BigRich954RR

iTrader: (1)

LS9 HEADS USE a different ALUM which is stronger and different casting method and a slightly different design for the ls9 FI engine. Which makes them nothing like the other heads. All info will not be worth anyting unless your using ls9 heads

OUTLAWZ RACING

iTrader: (9)

There are some retarded people out there that think they can have a well built boosted car for 500 bucks. None on this thread but you get my point. To the OP good luck with the build post numbers and times lol!

Pro Stock John

iTrader: (34)

The "line" depends on a lot of factors. Some of the aftermarket head offering have a much thicker deck so that's why you see a lot of racers jump to them once they get into the low 9's. They are leaving the 700-800hp realm and going for the 1000-1200 one.

themailman

iTrader: (12)

108Dragon my comments were not directed at you. I've asked the same question on this board as have several others many times. I'm still waiting for the answer I want. I built my motor with what I thought was decent stuff. Then doubt starts to creep in. I mean Vee8 ran a 8.6 with these heads and that's pretty impressive. I would be happy with 9.40's for a few years. I wish we had that magic number.
I had the reciever cut into the block, and the wire added to the heads so hopefully that might help me a little. I got -20cc Mahle pistons that are supposed to break super easy. It's always something you could have or should have done to make the package better. It always seems like I wind up buying the wrong parts, or the parts that are supposed to be suspect.
If I could do it over, I would buy an ERL shortblock, and some decent heads. Then I could start worrying about the 4L80 not holding up, or the 9" breaking.

When does all this end.

108dragon

iTrader: (5)

They aluminum density may be different. But not different enough from the LS3 head to negate the validaty of the information gained. The LS9 head is of the same semi permanent mold manufacturing technique as the LS3 and LS7 head as far as I know. And the LS9 head is closer to the L92 head than ANY aftermarket item from a materials and manufacturing standpoint. That, and the fact that it is a stock FI engine, makes it's structural and beta testing the closest comparison we have. ...short of 100 people physically FI testing the L92's and submitting thier data... which we both know ain't gonna happen. lol
Aternately, however, EPP and other companies like them do a lot of aftermarket FI upgrades on stock LS6, LS2, LS3, LS7s and such. They may prove to be a better (and RELIABLE) source of solid data on these heads in FI application. I intend to hit up Livernios and Lingenfelter as well. They actually have FI'd the L92's and can give us a high resolution answer to thier durability in this application.

veee8

iTrader: (40)

LS9 stuff is Rotocast......

108dragon

iTrader: (5)

I know what you mean about always ending up buying the wrong parts. I parted out my 2two 427s, but I kept the JE high comp pistons I was using to remind me of what happened. And its funny; my M6 and 10 bolt lived through the two 427s and blowers and then shelled out after I reinstalled the 410hp 346. hmmm.
Interestingly, I'm kinda happy with that for right now. But like you say, that probably won't keep. lol As much as I hate to admit it, I'm kinda at the point of buying a prebuilt shortblock as well.. It sounds like a copout. But it certainly shortens the buildtime of the engine. You just can't claim props for the total build at the end.
A little off subject; But I keep hearing about the merits of the coated Mahle pistons. Are coated pistons worth having in FI applications? Or does the coating burn/wear off quickly enough to negate that worth?

108dragon

iTrader: (5)

That is interesting that this late in the game and in view of thier financial situation that GM would completely change thier tooling to satisfy the manufacturing requirements for just one of thier engines. Is it possible that all the current production high performance LS heads are rotocast as well and of the same materials as the LS9 items? After all, the entire LS series was build under the concept of commonality of parts and manufacturing to save costs.

108dragon

iTrader: (5)

OK, I found something on that. Probably a press release as it didn't go into much depth on the scope of the process as applied to the rest of GM's engines other than the 2.0 turbo. Would still be interesting to know if this process and A356-T6 material is going to be used on the other LS heads as well.
http://www.autoblog.com/2007/12/19/d...e-ls9-is-born/

"The heads themselves are based on the design from the L92, LS3 and LS6 engines with a few modifications. A wing cast into the intake port induces some swirl in the air/fuel mixture as it passes the 55.0mm titanium intake valves. The spent gases exit past sodium filled exhaust valves on their way to the same fabricated dual wall stainless steel headers used on the LS7. The heads themselves are made from a premium A356-T6 aluminum alloy that is rotocast. The rotocasting process rotates the mold as the aluminum is poured in. This helps get gas bubbles out of the mold and the molten metal, reducing porosity and increasing ultimate tensile and yield strength. The material change provides a 15% increase in strength with a further 9% coming from the rotocasting. The same process is used on the heads for the 2.0L turbocharged engine used in the Sky Red Line and other vehicles."

themailman

iTrader: (12)

I really have no idea how long that coating last. Probably 1 good cycle.

I tore down a perfect running 10.90 all motor car to build this. I should have paid one of you with a 8 second car, a grand to give me a damn ride for an hour or so, and got this out of my system. Even if it didn't I could at least have something to smile about.

108dragon

iTrader: (5)

You'll be alright. It's only money.. and it only stings for a little while.. unless, of course, your wife finds out exactly how much you spent. Then the scab keeps getting picked off, and it never heals. hahaha

themailman

iTrader: (12)

Been there done that. No more therapy for me. I leave all reciepts at the vendors. I don't need to ever go through that again.

Texas_WS6

iTrader: (9)

I feel your pain. I to seam to always get the stuff that at the time is suposed to be the **** but now that I am almost finished, it looks like they are just ****. It will give you a stroke if you keep stressing over this stuff.

cjg454ss

iTrader: (27)

ill be testing some l92s with orings this winter. s91 on a 418cu. th400 mose 9inch, new l92s no port work, edelbroch intake. 15psi on the street with meth and 20-25 on race gas at the strip. im going to run standard arp hardware. copper gaskets. should make over 1000rwhp easily. ive pushed 317s to about 1000 with no sign of pushing water. and that was with enough cylinder pressure to wreck some rod bearings.

bad6as

iTrader: (17)

hey vee im looking to do a 370ci motor and i think im going with a turbo around a 88mm goals are low 9s, and 150mph traps in a 3200lb race weight. trans is gonna be a th400. any ideas?

veee8

iTrader: (40)

Good rods, pistons, fuel system and a set aftermarket heads, and you should be able to reach your goals.