam for my dads truck. It's a 2009 Chevy silverado LTZ. We deleted the VVT off his and its a whole different animal with the new cam. Runs super strong for a little 5.3.
This is every L92 fanboys defense. "If you like the cathedral ports over square ports, you just don't know what you're doing with square ports." Lol.
Are you taking the position that a set of stock 243/799 castings can hang with a stock square port head in a performance application?
I'm taking the position that on a 364ci LQ4 that will be going in a truck that will be drag raced, street driven, and used to tow a camper, a cathedral port head would better.