108dragon

iTrader: (5)

Just seems like if they were the be-all-end-all of LS heads, GM wouldn't have designed the LS7,LS3/L92 style squareport heads. None of the new design GM LS engines run cathedral ports anymore either. ...just food for thought.
Imagine what your engine could do with even bigger valves and a better port design! Even moreso with aftermarket CNC action that the cathedral port heads have seen.
Also, what do those teched out ETP 225's cost the average guy? ..as opposed to a set of stock LS3 heads that vastly outflow a stock set of 243's ...and VERY affordable. How much money, time, research, and maintenance do you have to throw at an LS2 to juice 1700hp out of it? Daily driver? How is it in traffic? What happens when you forget to refill your methanol res? Could you sneak it through an emissions test?
These are all very relevant questions within the scope of the OP.

BigRich954RR

iTrader: (1)

Please dont try and annoy one of the few people that come on here and really help out.

Just cause they stop putting cathedral ports on any of the new car has to do with keeping all part the same to cut cost.

Every thing is a trade bigger valves are not always better. the ls3 heads flow alot less exhaust

Who cares if the ls3 are cheaper then the etp225 heads if they will push water and slowly start to fail at a high power level you are going for. Sure they might last a little while but if they break and take out a part of your block then you still need better head and block work now

HP has nothing to do with DD the car. IT about how you build it and money you want to spend.

If you forget to refill your methanol reservoir. who fault is that? Also about design when you design you high hp engine leave it out. You surely dont belive some one with a 1700 Hp car is going to be dumb enough not to check the meth tank level. If for some reason they run one.

Could you sneak it through an emissions test? emissions are about how you design the car. I know some one that has a car with like 1600 hp and he DD the car as much as he can only because he has like 8 DD car to switch around with. he passed just fine car rides and drive like stock only sounds little different There a few 1900 hp vipers drives on the street There might be a 2200hp one now

Shawn @ VA Speed

iTrader: (3)

dude,what i your problem-all that i was stating is that there is nothing wrong with cathedral port heads.I not stating the intake ports aren't better in the square port stuff,but i will tell you they really missed on the valve placement and sizes.What you seem to fail to realize is that for a s/c engine the exhaust port is way more important than the intake port,and that is where the square port stuff falls short.
Just because you can make the same power with less boost from a bigger intake port,doesn't mean it's any safer.you still need to run the same timing,same fueling and meth if it's needed at that power level-cylinder pressure dictates this,not boost.Boost is just left over air.

108dragon

iTrader: (5)

Shawn- I have no problem... Not here to fight with you. Just pointing out the merit of using stock parts. What? Did I mess up a potential sale for you?
BigRich954RR- Trying to sneak a 1700hp LSX engine through emissions in Denver would be like getting an RPG7 rocket launcher through checkpoints at an airport. ..good ****** luck. And hp/tq has EVERYTHING to do with whether you're DD or not. I shelled out my 10bolt with just 410rwhp. Everything will need to be upgraded.. not just the price of extra parts to make the heads fit.
Not trying to annoy. You two need to reread the OP and get a grip. The OP didn't ask about high dollar aftermarket heads or 1700hp engines using them. And yeah.. I can see your point BigRich954RR. EVERYONE is rolling in dough enough to have 8 cars to switch out daily so he can have a 1900hp trailer queen. And yeah, there might be a 2200hp viper lurking around too.. but I'm sure it ain't runnin an LS engine.
I have followed the LS design from its inception from an engineering standpoint. Sperry and a few others pointedly admitted that the cathedral port was the "RESULT" of the designers "squeezing everything they wanted into the head" and working with what was left there, room-wise for the port. NOT an actual design feature. New computer modeling found a lot left on the table with older head designs. The newer LS7/LS3/L92 head is simply the newest revision of thier LS series design utilizing full computer flow modeling instead of knowledgable guesswork followed by extensive actual tests and revision.
And yes, Shawn, it is true that there is a large intake vs. exhaust ratio differential in the LS7/LS3/L92 port flow. They saw this as acceptable to gain the extra intake capacity and it is easily overcome with proper camming and extra lift on the exhaust side.
These heads are designed for the 4"+ bore, which the OP's LS2 has. And, OMG, a fraction of the cost of aftermarket CNC castings... which of course WAS what the OP was asking about.
The issue with the new port design is that it is EASIER to make the same hp and even better tq numbers and more of both under a broader curve than any comparable stock cathedral port head. Even the base model L92 head sports a bigger exhaust valve than the best stock 243 head does. ..and a more efficient exhaust port as well.
I sold off all my superchargers and power adder bullshit because it was simply a maintenance nightmare. I just want to get into my car and be able to put the **** to it for a steady 1500 miles without issues. NOT have to be worried about when I need to refill a meth container or getting gaffled by the emissions police. If I can do that with 800rwhp, with GMPP parts, and MAYBE 10 lbs. of boost, than WTF is the issue? The harder you push any mechanical device, the more likely it's failure, and DEFINATELY the sooner.
Also BigRich954RR, maybe you haven't been keeping up with current events here, but a large portion of the LSX parts for sale here are guys putting thier cars back to near stock or stock because of the headaches and maintenance nightmares of keeping thier cars at the power levels you are talking about -if they're honest about it. Or just say they are trying to get thier money out of thier investment that they would never get selling the car modified. I see a lot more F bodies with LS7 transplants going for better money than high mod forced induction cars. The latter are the guys selling out in parts.
Point is: OP question asked, OP question directly answered. Sorry if it hurt your feelings because you disagree.

Shawn @ VA Speed

iTrader: (3)

Just so you know,75% of the posts i make on this forum are to help people-not sell parts.

You certainly didn't hurt my feelings-i have very few and it would take somebody much better than you to do any damage.

The info i put out is first hand info(things i have done myself)not things i read in a book,forum,or somebody told me.

I try to steer people to make the correct choice for the most bang for the buck+the most longevity-this usually costs a little more up front but saves greatly in the long run.

While the l92 heads will make good power and will last a little while-sooner or later(probably sooner than later) at 800+whp it will have head gasket issues

A thick deck aftermarket head is always the best choice for an fi engine-even if it's a set of as cast heads.

My best advice is to save up for the correct part instead of buying the incorrect part you can afford now.

BigRich954RR

iTrader: (1)

My Supercharged 800RWHP Car is fine to drive on the street no issues. no headaches I drive the **** out of it just did a 1211 mile road trip in 4 days no issues no refilling the meth tank while on trip. At the end of the trip it was about half empty so i filled it. While i was filling the car up in a small town they only had Reg 87 octane. Fill the car up just didnt beat the **** out of it till i refilled with 93 still ran fine. Yes high HP breaks **** we all know this. But if done right the first time the chances are much lower

PEOPLE dont build these car to Drive then sell and make big money off of them. We build them cause we like fast cars. buying and selling cars to make money is done with stock cars

You didnt hurt my feeling I just saying if he looking to make FI power these are not the heads and in the long run when he has to buy new heads he lost more money.

NicD

iTrader: (7)

I don't understand why some of you guys have to argue FOR stuff just because you decided to build a combo that has it. ie saying L92 heads are just fine and won't have any head gasket issues at higher power levels. Everybody knows that a thin deck head like the L92s are definitely going to have more head gasket issues at higher power levels. It's common sense and people have put it to the test and have actual results to back up that common sense.

10SecDreamer

iTrader: (7)

So have you guys seen the l92 heads start to fail at similar power levels or is it certain boost setting that has the heads/gasket fail?

108dragon

iTrader: (5)

I was was running 821 castings with a centri on a 427 cid. Pushing over 800 rwhp with around 12 psi. The problem was never the heads. It was with the Darton sleeves I was using. Probably in the machining. I have tried this twice. I obviously don't have the cash outlay that you or your shop do. So my third try at it will be with an LSX or LS7 block. But it will be a while.
My experience is equally spread across 24,000hp military steam turbine engines, conventional and nuclear powerplants, roots supercharged diesel backups, turbogenerators, weapon systems design and manufacturing ranging from small combat arms to guidance equipment for ballistic missiles, and 12 years in steelmaking production as a mech/elec technician.... as well as my LSX hobby. Although my experience field isn't as narrow or specialized as yours, my advice in metalurgy, metal fatigue, and structural integrity are not merely academic. And just because I choose not to banner my accomplishments in my sig does not mean that I haven't any.
Secondly, "somebody better" is irrelevent as you have no idea how good I actually am. lol
Thirdly, "best" in the view of the OP and the question at hand, is a factor of budget and the "best" he can get away with within that budget. Your advice within the context you offered it is justified.
..can we be friends now?

108dragon

iTrader: (5)

BIGRICH
I just got a 800RWHP 15 psi car thought NJ emissions. im about to add more boost which wont change anything other then forcing more add into engine so will will see how much Hp the car makes at 22 psi hoping for 1200RWHP but wont affect getting the car though.
-I don't know about NJ, but around Denver they'll get really sad at you if they find you running non EO exempt headers or cats. So it is a visual inspection as well as pipe sniffer. I got gaffeled in California for non EO performance equipment. It was a STIFF fine.

Again- Not trying to annoy. You two need to reread the OP and get a grip. The OP didn't ask about high dollar aftermarket heads or 1700hp engines using them.

BIGRICH
You started talking about 1600 hp cars and getting them though DOT

-No.. I started talking about the merits of using a semiperm mold LS3/LS7 casting as opposed to a high dollar aftermarket set. YOU started talking about 1600hp cars and high dollar aftermarket heads.


BIGRICH
This has to do with hp and tq having nothing to do with driving it on the road

-DD means different things to different people, obviously. My interpretation is something that isn't a maintenance nightmare and didn't cost me more than the carwas worth to build it. You obviously missed my point on having to upgrade everything else to support extreme power levels as well.



BIGRICH
They didnt see this a acceptable gain for a FI engine cause none of the these engine use FI stock

-Try the LS9. Again, you haven't been keeping up with current events Rich.



BIGRICH
Cheaper is not better when the design is weaker starts to lift the head and blows out gaskets or the heads crack now you still need block work and new heads

-"Better" is a combination of positive result versus cash outlay. This is where I agree with Shawn in "bang for the buck". There is a difference in GM molding techniques. The semi permanent mold technique seems to produce a denser casting than the standard sand casting method. A lot like the differences between standard cast pistons and hypereutectic units- though not as drastically so. Ergo, my choice for FI application. There isn't much of a difference in price between the two in open market. Replacement parts for ANY stock GM application item are plentiful and relatively cheap.

Cobra Commander

iTrader: (12)

JMO but on a FI car at those levels I would think you want the safest, least likely to break combo possible (aftermarket casting).

108dragon

iTrader: (5)

What makes you think any of us haven't used aftermarket heads in comparison? I used and sold a set of Trick Flow 225's, AFR, and RHS units. The GMPP heads are great for the power levels I've consistantly produced using them. I guess the only real question left on the table is just how far exactly can we push these heads reliably. I'm not crazy about the L92s, but the LS3 and LS7 heads definately have pluses for FI application.
The only thing everybody knows is what everybody has heard. I can honestly say I've pushed all the aformentioned heads past 800rwhp. Beyond that, I can only speculate by metalurgy and what I have seen others do. I can also honestly say that the LS7/LS3 heads are more efficient at anything but all out racing applications than the aftermarket heads I've used -total usable power under the curve.
I have to respect Veee8, Shawn, and BigRich for thier experience. And I have to admit I've learned from all three of them from just this thread. I have only learned by comparing my experiences with thiers openly. In essense, I do not consider this an arguement, but an exchange of ideas and experience.
I'm not really sure what it is about turbo systems that have head gasket problems and pushing water. I've always run roots blowers and recently centrifugals. But I've never experienced this problem with my builds. Then again, I've rarely pushed past 12psi.

NicD

iTrader: (7)

Many of the people in this thread have pushed L92s harder than you have in a boosted app to come up with these results. You can go on about your metalurgy experience and this and that but you just don't have the experience about THIS subject. You yourself said you rarely pushed past 12 psi and you are making all of 800 rwhp. One guy in particular has built engines in this thread making twice that amount and done many combinations with all types of heads. It's simple, if you want a nice reliable build that you can beat on all the time and not worry about when it's going to be time to change head gaskets use a thicker deck aftermarket casting than the L92 heads and be done with it at power levels like that. Working on steam engines, nuclear powerplants, and whatever the hell else you came here spouting off doesn't have any relevance on this subject.

108dragon

iTrader: (5)

***Name calling is uncalled for...***

---LS1tech Staff

pwrtrip75

iTrader: (8)

BigRich954RR and Shawn @ VA Speed need to learn to have a logical conversation and leave the emotions out of it.... Not siding with anyone cause im curious of this info myself....but 108dragon just had some info and questions and you guys got all emo on him.
Just sayin. i didnt watch buddies die face down in the dirt to have to read this stuff...lol.

Shawn @ VA Speed

iTrader: (3)

i think you need to reread the posts-i have no emotions in this.I was just stating facts.My conversation is very logical.Could you please point out somewhere that i was being emotional.

108dragon

iTrader: (5)

BTW NicD, killer build and runs. Gotta give you props on that. What are YOU running for heads, why, and how is your combo holding up?

pwrtrip75

iTrader: (8)

I just read the first part of this and it was enough....
Sounds like an emo rant ....but I stopped reading it after that sentence.

I was just looking for info and started reading your guys' bickering and no i didnt read it all....sorry if I misinterpreted it as that instead of good info.

....back to the program.....

NicD

iTrader: (7)

I am not going to argue these facts with you. You obviously think you know more than everybody else even though people have been there and done that. Go ahead and argue with yourself, I'm done.

Shawn @ VA Speed

iTrader: (3)

i see,you're calling me gay and 108dragon is dropping 4 letter words every sentence-but i'm the one ranting-that's pretty funny.

anyway sorry for ranting and offending everybody.you guys have a great day.

P.S. thanks for all the info you contributed to this thread.